Pipelines 2002: Beneath Our Feet: Challenges and Solutions

The magnitude of infrastructure decay in Cleveland and Cuyahoga County had become widely recognized by 1980: streets were disintegrating; nearly 30% of the county's bridges were in need of major repair; the Cuyahoga River had become so polluted it caught fire; Lake Erie had been declared "dead"; and the new regional transit authority was attempting to reverse decades of deferred maintenance. This neglect and deferral of infrastructure improvements had serious impacts on Greater Cleveland's economic environment. For example, the City of Cleveland had experienced significant declines in manufacturing jobs and population, and had even entered fiscal default. In 1981, The Greater Cleveland Growth Association (chamber of commerce) and the Mayor of Cleveland initiated discussions among public and business leaders regarding the City's physical and economic problems. The local leaders became convinced that economic recovery was not feasible without infrastructure rehabilitation and expansion. After two years of discussions and negotiations, the participants developed a community capital investment strategy with three goals: (1) identify infrastructure needs; (2) secure financing to meet the needs; and (3) expedite project implementation. Build Up Greater Cleveland (BUGC) was established to implement this community capital investment strategy. During BUGC's first five years, The George Gund Foundation and The Cleveland Foundation provided 50% of the funding. The remaining portion was provided by public sector infrastructure entities: Greater Cleveland Regional Transit Authority; Northeast Ohio Regional Sewer District; City of Cleveland; Cuyahoga County; and Cuyahoga County Engineer. In 1987, these public entities, along with The Greater Cleveland Growth Association, assumed full funding responsibility. The Cleveland/Cuyahoga County Port Authority also became a BUGC funding partner in 2000.

There are many applications available in today's software market to conduct hydraulic modeling of water distributions systems. However, in a complex and dynamic system, there must be a method of keeping the source data components current. Although major components are not added daily, over time, significant changes are made that affect the overall performance of the distribution system. Cleveland's distribution system is made up over 5,000 miles of pipe with 56,000 valves and 71,000 Hydrants. Trying to keep the record drawings current in a system as large as Cleveland's is a difficult task which requires a high level of coordination and a sound process. A GIS (Geographic Information System) is the ideal application for storing the data describing the distribution system.

Hampton Roads Sanitation District (HRSD), Virginia Beach, Virginia developed an underwater inspection program for nine wastewater treatment plant outfalls. These outfalls are used to convey treated effluent using large diameter pipelines to adjacent rivers, the Chesapeake Bay and the Atlantic Ocean. A baseline underwater inspection of the nine outfalls was conducted in 2000 by a team of engineer divers. From inspection findings, guidelines on inspection intervals and repair recommendations were developed. Of the nine outfall facilities, four were found to have significant deficiencies. Three outfalls, the Boat Harbor Outfall, the James River Outfall and the Williamsburg Outfall, required immediate repairs. The Boat Harbor Outfall had serious damage to the main barrel and the James River and Williamsburg Outfalls were observed to have blocked diffuser ports. Repairs of the Boat Harbor Outfall, James River Outfall and Williamsburg Outfall were completed in 2001 and 2002. The fourth outfall found to have deficiencies was the Atlantic Plant Outfall. The multiport diffuser showed significant loss of sediment cover over a 732-meter (2400-foot) section 3 kilometers offshore in the Atlantic Ocean. The consequences of the loss of cover on the structural stability and durability of the Atlantic Plant Outfall was unknown. The primary concern was structural stability during heavy weather events. A study analyzed the overturning/rotational sliding of the multiport diffuser under heavy weather. This paper provides a synopsis of a program management approach to maintaining outfalls, a case study of the Atlantic Plant Outfall and an overview of repairs to the Boat Harbor and Williamsburg Outfalls. It also includes a checklist for the inspection of outfalls.

Performing internal pipeline inspections for condition assessment can offer valuable information on the conditions of water conveyance pipelines. Three common reasons for internal inspections of pipelines are: (1) Quality control during the construction of the pipeline; (2) Condition assessment as part of a preventative maintenance program; (3) Condition assessment after a leak. Presented herein are three case histories of projects that illustrate each of the above reasons for internal pipeline inspections. The projects include: the Parker Road/I-225 Project, the Lower Homes take Parallel Pipeline Project, the Fountain Valley Pipeline Project.

