Pipelines 2013: Pipelines and Trenchless Construction and Renewals—A Global Perspective

The American Water Works Research Foundation (AWWARF) and the American Water Company collaborated on research into pathogen intrusion into drinking water systems. The first author participated in these important research projects. The projects included the following: a) AWWARF Project #436 - Pathogen Intrusion into the Distribution System. b) AWWARF Project #2686 - Field Testing of Surge Modeling Predictions to Verify Occurrence of Distribution System Intrusion. c) AWWARF Project #2580 - Surge Modeling and Field Data Comparisons for a Large Water Distribution System. This work verified that significant amounts of dirty and possibly contaminated water could enter drinking water systems during an event which results in subatmospheric pressures. The dirty water enters through leaky seals and other leak passageways posing a serious health risk to its users. The most common event is a power loss to a pumping facility. This often results in low pressure transients propagated throughout the distribution system. The study recommended that drinking water systems install devices which would prevent the development of high-risk, low-pressure transients. A Midwestern city recently installed a 22,700-gallon (84,000-liter) Bladder Surge Tank at a new pump station. This follows a surge study of the effect of a trip of the new pumps on the distribution system which predicted large numbers of locations where subatmospheric pressure developed. These low pressures would cause significant intrusion of dirty water. The surge tank provides a short-term supply of water following the pump trip which prevents a large-magnitude, low-pressure wave from developing and propagating throughout the system. A Bladder Surge Tank was chosen because of reduced maintenance and high reliability of these devices.

Urbanization in the People's Republic of China increased in speed following the initiation of the reform and opening policy. By the end of 2011, mainland China had a total urban population of 691 million (or 51.3% of the total population), rising from 26% in 1990. With rapid urbanization, China's municipal pipeline is facing a serious challenge and sees a great increase during the 12th Five-Year Plan period (from 2011 to 2015). This paper will present the status of China's municipal pipelines (including water, sewer, city gas, etc.) and the government's plans to improve the municipal pipeline systems (such as new pipeline construction and pipeline rehabilitation), which will bring great business opportunity for the pipeline suppliers and contractors. As well, the research and technical needs to meet the demand of China's municipal pipeline construction and rehabilitation will be discussed in this paper.

The Town of Gilbert, AZ, decided to construct the Gilbert Road Force Main and Gravity Sewer (Gilbert FM/GS) to provide flexibility to transfer wastewater from one sewershed to another sewershed to utilize the full treatment capacity of their Neely Water Reclamation Facility (WRF) and delay expansion of the Greenfield WRF. The project included the installation of 15,500 LF of 12-inch ductile iron force main and 4,900 LF of 24-inch polyvinyl chloride gravity sewer with a budget of $7.0 million. Gilbert has used the alternative project delivery modes of Construction Manager at Risk (CMAR) and Design-Build (DB) to construct most of their water and wastewater projects as they provide: (1) the means to select the best qualified contractor, and (2) control and flexibility over the work process to meet unforeseen project challenges. CMAR was the delivery mode selected by Gilbert when the project was initiated in early 2008. As the economic downturn worsened and bid prices became extremely competitive, Gilbert's senior management decided to require all of the Town's capital improvement projects to be executed using traditional Design-Bid-Build (DBB). It became obvious at the 30% design level that the project carried a significant amount of risk and it may be beneficial to return to CMAR. The risk issues included: ≤ Gilbert Road, which was the best alignment for the pipelines, was a major north-south arterial with high traffic counts and numerous utilities. ≤ This was a highly visible project to all levels of the Town's government as the Municipal Complex was adjacent to Gilbert Road. ≤ Gilbert had experienced poor performance, delayed schedules, and a high number of costly claims on several DBB pipeline projects. Gilbert's management decided to return to CMAR for the following reasons: ≤ CMAR provided the means to select the most qualified contractor who understood the project challenges and had a well-thought-out approach to meet the challenges. ≤ CMAR provided the flexibility to issue multiple construction packages to take advantage of windows of opportunity to limit community impacts.

Various studies in the past 15 years have highlighted the dire consequences of failing to proactively protect buried metallic water distribution and transmission infrastructure from the effects of corrosion. Metallic municipal pipelines are composed of cast and ductile iron, composite concrete pressure pipes, and steel pipe. For more than a hundred years, the buried steel pipe industry has employed effective corrosion protection, both on the inside and outside walls of pipelines. Lines more than 100 years old serve as testimony of the effectiveness of these systems. Both rigid cementitious and flexible dielectric corrosion barriers - combined with cathodic protection, when required - have ensured long service lives. By the 1940's, the American Water Works Association (AWWA) had published two standards for corrosion protection of steel pipes,one for cementitious systems and the other for dielectric systems. With advances in technology, many other technologies have been added to the list of standards, the most recent as recently as 2008. This paper will provide an update on the state-of-the-art lining and coating systems currently specified for steel pipe by the engineering community at large. AWWA, NACE International, and other standards-writing organizations' documents will be discussed. Focus on corrosion prevention through surface preparation for lining and coating applications, quality control, handling, repair, joint completion, and installation will be highlighted.

This paper presents a methodology for developing a national database for wastewater and drinking water pipe infrastructure system. The database is titled as "WATERiD" and can be accessed at www.waterid.org. There are over 50,000 water utilities in the United States and no two are alike. However, there are common technologies used and lessons learned from their application can be shared. Until now, there has not been a platform where utilities can learn from the experience of others. The creation of WATERiD is enabling utilities to share their experiences and knowledge in a single point information center. Here, utilities can find relevant information on buried infrastructure sustainability from more than 150 American and 35 international utilities that participated in this research project. The data from utilities were compiled, taxonomically classified, and uploaded in WATERiD for sharing between the utilities. This paper describes a process for developing the database, including the architecture, critical functionalities such as upload and categorization, and future development work. Development of WATERiD was part of a cooperative agreement between the U.S. Environmental Protection Agency and the Water Environment Research Foundation (WERF). The proposed WATERiD+ the pipeline performance data project will build on the experience gained from developing and implementing WATERiD.

High-quality drinking water systems are essential to public health, business, and quality of life in the United States. Even though the current performance of these systems is moderate, the concern is about the future performance. Planning can be done for improvement once the current performance of utilities is evaluated and areas with a scope of improvement are identified. Benchmarking and performance evaluation are key components in the process of continuous improvement of utility's performance. There are many initiatives on performance benchmarking of utilities but a few of them focuses on one or few area of performance. There are a few initiatives which use subjective indicators. Additionally, consultants visit the utilities for performance evaluation. This paper documents the methodology, indicators and preliminary results of quantitative, comprehensive, and web-based performance benchmarking of ten drinking water utilities in seven key areas. The major contribution of this research is the creation of a database, and a web-based data collection and result display platform which is a part of WATERiD project.

Asset Management requires a dedicated commitment from management and O&M staff to have an effective program. Part of that process involves utilizing technology to determine the condition of assets. There is no silver bullet, but there are different technologies that provide the best return on investment for different asset configurations.

The Municipality of Riyadh, the capital of Saudi Arabia, is experiencing significant issues with its water supply as well as other essential infrastructure. Currently, water is supplied to water demand areas once every four days. Approximately 8% of the city's current population of 4.9 million is not served by the central water system. Large areas of the city are developed into subdivisions that do not contain houses due to the lack of water, sewer, and electrical service. This has resulted in a very inefficient provision of basic utility services.

More than 95% of large diameter steel (AWWA C200/C205), ductile iron (AWWA C104), and concrete cylinder pipelines (AWWA C303) used in water transmission contain a portland cement mortar lining that protects the interior steel or iron surface from corrosion. This lining has been used in water pipelines for at least 175 years. The mortar provides protection due to the highly alkaline environment produced by the hydration of portland cement which passivates the interior metal surface of the pipe. During the past 30 years, the mortar linings from numerous concrete cylinder pipelines and steel pipelines were evaluated to determine their condition after up to108 years of service. Properties (such as absorption, specific gravity, and compressive strength) and the available alkalinity, pH, and chloride ion content through the thickness of the linings were determined. The amount of leaching or carbonation found in the mortar lining was related to the various constituents in the water transported and to the mortar's absorption. Visual observation of the steel cylinder for the presence of corrosion was also made and related to the condition of the mortar lining. The test results of these case histories are presented and discussed.

On February 22, 2011, Christchurch, New Zealand experienced a magnitude 6.4 earthquake, killing 185 people in one of the country's deadliest peacetime disasters. The total cost to insurers has been estimated between $15-20 billion, making it New Zealand's costliest natural disaster and the third-costliest earthquake, worldwide. The earthquake caused widespread damage, especially in the central city and eastern suburbs, with buildings and infrastructure already weakened by a previous earthquake occurring September 4, 2010. The February 22nd earthquake caused significant liquefaction affecting the eastern suburbs and producing 400,000 tons of silt. While a conglomerate of diverse partners formed the Stronger Christchurch Infrastructure Rebuild Team (SCIRT) to assess the damage and undertake emergency repairs of public infrastructure and right of way, little focus has been dedicated to the condition assessment of underground infrastructure of property homeowners and educational institutions. While smaller diameter pipes were oftentimes inspected using high resolution push cameras, the inability of visual inspection techniques to adequately identify and quantify cracks and defects led consultants for the Ministry of Education to utilize a new technology, known as "electro scanning", to reassess previously televised drains. This paper describes the limitations of using closed-circuit television (CCTV) camera equipment and compares side-by-side results from electro scanning. By measuring the variation in electric current flowing through defects in non-conductive pipe walls, this paper explores the type of data, field set-up requirements, and diagnostic information resulting from both legacy CCTV and new electro scan technologies.

The Leon Creek Water Recycling Center (WRC) and Dos Rios WRC facilities, owned and operated by the San Antonio Water System (SAWS), treat the majority of wastewater produced by the City of San Antonio. The Leon Creek WRC Interconnect Project (the "Interconnect") has been planned to allow for the diversion of flows of up to 51-MGD through a new 60-inch pipeline that connects to the new Southwest Bexar Sewer Pipeline (SBSP), which ultimately ties in at the Dos Rios WRC headworks. This project will delay the need for further expansion of the Leon Creek WRC while maximizing SAWS' current investment in the expansion and re-rating of the Dos Rios WRC from 125-MGD to 217-MGD. This project also allows SAWS to shift more of the raw wastewater supply to the Dos Rios WRC, which services the leg of the recycled water system with the highest demand. In 2010, SAWS contracted with CP&Y, Inc. to study and design the Interconnect.

The City of San Angelo (City) faces immediate water supply challenges and the need to make critical decisions to secure long-term reliable water supplies is now. Once reliable supplies, in the form of lake and surface waters, are now threatened. An immediate solution is required to help the City preserve access to these water supplies while meeting regulatory and customer needs. The Hickory Aquifer located in the nearby McCulloch County, where the City owns existing water rights and represents a viable and consistent source of water to the City, is the solution. The major elements of the Hickory Water Supply Project include the development of a groundwater well field, pump station, water transmission main, and water treatment for the radium-containing groundwater. This paper focuses on the route study, water quality implications, and pipe materials evaluation for the transmission main consisting of approximately 63-miles of 30-inch diameter pipe.

Steel fiber-reinforced concrete pipe (SFRCP) has many unique benefits over traditionally produced reinforced concrete pipe (RCP). SFRCP is now being evaluated and implemented into standards in North America. This paper provides research data on the manufacturing and performance of this product when compared to traditional RCP. The most widely accepted way to evaluate the structural performance of RCP is to conduct D-load testing. Evaluations will be presented on 48-inch and smaller diameters of SFRCP that were manufactured in accordance with ASTM C76 for Class III, B-wall pipe and tested in accordance with ASTM C497. The only variation in manufacturing was the substitution of zinc-coated steel fibers for all of the traditional welded wire reinforcement found in RCP. SFRCP performance was recorded continuously using pressure transducers and deflection gauges. Loads on the pipe were noted when SFRCP developed a 0.01-inch-wide crack and when the pipe's ultimate structural strength was reached. The load performance was then compared to set values found in ASTM C76 for a Class III RCP. The SFRCP demonstrated some unique benefits over traditional RCP, but it also highlighted the need to more closely structurally evaluate the loads at ultimate with respect to the 0.01-inch crack because testing showed decreases in typical safety factors associated with the relationship between these two performance criteria. An evaluation of the manufacturing and handling performance of SFRCP against traditional RCP was also evaluated with SFRCP, showing many significant performance benefits.

The current generation of High Density Polyethylene (HDPE) pipe materials, classified as PE4710 by U.S. standards and PE100 by ISO standards, has greatly improved toughness characteristics over previous generation materials. Most noteworthy is an increased resistance to slow crack growth and fatigue. In the U.S., PE4710, PE3608, and PE3408 (previous generation material) pipes are used in water mains and forcemain sewers. These pipelines daily experience numerous pressure surges above their standard pumping pressure. For pipes operated at their rated pumping pressure, AWWA C901 and C906 allow "recurring" pressure surges equal to 0.5 times the pipe's Pressure Class (PC) and "occasional" surges to equal the pipe's Pressure Class. Thus, the surge allowance results in a total pressure (combined pumping pressure plus surge pressure) equal to 1.5 x PC during recurring surges and 2.0 x PC during occasional surges. While all three materials have the same long-term hydrostatic design basis of 1600 psi, a higher design factor for PE4710 pipe allows it to operate at a pressure 25% higher than either PE3408 or PE3608 pipe. This paper addresses the question, "Does the higher surge pressure resulting from operating PE4710 pipe at a higher pressure compromise PE4710 pipe's performance?". This paper gives an overview of design procedures for water and forcemain sewers given in current standards. It discusses considerations for a reasonable safety factor against over-pressurization during transient surge and shows that this factor is met by PE4710 material when designed in accordance with AWWA and ASTM standards. Aside from the pressurization itself, repetitive surge may lead to fatigue. This paper references studies wherein PE4710 material has a fatigue life in the millions of cycles when operated at its pressure rating and subject to recurring surge equal to 0.5 x PC.

The Central Arizona Project (CAP) owns, operates, and maintains 73 acoustic, ultrasonic, transit-time flowmeters measuring flow through 103 pipes - either measuring flow from pumping plant discharges, measuring water delivered to customers, or measuring flow for groundwater recharge credits. Flowmeters are essential to CAP's operations, water accounting, and customer billing. The CAP performed an analysis of each of its acoustic transit-time flowmeters in an effort to: (1) identify existing or potential problems with the accuracy of the flowmeters and make recommendations for corrective action; (2) review and improve maintenance procedures; and (3)examine the long-term viability of the flowmeters. Justification for the study was derived from the following difficulties: ≤ Inconsistent losses reported in monthly water balance studies ≤ Occasional discrepancies between CAP flowmeters and some customer's own metering systems. The desired outcomes of the investigation are to: ≤ Improve the accuracy and reliability of CAP's flowmeters by developing guidelines that are consistently applied in the maintenance and operation of the flowmeters ≤ Identify which flowmeters have reached, or are nearing, the end of their useful life and develop a program to replace those identified flowmeters This paper reviews the replacement project that resulted from the initial investigation.

When the City of Fort Worth, Texas, created a storm water utility in 2006, developing a detailed GIS-based inventory and map of the City's storm water assets was identified as a high priority because of the potential value added to the planning, design, and construction of over $1 billion in storm water infrastructure improvements. The Storm Water GIS Inventory would: ≤ Enable spatial planning of long-term capital improvement projects ≤ Provide accurate emergency response information for environmental spills ≤ Enhance reporting capabilities for permit requirements ≤ Track maintenance needs of source control and treatment control BMPs ≤ Provide data to support Watershed Planning Studies, hydraulic modeling, condition assessment, and asset management The program included the development of a detailed database, including a strategy to collect data and record attributes for the huge system. Over 20,000 plan sheets were catalogued, leading to link-node schematics for 36,000 inlets, 9,000 manholes, and over 1,200 miles of pipeline. The four-year program is now in its final year. The GIS is being prepared to enter into the maintenance cycle and feed into Fort Worth's new condition assessment and asset management program. A critical lesson learned is how to establish filters for data QC given the varying range of assets and attributes captured. Special training and standard methods were also required to read plans for pipeline features that date back 100 years to the oldest infrastructure in the city. Collaboration between teams entering and reviewing data was critical to final acceptance and use of the data.

The City of Baton Rouge/Parish of East Baton Rouge (City/Parish), Louisiana, has entered into a United States Environmental Protection Agency (EPA) Consent Decree. The City/Parish designed and is implementing a sanitary sewer overflow (SSO) abatement program that involves conducting comprehensive rehabilitation and capacity improvements to the collection system. To implement the program, the City/Parish has developed the Program Delivery Plan (PDP), which describes the 93 projects needed to rehabilitate the system and increase its capacity. The PDP includes replacement of approximately 150 pump stations and nearly 2,000 miles of gravity and force main pipe. The PDP outlines 31 comprehensive rehabilitation projects, 57 capacity improvements projects, and 5 wastewater treatment and storage projects. Each of these projects requires sequencing to ensure that they work together to create a collection and treatment system that will work for the City/Parish into the future. For instance, a comprehensive rehabilitation project may include rehabilitation of a certain pipeline that needs to be included in a capacity improvement project, so the City/Parish needs to make sure that they do not rehabilitate a pipe that then will be replaced with a new, larger pipe in the near future. Within the capacity improvement projects, projects are split by geographic sewer basin. The projects are also divided so that pipelines are replaced in one project and pump stations are replaced in a separate project. Within the capacity projects, several inter-related projects can be encountered, with one pipeline project tied directly with a pump station project, and both of those projects related to upstream or downstream projects within the sewer basin. Therefore, scheduling of the projects is very important within the Program. This paper will discuss project construction scheduling that allows the SSO system to continue to operate while portions of the system are under construction. Two case studies explaining lessons learned will be discussed, including a case study with a pipeline project behind schedule that required pump stations to be tested without the discharge force main in place.

Projects may begin in the office during design phases, but all successful projects end in the field. The trick for the civil engineer is to design a project that not only works well on paper, but can also be efficiently and effectively constructed and operated by human beings. During design, it can be easy to neglect the many components that will eventually result in the success or failure of a project. Field experience provides a vital link that allows each component of a complete system to be seen step by step. After beginning their careers in the office on the design of pipeline and pump stations for water projects, the authors had the opportunity to temporarily move to the field and see the many components of construction come together. They were on the construction management team for the Colorado River Municipal Water District's (CRMWD) Ward County Water Supply Project. One major advantage to seeing a design take shape in the field is the ability to focus on one project over an extended time. During a field assignment, engineers can delve deeper into construction specifications and plans, getting clear examples of how small words or sentences have vast impacts during construction. Throughout the construction management of this project, the authors learned countless lessons relating to installation and inspection of multiple types of pipes (bar-wrapped concrete, steel, and PVC) in extremely challenging native soils and sands; tie-ins to decades-old pipes and reservoirs; prestressed concrete tanks; vertical turbine and horizontal centrifugal pumps; communication systems; and electrical systems. Besides familiarity with the physical building blocks of a project, construction management assignments provide valuable lessons in construction documents, working with contractors, overall constructability, and client service. Experience in the field proves invaluable for an engineering career and future design capabilities. The experience lets engineers become familiar with all of the tangible and non-tangible components of a successful project while challenging and encouraging them to keep learning.

The Hanlan Water Project is a proposed 96-inch diameter potable water feedermain that will extend a total of 8.7 miles. Approximately 4.6 miles of the alignment is proposed to be tunnel, at depths varying from 52 feet to 92 feet. The remaining length will be installed using open cut trench. The feedermain will run through residential, commercial, industrial, and recreational land uses. Planning of the feedermain has included input from a variety of stakeholders including: traffic engineers, councilors, public relations representatives, operations and maintenance, provincial government, municipal government, local residents, and local business owners. The communications program implemented on this project has built trust and confidence between the public and the project team. Ensuring proper documentation, involvement, and consensus on decisions from the EA phase and through to construction will result in a community that is accepting of the infrastructure being implemented.

The Tualatin Valley Water District (District) located west of Portland, Oregon, manages a system of nearly 1,200 kilometers of pipe comprised of approximately 95% iron pipe. Seventy-five percent of iron pipe is ductile iron and 25% is cast iron. Iron pipe in its system is failing due to external corrosion in as little as 30 years. This paper describes the District's approach to addressing this problem, including the results of a pipe pilot study to evaluate other pipeline coatings and materials for use in its system. The goal of the pipe pilot program is for the District to be able to systematically assess and compare the different pipe and material installations for its own set of conditions and to establish new standards for pipe installations to assure greater long-term cost effectiveness for its pipeline infrastructure. These new installation standards consider soil corrosivity and criticality of the pipe installations, as well as regional seismicity concerns.

Due to repeated failures of an existing 36-inch steel force main, the City of San Francisco Public Utility Commission (SFPUC) elected to rehabilitate the sewer force main under an emergency procured design-build contract. The existing steel force main was installed along the historic road, The Embarcadero. This shoreline drive along San Francisco bay is adjacent to the Ferry Building.