In September of 2000 the City of Allen Park, Michigan experienced a 100-year intensity rain event which impacted their storm and sanitary systems. This rain event produced 4 inches of rain in a 3 hour period and caused a surcharge in their infrastructure which resulted in 2,900 basements being flooded or 25% of the City. This event along with other considerable rainfall intensities over a two year period has motivated the City of Allen Park to conduct a comprehensive evaluation of both their sanitary and storm sewers systems. The resulting investigation of their aging systems identified remaining cross connections, inflow sources, physical restrictions, failed piping and other impediments that impacted pipe capacities and reduced flow. This paper will present the approach and results of a comprehensive sanitary and storm sewer evaluation in the City of Allen Park, Michigan. The data used in making the evaluation was obtained from several sources including: flow monitoring, smoke testing, manhole/pipe inspection, dye testing, TV camera inspection and digital photography. Examples of actual field data will be presented to show typical problems found during the data acquisition phase of the project. Flow monitoring data will be introduced to show the effects of rainfall on the sanitary system and its direct correlation to the infiltration and inflow problems. The paper presented will show the merits of providing a pro-active approach to the maintenance of sanitary and storm sewer systems along with discussing why collection system problems occur. The paper will further discuss the benefits of providing comprehensive sanitary and storm sewer system audits for the purposes of rehabilitating aging systems and eliminating infiltration and inflow sources. The methods to collect field data and the tabulation of the data collected into a usable format will provide useful information to anyone interested in evaluating a collection system which will be required under the new CMOM (Capacity, Management, Operation & Maintenance) initiatives.

Effective decision making depends on effective information. Examples of the roles of inspection data, GIS systems and data management are demonstrated as part of an integrity management plan. The spatially-based correlation and presentation of data that Geographic Information Systems confers is a highly powerful and flexible tool for management of pipeline data. The RFEC/TC inspection technology, capable of detecting prestressing wire failures in PCCP, is currently being used to identify distressed pipe sections in previously uninspected lines as well as the re-inspection of sections to generate models and trends for pipeline deterioration. GIS models and data systems are demonstrated as part of a strategy for pipeline integrity management.

This paper presents an asset management program methodology for water and sewer utilities including determining remaining useful life and developing a predictive modeling tool. In addition, two case studies are presented, one for a water utility and one for a combined water/sewer utility.

Modern infrastructure systems are highly developed with considerable capital funding invested in them. While capital is spent on new infrastructure initiatives, the maintenance of the present infrastructure must not be neglected. Increasingly, public agencies are being urged to develop improved systematic methodology for allotting their period budgets more appropriately so that the capacity of the installed infrastructure is more fully utilized and sustained. When planning the allocation of investment funds, multiple objectives may exist which are dependent on the constraints, resources available for construction, and the interrelationships and dependencies among all of the alternatives. This makes the task of planning, prioritizing, and allocating funds a complex exercise. This paper presents a financial outlay model called PRISM, Proactive Rehabilitative Sewer Infrastructure Management, which uses linear programming to optimize allocation of funding for the local sewer network maintained by the City of Edmonton, Canada. By grouping sewer pipes into categories based on parameters of age, diameter, material type, waste types, and average depth of cover, the model provides a mechanism for determining the most appropriate allocation or appropriation of funding given a planning horizon and budgetary constraints.

The Tarrant Regional Water District supplies raw water to municipal customers who serve about 1.5 million people. Eighty percent of the supply is delivered through a large diameter pipeline transmission system. The costs associated with maintenance of the system are presented. Problems encountered with the system have increased the maintenance costs and these problems and associated increased costs are presented.

Ferrous pipes such as cast iron, ductile iron, wrought iron and mild steel form an integral part of the lifeline to major towns and cities. They carry water to, and sewerage away from, the centres. Their failure can have a disastrous impact on 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. Rock Solid (RS) uses specially configured geophysical techniques combined with its understanding of geotechnical and geochemical issues in the study of various sub-surface and surface engineering and geological structures, eliminating the need for destructive excavation or testing. Successful application of this technology requires both a clear understanding of each technique's strengths and limitations, and the ability to accurately interpret the data gathered. Experience has shown that ‘off-the-shelf' technologies often require modification in order to be applied to inspections of pipeline assets. Rock Solid offers a broad spectrum of geophysical and non-destructive inspection techniques to cater for various inspection requirements. Multi-disciplinary testing programmes are designed to generate data streams that are cross-correlated to provide increased levels of confidence in the final assessments. In addition to existing techniques such as ground penetrating radar, seismic and ultrasonic technology, electromagnetics, magnetics, resistivity and general geotechnical and geochemical testing, new technology has been developed and is now being applied to ferrous pipe wall condition assessment, yielding excellent results.

This paper discusses the principles of high-resolution shear wave acoustic methods for subsurface imaging, and the vibratory source. Two field applications are also discussed: (1) Void Detection: A major oil company sought to develop a surface geophysical method to locate voids on and around storm sewers in various refineries. The target size was specified as a 1-foot diameter void located on a 3-foot diameter sewer pipe. Both shear wave reflection seismic and a guided wave "refraction" amplitude analysis techniques were utilized on a test sewer constructed specifically for the evaluation of geophysical techniques. (2) Pipeline Locating: Because pipelines are normally fluid or air filled, shear wave reflection seismic can be used to locate larger pipelines buried at depth. In particular, the vibratory source is very useful in urban areas where the target pipelines are overlain by pavements, parking lots, and other structures.

A new method has been developed in Europe for identifying potential leaks in sanitary sewers (including joints, mainline and service connections). The First units are just arriving in the U.S. Pilot demonstration projects have been completed in Louisville, Kentucky (Louisville & Jefferson County Metropolitan Sewer District) and the City of Raleigh, North Carolina. The results are exciting. Results of these and several other demonstration projects will be discussed. Basically, the method locates leaks by pulling an electrode that emits electronic fields into the sewer system with pipe acting as an insulator. The rise and fall of the electrical signal as the probe passes through the sewer indicates potential sources of infiltration, as well as the magnitude of the leak. The purpose of this paper is to discuss this technology as well as its limitations. The discussion will be done through several case studies including: (1) Identifying leaking joints on mainline during dry weather. (2) Prioritizing leak repairs by intensity of readings. (3) Determining if service laterals leak. (4) Use of the technology as an alternative of accepting new and rehabilitated sanitary sewers. (5) Alternative technology for testing new sanitary sewers (instead of air pressure testing).

This paper presents two methods of analysis for buried pipelines subjected to seismic wave propagation effects, temperature load, and internal pressure. The use of closed-form equations for analysis of a single bend with arbitrary bend angle subjected to seismic ground strain, temperature load, and internal pressure is first presented. For pipelines with complex geometries, such as horizontal and vertical bends, compound bends, vertical risers, tees, and attachments to large structures, a finite element analysis procedure is developed to predict the seismic behavior. The three-dimensional finite element model can account for the pipe-soil interaction, joint slack, and other material non-linearities, such as, concrete tensile softening and steel yielding. The analysis is performed for combined effects of seismic wave propagation, temperature load, pressure load, equipment load, and permanent ground motion. As an example, the use of finite element analysis in predicting the seismic behavior of a circulating water concrete pressure pipe in a power plant is presented.

This paper discusses the inspection and assessment of the condition of air vacuum vaults, blowoffs, and in-line valve vaults along the Lower Homestake Pipeline owned by Colorado Springs Utilities (CSU). The Homestake delivery system provides water from the Continental Divide to the City of Colorado Springs. CSU has undertaken a project to expand the Homestake delivery system by approximately 13.5 mgd. The project includes expansion of two pumping stations and construction of 7 miles of pipeline, paralleling the existing 48-inch Lower Homestake Pipeline. The existing pipeline was constructed in the early 1960's and is 26 miles in length. The increased flows will result in higher velocities and pressures in the existing pipeline. Therefore, CSU wanted to ensure that the pipeline appurtenances would operate properly and commissioned an inspection and condition assessment.