The San Francisco Public Utilities Commission (SFPUC) is completing the $4.6B Water System Improvement Program (WSIP) which includes seismic upgrades to the Hetch Hetchy water system that crosses three major faults and several minor fault areas. Operating in close proximity to several significant seismic/geotechnical risks, the Hetch Hetchy water system stretches 156 miles from source water high in the Sierra-Nevada Mountain Range, stretching all the way to the City of San Francisco and providing water to 2.4 million people. Along with increasing levels of service concerning delivery, operational, and water supply reliability, the intention of the WSIP is to increase the seismic reliability of SFPUC's Hetch Hetchy water system with the primary level of service goal to maintain or restore - within 24 hours - potable water supply to 24 San Francisco Bay Area municipalities. The Crystal Springs - San Andreas Transmission System Upgrade Project (CSSATSUP), one of 81 WSIP projects, is spread out over 8 miles of environmentally sensitive San Francisco Peninsula Watershed and has 7 different project jobsites which cross, or are within close proximity to, the San Andreas Fault (SAF) as well as some other minor fault zones. The Crystal Springs/San Andreas Transmission System (CSSATS) transmits water between three reservoirs which, in turn, supply source water to Harry Tracy Water Treatment Plant (HTWTP) for use as both supplemental and emergency drinking water. The peninsula watershed reservoirs serve as the only emergency water supply for 1.4 million people on the San Francisco peninsula. The CSSATSUP includes seismic retrofit upgrades to a submerged culvert that crosses the SAF, four reservoir outlet structures less than 1000 feet away from SAF and a 6-mile long, 60" diameter steel pipeline rehab that runs adjacent to SAF, as well as construction of a new electrical substation and new pump station. This paper discusses how a diverse multi-agency project delivery team successfully developed and implanted seismic retrofit upgrades to an aging water transmission system which is subject to significant seismic risk. Also included are details regarding how the CSSATSUP design was developed, an overview of the CSSA system, system operational constraints, technical challenges and the implementation of design during construction of the San Andreas Outlet Structure 2(SAOS2).

Fyfe Co., LLC Tyfo® Carbon Fibrwrap® system (CFRP) has been utilized in strengthening structural elements for over 20 years. More recently, CFRP has been introduced as a repair alternative for failing pipe sections and joints, as well as other emergency applications that afford a shortened construction scheduled, minimal curing time and immediate return to service conditions and pressures.

Long aqueduct pipelines tend to operate under a wide range of head and flow conditions. Selecting the correct flow control valve can maximize overall system performance and value. This paper presents a variety of large (50 to 400 cfs) flow control valves for various head breaks (5 to 500+ psi) and compares the strengths of each valve. Flow control valves presented include sleeve valves, plunger valves, globe style valves, and butterfly valves. Typical installation conditions for each flow control valve are presented and the suitability of each valve for specific applications is analyzed based on overall capacity, energy dissipation, range of flow control, cavitation potential, and other characteristics. This paper documents the design, selection, and construction of multiple major flow control facilities for various large diameter aqueduct systems. Key attributes of the major flow control facilities are documented and a systematic review of the different types of flow control valves installed and reasons for their selection based on hydraulics, operation and maintenance, economic feasibility, expected service life, and constructability are presented. This paper identifies several fitting applications for a variety of flow control valves and how they are used to help maximize the overall value of the pipeline system which they operate.

The Fyfe Co., LLC Tyfo® Fibrwrap® system has been utilized in strengthening structural elements for over 20 years. More recently, the Tyfo® Fibrwrap® system has been introduced as a repair alternative for failing pipe sections and joints, as well as other emergency applications that afford a shortened construction scheduled, minimal curing time and immediate return to service conditions and pressures. The following report is a brief description of the background, design and method of installation of the Tyfo® Fibrwrap® system for the City of Houston North 60 pipeline.

The Integrated Pipeline (IPL) system is a raw water supply program that integrates Tarrant Regional Water District (TRWD) - and City of Dallas-owned water supplies from Lake Palestine, Cedar Creek Reservoir, and Richland Chambers Reservoir. As one of the largest water supply projects in the nation and one of the largest ever undertaken in Texas, the IPL will consist of a 350 MGD raw water transmission pipeline from Lake Palestine to Lake Benbrook, with connections to a new 250 MGD Pump station at Richland Chambers Reservoir, a new 277 MGD Pump Station at Cedar Creek Reservoir, and a new 150 MGD Pump Station at Lake Palestine. The pipeline will be approximately 150 miles in length and will contain 3 booster pump stations. As part of the IPL, TRWD retained a team led by CH2M HILL to study invasive species that might threaten the major components of the IPL system.

From 1992 until 2007, the Louisville Water Company (LWC) implemented an aggressive Main Replacement and Rehabilitation Program (MRRP) targeting approximately 500 miles of unlined cast iron pipe installed in LWC's system prior to 1931. With an annual budget between $8,000,000 and $10,000,000, cast iron pipes that were both structurally and hydraulically sound were cleaned and cement lined, and those that were not structurally sound or were hydraulically undersized were replaced. Following the completion of this targeted program in 2007, LWC has continued the MRRP with an annual budget of $5,000,000 targeting selected sections of lined cast iron pipe primarily for replacement. Selection criteria utilized included age, breaks, leaks, and main break frequency (MBF) as potential indicators of performance. LWC endeavored to find selection criteria that provided a more business-sense approach. The MBF has been a good standard measurement to compare breaks from one area or time period with another within LWC's system. It can also be utilized to compare against another water utility's performance, but it's not an indicator of how LWC is performing within an environment that speaks in dollars and cents. In selecting candidates, what level of MBF justifies the replacement of a pipe section? Because LWC is looking at a one-time capital cost for replacement in comparison to a series of recurring operations and maintenance costs for repairs, certain factors - including inflation, weighted cost of capital, service life, study life, and various other economic terms and calculations - need to be considered. In addition, the methodology employs "soft" data to "evaluate costs" of customer outages, traffic delays, criticality of pipe section, and likelihood of future failures. A Net Present Value (NPV) analysis is employed to examine a pipe section's candidacy for replacement. The paper discusses the background of LWC's original MRRP, previously utilized selection criteria, and details and illustrates how use of the NPV analysis has allowed the LWC's current MRRP to evolve and remain a prudent use of rate payer funds in an economically challenging business environment.

Determining losses through piping systems involves the selection of the appropriate friction factor and minor loss coefficient (K factor). The widely-used constant K values are applicable only for fully-developed turbulent flows. For laminar flows, the K factors must be corrected based ontheReynolds number because K factors start to increase when the Reynolds number falls to within the laminar flow regime. This paper reviews Hooper's 2-K method and Darby's 3-K method for determining K factors over a wide range of Reynolds numbers for both turbulent and laminar flows, and introduces an Excel-based tool for engineers to calculate K factors using the 2-K method and 3-K methods. One limitation in using the 2-K and 3-K methods is that both methods are based on available literature data, which are applicable only to commonly-used pipe fittings. For fittings not included in this list, CFD (Computational Fluid Dynamics) modeling becomes very useful to determine the dependency of the K factor on Reynolds number because of its flexibility and lower cost than experimental studies. CFD models described in this paper are examples of using this powerful tool.

Specifications are a critical component of construction projects involving water conveyance facilities. This paper discusses observations and lessons learned related to preparing specifications. Topics include a discussion on the value of maintaining and updating master or standard specifications, guidance on developing a system for feedback to improve the specifications, tips on how notes to the specifier can be incorporated into the specification, tips on how notes to the specifier can be made most useful, and a discussion of requirements that are frequently overlooked or have caused confusion on conveyance projects.

The North Texas Municipal Water District's (NTMWD) Lake Texoma Water Supply Project designed in the late 1980's and completed in 1991, conveys approximately 25 percent of NTMWD's total raw water supply. The project consists of a 72-inch pipeline from Lake Texoma to a discharge point at Sister Grove Creek approximately 30 miles to the south of Lake Texoma. Sister Grove Creek then flows into Lavon Lake to the south. The 72-inch pipeline also supplies water to the City of Sherman, Texas' water treatment plant. Zebra Mussels were found in Lake Texoma in 2009 and represented the first time this invasive species was found in Texas waters. Because the water from Lake Texoma was being transferred from the infested Red River to the un-infested Elm Fork of the Trinity River, the United States Army Corps of Engineers required NTMWD to cease pumping operations until a solution to mitigate the spread of the zebra mussel could be found. To compound this situation, 2010-2011 was one of the worst drought periods this area of the state had ever experienced and NTMWD's other raw water supplies were stressed. On October 1, 2011, with multiple options having been studied to re-establish the Texoma supply, NTMWD embarked on the selected project. This project entails extending the existing Lake Texoma pipeline system another 47 miles to the south to bypass Lavon Lake and connect directly to the head works of NTMWD's four water treatment plants in Wylie, Texas. The total program cost exceeds $300 million. The goal was to have water flowing into the water treatment plants by August 2013, less than 2 years after the project's inception. This paper provides a general overview of the components of the project and the approaches that were implemented to fast-track this critical project. These approaches included fast-tracking the typical design schedule, aggressive right of way acquisition, and the use of a Construction Manager at Risk to accelerate the execution of the project.

Water distribution networks (WDNs) are vital in transporting water to consumers as per demands. Traditionally, cost has been the main objective in the design of WDNs; however, minimizing cost may result in a system that is incapable of handling abnormal states such as demand uncertainties and pipe failures. Subsequently, various reliability and its surrogate measures (such as resilience metrics) were developed in the past for designing networks capable of handling uncertainties. Few studies exist that evaluate the performance of such resilience metrics in the context of mechanical failures such as water main breaks. This paper analyzes the performance of three resilience metrics: 1) Resilience Index (RI); 2) Network Resilience Index (NRI); and 3) Modified Resilience Index (MRI). Two popular benchmark WDN problems are considered in this research: a) A small Greenfield scenario and b) Expansion of an existing WDN to meet future demands. A genetic algorithm (GA)-based, multi-objective optimization formulation is employed for the design of WDNs by considering two objectives: a) Cost and b) Resilience. All single and double pipe breaks are considered as possible failure states for the performance evaluation of the obtained design solutions. The results from the analysis on limited number of benchmark networks indicate that NRI is a reasonable metric that is capable of guiding the design of resilient WDNs. Given the state of our underground water infrastructure, this research is very relevant and the results are immensely helpful in instilling resilience into existing or new water distribution networks.

Bar-Wrapped Concrete Cylinder Pipe (CCP), and the reasons why its configuration enhances its structural performance, may not be widely understood even though it has a long history of service. CCP steel reinforcement consists of a steel cylinder and a continuous mild-steel bar helically wrapped around the cylinder. CCP also has a centrifugally-cast concrete or cement mortar lining and a dense cement mortar coating which encases the steel cylinder and bar reinforcement. In addition to the steel cylinder, the bar reinforcement provides the balance of steel reinforcement for internal pressure design and it transforms the pipe wall into a composite structure by mechanically locking the mortar coating tightly against the steel cylinder. This feature was identified during initial testing for the development of the pipe and its specifications. This composite construction increases the pipe's stiffness and the external load-carrying capacity since it increases the ring flexural strength of the pipe which, in combination with the passive earth pressure on the sides of the pipe, resists the external loads by limiting pipe deflection. The composite construction also increases the pipe's rigidity and resistance to physical damage and corrosion which are very desirable attributes for water transmission pipelines. The history of CCP and its development milestones since the introduction of the product in 1942 by a U.S. West Coast pipe manufacturer (American Pipe and Construction Company whose name was changed later to Ameron) will be presented; in the late 1940's other pipe manufacturers started producing CCP. Pipe diameters were initially limited to 42 inches and gradually increased to 72 inches as more performance record was developed. CCP development coincided with the use of Carnegie Steel joints with rubber gaskets on the US West Coast in 1940. Performance testing by American Pipe and Construction Company and a few agencies, and early CCP standards prior to the development of the AWWA C303 Standard are reviewed. This paper presents the design concepts of CCP and details its complete components including the joints. The paper also reviews the performance record of CCP and a few major installations. Good practice installation recommendations are also given.

Large diameter conventional steel pipe with a typical 1/2-inch, spun-cast mortar lining is very flexible and must be strutted for handling, stabbing of the joint, and to prevent against over-deflection during backfill consolidation. Therefore, the standard trench requirements normally call for self-consolidating materials that can support the pipe and be placed with minimal compactive effort, which helps minimize pipe deflection. PressureCast Steel Pipe (PCSP) with pre-compressed high strength structural concrete or mortar lining is much stiffer, regardless of diameter-to-steel cylinder thickness ratio. The stiffness of this pipe eliminates the need for struts during transportation and installation. The increased stiffness, compared to conventional welded steel pipe, also permits the use of many native materials for backfill due to PCSP's semi-rigid behavior. In order to document the field performance of large diameter PCSP, two 120-inch pipe sections were installed in the Pima Feeder Canal Reach of the Pima-Maricopa Irrigation Project in Coolidge, Arizona for the Gila River Indian Community. The pipe sections are in an inverted siphon under the Florence-Casa Grande Canal and subjected to 15 feet of earth cover with a design pressure of 30 psi. A wide trench design was used due to the twin parallel pipes installed at 17 feet on center. Use of large diameter welded steel pipe for the other sections of the siphon utilized controlled low-strength material (CLSM) for pipe embedment to provide support in order to limit deflection. The inherent strength of the PCSP sections permitted the use of granular materials for the upper two-thirds of the pipe zone. To review the installed pipe's performance, deflection readings were taken and a complete visual examination of the pipe was performed two years after the pipe was installed. This paper presents the pipe installation details and procedures, the pipe design criteria, and the results of the inspection.

Significant thrust forces can be generated on a pressurized pipeline wall or fitting due to internal pressure, momentum forces, surge forces, and/or thermal changes. The produced thrust force can lead to longitudinal movement of a pipeline and its connections. Soil frictional resistance (which is a function of the pipe's surface area and coating material), depth of cover, and soil characteristics play key roles in restraining such axial movements. Thus, soil frictional resistance is an important factor in designing restrained buried pipes that operate under internal pressure. When soil conditions are stable, considerable economies could be realized by utilizing the embedment soil to restrain the pipe. A series of controlled laboratory tests were performed, aimed at establishing friction coefficient values for combinations of selected soil types and three external coating systems, namely: cement mortar, per AWWA C205; Polyurethane, per AWWA C222; and Prefabricated Polyethylene tape, per AWWA C214 (used in conjunction with steel pipes). The work was performed using the Trenchless Technology Center's (TTC) soil chamber testing apparatus (6 ft. wide × 12 ft. long and 5 ft. deep) which is equipped with an air bladder and a stiff steel lid capable of applying a uniformly distributed load of up to 18 psi on the soil surface. The internal diameters of the pipes were 14" for the specimens coated with polyurethane and prefabplastic tape and 12" for the specimen coated with cement mortar lining. This was done to obtain a comparable external surface area for the pipe specimens. The pipes were pulled through the soil using a horizontally-mounted, 150,000 lb., servo-controlled, hydraulic actuator. The embedment materials were compacted to the level of the crown of the pipe for conservatism. Earth pressure cells placed in the vicinity of the pipe registered stress changes in the soil medium due to longitudinal movement of pipe. All embedment materials underwent an array of laboratory soil characterization tests to establish key characterization parameters. Test results were compared with predictions provided by appropriate clauses in the current version of the AWWA M11 design manual for steel pipe design.

Thrust restraint design of buried pipelines is dependent on internal pressure, piping configuration, and the pipe-soil interaction at the pipe-soil interface. Pipe-soil interface behavior is dependent on the pipe material, native and backfill soil properties, and installation conditions. It is generally recognized that a buried pipe has to move through the soil to develop friction and adhesion resistance. It also has to move against the soil in order to develop lateral (passive) resistance forces which, in combination with the frictional and adhesive resistance forces, resist the unbalanced thrust. Axial and transverse pipe movements cause additional pipe stresses (axial tension, bending, and shear) on the pipe at or near the unbalanced forces, which are not considered in the current American Water Works Association (AWWA) pipe design manuals adequately, except to a certain extent in the M9 (AWWA 2008) procedure. The ASCE task committee on thrust restraint design of buried pipelines was formed in 2008 with the objective of documenting and reviewing the current practices, investigating the feasibility of a unified thrust restraint design framework for all materials, and preparing a manual of practice to improve current design practice for thrust blocks and thrust restraint systems. The proposed framework consisted of two distinct design solutions - for continuous (welded, fused or flanged) and segmented (those with some degree of joint flexibility and/or extensibility) - to accommodate the different types of joint types used in practice. Advancing the concept further for continuous pipelines, the task committee presented a case study in 2011 that compared restraint length and calculated the additional stresses in buried continuous steel pipelines. The approach used in the case study utilized analyses procedures outlined in AWWA M9 (2008), M11 (2004) and the simplified procedure published by Robertson (1980) for Reinforced Thermosetting Resin (RTR) pipes. In addition, the task committee has also undertaken a series of exercises towards developing the preliminary unified framework outlined in the draft white paper, which include the development of an analytical model and a software tool. As an initial step, the analysis approach presented in AWWA M9 (2008) for continuous pipelines has already been implemented in the software tool. This paper presents a detailed design example for the purpose of verifying and fine tuning this analytical model for the case of steel continuous pipelines.

Thrust restraint design of buried pipelines is dependent on internal pressure, piping configuration, and the pipe-soil interaction at the pipe-soil interface. Pipe-soil interface behavior is dependent on the pipe material, native soil and backfill properties, and installation conditions. It is generally recognized that a buried pipe has to move through the soil to develop frictional and adhesive resistance. It also has to move against the soil in order to develop lateral (passive) resistance forces which, in combination with the frictional and adhesive resistance forces, resist the unbalanced thrust. Axial and transverse pipe movements cause additional pipe stresses (axial, shear, and bending) on the pipe at and near the unbalanced forces. The magnitudes of the additional pipe stresses are also dependent on the axial and rotational flexibility of the pipe joints. Traditional thrust restraint design approaches have been based on simplified assumptions that relied solely on force equilibrium concepts that disregarded effects of force-displacement relationships at the pipe-soil interface. In a draft white paper published in 2010, the ASCE Task Committee on Thrust Restraint Design of Buried Pipelines proposed a preliminary unified framework for the design of thrust blocks and thrust restraint systems. The proposed framework consisted of two distinct design solutions for continuous pipelines (welded, fused, etc.) and segmented pipelines (those with some degree of joint flexibility) to accommodate the vast array of joint types used in practice. Advancing the concept further for segmented pipelines, the task committee has undertaken a series of exercises toward fully developing the preliminary unified framework outlined in the draft white paper, which include: the development of an analytical model and software tool; evaluation of alternate pipe-soil interaction concepts; and comparison of the findings against current practice and available experimental results. The concepts and analytical formulations being developed for segmented pipelines would also be applicable for continuous pipelines, as a special case. This paper presents current progress of this analytical model for the case of segmented pipelines, and a companion paper presents current progress for continuous pipelines.

AWWA C200 Steel Water Pipe, 6 Inch and Larger, is an industry consensus standard that is recognized throughout the world and is the preeminent guide for the manufacture of steel pipe for water and wastewater applications in North America. The first AWWA steel water pipe standard (7A.3 and 7A.4) were published in 1940. In 1949, 7A.3 was replaced with C201 and 7A.4 was replaced with C202. These two standards were later combined into the C200 standard in 1975. Since then, the document has undergone six revisions, each iteration marked by improvements to the manufacturing process as well as associated quality control procedures. The most recent revision, incorporating a number of significant updates, was approved by the AWWA Board of Directors on June 22, 2012 and became effective on September 1, 2012. This paper will provide a historical perspective of AWWA steel water pipe standards, followed by a discussion of some substantial improvements made in the latest revision of C200. Topics discussed will include considerations for the Charpy toughness or impact testing, new testing requirements for gasket materials, allowable steel grades and or characteristics, manufacturing test requirements, weld procedures and weld testing.

The Tarrant Regional Water District (TRWD) and the City of Dallas Water Utilities (DWU) are currently engaged in the planning, design and implementation of a 350 MGD raw water transmission system which will run across north central Texas from Lake Palestine to Lake Benbrook. Collectively, the system constitutes approximately 150 miles of 84-inch to 108-inch pipeline and six pump station sites. A geotechnical investigation was conducted along the pipeline alignment and included about 400 geotechnical borings, 150 miles of Electrical Resistivity Tomography (ERT), 100 Cone Penetration Tests (CPT), and geologic mapping. The vast amount of data collected was archived electronically in a geospatial database. Successful pipe design requires communication between IPL program management, the engineering geologist, geotechnical engineer and civil engineer. A unique planprofile was developed to illustrate the vast amount of geologic and geotechnical information collected for the IPL project. The plan-profiles were developed initially from correlation of strata using standard geologic techniques. The profiles were then modified using color codes to illustrate subsurface conditions and areas of geologic concern that are important to the civil engineer for design of the pipeline.