Non-destructive evaluation of the Prestressed Concrete Cylinder Pipelines (PCCP) enables the selective repair or replacement of distressed sections, and can alleviate the prohibitive cost of complete replacement. The RFEC/TC inspection technology is capable of detecting prestressing wire failures in PCCP and is currently being used to identify and assess distressed pipe sections. An update on the technology and its use is presented including field experiences from recent projects.

In this age of technology and scientific advancement, we are coming face-to-face with a crisis that cannot be challenged by technology alone. In large cites and small towns across America, sanitary sewers are failing, and they're failing at an alarming rate. Whether they are failing because of neglect, lack of adequate funding, or sub-standard construction practices, the rate of deterioration still out-paces the resources to fix them. The facts are plainly clear in a recent report card issued by the American Society of Civil Engineers (ASCE), which ranked America's wastewater infrastructure lower than every other infrastructure except for public schools. This paper will address the questions most commonly asked by public works officials: (1) Where do I begin? (2) How do I diagnose the problems? (3) How do I know what problems to fix? (4) How long will it take? (5) What rehabilitation options are available? What results can I realistically expect? (6) How much will it cost? (7) Where can I get more information?

"Find It & Fix It" is a project delivery system that saves time and money and assists owners in improving the operation of their underground infrastructure as well as meeting the requirements of the Clean Water Act. Improvements in evaluation techniques, advances in trenchless technology and increased requirements from the EPA's C-MOM Regulations bring together several forces that lead to an improved method of quickly taking a collection system rehabilitation project from evaluation to repair.

This paper presents an objective comparison of a number of completed rehabilitation projects in the United States that have been placed in-service over the past 30 years. Available results concerning application, performance, and overall performance were evaluated to assess the applicability, selection, and design considerations of various rehabilitation strategies. This evaluation was based on the performance of completed sewer rehabilitation projects as determined by effective flow monitoring activities. Using the results of this evaluation, the authors have characterized driving factors which influence overall performance of sewer rehabilitation projects by reducing the impact of sanitary sewer overflows (SSOs) and rain-dependent inflow and infiltration (RDII).

The City of Los Angeles is currently evaluating the methods that will be used to rehabilitate its major noncircular cross-section sewers. This paper presents the methods that are being considered, as well as a history of the methods that have been previously used to rehabilitate circular cross-section pipes in the North Outfall Sewer and a portion of the noncircular Central Outfall Sewer.

The Vallejo Sanitation and Flood Control District (District) is undertaking a pilot program to assess the effectiveness of sanitary sewer rehabilitation to reduce rainfall dependent infiltration and inflow (RDI/I). The pilot program includes measurement of flow and rainfall in selected basins within the District over an extended period, both before and after rehabilitation of the sewer pipes and manholes in the basins. The goal of the program is to measure the amount of reduction in RDI/I entering the system after completion of rehabilitation and to determine the level of RDI/I flow reduction that may be expected if rehabilitation is expanded to other basins. Due to a lack of standardized methodology for conducting RDI/I reduction assessments, a new methodology was developed for this project. The methodology includes use of control basins in which no rehabilitation was conducted. The control basins are intended to provide an indication of variations in RDI/I resulting from varying weather patterns. Data from the control basins indicates that wide variations in RDI/I flow were observed that were attributable to weather variations rather than sewer rehabilitation. This paper provides an description of the methodology used to assess RDI/I reduction in three basins including adjustments for variations in weather patterns. Varying levels of rehabilitation and replacement of service laterals, main sewer lines, and manholes were completed in the three selected basins.