Over two decades, and in design and construction of 60 miles of 126- to 60-inch pipelines, Central Utah Water Conservancy District (CUWCD) and CH2M Hill have addressed a variety of movable ground risks in several aqueducts. Figure 1 shows these recently constructed aqueducts and locates key movable ground risks addressed on each. 1. 120" Olmsted Pipe at Canyon Glen Landslide 2. 120" Olmsted and 90" Alpine-1 Pipes at Slow Moving Active Landslides 3. 120" Olmsted Pipe at 2 miles of Inactive Landslides and Talus Slopes 4. 96" Spanish Fork Canyon Pipe at Recently Active Blacks Slide 5. 60" Provo Pipe: 5-mile realignment to avoid Provo bench landslides and faults 6. 60" Pioneer Crossing Pipe: 4-mile pipe in compressible soils and highway fills 7. 60" Vineyard Pipe: 7 mile pipe in compressible soils, springs and fills. On each of the movable ground projects, the risks are identified and then the design and construction solutions are presented which were developed to address each risk. Each solution adds reliability to one aqueduct. Together they provide a highly reliable and redundant water delivery network.

The Southern Delivery System (SDS) Pueblo Dam Connection Project consists of a connection to the existing Pueblo Dam River Outlet Works with a stainless steel tunnel liner that expands from a 4-by-4-foot square connection to a 90-inch-diameter pipe. The 90-inch pipe leads to downstream valves for river releases and a wye turnout to the SDS transmission pipeline. The peak discharge for the existing Pueblo Dam River Outlet Works is 1,120 cubic feet per second (cfs), which equates to a maximum velocity of 70 feet per second (fps) at the connection. This paper discusses the results of the Computational Fluid Dynamics (CFD) modeling performed on both the existing Pueblo Dam River Outlet Works prior to modifications associated with the SDS Project, and the modified outlet associated with SDS Pueblo Dam Connection. Design provisions included in the contract documents that were developed to reflect the recommendations developed from the CFD models are discussed. For example, special guidelines were specified to minimize deflections between joints, offsets, and weld groove thicknesses within the stainless steel tunnel liner section to minimize the possibility for cavitation under high discharge flow conditions.

West Texas has experienced sustained drought conditions for more than 10 years; however, the drought of 2010-2011 was particularly brutal to surface water supplies. Soaring temperatures and lack of rainfall led to high evaporation, dry soil conditions and minimal runoff for supply reservoirs. The Colorado River Municipal Water District (CRMWD) owns and operates three supply reservoirs in West Texas, but the combined storage volume in their reservoirs fell to 5.5 percent, creating a severe water-supply crisis and forcing CRMWD to build an emergency ground-water supply for Odessa, Midland, Big Spring and other water supply customers. Design for the $130-million Ward County Water Supply Project began in June 2011 and operation started in December 2012, just a few months before CRMWD's three surface water supplies would not be usable for water supply. The project is critical to the economic vitality of the region, which is experiencing one of the largest oil booms in decades, and is vital to our nation's energy independence and economic sustainability. This paper presents the challenges and lessons learned for the design, permitting and construction of CRMWD's new 30-million gallon per day (MGD) water supply system that includes 21 groundwater wells, 65 miles of pipeline, four pump stations and other related facilities. The paper discusses the following: ≤ Measures taken to complete the design and construction in less than 18 months ≤ Easement acquisition and permitting challenges ≤ New alternate delivery methods to expedite construction, manage risk and improve quality ≤ Pipeline construction using on-site mixed controlled low-strength material (CLSM) ≤ Use of new technology tools for design, construction and managing the project ≤ Drilling, producing and equipping 21 wells in record time. With solid planning, teamwork, heroic effort and a little luck, the new supply began operations before the lakes went dry.

The City of Cambridge is pursuing sewer separation in the Concord and Huron Ave. neighborhoods. Hydraulic modeling of the separated system indicated that the proposed network would not achieve the desired level of protection. This is mostly caused by limited downstream capacity of the regional interceptor that backs up into the municipal sewer system, impeding free discharge conditions as well as significant upstream inflow contributions generated from private properties. Since addressing regional downstream conditions is not cost effective, the hydraulic and financial impact of removing these private inflow sources was evaluated. An extensive building inspection campaign was carried out and, based on the field information, private properties with inflow sources were ranked based on the cost-to-inflow removed ratio. Then, the hydraulic model was run assuming the top 25, 50, 75, or 100% of the private inflow sources had been eliminated. The model indicated that a 75% level of control is necessary to achieve adequate level of protection for the desired 10-year, 24-hour storm. This option would save the City of Cambridge close to five million dollars in the next twenty years due to reduced inflow treatment fees and would reduce Cambridge's Combined Sewer Overflows (CSO) to the Alewife Brook by approximately 4000 cubic meters per year.

Underground pipelines are vital infrastructure and are mostly used to transport energy and other essential commodities. These pipelines are generally buried within the top layer of soil deposits and are, therefore, highly affected by different environmental conditions applied on the ground's surface. These environmental conditions may include seasonal climate changes (i.e. wetting and drying cycles), park watering, or any substantial water leakage. These changes result in variations in soil moisture content which, in return, may cause extensive soil movements. Additional stresses and deformations can be developed on the buried pipelines as a result of differential soil movements. An understanding of the response of buried pipes to surrounding unsaturated soil conditions can be useful for establishing modified design practices and maintenance. This paper presents the results of a soil-pipe interaction model that considered the effect of variation in soil moisture on the deformation of buried pipelines. This model implemented the soil-structure interaction relationships for unsaturated soils by using a general purpose partial differential equation solver named FlexPDE (PDE solutions Inc). Unsaturated soil suction stresses and the relative vapour pressures of the soil structure were estimated based on unsaturated soil characteristics and then used as an input for the model. The results of the modelling analysis showed a significant influence of the change in soil suction on the displacements of underground pipelines.

This paper presents the development of allowable stress methodologies for polyethylene pressure piping compounds from the early materials of a half-century ago through today's high performance piping compounds. Early assumptions that polyethylene compounds could be stress-rated like metals proved to be false. Investigations of premature field failures identified that sustained long-term stresses generated a slow-crack-growth failure mechanism that was not revealed through short-term strength evaluations. This led to the development of long-term stress evaluation methodologies, refinements and stronger requirements for polyethylene compounds to assure that slow-crack-growth failure would not occur within acceptable design lifetimes for polyethylene pressure piping. Recent developments in water piping standards have been questioned because out-of-date misconceptions have been misapplied to newer, higher-performing polyethylene piping. This paper tells the history of HDPE piping compound performance development to correct misconceptions and misunderstandings of HDPE piping performance.

In 2002, the North Texas Municipal Water District (NTMWD) began installing a large-diameter pipeline in the northern end of their service area to meet the growing demands of the North Texas area. The project name was the Allen/Plano/Frisco/McKinney Pipeline (APFM). To meet the population growth and projected demands of NTMWD's customers, the entire pipeline would need to be in service in 2010. This pipeline was planned as a 20-mile pipeline consisting of 72- to 84-inch diameter piping. The pipeline was also planned to run through some of the most congested and active construction areas in the North Texas area. For design and construction reasons, the project was broken into four separate pipeline segments to be done in succession. As of 2007, three of the four segments were completed and in service supplying needed capacity to many of NTMWD's growing customers. In 2008, the planning and design began for the fourth and final phase of the pipeline. This was the southernmost section that would tie to the NTMWD treatment plant and high-service pump station. This last segment was approximately five to six miles and was planned as an 84-inch diameter pipeline. The pipeline route would start at an existing connection to the third segment of the APFM Pipeline in the Town of Lucas, and continue south and east to the NTMWD treatment facility where it would tie into an existing high-service pump station discharge header. Along this projected route were multiple types of land usage areas, including large sections of U.S. Army Corp of Engineers (USACE) property. NTMWD's facilities border the southern side of Lavon Lake in Wylie, Texas. The lake is a USACE lake and, to bring the pipeline into the NTMWD facilities, the pipeline would almost certainly have to cross USACE property. This, along with some of the active construction and the various congested areas that the pipeline would need to cross, posed many different planning and design difficulties when developing the preliminary and final design of the final section of the APFM Pipeline. The proposed paper will detail the preliminary and final design problems encountered by routing a minimum 84-inch diameter pipeline through rural, urban, and USACE property, along with the additional effort that was needed to acquire the necessary land to construct the large-diameter pipeline. The planning and execution of the design and construction of the pipeline had many different aspects and parameters that had to be addressed throughout the process that will also be discussed throughout the paper.

The Provo Reservoir Canal Enclosure Project (PRCEP) replaced a 160-year-old, 21-mile (34-kilometer) -long open canal with a 126-inch (3200-mm) -diameter steel pipeline to help address public safety concerns, reduce evaporation and seepage losses, improve water quality, increase capacity, and provide a reliable water delivery system to help meet the growing water needs of more than one million end users along the Wasatch Front of Utah. The canal alignment is primarily located on unconsolidated ancient lake sediment deposits, alluvial fans, stream deposits, and landslide deposits from the Wasatch Front Mountains. This paper presents a detailed discussion of the geotechnical challenges associated with these geologic materials. The geotechnical challenges of the project were further complicated by the need to design and prepare bid documents for several alternative materials for the enclosure, with the goal of identifying the most cost-effective method of construction and water conveyance for the project. These designs included precast concrete box culverts, cast-in-place concrete box culverts, non-cylinder reinforced concrete pressure pipe, and welded steel pressure pipe. With the challenges properly addressed, this monumental $150 million landmark project was completed one year ahead of schedule.

Large-diameter pipeline design in a fully-developed urban environment presents many challenges. The designer has to work around or relocate existing obstacles while keeping water, sewer, and traffic disruptions at a minimum. This paper will discuss: (1) the design of the City of Fort Worth East Side II 54-inch Water Main (E-2); (2) how existing development presented multiple design challenges; and (3)how the design compensated for these challenges. The E-2 pipeline is a key component of the City's water transmission system. The pipeline supplies water from the City's Rolling Hill's Water Treatment Plant to northern sections of the City and several wholesale customer Cities. The current pipeline was built in multiple stages from 1972 to 1985. The E-2 is primarily a 54-inch pipeline. There is, however, a 42-inch section in the middle of the alignment that limits the full use of the entire line. The City of Fort Worth hired Freese and Nichols, Inc. to design a 54-inch replacement for this section of the line. The original concept was to construct the replacement 54-inch pipeline parallel to the existing 42-inch. However, the 42-inch alignment is very congested and an alternate route had to be developed. The E-2 pipeline runs through the heart of Fort Worth's east side, primarily along the Beach Street Corridor. The area has been developed for many years (in some cases over 100 years), and existing water, sewer, franchise utilities, and gas well sites occupy much of the open space and City Right-Of-Way. While selecting the route and designing the 54-inch line, the project team had to consider all of these potential conflicts as well as two major urban highway crossings, a railroad crossing, and a crossing of the Trinity River. The design also had to allow for keeping the existing 42-inch water line, a 36-inch water line and numerous smaller water and sewer lines in service, while keeping all major streets open during construction.

Anchor blocks are a key component of many above-ground pipelines. Anchor blocks are typically used in waterworks applications where thrust restraint of a pipeline is desired. Some design guidance can be obtained from several sources including Steel Penstocks, Second Edition, ASCE Manuals and Reports on Engineering Practice No. 79. However, the analysis and design of anchor blocks for waterworks applications could use some improvements for easy use in the design office. This paper will address the fundamentals of designing anchor blocks for elevated welded steel pipe and will explore the geometry and mathematics with emphasis on design simplicity. Significant computational advantage can be obtained by application of vector algebra to resolve forces that often act along the pipeline axes. Further computational simplification is possible by approximating the center of gravity of the anchor block, recognizing a volume is calculated by revolution of a planar section and application ("Pappus's Centroid Theorem". A common design issue is what to do when stability cannot be achieved economically by adding more concrete weight? Adding rock anchors to provide stability is typically more cost-effective than adding weight. The goal of this paper is to provide a useful tool to pipeline designers who may have struggled in the past with design issues related to anchor block design. An example problem is included. Figure 1 indicates an idealized anchor block for an elevated, welded-steel penstock where geometry of the bend is defined. The anchor block is constructed of reinforced concrete and the steel penstock passes through it as indicated in Section A. Often for constructability and forming purposes, concrete anchor blocks are built with multiple straight-sided surfaces with tangents that extend beyond the points of tangency of the bend. Analysis of the component prisms that make up an anchor block can make calculations of volume and center of gravity very tedious and complex. In order to simplify calculations, an idealized anchor block is substituted as shown in Figure 1 where a planar section is rotated about an axis forming a geometric solid of revolution. With this figure, simple calculations can be performed to compute volume and center of gravity with reasonable accuracy, recognizing that a precise model requires more computational effort. Typical anchor block forces include: (1) the axial forces acting along the penstocks reach both upstream and downstream of the anchor block and include gravity loads from penstock and water, friction loads from pipe supports, friction loads from expansion joints, and pressure loads acting on ends of expansion joints and internal pressure; (2) the fixed-end beam moments and shears acting at the faces of the anchor block where the penstock penetration occurs; and (3) the gravity load from the anchor block itself that includes components of weight from concrete, water, and steel within the anchor block. To properly evaluate all the effects of all the above forces requires very detailed calculations. However, the author believes that reasonable preliminary design accuracy can be obtained by selecting the primary loads only that include (1) destabilizing force from internal pressure force acting at the anchor block along the bend bisector together with (2) stabilizing force from the anchor block weight. Resolution of forces and moments about the base of the anchor block is necessary to calculate, sliding and overturning stability and bearing stresses. The selection of a plane to perform the analysis should be based upon an understanding of the geology of the site however, Line "A" in Figure 1, located near the base of the anchor block at right angle to the bend bisector has been chosen for illustration. The mid-point of Line "A" is the location where summing of forces and moments is performed. Typically the anchor block alone is inadequate to provide stability and the addition of weight in the form of pre-stressed rock anchors will assist in attaining stability.

Geopolymers are a new class of cementitious binders that are gaining considerable attention in the construction industry in recent years. Their inorganic polymer composition offers a number of advantages over traditional hydrated Portland cement systems. One promising potential application for this technology is the manufacturing of pre-cast geopolymer concrete pipes, which are currently being produced in Australia on a pilot-scale, but not in North America. Among the advantages that geopolymer technology offers in comparison with traditional Portland cement concrete are: a higher durability, superior corrosion resistance, and lower carbon footprint. This paper presents an optimization process to create a mix design suitable for geopolymer concrete pre-cast pipes. Results show that the final mix design satisfies rheology and compressive strength requirements using an 8-hour vapor cure and temperatures close to ambient (~50°C). The results of a comprehensive durability and corrosion resistance investigation, which include alkali-silica reaction (ASR), freeze-thaw resistance, sulfate attack, sulfuric acid attack and nitric acid attack, are also presented.

This paper describes the fault-crossing design of a new 66-inch pipeline within the Sunol Valley portion of the San Francisco Public Utilities Commission's (SFPUC) water transmission system. The new pipeline, together with three existing pipelines (69-, 90- and 96-inch diameter). crosses the Northern Calaveras Fault, a major strike-slip fault with a high probability of a Magnitude 6.7 or greater earthquake in the next 30 years. The new pipeline was designed to remain in continuous operation when subjected to more than four feet of surface rupture on the fault to meet the SFPUC's reliability goal of providing 120 million gallons per day (mgd) of water within 24 hours of a major earthquake. The design was developed using nonlinear analyses with consideration to soil-structure interaction effects. Imposed fault deformations were accommodated through slip between pipe and soil and controlled plastic deformation of the pipeline. Backfill soil properties and pipeline coating were designed to provide sufficient friction between the pipe and soil to minimize loads at the tie-in to the 1933 era infrastructure. Design specifications for the pipeline included special metallurgical requirements for steel, shop and field welding and material traceability requirements to control the plastic response of the pipeline.

Finite Element Analysis (FEA) is a widely used, computer-based tool for the analysis of complex systems. While civil engineering uses are largely limited to physical structures, such as buried pipes, the underlying use of the computer to analyze the response of models of real systems (physical, biological, economic, etc) to various stimuli is widespread and is valuable. However, the use of these computer models of real systems has become ubiquitous and, as a result, it has become unfashionable to question their validity. This tool has become the master! The validity of any computer simulation, such as FEA, is dependent on the accuracy of the computer model of the real system and the appropriate application of natural laws governing its performance. Thus, it is imperative that the FEA process include an explicit validation that demonstrates that the computer output is supported by sample calculations by standard analytical techniques or physical test data (when possible). Recent events have demonstrated that such validation is not routinely performed and the models used were erroneous. Examples from engineering papers/reports are discussed in this paper.

The use of polyurethane materials as corrosion protection for welded steel pipe has increased in the past decade. Application of the polyurethane materials is primarily by steel pipe fabricators and the fast-setting properties of the polyurethane materials lends to their use in production line environments. Some manual or spray application is still required for non-production pieces (specials, outlets, etc.). Post-production quality testing required by AWWA C222 and most specifications has focused on adhesion testing using ASTM D4541 with wide-ranging results and levels of satisfaction from fabricators, engineers and owners. The systematic and random error inherent to this type of adhesion testing is documented in the governing standard and in the more recent literature, particularly when applied to curvilinear pipe surfaces and plant (non-laboratory) environments. Corrosion protection by a coating is provided by providing a barrier between the environment and the steel surface. A more monolithic barrier provides better protection. Despite the amount of testing and investigation of polyurethanes by coating manufacturers and others, little attention has been paid to the characteristics of the resulting polymer film. In this work, we investigate the characteristics or "microstructure" of a variety of polyurethane materials. Both hand-applied and plant-applied polyurethane materials were compared and analyzed. The microstructure may include interfacial planes (if the film was applied in multiple passes) and voids or bubbles resulting in porosity. Hand-applied material was, in general, more porous than plant-applied with the degree of porosity of plant-applied material varying over a wide range. The impact of porosity on corrosion protection effectiveness is discussed.

This paper describes the issues associated with the fabrication of a seismically-designed, 66-inch pipeline within the Sunol Valley portion of the San Francisco Public Utilities Commission's (SFPUC) Hetch Hetchy Water System to near the eastern end of the valley, the pipelines cross the Northern Calaveras fault, a major strike-slip fault with a high probability of magnitude 6.7 or greater earthquake. Surface rupture for this event is expected to be more than four feet. The new pipeline was designed to remain in continuous operation when subjected to more than four feet of knife-edge type displacement during a surface-rupturing event on the Northern Calaveras fault. The fault-crossing design was developed using sophisticated numerical analyses. This paper discusses the metallurgical requirements of the steel plate material, the procedures utilized for maintaining material traceability, fabrication of the pipe sections engineered for the specific fault crossing, in-plant quality control and SFPUC shop inspection requirements. Standard industry practice for the fabrication of the AWWA pipe was used as a basis for manufacturing with additional requirements for pipeline material, coatings, nondestructive testing, shop welding requirements, fitting geometry and material traceability requirements to reproduce the numerical model in the real world.

The EPA estimates that major increase in inflow and infiltration (I/I) is caused by the leaking residential laterals. Several types of grout materials have been used in controlling I/I problems in wastewater systems and storm systems. In this study, a test protocol was developed by the Center for Innovative Grouting Materials and Technology (CIGMAT) and was approved by the USEPA to evaluate the performance of polymeric grout used in the rehabilitation of lateral joints in wastewater facilities and to quantify the infiltration at pipe joints using a combination of model and laboratory tests. The polymer grout was used to control the leak of over 1000 gallons/day at a leaking lateral joint. For the leaking joint model test, 203-mm (8-in.) diameter leaking pipe joints were used in soil box. The grout used in this study was characterized using the working, physical, mechanical and durability properties. It was observed that the polymeric grout, which had a gelling time of 24.5 seconds, was impervious to water when grouted in soil when the hydraulic gradient was 100. The durability test results showed that the grouted sand was extremely resistant to varied chemical environments and the strength deterioration was negligible for a period of one month. The grout was effective in reducing the discharge from over 1000 gpd (4940 liter/day) to zero at hydraulic pressures of 3, 4 and 5 psi (21 to 35 kPa). The large scale model test was simulated using a numerical finite element model which predicted the results well.

This paper presents the key findings of the condition assessment effort for 7 Force Mains in terms of existing condition and projected useful life. The Clark County Water Reclamation District (District) provides wastewater treatment for over 110 mgd. The wastewater is generated by the unincorporated part of Clark County, the Strip, and the communities of Laughlin, Blue Diamond, Overton and Searchlight. The District (created in 1954) operates and maintains 30 lift station facilities in the service area. These Force Mains are associated with the Casa Buena, Mountains Edge, Pebble II and Whitney Lift Stations that service a substantial portion of the collection system tributaries in Clark County. The efficient and effective operation of these stations and Force Mains is critical in the overall operation of the District's wastewater collection system. The District determined that a general condition assessment was required for the 7 Force Mains (4 PVC, 1 DIP and 2 ACP) and that the results would be extrapolated to the balance of the District's Force Main inventory. A proactive approach toward preventive maintenance reduces the operation and maintenance cost of the Force Mains over time and considerably reduces the capital cost of rehabilitating the Force Main systems in the future. The condition assessment performed by the V&A Consulting Engineers team included the following technical disciplines: ≤ Hydraulics, determination of the actual C Factor ≤ Removal of 8 pipe samples for destructive testing ≤ Corrosion Assessment ≤ Coatings Evaluation ≤ Leak Testing ≤ Determination of Baseline Condition for PVC, and Remaining Useful Life for DIP and ACP Force Mains

The North Charleston Sewer District (NCSD) System includes 62 pump stations and approximately 475 miles of gravity and force main piping. This infrastructure serves approximately 100,000 customers over a 59-square-mile service area. The Felix C. Davis WWTP is permitted to treat 27 MGD and is the only plant utilized by NCSD. Currently, the plant averages approximately 15 MGD and recently completed an expansion to treat 34 MGD.

The existing water distribution network in Abu Dhabi Island has been constructed in the last 35 years. Operation and maintenance reports indicate that the condition of the older sections of the existing network is deteriorating and pipelines may need to be rehabilitated or replaced. There has, therefore, been a growing need for the Abu Dhabi Distribution Company (ADDC) to develop a renewal plan due to more stringent service levels enforced by the regulator (Regulation and Supervision Bureau), namely, more stringent water quality requirements, increases in water demand due to new developments, and increased accountability towards the public. In order to address this issue, ADDC commissioned MWH in April 2010, to undertake a Condition Assessment of the Abu Dhabi water distribution network on Abu Dhabi Island within 52 of 152 sectors.

This paper summarizes recent efforts to capture some key economic, social, and environmental costs related to wastewater pipeline condition assessment and renewal engineering in a better way to help utility managers understand what factors drive project cost and, moreover, what are the true costs of the work to society as a whole. Data for the direct costs of two popular industry practices - namely CCTV pipeline inspection and CIPP liner installation - was gathered from wastewater utilities across the U.S. of varying size and location. Further, social and environmental costs were derived for each instance including traffic disruption, loss of business revenue, and the effect of noise pollution from construction on property values. Nearly 400 cost examples were collected from over 30 wastewater utilities. Direct, social, and environmental costs were then compared as a percentage of the total pipeline work cost to ascertain cost drivers. The results showed differing cost trends based on the parameters for the selected technologies, as well as values for the social and environmental costs accompanying these same technologies. The analysis further showed the gap between what data utilities are currently collecting and what they need to collect to understand the true cost. The exercise was a pilot study for capturing vast datasets in a uniform manner for advanced trend analyses in a centralized database as part of the WATERiD project.

This paper describes research into the effects of corroding cast iron pipes on the properties of surrounding clay soil. Accelerated corrosion tests, employing electrokinetics to simulate the galvanic cell that is set up naturally when cast iron comes into contact with clay, have shown that the chemical changes (e.g. pH) are more marked than for cases in which inert electrodes were used. These chemical changes result in both cast iron and clay mineral dissolution, ion migration and the precipitation of reaction products close to and - to a lesser degree - away from the pipe wall. The paper describes a laboratory study of the effects on a pure form of kaolinite after different lengths of electrokinetic treatment and draws conclusions on the potential effects that are likely to be found for old cast iron pipes in clays.

In December 2011, the San Diego County Water Authority (Water Authority) successfully used extra-high-resolution Magnetic Flux Leakage (MFL) technology to non-destructively assess a steel pipe reach. The pipe reach consisted of five miles [8-kilometers] of 75- and 72-inch [190- and 182-cm] diameter, cement mortar-lined and -coated steel pipe. After reviewing the data, the Water Authority was able to verify the metal loss, both internally and externally, in three areas. MFL uses magnets to generate a magnetic field in the steel wall of a pipe. Anomalies in the steel can be detected by leakage in the magnetic field. The anomalies can be analyzed to determine the depth and size of metal loss. In the past, direct contact of the magnets with the steel was required. However, new technology allows a nondestructive assessment of the steel from the inside of the pipe through the mortar lining. This paper will cover the implementation, results, and verification efforts of the MFL condition assessment. In addition, the paper will provide important considerations and potential improvements for pipeline owners who utilize MFL technology.

As part of the conveyance system for the Carlsbad Seawater Desalination Project, the San Diego County Water Authority plans to reverse the normal flow direction for a five-mile reach of its existing steel 72-inch and 75-inch Pipeline 3, thereby subjecting the pipeline to steady-state and transient operating pressures in excess of the pipeline's design criteria. To evaluate the pipeline improvements needed to accommodate this reoperation, the Water Authority worked with the project's private developer to conduct a range of pipeline condition assessments and evaluations, including: out-of-roundness evaluations, magnetic flux leakage testing, internal and external inspections, and others. This paper describes the pipeline condition assessments and evaluations undertaken. The results of the investigations ultimately led the Water Authority to elect to structurally re-line the entire reach of pipeline.

This paper presents the design approach and results for full-scale hydrostatic tests performed on prestressed concrete cylinder pipe (PCCP) sections strengthened with the StrongPIPE Hybrid FRP system. The system is a trenchless technology for PCCP rehabilitation that consists of continuous, high-strength steel wires wrapped inside a pipe and sandwiched between two layers of fiber-reinforced polymer (FRP) composites. Installation of the system is automated which improves the quality of the final product and expedites production. The system combines the durability of FRP composites with the ductility, stiffness, and lower cost of steel. It can be used for the rehabilitation of short and long runs of pipes. Three full-scale pressure tests were performed on two 66-in (1676-mm) diameter, 20-ft. (6.1-m) -long PCCP sections (one benchmark and one strengthened with StrongPIPE system). The original unstrengthened pipe had a design bursting pressure 291 psi (2 MPa). However, original pipe section failed at a pressure of 140 psi (0.97 MPa) after only 25% of the original prestressing wires were cut. Testing of the pipe section strengthened with StrongPIPE system was conducted in two phases. In Phase I, all of the existing prestressing wires were cut in four stages (25% cut in each stage) to simulate progressive damaged condition of the pipe. In each stage, the pipe was pressurized to 300 psi (2.07 MPa) after the wires were cut. After all the wires were cut, the pipe was pressurized to 450 psi (3.1 MPa) and no failure occurred. In Phase II, the outer concrete core of the host pipe was completely removed in the test region to mimic further damage to the host pipe and was again pressurized to 450 psi (3.1 MPa). The overall performance of the system was excellent. The high stiffness of new steel wires prevented excessive deformation and dilation of the system at higher pressures, which resulted in more pressure resisted by the system and less pressure transferring to the host pipe. The hybrid FRP system provides a cost effective and durable solution for repair and strengthening of PCCP.

There are a number of large, beer-brewing facilities throughout North America. As with all manufacturing facilities, there is a significant inventory of very critical assets that play a critical and supporting role in the entire process of making and shipping a variety of malted beverages that are enjoyed by many responsible adults. One of these critical assets is the complex network of drains that carry process and manufactured wastes from various process buildings to a treatment or pre-treatment facility at many of these brewing locations. Due to a number of unusual wastewater properties - including elevated BOD, very high and short-term temperatures, extreme variations in hydraulic loading, and gritty materials (such as broken glass) - drain systems require constant attention to their structural integrity and hydraulic reliability. In 2012, CH2M HILL was commissioned to conduct a comprehensive and baseline assessment of the entire drain system network at eight large brewing facilities in North America. The purpose of this comprehensive drain assessment program was to ultimately develop a prioritized list of capital improvement projects over a 5-year period based on risk and asset management principles for each of these facilities. The paper will describe the unique challenges of performing a successful condition assessment program for drain assets in facilities that operate non-stop, 365 days a year. Specifically, the paper will explore the early discussions and strategies necessary to evaluate a wide range of technologies and diagnostic tools to enter these drain lines and the final approach and work plan that can be endorsed to ensure a successful rehabilitation program outcome. During periods of active deployment and inspection, we will highlight solutions to problems that could be encountered such as the following: .. Management of heavy, sticky, and gritty brewery solids .. Avoidance strategies with situations such as unmanned, laser-guided robots .. Internal navigation through severely corroded drain lines .. Inspection and cleaning of chronically surcharged drains .. Redundancy planning to ensure zero-tolerance of potential backups and surcharging Once completed, inspection data can be post-processed using modified NASSCO/PACP codes better suited for manufacturing facilities with each individual drain asset being separately evaluated for two important categories: Structural and Maintenance. The final element of the program to be discussed is a sensible data migration of these final condition scores to a riskbased asset management model that can create a final and prioritized list of capital and O&M projects for implementation by larger brewing facilities in the years to come.

Much research has been conducted for Prestressed Concrete Cylinder Pipe (PCCP), focusing on the performance of the pipe under normal loading conditions. However, little has been done to analyze PCCP's performance under negative pressure that could be created by malfunctioned valves during the dewatering. This paper presents the results of a case study investigating the failure causes of a 54-inch PCCP failed under negative pressure. This investigation will improve the understandings of PCCP's performance under negative pressure and the findings of this research will help utility owners better manage their PCCP pipeline systems. A 54-inch PCCP failed when Washington Suburban Sanitary Commission (WSSC) was dewatering the pipeline which had one valve that stopped working and created negative pressure. The engineers were trying to investigate the failure causes of this pipe, but they were not sure if it was the negative pressure that caused the failure. Therefore, it is very important to know the influence of negative pressure on the structural safety of the pipe to identify the actual failure cause of the pipe. If the negative pressure can cause failures of PCCP, then a condition assessment program has to be developed to examine all the valves in the pipeline periodically, which will be very costly and take a long time. In this paper, a finite element (FE) model is developed to simulate the structural response of PCCP to the negative pressure, considering the number and location of broken prestressing wires. In the FE model, the weight of soils and pipe is also considered. The structural details - such as concrete core, steel cylinder, intact and broken prestressing wires, and coating - are simulated to fully represent the structural performance of PCCP under actual loading conditions.

Baltimore County's 48-inch PCCP Kenilworth Transmission Main, constructed in four phases between the 1970's and 1990's, serves 125,000 customers in the central part of the County. The main provided potable water, without incident, until it failed catastrophically in June 2003, adjacent to a local high school. Following an emergency repair, the same transmission line failed again nine months later, this time causing more severe damage to roads, underground infrastructure, and homes. After this second event, condition assessments and forensic analysis were conducted in late-2004, employing both visual and electromagnetic inspection technologies to evaluate the overall structural integrity of the pipeline, resulting in an emergency contract to replace four PCCP segments. Six years later in late-2010, in keeping with the County's policy to periodically inspect major transmission mains of questionable integrity, another re-inspection was performed, this time employing more advanced technologies as well as structural risk analysis and 3D finite element modeling. This led to the discovery of 33 PCCP sections that needed to be structurally rehabilitated or removed-and-replaced; decision needed to be made on the rehabilitation of the structurally deficient sections only, or the renewal of the entire length of pipeline in question. After considering various repair options -including carbon fiber reinforced composites (CFRP), removal-and-replacement with new PCCP sections, and structural sliplining with steel pipe or high-density polyethylene (HDPE) pipe - the County decided to slipline the PCCP host pipe with spiral welded steel pipe. This paper not only discusses the history of the pipeline and its condition assessment and forensic analysis in detail, but also reviews the innovative decision processes involved with the selection of the appropriate rehabilitation method, material specification and drawing development. Discussion on the construction process of sliplining with steel pipe along with an evaluation of lessons learned is also provided.

MWH has been undertaking a two-year Water Research Foundation project, investigating the state of the art within the global water industry regarding the use of condition assessment techniques in small-diameter cast and ductile iron water mains. The objective of this research project is to provide an evaluation of existing condition assessment (CA) technologies and a development plan for future technologies that can be applied to non-interruptive, non-destructive condition assessment of small diameter (less than 16-inch or approximately 400 mm) cast iron pipe (CIP) and ductile iron pipe (DIP). The focus has been on technologies which can estimate the amount of remaining structural metal in the pipe wall compared to the amount of non-structural material (i.e. graphitized material, slag inclusions, casting porosities or other manufacturing defects, corrosion pits, etc.), or as close to that as possible, for both unlined and cement mortar-lined CIP and DIP of small diameter. The final written report of the study (due for publication in 2013) will identify and demonstrate the benefits of condition assessment to assist with the asset management of small diameter CIP/DIP. By raising industry awareness and interest, the next generation of low-cost Condition Assessment (CA) technologies that meet industry performance requirements will be prioritized for further development.

Explosion blasts can produce an overload much greater than the design load of a pipeline, potentially causing catastrophic damage to pipeline networks, both externally and internally. Given the considerable effects of explosion waves and the recommendations in related design codes, evaluation of blast waves on pipelines is important. This research evaluates the effect of pneumatic dampers on water pipelines subjected to blast loading. For this purpose, the water pipeline network of a district in Tehran was modeled using Finite Element Method (FEM). Then, an accelerograph record of a standard blast wave was applied to the model. The results indicated critical points of a network which failed due to explosion waves. Thus, pneumatic dampers were employed for behavior improvement of the mentioned points. The results demonstrated that the failure points were retrofitted efficiently by pneumatic dampers. Finally, a statistical test indicated a significant difference of the blast response effect on pipeline network before and after applying pneumatic dampers.

Water pipeline networks make up vital infrastructures throughout the world. Since water pipelines operate under high pressure, their failure can cause severe damage to human health and property. In this study, the water pipeline network of a district in Tehran was modeled using the Finite Element Method (FEM). Also, nonlinear time-history analysis was performed via seismic scaled records of Near-Fault (NF) and Far-Fault (FF) earthquakes. Furthermore, Optimal Sensor Placement (OSP) procedure was done in which a Genetic Algorithm (GA) was selected to act as the solution of the optimization formulation. Only TYTON joints in the modeled network were considered for OSP due to their vulnerability against seismic loads. Unlike the common algorithms that employ modal analysis results, the authors propose a novel approach for OSP that uses nonlinear time-history analysis results as an exact seismic response. Statistical results showed that there is a significant difference between the obtained OSP results of NF and FF earthquakes.

Internally-bonded, fiber-reinforced polymer (FRP) composite liners have been successfully used to rehabilitate damaged and deteriorated prestressed concrete cylinder pipes (PCCP) since the early 1990s. These systems consist of multiple layers of longitudinal and circumferential FRP sheets that are saturated on site with epoxy and installed using manual wet lay-up process to produce a cured-in-place composite pipe within the existing pipe. FRP liners have gained popularity as they do not require excavation and can be installed in a relatively short time. However, these systems are relatively expensive and are more suited for individual and short runs of pipes. A more cost-effective solution for pipe habilitation can be achieved using a hybrid steel-FRP rehabilitation system. The system consists of high-strength steel wires continuously wrapped inside the pipe and embedded in a high-performance polymeric matrix. The steel wires are placed between two layers of FRP to produce a sandwiched composite structure. The hybrid system combines the stiffness, ductility, and low cost of steel with the durability and excellent performance of FRP to produce a structural liner with bidirectional strength that can be used for repair and renewal of both short and long runs of pipe. This paper presents a case study for the rehabilitation of 120-in. (3.05-m) diameter PCCP in a power generation facility located in New Mexico. Both carbon FRP (CFRP) and Hybrid FRP systems were used to upgrade the deteriorated pipe sections. The CFRP system was installed in the discharge line, while StrongPIPE Hybrid FRP system was installed in the intake line. The paper highlights the features, limitations, feasibility, quality control requirements, and cost of the two rehabilitation systems.

The huge annular area between borehole wall and drill rod leads to a low velocity of drilling fluid in the reaming procedure of large diameter Horizontal Directional Drilling (HDD) crossing project. In order to ensure efficiency of cuttings transmission, the viscosity of the drilling fluid is always increased. The drilling fluid filled in annular area is always mixed by several fluid models, so it's difficult to analyze the flow field of the high viscosity drilling fluid in the annular space of borehole using a single fluid model. The simulation herein classifies drilling fluid into two parts: (1) the fluid close to the drill rod and borehole wall, and (2) a gel which is in the middle of the first part. This paper uses the N-S equation to determine the relationship between the velocity and the viscosity of drilling fluid. Furthermore, the equation obtained from the N-S equation shows that boundary thickness depends on the drilling fluid's viscosity. The author used the Herschel-Bulkle model to describe the drilling fluid and obtain the shear stress equation.

Breakage of prestressing wire wraps is an indication of damage in Prestressed Concrete Cylinder Pipe (PCCP) due to corrosion, hydrogen embrittlement, overloading, and manufacturing defects. The strength of the damaged pipe is not only related to the number of broken prestressing wire wraps, but also to the location of the break regions along the length of the pipe. In this paper, a nonlinear Finite Element Method (FEM) was used to compare the structural integrity of a PCCP when wire wrap breaks occur at the spigot joint, the bell ring joint, and in the middle of the pipe section. For the structural evaluation, stresses and strains developed in the damaged PCCP were recorded and compared using the FEM computer modeling software, Abaqus. The Cracking and Ultimate Strength Limits, as defined in the American Water Works Association (AWWA) C304 Standard for Design of Prestressed Concrete Cylinder Pipe, of a damaged PCCP were investigated by increasing the internal pressure of the pipe while the severity of damage was manipulated by increasing the number of broken prestressing wire wraps. The results were obtained for a 60-inch embedded cylinder pipe (ECP) with 5, 35, 70, and 100 wire wrap breaks. The proposed model was applied to evaluate the effects of wire wrap breaks at the joints and in the middle of a pipe section. Based upon the obtained results, a comparison between wire break wrap in the middle of the pipe and the joint are presented and discussed.

Effective asset management requires that utilities allocate scarce resources to high risk sections of their pipeline system while maintaining an acceptable level of risk throughout the system. This asset management approach requires the ability to evaluate criticality, extents of distress, and failure margin of each section of the pipeline system in order to identify pipes with unacceptable risk of failure. A geographic information system (GIS) containing pipeline design and installation data, pressure scenarios, results of condition assessment, and embedded programs for structural evaluation and failure margin analysis contributes to an asset management program by aggregating pipeline data and allowing Utilities to make risk-based decisions. GIS-based tools allow Utilities to continually update the risk of failure of pipes in their system based on the latest condition assessment results and to select the most critical pipes for rehabilitation. Tarrant Regional Water District (TRWD) utilizes a GIS database as a part of their asset management program. TRWD has performed electromagnetic inspection of their pipelines using remote field transformer coupling (RFTC) technology for the past 14 years, and the GIS allows TRWD to update the risk of failure of distressed pipes based on the latest RFTC results. By continually re-analyzing each distressed pipe's risk of failure, TRWD has been able to repair the pipes at highest risk of failure. This paper presents the GIS database and the programs written to perform structural evaluation and failure margin analysis within the database, and how TRWD has used the database in their asset management program.

Communicating the condition of underground utilities to decision makers can be a challenge. Buried infrastructure is unseen and the ability to assess its rate of aging is difficult. This is especially true of Prestressed Concrete Cylinder Pipe (PCCP) which has a multitude of potential failure modes beyond wire breaks alone (Faber et al. 2012). The owner's decision on whether to conduct a localized PCCP repair or a comprehensive rehabilitation project relies on evaluation of technical data, risk tolerance, fiscal impacts, policy, and engineering judgment. Each owner is required to formulate an equation in support of their decision-making process with each component being weighted according to the owner's particular needs and circumstances. Developing and implementing that formula may be relatively straightforward for the pipeline engineers involved. However, the successful communication of the problem, the analysis, and the recommendations to high-level decision-makers may be the most important attribute required of those engineers. Adoption of the latest pipeline monitoring and condition assessment technologies for PCCP pipelines can sometimes confuse the decision-making process when a high level of emphasis is placed on only that part of the equation. A more comprehensive analysis of all factors involved is required when making a decision to undertake a full-scale rehabilitation projec,t and a logical methodology is required when presenting this analysis to high-level decision makers. This paper will examine the factors that require consideration when communicating the need for a comprehensive PCCP rehabilitation project. This will be illustrated using a sample case study undertaken at the San Diego County Water Authority to show how a solution can be presented to parties with different vested interests using a series of communication tools to assist with the decision-making process.

Rock Solid Group (RSG) has been using specially configured micro-geophysical techniques, combined with its understanding of geotechnical and geochemical issues, in the study of various sub-surface and surface engineering structures eliminating the need for destructive sampling and testing. To successfully apply suitable technology for condition assessment, a clear understanding of the techniques' limitations and manipulation of recorded data is essential. Lack of suitable and efficient methods for assessment of pipelines - commonly forming parts of urban water, sewer and gas infrastructure - has lead RSG to develop unique technology to tackle this issue. Key issues are the pipeline itself, as well as the embedment of buried infrastructure. Pipes form an integral part of the life-line to all major towns and cities. They carry water or gas to, and sewerage away from, these centres. Their failure, in many instances, is unacceptable to the communities they service. The ability to accurately assess their current condition and continue monitoring any condition changes during their life cycle is essential to enable the development of a budgeted and targeted maintenance program. The application of RSG's patented Wave Impedance Probing (WIP) and Broadband Electromagnetic (BEM) technology has found a large range of applications globally. The flexibility and ease of use of these technologies has seen the development of both in-line, as well as external, inspection methods of buried, as well as exposed, pipelines. BEM technology is now also being applied to a variety of other engineering structures, such as underground tunnels and bridges, where wall linings and supports are constructed from ferrous materials.