Trenchless technology has attained significant utilization for the renewal of the infrastructure of much of the civilized world. The distribution and collection systems of the world enabled the industrial revolution by permitting large population to live with in close proximity. The deteriorations of these underground assets threaten to erode the foundation of modern society from beneath our feet. The sewer and storm drain infrastructure is only thought about when they fail catastrophically, with blockages, backups, or overflowing. Indeed, while this process is on going, the industry is faced with increased expenditures often presently uncontrollably. Sewer and water rehabilitation surveys with municipal water and sewer owners, pipeline rehabilitation contractors, engineers and other industry experts are in national agreement that due to the tremendous growth in the industry we collective need to insure the stability of our systems. Infiltration and in flow can greatly increase the amount of water conveyed by the sanitary and storm drain system. A system with a big I/I problem could experience wet weather flows twelve times its normal sanitary flows plus a little infiltration, so excessive I/I can over load both the sanitary sewer and the treatment plant. Pipe rehabilitation methodologies can ensure the stabilization of our infrastructure and contribute to cost saving advantages. Through standard practices and understanding of methods of rehabilitation the tax payers will be long term beneficiaries.

Flow monitoring in gravity sewer systems poses challenges of complexity and interpretation of data. The success of sewer renewal work needs objective measures to determine effectiveness of I/I removal, overflow abatement, and customer service. The value of sewer renewal has been underestimated in many cases because the initial loading of I/I was underestimated due to misinterpretation of data. This paper will explain how to avoid these errors, and how to develop baseline relationships between I/I and rainfall. Case histories for Nashville and Jackson demonstrate that improved interpretation enabled designers to identify instances when upsizing was not needed. Analysis of the data "signature" showed that correction of downstream blockages would recover the required capacity. The US-EPA's national CMOM initiative will require flow monitoring for documenting municipal program performance. A common strategy for deploying temporary meters is to use two consecutive months between September and April. During a year of flow monitoring in a North Carolina community, only one of the seven possible combinations of two "wet" months would have replicated the correct estimate of annual I/I with that strategy. Analysis of 12 individual months resulted in projections of annual I/I that varied from –49%, to +85% compared to the total I/I for that location in one calendar year. Permanent flow monitoring conducted for periods greater than a year will help increase the reliability of projected sewer system characteristics. However, annual variations must still be considered based on variations observed in system characteristics during a study of four permanent monitoring sites over a period of three years in Nashville.

The operating envelope for trenchless technology continues to expand. Trenchless techniques are now being used for some of the most demanding applications and in difficult geological conditions. For virtually any size project, the owner, engineer and contractor need to undertake a risk identification and assessment. This paper will explore some of the methods that owners and engineers can utilize to manage the known and unknown risks when utilizing trenchless methods in constrained or difficult urban environments. The experiences are based upon actual projects designed and constructed in congested urban conditions. Our experience has shown that contract documents should be prepared that identify the major risks for the project and then describe how the risks will be allocated. An ideal contract is the one that assigns each risk to the party that is best equipped to manage and minimize the risk, while recognizing that each construction project is unique. Any actions that can reduce risk more than the corresponding reduction in return are beneficial. The advantages and disadvantages of the various methods will be explored. Proper evaluation of risk can help to minimize problems, and most importantly, minimize overruns, claims and injury to personnel while completing the job in a timely manner.

The San Diego County Water Authority (Authority) completed construction of the Olivenhain Pipelines in April 2002. This project was one of the most difficult pipeline projects constructed by the Authority due to extremely steep terrain, narrow access roads, and extensive environmental constraints, which substantially limited the work area. The project incorporated an Owner Controlled Insurance Program (OCIP). The OCIP provided for safety audits and reviews performed by the on-site safety officers (Safety Team) from the insurance company, insurance broker, and Authority. This paper describes some of the construction operations that were implemented by the Contractor, as well as those recommended by the Safety Team in response to a series of heavy equipment rollover and layover accidents, such as designated "four wheel drive only" areas, a job site Safety Committee comprised of labor and management, and job site orientations for new employees, including subcontractors and vendors.