Permeation of high-density polyethylene (HDPE) pipe in potable water applications is a rare event. It is important, however, to understand and characterize the potential health risk that could arise should such an event occur. The most common potential permeant is gasoline, particularly the components Benzene, Toluene, Ethybenzene, and Xylene, commonly referred to as BTEX. Previous research has shown that pipe materials including joint gaskets and packing glands, may be subject to permeation by BTEX. To address this concern, all AWWA pipe standards contain boilerplate language requiring users to consult with the manufacturer regarding permeation through pipe walls and joints before selecting the materials for use in such contaminated areas. To assist designers and owners in the selection of HDPE pipe, a calculator has been developed that allows the user to vary design inputs such as groundwater saturation, flow velocity, water stagnation, pipe thickness, and ground temperature to estimate the BTEX permeation. Relevant variations in the position of the pipe within the water table, water flow rates, or PE pipe wall thicknesses can result in orders of magnitude differences in permeation. This paper presents the development of a BTEX permeation calculator and demonstrates permeation estimations based on various design inputs.

This paper presents a novel, patent-pending, "waterless" method of pressure pipe-cleaning using airborne abrasives. This new method not only removes corrosion products quickly, it leaves the pipe interior in a "ready state" for the trenchless application of spray-in-place (SIPP), cured-in-place (CIPP) and/or cement linings. It also provides pipe surface preparation and dries the pipe for superior liner bond. This paper highlights the importance of pipe cleaning and preparation in advance of installing certain pressure-pipe liners and outlines the details and limitations of this new technology. Early, promising results from a recent trenchless water main rehabilitation project in Cambridge, Ontario, showed that coal-tar coatings on ductile/cast iron pipe can be removed effectively and efficiently.

This paper presents a study of water main inventory and performance for diameter sizes of 24-inch and larger from 21 water utilities and 16 states across the United States. The study is conducted by the Center for Underground Infrastructure Research and Education (CUIRE) and focuses on different pipe materials used nationally in water transmission applications. Objectives of this study were to gather data from different water utilities to analyze the population served by the pipeline facility, miles of pipeline material in use, age and diameter, and the performance rates of each pipeline material. This paper concludes with comparison of diameter range, age, and failure rate for the pipe inventory of responding water utilities.

The wastewater system backbone of the New Orleans Sewerage & Water Board (the Board) is comprised of large-diameter, steel force mains in diameters from 54- to 72-inch size. During Hurricanes Katrina and Rita, the town and associated infrastructure experienced damages associated with the flooding resulting from these storms. In 2005, two back-to-back major storms inflicted great damage on the City and the surrounding area. On August 29, 2005, Hurricane Katrina hit the Louisiana coastline as a Category 4 storm. The water level in Lake Pontchartrain peaked at 8.6 feet (7.6 feet above the normal sea level). Breaches in the levees built to protect the City occurred at the 17th Street Canal, the London Avenue Canal, and the Industrial Canal. The breaches led to flooding in nearly 80 percent of the City with water depths reaching 25 feet in some areasand adding very large external loads to the existing forcemains. Less than a month later, Hurricane Rita made landfall on September 24, 2005, as a Category 3 storm. Levees were again overtopped in at least three locations along the Industrial Canal, re-flooding the City's Lower Ninth Ward, a few neighborhoods surrounding Lake Pontchartrain, and neighboring St. Bernard Parish.

Playa lakes abound in the Texas panhandle. These lakes have been used successfully as stormwater detention facilities in several West Texas cities, including the City of Amarillo. Since these detention ponds occurred naturally and urban development ensued around them, the outer edges of these lakes were filled and the centers of the lakes were excavated. Several playa lakes are now surrounded by developed areas and receive stormwater runoff from multiple outfalls. The discharge of these pipes has caused severe erosion to occur on the slope, and several temporary low-cost repairs were attempted. In 2009, lots adjacent to Lawrence Lake were being evaluated for development. The City of Amarillo, in an effort to minimize further erosion from occurring at this lake, identified several phases to improve the lake's slope and outfalls. This erosion was causing severe settlement in the roadways adjacent to the lake, and several utilities were threatened. Lawrence Lake has 16 stormwater inflow points — some convey flows from storm sewer systems and others convey sheet flows into the lake. Phase 1 of the project included the evaluation of each inflow location and the prioritization of repairing the sites. This phase featured an extensive evaluation of the soil conditions and slope stability around the lake and identified several places where unconsolidated fill may have been used. Phase 2 included the design of various let-down chutes at four sites. These chutes conveyed the flows in channels that have 30-40 feet of vertical drop. The design included optimizing channel width-to-depth ratio to minimize velocities and reduce construction cost. Additionally, recycled concrete was used in-lieu of gabion rock which used available material and reduced construction cost. The City completed the construction of these outfalls in 2012.

Proven technologies (such as straight-line, conventional microtunneling) or curved solutions (like horizontal directional drilling (HDD)) have served the pipeline industry well, but have their limitations. Less well-known (especially in the United States) solutions such as Direct Pipe^TM (DP) and vertical-curved Directional Microtunnelling (DMT) are beginning to find acceptance and application. Existing microtunnelling and HDD engineering design methods do not address the specific issues involved with the estimation of jacking forces or the specific stress analyses of a curved steel pipe loaded in compression. Building on conventional microtunnelling theory and API Recommended Practices, the authors developed a design method for estimating the anticipated loads generated during a curved steel pipe drive and for assessing the steel pipe axial, bending, and hoop stresses along with buckling and combined stress conditions. The design method includes calculations for estimating jacking loads and for calculating a maximum allowable (not to exceed) axial loading for a given geometry and pipe specifications. This paper will introduce the DP and DMT methods, detail the authors suggested design methodology, and give example applications of completed DP and DMT designs slated for 2013 construction in the United States.

The main purpose of this paper is to present considerations for the selection and design of trenchless pipeline projects. The information and recommendations herein are based on numerous trenchless projects performed by the authors. The two sections of this paper document the two major phases for typical trenchless projects - the first documents the evaluation and data collection phase required to evaluate trenchless methods, and the second section details aspects of the specifications and other contract documents affected by the selected trenchless methods. The abilities and limitations associated with various trenchless techniques can vary substantially from one method to another, leaving many owners and engineers uncertain of how to proceed when project requirements merit the consideration of a trenchless crossing. This first section chronicles the typical trenchless evaluation phase performed for trenchless crossing projects in order to examine the methods, risks, benefits, capabilities, and process for selecting crossing methods compatible with the project's specific site conditions. Trenchless options examined include horizontal directional drilling, microtunneling, pipe-jacking, auger-boring, and pipe-ramming. Geotechnical conditions and crossing requirements are alsoexamined on how they affect the selection of a trenchless method. Following the selection of a trenchless method, the specific risks and constraints of the particular trenchless system have to be addressed in the contract documents. The second part of this paper highlights several specific, trenchless-related sections that warrant consideration and discussion for inclusion in the contract documents, including the trenchless specification, bidder qualifications, differing site conditions, measurement and payment, excavation support systems, and geotechnical documents. During the design process, the engineer and owner should work together to address the risks of the selected trenchless method(s) while striving not to limit the contractor's means and methods.

Starting in early 2010, Carollo Engineers Inc. was retained by the Weber Basin Water Conservancy District staff to assess the condition of the Weber and Davis Aqueducts. The two aqueducts consist of 26 miles of 21- to 84-inch pipelines constructed in the early 1950's. As part of the investigation, the team utilized various technologies and manned entry to observed five percent of the joints in the Davis and Weber Aqueducts. Upon completion of the detailed investigations, it was determined that 23 percent of the joints observed needed repair or rehabilitation. If 23 percent of the joints in the entire aqueduct need to be rehabilitated, then approximately 1,900 joints are in need of repair. This paper covers the joint condition assessment and resulting innovative approach developed to demonstrate a cost-effective joint rehabilitation design. This innovative approach was subsequently installed on 229 joints on the 60-inch reinforced concrete pressure pipe (RCPP) Davis Aqueduct.

Replacement of aging pipeline infrastructure is requiring construction along alignments that are highly contaminated and subject to costly and stringent regulatory controls. New installations where favorable routing is not available are also subject to similar constraints. Examples of where these installations can be found are: former industrial sites, reclaimed or filled urban lands, and rivers impacted by past industrial activity and navigation. This paper examines some adaptations to the trenchless construction processes that lead to risk minimization, thus enabling installation in these environmentally adverse ground conditions. To illustrate adaptability of trenchless methods, this paper presents a successful case study where pipe installation in highly-contaminated subsurface conditions was accomplished using trenchless methods, namely: horizontal directional drilling (HDD) launched from a former industrial site.

Pipe-jacking is widely used in municipal pipeline installation, and accurate calculation of jacking force is essential for construction design. Various formulas exist to calculate jacking force, which greatly differ in results. Most formulas are based on classical soil mechanics theories and some simplified assumptions that consider friction coefficient between soil and pipes as a fixed value or neglect the effect of slurry thixotropic. Considering the interaction of soil layers, thixotropic slurry and tube wall, friction is consistently changeable during the jacking process; thus, these formulas and theories cannot meet construction demands. This research is based on the Changchun Yitong River drainage pipelines reconstruction project which used slurry balance pipe-jacking machines to handle mudstone geological conditions. The authors used MATLAB to calculate, analyze and compare jacking force with field measured data. Finally, calculation formulas of jacking force and friction force were derived which took mudstone formation and interaction of soil layers, thixotropic slurry and tube wall fully into consideration

Within the past 15 years, three major utility crossings have been completed below the Chelsea River adjoining Boston Harbor using trenchless construction methods. These crossings were for natural gas distribution (installed by horizontal direction drilling [HDD]), electric transmission (HDD), and municipal drinking water delivery/enhanced fire service protection (microtunneling). Although the crossings were located less than one mile apart along the river, significant variations in the subsurface conditions were encountered requiring careful geotechnical engineering evaluation of the overburden soil, bedrock, and groundwater characteristics.

The Etiwanda Pipeline is a 144-inch diamete,r welded steel pipe, approximately 6.4 miles long connecting the Metropolitan's Rialto Pipeline to the Upper Feeder. The pipeline, constructed in 1993, has dual functions: an untreated water transmission pipeline and a penstock supplying water to the 24 MW Etiwanda Hydroelectric Plant. The pipeline experiences significant daily pressure fluctuations as flows change to optimize power plant revenue. A 2008 inspection revealed that over 35 percent of the field applied cement mortar internal lining had fallen off or had become delaminated. The unique operating conditions, the large diameter of the pipeline, the length and limited access opening for repairs and, in particular, the dual purpose of the pipeline presented unique challenges to replacement of the lining. There are few, if any, precedents for this type of pipeline, which makes the selection of the replacement lining very challenging. This paper will describe the approach adopted to evaluate potential lining repair alternatives in order to select the most cost-effective and constructible lining. The paper will review the life cycle costs of various lining systems, and provide a history of similar flexible lining repairs. The repair technique ultimately selected was complete removal of the mortar lining and installation of a flexible lining system over the entire length of the pipeline. This lining system should provide the desired 50-year service life.

Pull-back force is a critical parameter to decision-making for suitable rig, drilling fluid and weight-adding in a horizontal directional drilling (HDD) crossing project. However, borehole instability - frequently occurring in medium and coarse sand - usually leads to undervaluation of pull-back force, which could trigger broken drilling pipe, stuck pipe, and even installation failure. Borehole collapse in sand dramatically increases sand concentration, viscosity, and friction of drilling fluid, which leads to much more pull-back force increment than the partly-blocked borehole due to borehole collapse in clay. This paper takes into account risk of borehole instability in order to estimate the pull-back force. Furthermore, the authors present a calculation model to support pull-back force estimation of HDD in medium and coarse sand.

A pipeline soil box experiment is designed to research the response characteristics of interaction between underground pipeline and soil. It simulates pipeline installation, operation, and rehabilitation, and provides an effective guidance for theoretical study and actual construction. This new modular pipeline testing soil box system is assembled by several modular walls which allow dimensions to be easily changed. It can also undertake a variety of pipeline simulation experiments and can meet the need for multi-diameter pipeline experiments by changing the size and number of the end wall flange holes. In addition, there are several rubber bladders installed that can simulate 100-m water pressure or about 40-m soil pressure. To reduce the effect of box wall interface friction, wall surfaces are covered with lubrication materials. This soil box can be widely used in the study of buried pipelines or pipelines installed by horizontal directional drilling and pipe jacking technology.

This paper presents one of the most difficult tunnel construction cases in China's modern-day history, which is now a part of the connect-line of the Hong Kong-Zhuhai-Macau Bridge Project. The tunnel passed through soft stratum with a high groundwater table, which involved an underpass section with a shallow overburden of 5-7 m, a curved length of 255 m (consisting of an easement curve and a round curve), a width of 18.7 m, and height of 20.8 m. The curved pipe roofing method was used due to disturbing and complex geographical conditions. The pipe roof, composed of 10 pipes with a diameter of 1800 mm and 30 pipes with a diameter of 1440 mm, was constructed using the slurry pipe jacking method. The critical methods and the main procedures involved in this project are elaborated in this paper.

Dallas Water Utilities (DWU) supplies the DFW Airport and the City of Irving Hackberry Pump Station (HPS) with treated water from the Elm Fork Water Treatment Plant (EFWTP) via a water transmission main with pipeline diameters that include 60-inch, 54-inch, 48-inch and 30-inch. This water transmission main was installed in the early 1970s inside a 20-foot City of Dallas easement when most of this area was undeveloped. Since then, the area has been significantly developed and densely populated by residential development. In 2007, the water transmission main was highly at risk due to a slope failure in close proximity to a section of the 48-inch diameter pipeline located at the top of a hill between Ranchview Drive and Rodeo Drive in the City of Irving. DWU retained the Engineer to evaluate alternatives for restoring the water service to the City of Irving and DFW Airport. It was quickly determined that the waterline should be taken out of service immediately to prevent a catastrophic failure. DWU had to provide a way to bypass the at-risk segment of the existing 48-inch line and implement the necessary corrective actions to put the line back in service. An innovative, short-term, immediate solution to the problem with minimal pipe and appurtenance installation was developed and implemented. The project included conducting a non-destructive condition assessment using ultrasonic technology and the evaluation of options available for a long-term solution. These options included avoiding the area altogether and installing a new pipeline, removal and lowering of the at-risk segment, relocating a portion of the pipeline to an adjacent easement, relocating to adjacent roadway, tunneling a new pipeline alignment below the existing water main, and installing a drilled pier wall between the pipeline and the slope failure area. Although the recommended tunnel option had the highest construction cost, it had the least impact to residents and public thoroughfares and could be initiated quickly to restore service with minimum risk during construction. This paper will present the details of the initial assessment of the site right after the slope failure and the emergency connection developed and designed to provide water service to DFW for the high-flow summer demand. This paper will also present the criteria and step-by-step approach used to evaluate the options available for a long-term solution for maintaining service to DFW Airport while running the supply pipeline though a densely-populated area, and the low-impact design that was recommended to protect the existing 48-inch pipeline, and the challenges and lessons learned during construction.

Understanding the jacking forces and productivity of trenchless construction is critical for appropriate technology selection and proactive control of boring operations. Civil engineers can correlate construction operation parameters (e.g., equipment, forces, and timing) with contextual information (e.g., soil characteristics) for identifying issues influencing the trenchless construction productivity. Manual data collection methods for capturing the tunneling construction operations lack the capabilities of acquiring details of the construction, making detailed workflow analysis difficult. This paper presents an automated data collection and interpretation approach for supporting detailed tunneling productivity analysis. This approach uses a data logger to automatically record the hydraulic pressures of various construction equipment used during Pilot Tube Microtunneling (PTMT) installations. A pattern recognition method can then automatically classify time series patterns of the hydraulic pressure, and detect cycles of construction operations within the three phases of the PTMT process: 1) pilot tube installation; 2) casing installation; and 3) product pipe installation. This method first uses the Artificial Neural Network (ANN) algorithm to classify the time series of the hydraulic pressure for determining the phase. It then uses an anomaly detection algorithm to split the time series into boring operation cycles and individual operations (pushing, retracting, etc.) through detecting discontinuities in the time series pattern. Results from a case study indicate that this approach enables detailed productivity analysis of a typical PTMT process.

This paper evaluates the fundamental nature of communication as it relates to both the contractual and human aspects for development and execution of design-bid-build trenchless projects. The challenges that arise at different stages of these projects are in part related to the project team structure, leadership, personalities and the level of trust developed amongst the team members. The contract documents are examined as a means of communication and as a risk management tool in order to determine why some projects appear to encounter more challenges than others during construction. The clarity in the development of these documents can either enrich or burden the working relationship between the owner, the engineer, and the contractor at the execution stage of the project.

Replacing utilities in urban areas presents challenges to all stake holders. Easement issues, street closures, traffic congestion, disturbing surface works and customer inconvenience are all areas of concern that communities must address. City administrators, engineers and residents are starting to demand more efficient and less disruptive methods of replacement to ease these concerns. As pipelines are coming to an end of their useful life, replacement methods - such as Swagelining - are being selected to add value to all stake holders involved.

One of the challenges facing municipalities in the replacement of failing pipelines is that many of these pipelines are located in developed and populated areas. Open cut replacement can disrupt or damage other existing utilities and surrounding property. Horizontal directional drilling (HDD) techniques have offered ways to avoid some of these issues, but these require special pipe and/or joining methods. Still, HDD is becoming more and more common because of the reduced damage to property, decreased inconveniences for local property owners, and avoidance of other installed utilities. This paper discusses a recently-installed project in the City of Houston that required the replacement of failing 8-inch and 12-inch asbestos-cement pipes utilizing trenchless installation techniques. There were a number of fitting connections that were required along the route, and the contractor for the project chose to make use of standard AWWA C900 PVC pipe with a new product, the Mega-Stop® bell protection system from EBAA Iron, Inc. Use of this new product enables the installer to push standard bell & spigot PVC pipe through bored or cased holes without the danger associated with over-belling the joints. The device attaches very simply to the spigot of each piece of pipe and is comprised of a fixed stop ring and an expansion retention spring to maintain joint flexibility. Previously published papers and the lead author's experience have shown that over-inserted pipe joints can result in leaky joints or fractured bells. Utilizing the Mega-Stop product with standard PVC pipe enabled the contractor to save as much as 40% in material costs and provided a simple installation process. An additional benefit is that standard C900 PVC pipe is more readily available than pipe with special, restrained-joint systems, resulting in an increased availability of pipe.

Many existing hydroelectric penstocks that were placed into service 80-90 years ago are showing signs of deterioration. As a result, Owners are more concerned about the dependability of these important assets that generate revenue 24 hours per day, 365 days every year. This paper presents the condition assessment investigation on two large-diameter, riveted-steel penstocks and the remediation actions (repair or replacement) offered by the design team along with the ultimate solution that was acted upon by each owner. The first penstock, 96" x 1/4" steel pipe, riveted construction, was partially buried with constructing commencing in 1924. The assessment and design for this penstock was completed in 2011 with construction commencing in 2012. The second penstock was installed in 1924 and consists of a buried, 216" x 3/8" steel pipe, again riveted construction. The assessment and design was completed in 2012 with construction commencing in 2012.

Since 2007, three projects have been completed in the City of Lee's Summit, Missouri, to rehabilitate over 15,000 linear feet of water mains using pipe bursting. Most of the pipe bursting occurred in residential areas where significant disturbance would occur by using conventional open-trench installation. Of the three previous projects including pipe bursting, two projects bid Fusible PVC pipe (FPVCP) and high density polyethylene (HDPE) as equals and allowed the contractor to decide which material to install, while the third project only specified HDPE pipe. These projects installed 6-inch FPVCP and 10-inch and 12-inch HDPE pipe, with some of the water mains being upsized; but, a majority of the mains being replaced size-for-size. Pipe bursting was found to be successful at greatly reducing surface disturbance and restoration of driveways, street pavements, and lawns, while it was also shown to be cost-competitive with open-trench construction, depending on the specifics of the installations. The City of Lee's Summit, Missouri, continues to use trenchless technology for replacing water mains today. Lamke Trenching and Excavating, Inc., of Marthasville, Missouri, is currently installing over 32,600 feet of pipe to replace mains in residential areas having a high break history due to exterior corrosion. Over 27,400 feet of pipe will be installed using a combination of pipe bursting, sliplining and directional drilling. The current project includes 24,916 feet of FPVCP, 3,909 feet of HDPE, and 3,800 feet of PVC. Construction began in May 2012 and is scheduled for completion in 2013. With over half of the project completed, Lamke is using trenchless technology to minimize impacts to residential areas and reduce disruption to traffic. This paper will review the City of Lee's Summit's previous experience with pipe bursting and trenchless technology and the decision to utilize it for most of their current replacement projects instead of traditional `dig and replace' technology. Project details - along with installation specifics, general cost comparisons, and a progress update - will be provided.

In the USA alone, the number of manholes is estimated to be from 12 to 20 million. According to the Trenchless Technology Magazine (2010), 20% of the manholes are at least 50 years old and another 25% are 30 to 50 years old. Additionally, more than three million are believed to be suffering from serious structural decay and are in need of immediate rehabilitation or replacement. To date, there have been a number of research studies on pipeline rehabilitation; therefore, there is a wealth of experience and tools for engineers to evaluate their options while selecting the material and technology to rehabilitate sanitary sewer pipes. Manholes, on the other hand, although a vital part of sanitary sewer systems, are often overlooked. There are very limited studies, but numerous options to rehabilitate manholes. This paper discusses manhole rehabilitation knowledge gaps based on a USEPA/Water Environment Research Foundation (WERF)-sponsored project. Particular emphasis will be given to the structural capabilities of no-dig manhole rehabilitation materials and methods.

Jacking forces required to advance pipe string in rocks are primarily controlled by the self-weight of the pipe, cutting resistance at the face, rock load-induced friction around the pipe circumference, and resistance to machine advance from a loosened rock wedge at the front face of the advancing pipe bore. This paper discusses application of analytical and finite element approaches to predict jacking forces in rock strata, which varied from medium-strong to strong, jointed, blocky rock mass for a 3.8 km-long gravity sewer in Brisbane, Australia. In stronger and distinctly jointed rock mass, the number of joint sets, their spacing and orientation with respect to the pipe alignment were found to be key factors influencing the rock loads on the pipe. Detailed interpretation of site investigation and testing data was undertaken to estimate strength, hardness, and spatial properties of the rock mass and discontinuities. Combined effect of pipe self-weight friction, and resistance at the face and around the pipe were assessed to determine safe and economic length of jacking drives.

To enable industry stakeholders to improve their understanding of horizontal directional drilling (HDD) construction risk and effectively plan a risk response resulting from risk, an HDD construction risk management framework is necessary. The process of risk management involves the identification, assessment, and prioritization of risk events, followed by the development of a risk response strategy in which risk is managed by avoiding, transferring, absorbing or mitigating risk. A quantitative historical dataset has been developed to identify, assess and prioritize the risk events that have occurred during one hundred, large-sized, HDD construction projects. Twenty-one risk events have been identified and have been categorized into risks occurring within the subsurface or at the surface. The average overall schedule impact accounts for approximately 40 percent of the final construction schedule, with subsurface risk events contributing 33 percent of the final schedule. The implications of risk response strategies have been evaluated showing the benefits of developing risk mitigation strategies and implementing a Risk Register.

The following two options were contemplated: Alternative 1 - Approximately 9,500-linear-foot, dual-barrel, 36-inch diameter HDD with steel casing. This alternative recommended the use of the HDD "intersect" construction method because of the long lengths involved. Alternative 2 - approximately 4,500-linear foot, HDD, dual-barrel piping. Evaluation Approach: We reviewed the current state of the Horizontal Directional Drill/Bore technology with respect to completing 30-inch or greater diameter bores for drill lengths greater than 4000 linear feet. We identified contractors and installations where "single pass" or "intersect" drilling for long-length crossings were successful. Additionally, we contacted local and national HDD Contractors with a successful record of performing this work and solicited feedback on their perceptions of the risks and/or limitations in undertaking a similar exercise. The availability of the drilling equipment was assessed and lead time associated with mobilizing Contractors to the site was obtained. This element of the evaluation was crucial in determining whether the work was both: (1) technically feasible; and (2) capable of being accomplished within a reasonable timeframe. We reviewed the technical merits of the alternatives by: performing a hydraulic analysis of the scheme; determining operational pressures and potential head losses; and, finally, assessing whether the pipe sizes proposed were satisfactory. We conducted a complete geometric analysis of the HDD alignment, validating the recommendations for the horizontal and vertical curves. This analysis identified launch/exit angles, ultimate elevation, setback distances, horizontal length, and final lay lengths of the pipe. We determined the design requirements for the HDD casing by establishing the pipe diameter, thickness, and material of construction following a detailed analysis of the allowable bending and hoop stresses. We incorporated geotechnical data in the analysis of loads and stress in the various pipe segments (along the HDD bore path), and consequently calculated the total "pulling force" required to successfully complete the installation. Following review of the geotechnical data, we made recommendations on the minimum vertical or horizontal clearance required between the two bores, and consequently recommended the width of the easement required to accommodate the pipes. We evaluated the feasibility of constructing both options using standard drilling equipment on the market today. We sized the equipment, determined availability, staging requirements, and drilling risks by considering the reliability/accuracy of the cutting tools and guidance system of the HDD equipment. We provided recommendations on the methodology ("single pass" or "intersect" HDD) by considering the minimum clearances (vertical and horizontal) required to successfully complete a dual bore.

The Brazos River Authority (BRA) currently owns and operates a raw water intake structure, pump station, pipeline, and water treatment plant on and near the U.S. Army Corps of Engineers' (USACE) Granger Lake in east Williamson County, Texas. The existing intake structure and pipeline do not have adequate capacity to meet the projected demands of the East Williamson County Regional Water System (EWCRWS) and they are having operational problems with the pool elevation and sedimentation of the upper reaches of the lake. BRA hired Freese and Nichols to provide final design and construction management for the project which was funded by the Texas Water Development Board. The following facilities were included in the design of the new transmission system: ≤ A new raw water intake pump station with an ultimate pumping capacity of 54 MGD and an initial capacity of 15 MGD ≤ A 4-mile, 48-inch raw water transmission pipeline to BRA's existing East Williamson County Water Treatment Plant ≤ The recreation mitigation plan agreed upon between the USACE and the BRA The available footprint for the pump station was small and required an innovative design to reduce the impact on the UASCE Park. The final design called for a 40-foot circular sump constructed using tunnel liner plate to a depth of 70 feet. Two 54-inch intakes were constructed into the lake using microtunneling equipment to allow the sump to remain dry while tapping into the lake and minimize the disturbance in the lake. The pump station includes six pump slots with three vertical turbine pumps installed initially. This paper will conclude with a discussion how the pump station project will meet the triple bottom line of reducing environmental, social and economic impacts.

The Southern Delivery System (SDS) is being developed by Colorado Springs Utilities as a regional water delivery system that will serve the city of Colorado Springs, the city of Fountain, Security Water District, and Pueblo West Metropolitan District (collectively, the project participants). SDS consists of multiple proposed components to convey and/or store, treat, and deliver water. One of these components is the 66-inch-diameter South 1 (S1) raw water pipeline that connects to the future Juniper Pump Station at the existing Pueblo Reservoir in Pueblo, Colorado. The S1 pipeline must rise approximately 150 feet vertically from the Juniper Pump Station onto an existing bluff while passing beneath an existing Union Pacific Rail Road (UPRR) rail line rock cut that runs parallel to the bluff. The bluff in question is located only a few hundred yards laterally from one of the globally-recognized type sections for the K-T (Cretaceous-Tertiary) boundary. The K-T boundary is the marker bed of the geologic period approximately 65.5 million years ago, which included a large-scale mass extinction of animal and plant species, most notably dinosaurs. It is also known as the K-T extinction event. The paper will describe the process by which the designers elected to design the tunneled rail crossing and bluff riser in a geologically important region using conventional tunneling techniques to install a 10-foot-diameter, initial lining system through the shale and limestone bedrock. Also presented will be a discussion of the permitting, operational, geologic/geotechnical, and non-engineering factors that went into the decision. Finally, the paper will present construction observations and lessons learned from the design and construction, including the use of baselines in tunneled construction.

This paper describes a $70-million project that will deepen a critical, 30-year-old, 54-inch collection system sewage force main below the shipping channels of the Port of Miami. The impetus for this project is the deepening of the Panama Canal, which will ultimately result in larger, "New-Panamax" ships engaged in commerce, hence requiring deeper ports. The deepening of the force main requires a 72-inch diameter micro-tunnel from Fisher Island to an in-water shaft south of Miami Beach. A pipeline inspection of the existing sewage force main, conducted during construction, found several defective segments between the in-water shaft and Miami Beach. As such, the project was amended to include a second 72-inch micro-tunnel to replace the defective pipe. This paper describes the alternatives evaluated for the pipeline replacement across an urban corridor, as well as the challenges faced during construction in Miami Beach.

There is no doubt that pipeline systems, in general, and potable water pipelines, specifically, form an important part of our infrastructure. These pipelines constitute a large and complex system that has been expanded and developed during the last century. Usually, signs of wear and failure for underground infrastructure - such as water transmission and distribution systems- are not apparent until a major leak or collapse is found. This commonly leads to emergency repairs, which may cost 10 times more than planned repairs and may result in the loss of millions of gallons of treated water, as well as inconveniences to consumers and the general public. Specifically, the existing cast iron pipes have become corroded over time, both internally and externally, resulting in water loss through holes and cracks, and water quality and hydraulic capacity problems. Spray-on lining methods have effectively been used to renew deteriorated water pipelines for more than 20 years. Depending on the method and product used, these liners can potentially eliminate most of these problems. This paper provides a comparison of spray-on lining methods - including cement mortar, epoxy, polyurethane, and polyurea linings - and an overview of their advantages and limitations. It also provides the physical properties of different lining materials available in the market. Additionally, long-term testing plans and equipment for tensile, flexural, and internal pressure are described.

Box jacking (BJ) is an open-face, trenchless, construction technique used for installing underground precast concrete segments having box or rectangular cross-sections. In this method, culverts and drainage structures, which are box or rectangular in shape, are installed through the ground from an entry shaft to an exit shaft. Box Jacking projects often face schedule delays or loss of productivity due to inherent uncertainties in identifying unknown underground conditions, change of soil, and groundwater level on culvert alignment. This leads to imprecision in cost estimates; thus, bidding prices for box jacking projects are usually kept on a higher side. In this paper, a need to document major productivity factors in BJ process is highlighted. This study identifies and ranks productivity-related factors in BJ process, and develops an analytic hierarchy model (AHP) to understand the relative interdependency among various factors that contractors and engineers consider to avoid delays and improve productivity. Ranking of these factors is expected to improve the productivity by planning and executing BJ projects in a more efficient manner. A total of 27 productivity factors are considered of which six factors - type of soil, shaft design, use of intermediate jacking stations, crew and operator experience, obstructions, or unexpected soil conditions and drive length - are identified to be critical.

A proposal to use uniform soil groups for ASTM, AWWA, and ASCE pipe installation standards, manuals, and documents was first presented at the ASCE Conference "Pipelines 2009." Since then, two ASTM standards and an AWWA specification have been changed to incorporate the proposed soil groups. Currently, work is under way to use the uniform soil groups in three AWWA manuals and one additional ASTM standard. ASTM D 4253 has been the standard for determining the laboratory maximum density for cohesionless soils. The procedure used a vibratory table that involves an expensive and time-consuming calibration process. There is now a new, improved procedure described in ASTM D7382 that replaces the vibratory table with a vibrating hammer. Also known as an impact drill, the tool creates a pulsing, hammering motion while the shaft rotates. The equipment is more durable than the vibrating table and provides more consistent results. The procedure uses a standard sand as a calibration procedure. Instead of the myriad phrases used for describing degree of compaction, the term "percent compaction" should be used as standard terminology. ASTM recommends using percent compaction followed by the standard used to determine the maximum density, e.g. "95% (D 698)." Relative density is the ASTM and soil mechanics term for evaluating the in-place density of cohesionless soils. The procedure is entirely different from using a Proctor type test to judge compaction. Currently, the approach determines the minimum density of the soil as well as the maximum density, and the in-place density is compared to the two. Typically, 70% "relative density" is roughly equivalent to 95 percent Proctor. This provides a source of confusion for contractors who are not familiar with the term and assume the soil does not need much compaction. Adding to the confusion, some agencies use the term "relative compaction" instead of percent Proctor. The use of "percent compaction" for cohesionless soils using only the laboratory maximum density as the control value is useful for pipeline installation work. The same relationship as "percent Proctor" is used except a different laboratory test is used as the maximum value. A new ASTM Manual 70 "Quality Control of Soil Compaction Using ASTM Standards" is now available and presents useful information on the applicability of various ASTM standards for evaluating soil compaction.

The Tarrant Regional Water District (TRWD) with the City of Dallas Water Utilities (DWU), are currently engaged in the planning, design, and implementation of a 350 MGD raw water transmission system, which will run across north central Texas from Lake Palestine to Lake Benbrook, with connections to Cedar Creek Reservoir, Richland Chambers Reservoir and a Dallas delivery point. Collectively, the system consists of: approximately 145 miles of 84-inch to 108-inch pipeline; a 5-mile, 120-inch diameter tunnel; six 100-350 MGD pump stations; one 300 MG balancing reservoir; and ancillary facilities. The program developed by TRWD to accomplish these improvements is called the Integrated Pipeline Project (IPL). As a means to deliver this important infrastructure project in a sustainable manner, the IPL has conducted several specialty studies into the re-use of native soil as pipeline embedment. Specialty studies include: a. Route Characterization - Geophysical and geotechnical investigation to categorize soils by re-use potential and to identify marginal soils, b. Chemical Stabilization - Laboratory treatment of marginal soils to increase engineering properties such as strength and durability, c. Native Soil Flowable Fill - Laboratory and field trials to make flowable fill using native soils found along alignment including sands, clayey sands, limestone and lean-to-fat clay, d. Soil Box Testing - Laboratory investigation of large-diameter steel pipe determining pipe wall stresses and pipe deflection under various embedment configurations. e. Finite Element Analysis - 3-dimensional FEA study to test conventional and alternative embedment options for steel and prestressed concrete pipe, f. Flowable Fill Full Scale Pilot study - 2-mile installation of 108-inch pipe embedded in native soil flowable fill, and g. Cost and Sustainability - Analysis of various embedment options with a focus on the sustainable triple bottom line of people, planet and profit. This paper describes the various studies (with a particular focus on the cost and sustainability aspects), presents initial results, and describes a path forward for an innovative and sustainable approach to soil re-use on a water transmission pipeline project.

This paper will discuss the systematic replacement of over 7 miles of water transmission main (36" to 48") along US Route 29, a very highly traveled corridor in Howard County, MD. The water main replacements are part of a holistic approach to upgrade aging pipelines in the municipality's distribution system, as well as to provide water to areas of projected growth within the system and to alleviate water pressure problems that have been experienced within the system. Initial work started with internal visual investigations, acoustic assessment of the existing PCCP mains and forensic testing of selected sections, followed by detailed evaluations for replacement of the failing mains along this selected 7-mile corridor. The County's distribution system includes many pipelines that have either reached or surpassed their useful life or that are too small to meet future demand projections.

The use of thermoplastic pipes for cross-drain culverts and other highway applications is increasing. Relative to other materials commonly used for culvert pipes, thermoplastic pipes are comprised of materials with low strength and stiffness, which makes them more susceptible to buckling and excessive deflection. These attributes, however, are balanced with positive characteristics such as ease of installation, improved safety during construction, and lower costs. Carefully developed, minimum cover depth guidelines for thermoplastic pipes that are subjected to heavy construction equipment loads during construction are, therefore, needed. The objective of this study was to evaluate the minimum fill height requirements for safe use of thermoplastic pipes under construction equipment loadings. The research was accomplished through analytical methods. High-fidelity analyses were carried out using the finite element method based on a plane strain element formulation, nonlinear soil models, and the geometric nonlinearity of the soil-pipe system. This study will provide a basis for developing guidelines for engineers, designers, and contractors tasked with specifying temporary burial depths of thermoplastic pipes under heavy equipment loading during construction.

Constructability issues for the dual 102" ID Circulating Water (CW) project surfaced during the conceptual design phase of the Wayne County Project, when the original idea was to install these lines using a trenchless method under the Neuse River Canal. This idea was quickly abandoned due to the critical schedule for this project and the uncertainty of not knowing how long the Corps of Engineers 404 Permit process would take. The objective became to carry the 2 CW lines across the 158' span of the canal. Several concepts were considered for this process and three different analyses were completed on the pipe span to ensure that no vibrations would coincide with a natural frequency of the pipe. The paper will discuss the different considerations taken in order for this project to have been successful. Additionally, we will discuss how the interactive communication between the Owner, Engineer, and Contractor - facilitated by a single procurement contract - made this a success.

The San Antonio Water System's (SAWS') C_13 - Broadway Corridor Wastewater project is an important step in SAWS' implementation of its Wastewater Master Plan created to reduce overflows throughout the system. The project is located in SAWS' Central Sewershed, which collects wastewater from the central area of San Antonio (including downtown) and transfers it to the Dos Rios Water Recycling Center (WRC). Six unique alignment alternatives were developed. Each of the alternatives was compared against a set of criteria to determine the most preferable option. These criteria included: cost; constructability; permitting concerns; utility coordination; environmental concerns; cultural resources sensitivity; and impact to local businesses, construction conflicts, traffic control, and pavement repair. A combination of rehabilitation and new construction was determined to best meet the project criteria. To aid in the optimization, a hydraulic model using InfoWorks CS (version 10.0) was developed for the project. A total of eight InfoWorks model networks were created and evaluated. By performing the alternatives evaluation and developing the InfoWorks model, the project team was able to reduce the cost of the sewer improvements from the original conceptual cost of $46M to the current estimated cost of $26.5M. Additionally, this combination of new construction and rehabilitation of existing lines greatly reduces potential disturbances to the historical and central business districts of downtown San Antonio.

Controlled Low Strength Material (CLSM), as a structural material for bedding vitrified clay pipe (VCP), is a mix consisting of Portland cement, fine aggregate, coarse aggregate, water, entrained air, and chemical admixtures to accelerate cure time. CLSM is gaining popularity as a bedding material for VCP due to simplification of pipe installation, reduction in labor and inspection costs, and the benefit of a 2.8 load factor. Computation of predicted backfill load on rigid pipe is performed utilizing the Marston Equation originally developed by Professor Anson Marston in 1913 and 1930. The variables of the Marston Equation consist of the depth of cover, the unit weight and type of the backfill soil, and the width of the trench measured at the top of pipe. This design theory is still used today for rigid pipe design even though bedding system standards were yet to be adopted when it was developed. At that time, rigid pipe were generally laid on a hand-shaped trench bottom and imported bedding was rarely used. Professor Marston theorized that the material at the sides of rigid pipe was so loose compared to the rigidity of the pipe that the support of any backfill load by the sidefill would be negligible resulting in a conservative design. The presumed inability of the sidefills to carry a significant share of the backfill load is not applicable when CLSM bedding is used since it neither settles nor compacts or shrinks significantly. CLSM will support a large portion of the backfill load, which would otherwise be carried by the pipe. Thus, utilizing the Marston Equation in its conventional form has proven to be inappropriate on CLSM projects. The growing and successful use of CLSM as a bedding material led the clay pipe industry to conduct research on actual loads received by the pipe both in field installations and laboratory environments. This research demonstrates a load transfer mechanism in which the load on the pipe can be reduced by a ratio of the outside diameter of the pipe to the width of the trench at the top of the pipe (B_c / B_d), resulting in the Modified Marston equation.

The Tarrant Regional Water District (TRWD) and the City of Dallas Water Utilities (DWU) are currently engaged in the planning, design, and implementation of a 350 MGD raw water transmission system. The approximately-150-mile pipeline will run across north central Texas from Lake Palestine to Lake Benbrook. The program developed by TRWD to accomplish these improvements is called the Integrated Pipeline Project (IPL). To reduce the project costs and the impact on the environment, project management is investigating construction methods that re-use as much of the native soil as possible. One approach is to use native soils to make flowable fill for the pipeline embedment. Laboratory trial mixes of soils from along the alignment demonstrated that the various soil formations have the potential for use in flowable fill using either Portland cement or Class C flyash. Field trials were then conducted to evaluate the potential of making flowable fill using typical construction equipment and methods with the native soils. While laboratory mixes are conducted under controlled conditions with exact amounts of material, the field trials were used to see if the laboratory procedures can be adapted for actual construction methods. The flowable fill field trials demonstrated that soil shredders can process the various native materials, showed how commercial mixing of materials can make flowable fill, and verified that native flowable fill can be used for pipe embedment. The soils were mixed with either Portland cement or Class C flyash to meet a target strength of 40 to 80 psi.