On March 28th, 2001, a 36-inch cast iron main failed in West 38th Street in Cleveland's Ohio City neighborhood. Five million gallons of water flooded the streets of the area, causing significant disruption to the area. It was the third such large main failure in the previous 14 months, and drew major media attention, as had the other recent failures. As a result of that history, then-Mayor Michael R. White, who has been personally concerned about all of the city's recent big main breaks, asked that a Task Force be formed to study the problem of large main failures and examine possible ways of mitigating such catastrophic failures. On May 15th, 2001, the Task Force convened for the first time. As part of that Task Forces work, the Division of Water conducted a major review of its trunk main system. This report resulted from that CWD review.

The threatened washout of the Santa Ana River Interceptor (SARI) pipeline endangers not only the treatment plants and industries discharging into the pipe, but the major groundwater basin recharged by the river, and the downstream treatment works of the Orange County Sanitation District (OCSD) as well. This paper discusses the proactive efforts of OCSD and the Santa Ana Watershed Project Authority (SAWPA) to save the segment of the pipeline exposed to erosion in a canyon area. An effort to relocate the pipeline via a fast-track construction approach was deferred due to public concern and funding issues, but planning continues for interim protection and ultimate safety of the SARI.

During the reconstruction project of two water transmission mains for the City of Akron, Ohio, contaminated groundwater was discovered in an open trench. This incident delayed the continuation of the project until a method could be developed and plans prepared to complete the construction of this portion of these vital mains. The following paper describes the design, materials, and procedure used to successfully replace a pair of antiquated steel transmission mains through a 160 m (525 ft) long area containing heavy petroleum contamination. Completion of this section of mains restored full operation of the water transmission main system and allowed the replacement project to continue. Prior to the design of all major transmission main projects, it is recommended that environmental exploratory studies be performed.

The likelihood and consequence of failure of a single pipe plays a large role in the effective operation of a pipeline system. Condition assessment on each pipe is possible using recent and historical data and identifying potential failure points along a pipeline. Cost-effective rehabilitation strategies and plans are based on the prioritization of such analyses. Predictive methods for pipeline failure and consequences are possible as well, allowing proactive preventive maintenance. The stages of collection, assessment and analysis, prioritization and action form a risk management strategy, demonstrated here as a composite case study.

Nashville's Metro Water Services Department (Metro) has embarked on a one-of-a-kind design/build contract to reduce infiltration/inflow (I/I) from a large sewerage basin, Whites Creek. Nashville and other cities have used design/build and performance-based contracts for many types of construction projects, but not for sewer rehabilitation. Typically, cities and their engineers design sewer rehabilitation projects, issue a detailed set of bid documents, and select the low bid contractor. Contractors and engineers are compensated regardless of the effectiveness of their solution. However, for the Whites Creek project, Metro required proposals to include engineering and construction services and to link compensation to demonstrated performance.

The Clear Spring Ranch Sludge Pipeline Replacement Project (Sludge Pipeline Replacement Project) is a multi-year replacement project for Colorado Springs Utilities (CSU) in Colorado Springs, Colorado. The project was planned to be constructed in several segments. The final segment is projected to be completed in 2005.This project is unique due to the fact that the first four segment used three different project delivery methods and the objective of this paper is to evaluate these different delivery methods. The approach of the paper will take a position of what makes a "good" project from the owners perspective. Four goals for a successful project were identified by the owner and will be discussed with each project delivery method. This paper will discuss the alternative project deliveries (APDs) used on four segments of the Sludge Pipeline Replacement Project.

In the state of Texas, the Texas Natural Resources Conservation Commission (TNRCC) establishes minimum sanitary sewer design criteria. The TNRCC provides criteria such as minimum slope, maximum manhole spacing distances, separation distances between water and wastewater pipelines, etc. All of these are elements of standard sanitary sewer design. This paper categorizes sanitary sewer design into that of development design and of rehabilitation design. Development design includes the installation of new lines and the connection of new services. Rehabilitation design includes the replacement/improvement of existing lines and the reconnection of existing services. Concerns of both design methods include that of alignment, construction, and material. The optimum alignment considers the present, future, and ultimate land use demands. The best construction method considers the minimal disruption to the existing land while providing a safe, cost effective, efficient way to install the pipe. The carrier pipe material considers the physical characteristics of wastewater flowing in it and the physical interaction with the surrounding environment.