The Tarrant Regional Water District (TRWD) and the City of Dallas Water Utilities (DWU) are currently engaged in the planning, design, and implementation of a 350 MGD raw water transmission system. The approximately-150-mile pipeline will run across north central Texas from Lake Palestine to Lake Benbrook, ending near Fort Worth, and will include a Dallas delivery point. Collectively, the system will consist of the pipeline, pump stations, a balancing reservoir and ancillary facilities. The program developed by TRWD to accomplish these improvements is called the Integrated Pipeline Project (IPL). The 84-inch to 108-inch pressure pipeline will have about 5 to 10 ft of cover in most locations. For flexible pipe, the project established that the embedment stiffness (E') needs to be about 1500 psi or higher. Additionally, the project established that the stiffness (E') of the trench walls will also have to be a minimum of 1500 psi to provide the total pipe support for either rigid or flexible pipe. Since the alignment traverses different types of soil and insitu conditions, the stiffness of the native soils will vary considerably. Fugro Consultants, Inc. (Fugro) has developed a preliminary rating system for the stiffness of the native soils based on their estimated E' (E Prime). For areas with poor support, the design of the pipe, or the design of the installation method will have to modified. For areas with good support, conventional design and installation can be used. For the marginal areas, additional investigations would be required to definitively describe field conditions. The evaluation is based on the collective results from unconfined compression tests, N values from Standard Penetration Tests, and pocket penetrometer values. Fugro has developed a relationship between pocket penetrometer values and unconfined compression strength for soils in the Dallas area. While the correlation coefficient is low, the relationship seems useful for the IPL project. All of these tests form a screening system to indicate where additional testing may be required or where special installation design may be necessary.

This paper presents a summary of design challenges associated with the lowering of approximately 1,500 linear feet of 90-inch diameter prestressed concrete cylinder pipe to accommodate the proposed crossing of up to three (3) 108-inch diameter pipelines. The project was part of the $2+ billion Integrated Pipeline project currently being pursued by the Tarrant Regional Water District and Dallas Water Utilities to increase water supply to the Dallas/Fort Worth metroplex. The design included evaluation of numerous profile alternatives, pipe materials, and cathodic protection requirements to accommodate a tight construction window of roughly 45 days.

Many models are used to evaluate and predict risk analysis, as well as renewal prioritization, of drinking water and wastewater pipelines. The majority have not been accurate enough to be used for real decision making applications. This paper proposes a model framework for asset management programs with two major stages; verification and validation. The verification stage confirms that there are no errors in the code or logic in the model's algorithm. Two approaches make up the models' verification framework--tests with artificial data and tests with field data. The second stage of the proposed framework validates that the model goes through three steps: lab tests, expert opinions and model's outputs. Evaluation results were compared to confirm the model's accuracy. This framework is precise enough to prove the correctness and accuracy of many different types of models created for decision support for asset management of drinking water pipelines.

Metropolitan Water District of Southern California (MWD)¹ was one of the first agencies to adopt the use of Carbon Fiber Reinforced Polymer (CFRP) as a method to repair distressed Prestressed Concrete Cylinder Pipe (PCCP) starting in the mid-1990's. At that time, MWD performed tests to determine the best method to bond the CFRP to the inner core of the PCCP and tested distressed PCCP repaired with CFRP to validate its ability to resist external ground load. MWD studied the other tests conducted by the industry to insure the distressed PCCP reinforced with CFRP could resist the internal pressure³. MWD was one of the first agencies to adapt the use of CFRP as a method to repair distressed PCCP. However, at that time the need for the CFRP to terminate on the steel cylinder was not recognized. Over the last 10 years, the need for the CFRP to be terminated by attaching it to the steel cylinder has become the industry standard⁴. Another advancement in CFRP design methodology was the need for and the quantity of longitudinal CFRP reinforcement applied in these repairs. IMWD recently upgraded all of its CFRP installations to bring them up to the requirements of the new draft code which is currently in development through AWWA. This was accomplished by removing the CFRP lining in the region adjacent to the joints, exposing the bell and spigot, which was followed by attaching new CFRP to the cylinder and overlapping the new CFRP onto the existing CFRP. In addition, more longitudinal layers were installed to resist the longitudinal stresses in the CFRP. This paper will discuss the reasons MWD decided to retrofit their existing installations, the construction challenges of installing the CFRP over the PWC, and the effect that the changes in the recent draft code had on the existing number of longitudinal and hoop layers of CFRP layers. PWC stands for potable water coating and is the final coating covering the CFRP. During construction, MWD performed adhesion pull tests to insure that the new CFRP would bond properly with the existing CFRP. Several different pull tests were performed to determine how much PWC had to be removed to insure the CFRP would bond together properly. Construction has now been completed on these projects.

Pipe materials used in underground water, wastewater, and storm drainage infrastructure are manufactured according to published national standards such as AWWA and ASTM. The pipe bedding, embedment, backfill, and shoring systems, however, vary regionally across the country. This is due to variations in native soil conditions, availability of pipe zone materials, and local pipeline contractor preferences. The varying regional practices often limit an engineer's ability to specify trench and shoring conditions without adequate knowledge of local practices. The task committee conducted a national survey in 2009 to document the varying regional practices across six different regions of the country. Due to limited participation, the survey did not generate a complete and comprehensive response of pipeline installation procedures across the country. In order to address this shortcoming, a revised national survey is being conducted by the task committee to collect existing data on specifications, standard details, design criteria, and material specific concerns with an aim to document regional variations of specifying and construction practices and constructability issues associated with local native ground conditions, including interaction between native ground and bedding, embedment, and backfills placed and compacted, testing requirements, use of waste or recyclable materials, sustainable materials, and construction methods such as use of varying types of trench boxes, sheeting and shoring systems. The survey is targeting various state Department of Transportation (DOT) or similar local jurisdictions, large municipalities, water or wastewater agencies, national engineering firms, national pipe suppliers, contractors, and pipe vendors. This paper presents the details of the improved and comprehensive survey currently being planned to be conducted in early 2013. A summary of the nationwide findings based on the improved and comprehensive survey will be presented during the Pipelines 2013 conference to be held in Fort Worth, TX, with the primary objective of soliciting feedback and collecting additional input.

Utility data are used by many stakeholders for many purposes. Utility data now reside in a variety of repositories, in a variety of formats, and with highly variable reliability. As a result, there are many different data standards now in use. They serve specific needs of the user groups. Yet even with all these user standards, more are necessary. So far the civil engineering community's needs pertaining to location standards for our existing underground utility network are rarely met for planning, design, and construction. The American Society of Civil Engineer's (ASCE) Construction Institute has become the home for a basket of revised, new, and proposed standards to assist all stakeholders in utility location, conflict analysis, and safety issues. Its latest standard now under development is for the "as-built"-ing of utilities. This addresses how exposed or newly constructed utilities should be surveyed and documented for future users of the data. ASCE 38, Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data, was recently updated to reflect a decade of successful use and increasing specification by project owners and regulatory agencies. Finally, a standard on Radio Frequency Identification (RFID) emplacement and data is underway, due in no small part to a successful implementation program by the Virginia Department of Transportation (VDOT). ASCE standards, developed under a strict ANSI consensus process, play an important part in the engineers' and constructors' practices. These standards supply technical information from a broad consensus group of experts, and are frequently used by courts to assist in determining the standard of care. This paper outlines the scope of each of these standards and how, when bundled together, they can assist engineers and constructors in managing their risks during pipeline projects.

Design and construction of over 15,000 linear feet of pipe will allow the City of Boerne, Texas to decommission two lift stations, convey flow to a new wastewater treatment plant, transport treated flow back to a local stream to maintain flow during drought conditions, and initiate the City's first re-use water system. Limited easement width and construction access locations, extensive sewer depth in limestone bedrock, and environmental sensitivity make the design, coordination and construction of this project unique.

The San Francisco Bay Area's primary water supply system, the Bay Division Pipelines, is highly vulnerable to seismic damage from the nearby San Andreas and Hayward fault zones. The San Francisco Public Utilities Commission's (SFPUC) $4.6B Water System Improvement Program (WSIP) consists of 81 projects to improve the seismic and delivery reliability to its customers. The Bay Division Pipelines (BDPLs 3 and 4) are two major SFPUC water transmission pressurized pipelines that extend 34 miles from Fremont to Redwood City in California, serving the heavily populated South Bay and southern Peninsula customers. BDPL 3 is a 72-inch diameter, welded steel and reinforced concrete pipe, depending on location. BDPL 4 is a 90-inch diameter, welded steel and pre-stressed concrete cylinder pipe, also depending on location. The BDPLs also convey the majority of San Francisco's water and replenish reservoirs in the Peninsula, enabling the SFPUC to meet peak summer demands.

To transfer potable water from north to the Khoramshahr port in southwestern Iran to meet urban and agricultural demands (where???), a combined unit of five carbon steel pipes, 1600 millimeters in diameter, had to cross the Karun River bed. Karun is the biggest river in Iran. The project location was 12 meters deep and 150 meters wide. This report describes the method used to complete this major pipeline installation. Pipes with the total required length were assembled in a dry dock. One-stage sinking was planned; hence, all pipes were connected to each other by steel structures forming one combined unit. To keep pipes from floating while being lowered to the river bed, sand bags were attached to the middle section of pipes and two air bags were placed on each side of the connected pipe unit. Also, to increase the accuracy of positioning in the face of river current, the pipe unit was anchored by cables. Four winches tensioned anchoring cables and controlled the position and alignment of pipe unit during the sinking maneuver. The unit was submerged by filling pipes in specific sequences. The sinking maneuver was modeled by ANSYS software.

The soil around the buried pipe may become loose locally because of large earthquake and torrential rain, and the bedding may become non-uniform. However, the effect of non-uniform bedding on buried pipe remains to be clarified. In this study, experiments were conducted in order to clarify the behavior of buried pipe on the non-uniform bedding. The experimental pit has 64 holes (100 mm×100 mm) with valves at the bottom to create the non-uniform bedding. Polyvinyl chloride pipe, having a diameter of 600 mm and 3 measuring sections (Section-A, B, and C), was used. The distance between sections was 200 mm. The test showed that, when the sand was removed from the pipe bottom level around Section-A and Section-C, the pipe moved asymmetrically. As a result, when the ground becomes loose locally, large tensile strain acted on a Section-A (C) of the pipe closest to loosened ground, but maximum shear strain decreased. On the other hand, at the mid-section (Section-B) between the sections, which was close to loosened ground, circumferential tensile strain hardly occurred, but principal tensile strain acted almost in a pipe axial direction. Maximum shear strain at the mid-section increased to have a risk of yield failure.

Embedment design - specifically, selection of embedment materials - is critical to the sustainable design of large-diameter pipelines. Selection of embedment materials has been a topic of special interest to the water industry for several years. It holds great potential for sustainable improvement, but it also requires detailed evaluation of the interaction between the pipe and the soil around it in order to provide adequate structural support to the pipe. The purpose of this paper is to present the sustainable characteristics of different embedment systems from a triple bottom line (TBL) perspective. The TBL analysis quantifies the economic, environmental, and social impact of each material as applied to an example project in the North Texas area. Two types of embedment systems are evaluated in this paper: ≤ Embedment Design -Type 1 consists of granular materials; and ≤ Embedment Design -Type 2 consists of controlled, low-strength materials The TBL evaluation is concluded with a presentation of results and conclusions regarding the sustainable design of embedment materials. Additional studies have been prepared by the authors regarding the sustainable characteristics of each embedment system using Envision^TM. The authors have found Envision^TM to be a practical, efficient, and comprehensive system to rate a wide range of infrastructure facilities and systems, such as water transmission systems. Due to the complexity of the evaluation and the length of the analysis, the Envision^TM rating of this North Texas example project is not presented in this paper.

The Region's Hanlan Water Project is a 96-inch diameter feedermain extending 8.7 miles. CH2M HILL and the Region of Peel implemented a thorough two-phase approach to their geotechnical subsurface investigation on the southern 5.6 miles of the project, consisting of approximately 3.7 miles of tunnel at depths varying from 52 to 92 feet, and 1.9 miles of open cut. Phase I of the geotechnical site investigation included a review of existing geotechnical information. A borehole plan was developed and executed to provide information for the entire alignment and to focus in on site-specific issues. A seismic survey was performed to further confirm the competent rock boundary. Phase II of the investigation included review of the Phase I information and the placement of additional boreholes and tests in order to fill gaps in the data. The results will be used to mitigate risk through the Geotechnical Baseline Report and specific risk mitigation articles in the Contract.

The Southern Delivery System (SDS) is a regional project currently under construction in Colorado that will bring water from the Arkansas River to the City of Colorado Springs, the City of Fountain, Security Water District, and Pueblo West Metropolitan District. SDS is critical to firming the region's water supply and is needed to provide a redundant delivery system for Colorado Springs' water sources originating in the Colorado Rocky Mountains. The SDS includes 45 miles of 66-inch welded steel raw water pipeline that was designed with both single-lap and double-lap welds and required weld after backfill for single-lap welded joints. Weld after backfill for single-lap welds was specified in the SDS Contract Documents requiring the contractor to develop a weld after backfill plan and demonstrate the acceptability of the plan and welding procedure for each wall thickness by testing similar conditions in the field prior to production. Demonstration of each welder's capability to complete weld after backfill without damaging the coating was also required. Periodic excavation and inspection of selected joints was performed during pipeline installation as an ongoing field quality control measure. This paper will discuss the weld after backfill single-lap weld criteria, design, demonstration results, and post-demonstration testing for construction packages on the SDS Program. This paper will benefit the professional community by showing how weld after backfill demonstration testing and field quality control measures during pipeline construction can provide the client a method that does not compromise the integrity of the pipeline system and results in a cost savings due to increased production rates.

This paper describes the challenges that were faced and the successful results that were achieved regarding the fabrication and installation of a 42"- and 38"-high-pressure hydroelectric pipeline in the rain forest of Guatemala. The government in Guatemala has promoted development of renewal energy generating sources; specifically, small- to medium-size hydroelectric plants in the rain forest of Guatemala. The financial model has proven to be profitable to private investment and creates a low-cost source of electricity in this country as its energy demand continues to increase. The geographic characteristic in the rain forest of Guatemala provides an ideal condition to harvest power by using hydroelectric generation. Rivers are abundant in the northern part of the country and the drops in elevation are ideal to temporarily divert a portion of the flow of the river to generate power and to return the water at a point downstream back to its original course. The project involved 6,000 meters of low pressure gravity line collecting water from six small diversion dams to a storage reservoir, and 3,050 meters of high pressure line that will convey the water from the reservoir to the powerhouse. The generating capacity of the hydroelectric plant is 9.7 MW. The 42" and 38" welded steel pipe for the high pressure line was manufactured in the United States and transported by sea and through the Guatemalan rain forest to its final destination where the installation process was done with minimum impact to the environment. Key to the success were the processes integrated throughout the whole manufacturing process, so the product would require only minor repairs, if any, and changes allowing for ease of installation in the field due to the remoteness of the location. The new pipeline was designed to remain in continuous operation for 25 years and must require very little maintenance due to the remoteness of the location. Lining and coatings for the steel pipe were chosen not only for their service life, but also for their robustness needed for this particular application, and the field conditions they were subject to during the transport and installation. Very unique installation processes had to be used due to the geography and primitive environment, the change in elevation is close to 600 meters over the 3,050 meters pipeline route. This required the use of unconventional laying operations to minimize disturbance to the rain forest.

The Southern Delivery System (SDS) is a regional project in Colorado currently under construction that will bring water from the Arkansas River to the City of Colorado Springs, the City of Fountain, Security Water District, and Pueblo West Metropolitan District. Colorado Springs needs SDS to help protect the community against drought, to provide water for the growing population, and to provide redundancy in Colorado Springs' water delivery system, which originates in the Colorado Rocky Mountains. A core component of SDS consists of approximately 45 miles of predominately 66-inch diameter raw water conveyance pipeline. Welded steel pipe conforming to American Water Works Association (AWWA) Standards has been specified for the pipeline. Weld-after-backfill (WAB) is a construction sequence for steel pipe in which the bell and spigot lap joint is internally welded after the heat shrink sleeve has been applied over the external coating hold back area and the pipeline backfilled. WAB is generally desirable for larger diameter steel pipes (such as the SDS raw water conveyance pipeline) because internal welding can be undertaken independent of pipe laying, joint assembly and backfilling. Consequently, increased pipe installation rates are possible with a corresponding reduction in installation costs and public impacts when compared to non-in-situ joint welding. As with any program, the magnitude of SDS' cost-effective design is critical. To this end, the SDS program has specified WAB for the 66-inch diameter raw water conveyance pipeline where single-welded lap joints are required. To date, over 100,000 linear feet (lf) of SDS pipe, comprising over 2,000 joints have been successfully installed using WAB. This paper will provide background on the application of WAB for SDS, projected cost savings and emerging technologies associated with WAB for pipe of variable wall thicknesses, joint welding techniques and backfill systems required for the Program.

Peace River Manasota Regional Water Supply Authority contracted Atkins for design and construction inspection services on their Regional Integrated Loop System, Phase 3A Pipeline project located in Sarasota County, Florida. The project included 8 miles of 48"-steel pipeline, a 5.0 MG Ground Storage Tank, and a Regional Pump Station that strengthened Sarasota County's water system. To expedite the construction schedule, a limited Notice to Proceed (NTP) was given to the Contractor while property negotiations along parts of the proposed route were still on-going. During negotiations, modifications to the design were undertaken in the areas where the pipeline route crossed another municipality's newly developed property. Between the time of the design survey and the NTP, a separate municipality constructed a public park on property they owned adjacent to an affluent gated community. This park was funded by a Florida Department of Environmental Protection grant that required the park construction to be finished just a couple of months prior to the construction of the pipeline. Negotiations with the other Municipality and the homeowners adjacent to the pipeline route created numerous opportunities to improve the surrounding roadways, further improve the park, and eliminate invasive species from the surrounding environment, while also modifying the construction methods through shorter pipe lengths and shallower depths to minimize disturbed areas during construction. The final restored areas created a better environment for all interested parties.

Cross-County Water Supply Corporation (CCWSC) was formed in 2008 to transport up to 20,000 acre-feet of water from Burleson County to the growing area northeast of Austin, Texas. The project included the design and construction of a 53-mile, 30-inch water transmission pipeline, high-service pump station and customer interconnects. In February of 2010, approval for final design, permitting, and construction of the project was approved by the Board. The project was awarded as a CMAR contract with Garney Construction. Within 15 months, the team completed final design and constructed the new water supply system which, at ultimate build-out, will have the capability of delivering 18-MGD. The project included many unique challenges during the CMAR design and construction process. This included extensive geotechnical and corrosion studies to optimize the backfill design and determine soil characteristics and cathodic protection requirements. This also included a hydraulic analysis that accomplished a maximum capacity with phased expansion approach in order to meet a phased start-up system. In addition, permits with agencies were required that spanned over five counties and sequenced with multiple design packages in order to allow for concurrent construction. The project alignment spanned over 53 miles from Burleson County to Travis County. Due to the geology in the eastern portion of the project, the project design was able to utilize native material for backfill. To locate the native material that was suitable for reuse, the geotechnical study commenced in February 2010. Fifty bores were drilled along the 53-mile pipeline alignment. The results of the bores showed that the soils on the western portion of the project are mostly clays and unsuitable for reuse. The soils on the eastern portion of the project are clayey-sands and, in many locations, suitable for use in the pipeline backfill. To determine exactly where the native soils would be used as backfill, a secondary geotechnical study was conducted in which the contractor used a backhoe to dig test pits at 26 locations. The soils in these test pits were field analyzed by a geologist who then made the final decision as to whether or not the soils met the backfill requirements. The results obtained from the initial set of borings were also used in the corrosion study. Based on these bores, it was determined that portions of the pipeline did span soils where cathodic protection would be considered. The project design included nearly 200 test stations and pipe continuity bonding being installed along the pipeline and the protocol for a future corrosion monitoring program and cathodic protection system. This project is an example of using extensive geotechnical field studies and field inspections to determine backfill requirements for a long distance transmission main project. This paper will provide details of a CMAR design and construction project, including the selection of a highly qualified contactor and schedule and review coordination efforts.

In today's world, fiberglass products are being used in many different forms and applications. Even though fiberglass piping has a history of more than 60 years, some consider it to be a modern day product material with many new emerging applications that take advantage of its corrosion resistance, high strength-to-weight ratio, low maintenance and life cycle cost [4]. There are multiple methods of producing fiberglass pipe, but the focus of this paper is specific to filament wound fiberglass pipe in pressure applications. This paper discusses the history and recent developments of large-diameter fiberglass pipes as well as the review of a recent pressurized pipe project in which fiberglass pipe was utilized.

Five tests on large-diameter steel pipe were conducted at the Center for Underground Infrastructure Research and Education (CUIRE) laboratory at UT Arlington. The tests were conducted on a 19.75-ft.-long, 72-in. nominal diameter bare steel pipe with D/t of 230. For each test, the test pipe was placed inside a concrete load cell, embedded in compacted soils, and subjected to surcharge load of cover. The embedment soils included clayey soils obtained from the Integrated Pipeline (IPL) project site in Texas in both natural and lime-treated forms, crushed limestone and their combinations. Clayey soils were compacted by using tamping foot compactors, while crushed limestone was compacted using vibratory plate compactor. Peaking deflections or vertical elongations of steel pipe were observed in each of the tests during embedment construction. Static cover loads of pea gravel were placed over the embedded pipe. Pipe deflections and pipe wall strains were measured during and after placement of cover load construction using convergence meters and strain gages. Lateral earth pressures at pipe springline and load cell wall, and vertical loads at top and bottom of pipe were also measured. This paper presents and compares the results of the laboratory tests. The discussions and comparisons include deflection ratios (ratio of horizontal to vertical deflection), bedding angles, and moduli of soil reaction observed in each of the tests. Comparisons are also made with respect to assumptions in Spangler's soil pipe interaction model that was used to derive the Iowa Equation.