In 1990, the Nashville Metropolitan Department of Water Services began work on its $800 million Overflow Abatement Program to mitigate combined and separate sanitary sewer overflows from its wastewater collection system. Since then, with the cooperation of the community and through an agreement with the Tennessee Department of Environment and Conservation, the program has completed system improvements costing more than $500 million. The completion of the $26 million Demonbreun Combined Sewer Separation Project played a significant role in the success of the program — eliminating eight overflows from the Demonbreun drainage basin.

The East High North Water Transmission Project in Dallas, Texas, is a capital improvement project funded and managed by the City of Dallas Water Utilities Department (DWU). The purpose of the project is to improve water pressure during peak periods and enhance fire flow protection for the northeast section of Dallas through the design and construction of approximately 4.5 miles of 48-inch, 42-inch and36-inch water transmission mains. The project area is located in northeast Dallas with Northwest Highway as the north boundary, Easton Road as the west boundary, Shiloh Road as the east boundary, and Ferguson Road as the south boundary. The project area is primarily a fully developed residential area with some commercial and retail development intermixed. The water line alignment crosses one park, two creeks, one junior high school, four retail/commercial areas, one Texas Department of Transportation (TxDOT) roadway, one railroad, Four churches, one nursing home and 18,000 linear feet of residential streets.

This paper examines and characterizes the structural response of intimately fitted repaired sewers due to disturbance in the vicinity (e.g. vehicle loads). This soil-host pipe-liner interaction is investigated by full scale laboratory testing. The test geometry and measurement scheme are described. Mechanisms affecting local bending at host pipe fractures are identified. A comparison is made between response for the HDPE liner within a fractured non-reinforced concrete pipe, and that same HDPE liner buried alone in soil. Under earth disturbance, the fractures in the host pipe expanded at the inner surface at the crown and invert, and at the outer surface at the springlines. This expansion of fractures caused contacts between the inner edges of the host pipe and the liner at the crown and invert. The liner response was dominated by the local bending that resulted.

The discharge from the Smith Springs Wastewater Pumping Station had created known odor problems for many years; however, the corrosion — induced collapse of a manhole added a new dimension to the problem. After years of feeding chemicals into the receiving sewer to control the problem, which did nothing to address the corrosion element just upstream, Metro Water Services applied both new technology and old, common sense concepts to erase the odors and corrosion concerns.

Over the past decade, inspection and rehabilitation programs have been increasingly implemented to address collection system structures that are quickly deteriorating from increasingly aggressive sewer environments, late stages of design life and, sometimes, poor construction. Programs have included the replacement or rehabilitation of pipelines, lateral lines and manholes. Specifiers, contractors, owners and operators need to be informed of the impact of manhole rehabilitation, methodology of manhole inspection and dissemination of relevant characteristics, advantages and disadvantages of prevalent technology and materials.

Corrosion impacts the design, operation and maintenance of every element of a water system. Water wells, treatment equipment, storage facilities and piping systems are all vulnerable to accelerated deterioration from corrosion. Numerous studies have been published that document the causes of corrosion and successful methods of control. The problems related to corrosion in water systems are not new. As early as 1939, the results from a survey performed by the Illinois State Water Survey indicated that 41% of the water systems responding were experiencing corrosion problems involving well pumps, water mains, storage facilities and service lines. Over the years, the basic problems have changed very little, although our understanding and technology for controlling corrosion have improved significantly. Corrosion in water systems must be addressed by every operator to ensure economical supply of high quality water and safe operation of fire protection systems. By properly addressing corrosion mitigation through material selection, coatings and cathodic protection, system life will be extended and operational costs reduced. The economic benefits accrue to both the system operator and ultimately the consumer.