It is inevitable for most long-distance oil pipelines to encounter underground obstacles when tunneling through a complex and changing geological environment. The growing maturity of trenchless technology has gradually overcome most pipeline construction problems. However, one weak area is the failure of the elbow segment due to its inability to meet strength requirements. Additionally, structural design of trenchless technology tunnels depends only on empirical parameters, while stress analysis of pipelines is generally overlooked.. This paper establishes a pipeline stress analysis model with CAESAR II software. The model covers pipeline stress distribution, the stress problems' key points, and the pipeline's strength. The model will provide guidance for tunnel construction engineers wanting to design stronger pipelines through pipeline stress distribution analysis.

Submarine gas pipelines usually operate in complicated and changeable regional environments and can generate corresponding stresses and displacement under the influence of internal pressures, earthquakes, waves, and other loadings. An unevenly-distributed stress will lead to shallow sea gas pipeline failure easily. Therefore, it is necessary to research the stress conditions of the shallow sea gas pipeline and check whether it can meet the safety requirements or not. In this paper, we analyze the stress conditions of shallow sea gas pipelines of two laying modes in XX areas using stress analysis software CAESAR II, discuss the loading conditions under the operating condition, and determine the position of the key point where pipeline damage is most likely to happen, the bend pipe. We concluded that the underground method and above the sea-bed method are safe. Our research provides a theoretical basis for the construction of shallow sea gas pipelines and has very important research significance and engineering value.

An intelligent, real-time pipeline surveillance system was recently developed to support the operation of a new multi-products fuel pipeline and terminal system on the Island of Trinidad. The real-time operations surveillance system is a tool for the Liquid Fuel System (LFS) operators to use in monitoring and controlling the movement of fuel products though a system of storage tanks and pipelines. With its own permissive warnings, coupled with those additional alarms of related control systems, the real-time surveillance system provides a major built-in deterrent against tank over-filling and excessive batch mixing. The real-time operations surveillance system shows the status of fuel movement throughout the system at all times, prompts the system operators in making tank switches, and continually monitors the system for operational errors. The software is also used with an operator training simulator to validate operating procedures and train operators.

Any trenchless installation project is associated with some level of risk. Conventional risk assessment approach quantifies risk as a product of likelihood and severity of risk, and does not consider the interrelation among different risk input variables. However, in real life installation projects the input factors are interconnected, somewhat overlapped, and exist with fuzziness or vagueness. Fuzzy logic system surpasses this shortcoming and delivers the output through a process of fuzzification, fuzzy inference, fuzzy rules, and defuzzification. In this study, site condition, geological condition, installing geometry (IG), project contract, and trenchless method are addressed as input variables that cause significant risk in the installation of trenchless technologies. It is assumed that input variables are trapezoidal and output variables are triangular fuzzy membership functions. Furthermore, input members are classified as poor, average, and good; whereas, output members are classified as low, medium, and high risk. The fuzzy rules governing the input-output relationship are if-and-then as well as if-or-then. The resulting risk score is observed on a scale of 0 to 7. It is found that the risk score/ranking decreases while the input variables gradually proceed from poor to good. Thus, this paper proposes a novel approach towards the analysis and assessment of risk associated with the installation of trenchless technologies using a fuzzy logic system model.

Pigging is an effective way of removing condensate liquid and improving the transportation efficiency of condensate gas transportation pipelines. Prediction of pig velocity, total pigging time, and slug length are of great importance for pigging operation. The pipelines are divided into a reformation two-phase flow section, single-phase gas, liquid slug section, and downstream undisturbed two-phase flow section to model the pigging process. The dynamic model for each section is built based on the mass, momentum and energy conversation equations of the liquid and gas phase. Since the locations of the pig, liquid slug front, and reformation two-phase section front are moving, a couple of methods based on the fixed coordinate system and internal moving boundaries are applied to the pigging model. Finally, a condensate gas transportation pipeline is used to validate the methods. The simulation results show how to predict total pigging time, pig velocity, and its position reasonably.

Underground natural gas storage can carry out seasonal peak regulation and provide emergency gas supply to industry; however, its completion casing string is subjected to many undesirable influences by high-pressure gas injection and corrosion environment. Therefore, the bearing capacity and service life of casing string will be reduced. By establishing the reliability life prediction model of casing string, the expected life of casing can be computed quantificationally. The collapsing strengths are calculated based on the API 5C3 standard and the ISO10400-2007 standard, respectively. The results are compared with that of a casing collapse experiment; the application ranges of the two standards are obtained under different casing thicknesses. In this paper, the authors calculated the casing collapsing strength and the collapsing safety factor of the Su-11 well according to the casing collapsing strength theory. The results indicate that collapsing strength satisfies the strength requirement of casing in the whole range of well depth. According to the Norsok corrosion model, casing corrosion rates are predicted in an acid environment considering the impact of corrosion protection film. The actual casing corrosion rates and the life span of the Su-11well's casing string are calculated by the casing string residual life comprehensive evaluation theory, which gives the well a remaining casing life of more than 30 years for underground gas storage.

When using thermal recovery for the exploitation of heavy oil, the casing is the only channel of steam injection and crude oil extraction. Keeping the casing safe is critical to the operation. The authors conducted low-cycle experiments using strain-controlled material and the MTS809 material testing system. Mechanical property parameters of thermal recovery casing in high-temperature conditions were obtained. The experimental data and stress-strain constitutive relation led to numerical models of formation-cement sheath-casing based on actual geological structure and rock parameters of the recovery wells. Mechanical responses of casings in the thermal recovery wells were simulated for different high-temperature constitutive models and creep constitutive models of casing materials. Under Results indicate that the stress and strain caused by bending loads on casings change greatly at the dogleg part. Moreover, creep has a remarkable effect on casing strain in a thermal recovery well, which cannot be neglected in design. This research provided the basic parameters and technical references for strain design of casing in a thermal recovery well.

Liquid petroleum gas (LPG) is a mixture of ethane, propane and heavier hydrocarbons used as a fuel in heating appliances and vehicles. Due to the composition of LPG, phase transitionoccurs easier than gas and oil. Therefore, the running parameters of LPG pipelines are different from those of the gas and liquid pipelines. In order to predict the pressure, flow rate, and temperature within the network, the network is divided into the node, pipeline element, and non-pipe element sub-systems. The mathematical models for each sub-system and the whole network are built. The solution method that unites the network model and physical parameters model is discussed based on the Newton-Raphson method. Finally, the methods are applied to a branching and loop LPG network. The results show the achievements of the paper are valid for steady state simulation of LPG pipeline network.

Reducing energy consumption in oil and gas pipelines is a world-wide concern. In the past, China's operation dispatchers and energy managers used the year-on-year growth method and period-on-period growth method to evaluate energy consumption. Energy consumption indicators focused on production energy consumption per turnover volume (kgce/(10⁴t·km) for oil pipeline and kgce/(10⁷Nm³·km) for gas pipeline) as well as total energy consumption per turnover volume, power consumption per turnover volume, oil/gas consumption per turnover volume, etc. The main problem with these evaluation methods is that they are based on throughput. In general, when the throughput increases, the production energy consumption per turnover volume indicator will also increase. Because the practicability and reliability of year-on-year growth methods and period-on-period growth methods are often disputed, evaluation of energy consumption levels should be more objective, based on probability and statistics. According to historical energy consumption data from oil and gas pipelines, energy consumption is divided into five levels: very high, high, medium, low, and very low. Furthermore, a key energy consumption index compares current energy consumption data to historical energy consumption data where operating conditions are similar to present operating conditions such as throughput, turnover volume, and underground temperature. However, the key energy consumption index is not associated with throughput, so it is a more objective method for evaluating the current energy consumption level of oil and gas pipelines. This paper presents a corresponding calculation process based on the new energy consumption index and verifies its applicability.

A major energy company wished to determine the viability of converting a refined product transmission line for transmission of crude oil. Although the transmission line condition may not have been adequate to operate at the original design pressure, it was decided to carry out a condition assessment of the pipeline to determine whether it could be operated safely at a lower pressure that would be acceptable to transport a required volume of crude oil. In order to determine the condition of the pipe and an acceptable operating pressure, specialized electromagnetic tools were introduced into and passed through the pipeline to assess the condition of the same. This paper will discuss a condition assessment that was carried out to help determine the viability of reusing the pipeline for use to transport the new product.

The U.S. natural gas industry shows growth in revenues and an all-time high in net incomes. Project costs, however, are on the rise and cost overruns seem to be more common than in the past. Organizations are, consequently, interested in benchmarking, or comparing their organizations with industry leaders in order to potentially emulate best practices. Benchmarking, however, is often difficult because the required data is either proprietary or not available. The purpose of this study is to use a public data source to identify factors that affect project performance and, based on these performance indicators, propose a benchmarking model. The data for this study is gathered from submittals to the Federal Energy Regulatory Commission (FERC) for natural gas projects completed from 2005 to 2010. The method used for this study is a covariate analysis, and model validation includes residual diagnostics. Findings are that project type, pipeline length addition, compression/power addition, storage capacity addition, and construction duration are significant predictors of cost performance. The discussion includes a practical application of how organizations may use this model to measure performance and identify best practices. The conclusion includes recommendations on how this model may be expanded with ongoing research.

This paper addresses fracture failures for drill pipes in a directional drilling construction project for an oil and gas pipeline. The authors analyzed failed drill pipe samples through fracture macro analysis, nondestructive testing for micro-cracks, mechanical properties testing on drill pipe material, microscopic microstructure analysis, the cross-section morphology analysis, and the service conditions analysis. This study determined that drill pipe failure is caused by a repeated overload thrust applied to a drill string for the purpose of freeing a stuck drill, resulting in a bent drill string and a drill pipe fatigue crack initiated on the outer surface of the bent drill pipe and propagated rapidly. Theoretical calculation and finite element simulation based on the drill string service condition showed a helical buckling deformation before fracture, leading to the conclusion that it was the repeated overload thrust that caused the drill pipe fatigue fracture.

The design factor of gas transmission pipelines is a safety factor which controls the operating pipelines at stress levels below a certain range of the specified minimum yield strength (SMYS) of the pipe material. The improvements of the pipeline manufacturing technology make it possible to increase the design factor from 0.72 to 0.80 for more financial benefits. Based on the basic theory of reliability and the assumption that both the quality and operating parameters of the pipeline are in accordance with the normal distribution, a reliability calculation model for gas transmission pipelines is established. By the transformation of the non-standard normal distribution function, the solution of the model is obtained. The applications calculate the reliability of an X80 steel pipeline. By changing a single variable, the impact of the different parameters used in the model is also discussed. The application results show that application pipeline is reliable under the design factor of 0.8, and the deviation coefficient of the minimum yield strength is of the greatest impact on the reliability of the application pipelines.

The past decade has seen the proliferation of many alternative thermoplastic pipeline products and materials that continue to gain market share. The diversity of these products and their complex behavior has given rise to new standards and specifications, largely developed by the manufacturers themselves. Despite widespread acceptance, industry understanding of the mechanics of reinforced and composite thermoplastic materials is still limited compared to that of more traditional materials such as steel and concrete. As one of the newest entrants to the pipeline technology stage, thermoplastic composites offer solutions to some of the current problems faced by traditional construction materials, as well as superior performance over current technology offerings. With the development of a body of industry knowledge and further understanding of the behavior and benefits of these materials, thermoplastic composites have the capacity to change the face of the pipeline industry.

The FlexSteel flexible steel pipe system is analogous to those deployed in the offshore oil and gas industry for over 30 years, but designed and optimized for onshore and shallow water applications. The pipe construction consists of a flat steel strip reinforcement helically wrapped around a thermoplastic liner, combining the advantages of bimodal high density polyethylene pipe with the established properties and strength of steel. The steel reinforcement is isolated from the pipe contents and external fluids by the thermoplastic corrosion resistant liner and external cover. The 8-inch nominal diameter pipe offers a cost-effective, larger diameter spoolable solution. This paper details the qualification of the pipe to API 17J requirements for burst, tension, and hydrostatic collapse testing, as well as API 15S/ISO 18226 requirements for accelerated life testing of end connections. Details of a custom system for swaging end fittings and midline connections are presented along with field handling trials.

Oil production subsea systems consist of floating platforms connected to subsea wells by a network of pipelines. These pipelines, when transporting oil and gas in deepwater, undergo significant changes in temperature and pressure during service life. In addition, some of the deepwater oil pipelines are on very soft sea bed and are susceptible to axial and lateral movement (or walking) of pipelines due to cyclic thermal changes and lateral buckling due to thermal expansion under operating conditions. Correctly predicting axial `walking' and controlling lateral buckling are extremely sensitive to the selection of pipe-soil interaction parameters during the safe design of the network of pipelines. However, the soil resistance to various types of pipe movement is a significant uncertainty and, hence, the current practice relies on empirical expression for pipe-soil resistance. Although there are several numerical approaches proposed to model the pipe-soil interaction, there are very limited experimental studies and quantification of various important parameters for designing and maintaining a network of pipelines. Several physical models have been designed and constructed at the CIGMAT Laboratory to investigate the behavior of pipes on the sea bed. In this preliminary study, series of small model tests were performed using instrumented 1.625 in diameter (40 mm) pipes placed on the soft clay soil (undrained shear strength of 1.4 kPa or 29 psf) to better quantify the axial and lateral soil pipe interactions. Effect of displacement rate and weight of the pipe (vertical load) were also investigated in this model study. Deepwater pipes are insulated with layers of polymers and the outside layer in contact with the soil is solid plastic. The interaction of loaded pipe with soil berms created as the pipe displaced laterally was also studied and quantified. The variation of the frictional parameter with the type (axial and lateral) and rate of loading and weight of the pipe have been quantified. The test results showed that when the axial rate of loading was increased the frictional coefficient between the pipe and the soil reduced and the weight of the pipe had no effect on the frictional coefficient within the range of variables studied. The lateral frictional coefficient was higher than the axial frictional coefficient.

In this study, the tensile behavior of a glass-fiber reinforced polypropylene composite, used as part of the thermal insulation system of pipelines, was investigated at room temperature. The insulator samples were obtained directly from an insulator coated deepwater pipe obtained from the field. Direct tensile tests on the composite polymer were performed at variable strain rates. The test strain rate varied from 0.2%/min to 34%/min, about 170 times increase in the loading rate. The effect of strain rate on the stress-strain relationship, yield strength, and yield strain have been quantified. The strain rate dependency of the polymer composite stress strain relationship was quantified. Also the mechanical properties were compared to the published data in the literature on polypropylene composite used for subsea pipeline insulation. A new stress-strain relationship was developed to model the nonlinear behavior of the composite considering the strain rate dependency of the material behavior. The model parameters were also related to the strain rate.

Damage to pipe coating is almost unavoidable during transportation and construction, and damage or holidays in pipe coatings may expose the pipe to possible corrosion. Cathodic protection systems are installed to act as a back-up for coating imperfections. However, cathodic protection systems themselves interact with the coating by chemical and physical phenomena. This interaction can lead to cathodic disbondment of the coating. Corrosion may occur underneath the disbonded coating, which is a risk for pipeline owners. Cathodic disbondment testing for all types of "conventional coatings" will frequently reveal disbondment to one degree or another. On the other hand, properly formulated visco-elastic polymer coating systems do not show disbondment at all due to the unique self-healing features of the coating. Testing for cathodic disbondment is routinely done for newly applied coatings and are only tested for a short period of time (e.g., 30 days). Lifetime expectancy for pipelines is, however, much longer - typically 30 years or more. During its operating lifetime, a coating will age and lose certain essential properties such as adhesive strength. This ageing process can be simulated by Hot Water Immersion testing followed by peel-testing. Results obtained from routine short-term cathodic disbondment testing are, thus, unsatisfactory and make little sense if, over time, the coating disbonds because of its ageing processes. Stopaq visco-elastic coating systems are proven to withstand Hot Water Immersion tests. Values obtained with peel testing after Hot Water Immersion at Tmax + 20°C for 100 days were similar to values obtained with non-aged test specimens. In addition, the coating's self-healing effect - a typical property of Stopaq coating systems - recovered holidays within the expected time period of testing.

The interplant High-Pressure Digester Gas Line (HDGL) allows Orange County Sanitation District (OCSD) the flexibility to move digester gas between two wastewater treatment plants (which are about four miles apart)for waste-to-energy conversion. Portions of the pipeline are located in public right-of-ways. The pipeline was designed and constructed in 1993 and operated for about 20 years without incident. During a master planning effort in 2004, the pipeline was assessed using standard gas pipeline indirect methodologies. Subsequent investigations identified deficiencies and the need for rehabilitation to bring the pipeline into compliance with changing regulatory requirements and District maintenance and design restrictions. This paper documents the projects and design decisions made along the way to rehabilitate the pipeline using high density polyethylene (HDPE) slip lining materials. The decision process that led from considerations of replacement in kind to the final selection of HDPE as a lining material are discussed and the lessons learned are documented.

In 2007 and 2008, flooding of the Rio Grande River to the east of Santa Cruz de la Sierra in Bolivia (Figure 1) undermined and endangered a 32-inch diameter gas transmission line, operating at 1,400 pounds per square inch (psi), which was providing an important part of the daily energy consumed in Brazil. In 2009, explosions attributed to subversive activity damaged a control valve station in Mexico. The station is used to isolate the river crossing of a 48-inch diameter, 960-psi natural gas transmission line that supplies the country with natural gas from the country's southern gas fields. This paper will discuss how the operational safety of both river crossings was enabled without interruption of service by the use of in service welding and tapping and plugging techniques.

Risk associated with the increased use of trenchless technology for both new and replacement construction of natural gas distribution systems must be addressed to comply with recently enacted Distribution Integrity Management Program (DIMP) regulations adopted by the USDOT. DIMP regulations require that all gas operators rank system risks and define actions to mitigate these risks. Most gas operators currently utilize trenchless construction methods due to the reduction in construction cost and the minimal impact to surface features. Adoption of a comprehensive crossbore inspection program is critical for utility companies to comply with DIMP regulations. Due to recent incidents nationwide associated with this issue, several major gas distribution companies have instituted inspection programs to mitigate the related risk and insure the safety of their customers. This paper addresses components that should be addressed when either initiating or modifying existing crossbore inspection programs.

This paper presents a comprehensive hydraulic transient analysis, performed using the latest computer modeling programs, for evaluating three pump stations and the connected raw water transmission main system, originally designed for surge control utilizing hand calculations. The Waurika Lake Master Conservancy District (WLMCD) provides raw water to the cities of Lawton and Duncan, Oklahoma from Waurika Lake via three pump stations. These stations are: 1) Waurika Lake Station; 2) Lawton Relift Station; and 3) Duncan Relift station. WLMCD was concerned about the adequacy and reliability of the aging infrastructure and existing surge protection systems due to sticking surge anticipator valves at the pump stations and excessive transient waves causing issues in the pumping and transmission system over time. WLMCD initiated a project to study and develop recommendations to address these concerns. The project consisted of analyzing the system facilities -including pumping, piping, and related appurtenances - for potentially damaging levels of surge and providing recommendations to help protect the system more effectively. The original 1970's design of the Lawton and Duncan systems used hand calculations to evaluate and configure surge control systems using best practices available at that time for selecting, sizing, and locating equipment and controls. Over time, improved tools such as sophisticated computer modeling programs were developed to help analyze, refine, and devise functional solutions for surge problems. This project was intended to take advantage of these new analysis tools to refine surge protection systems that were originally designed more than 30 years ago.

The planning of pipeline routes in both ujrban and rural environments introduced complex inter-relationship and potential conflicts with various utilities, environmental features, crossings, sites, and sizing of appurtenances and structures along the alignment. Many engineers/planners begin the pipeline planning process with a desktop study of a potential route utilizing topographic maps, aerial photography, and utility research. However, the alignment inevitably changes after an engineering and environmental alignment walk-through. Oftentimes, the alignment experiences several iterative renditions. In lieu of rolling up all the maps and information and heading out to the field, a digital data collection device that operates on a Smartphone with geo-referencing capabilities was utilized. The device digitally records real time alignment changes that are dynamically made in the field as observations are made and noted during the walk-through. Additionally, the device allows for speech-to-text notes as well as photographic documentation to be developed, logged, and geo-referenced to any spot along the alignment. The use of real-time logging and geo-referencing greatly increases accuracy of field notes and observations documented in the field. This paper will provide an overview of the software utilized in addition to describing the applications and potential uses of geo-referencing devices as real time data loggers for future operation and maintenance of the pipeline system.