This paper describes a research project sponsored by the Pipeline Research Council International (PRCI). The objective of the research was to provide designers with hard data for use in specifying steel pipe coating systems for horizontally directionally drilled (HDD) pipeline crossings. This was accomplished by determining the performance characteristics of various coating systems when subjected to simulated HDD installation loads in rock. A testing device utilizing rock core samples from actual HDD river crossing projects was designed to replicate, as close as practical, HDD installation loading conditions. Testing resulted in determination of coating wear rates for various coatings.

The UK water industry has utilized spray applied linings for water mains rehabilitation since the early 1900's. The original process used cement mortar but over the last 20 years this has been succeeded by epoxy resin with over 11 000 miles of pipe lined. Although offering a durable, inert and proven coating which can be applied quickly and at low cost, the 16 hour cure period has led the industry to develop products which cure within 2 hours. Since the recent introduction of such a rapid-setting product, numerous water companies and contractors have assessed the potential advantages of its use and over 300 miles of water mains of diameter 3 to 33 inches have been lined to date. Now approved and starting to be used in North America, this paper outlines the process and the current status of the materials. It will highlight, from an independent viewpoint, the apparent advantages, limitations and experiences gained through research and monitoring actual rehabilitation projects.

For more than a decade, the City of Columbus, Ohio has utilized trenchless technology to renew its existing infrastructure. A renewal method popular with the City is cured-in-place pipe (CIPP), technology that has been used extensively to rehabilitate its collections system in the historic, congested and heavily traveled areas of downtown. Many of these sewers are brick combination lines or interceptors that were originally installed as early as the late 1800's. The City's recent focus to revitalize these downtown areas has led to new development that is attracting more businesses and new permanent residents. One such community, the Brewery District, is undergoing a major facelift. Located just south of downtown, an area that was once an eyesore is developing into a local attraction. Improvements to the infrastructure have been given a high priority in areas of development. This report discusses the "Brewery District Sewer Improvements — Franklin Main Interceptor Sewer Rehabilitation Project" constructed by Rinker Pipeline Renewal (formerly CSR Hydro Conduit — Pipeline Rehabilitation). The project was funded by the city and private developers and involved the renewal of the southern section of the Franklin Main Interceptor with National Liner^TM CIPP, installation of new precast structures, pipe preparation, cementitious grouting and manhole rehabilitation. The CIPP lining operation was accomplished in two (2) setups; currently the longest and largest successful inversions of National Liner^TM ever recorded.

Cambridge is an old city that is seriously in need of the infrastructure improvements that are now being implemented. Sewer separation and stormwater management projects will alleviate the problem of flooding and threats to public health caused by untreated wastewater discharged to low-lying neighborhoods and the Charles River during heavy rainstorms. Since 1998, S E A Consultants Inc. and Montgomery Watson Harza (S E A/MWH) have been working with the Cambridge Department of Public Works to pinpoint problems within the existing system; develop ways to achieve the program objectives; and plan, design, and oversee construction of over $325 million in city-wide infrastructure improvements over the next 15 years. Unconventional construction methods in heavily developed urbanized areas such as use of large underground storage tanks, maximizing use of surface storage potential, use of best management practices to reduce floatables and sediment discharges to the Charles River, and applications of trenchless technologies to minimize construction disruptions while improving the infrastructure have been highlights of the program. The paper describes various aspects of the Cambridge sewer separation and stormwater management program, the condition of the existing infrastructure, improvements needed to support future growth, and innovative techniques used to address water quality and quantity considerations. Planning, design, construction, utilities, traffic and pedestrian management, and community participation will be explained as they relate to this program.

The air conditioning system serving the Farragut North Metro Station in Washington, D.C. , is served by a chiller plant, cooling tower, and a supply and return line. The chiller plant is located in an underground structure in Connecticut Avenue, northwest of 17^th Street. The cooling tower end is located in the basement of 1100 Connecticut Avenue. There is a 16" steel supply line, which runs between the chiller plant and the cooling tower, which is approximately 416 feet long and changes to 14" diameter in the vicinity of 1101 Connecticut Avenue. This line changes vertical and horizontal direction several times by various degree bends in the line. There is a 16" steel return line, which runs between the chiller plant and the cooling tower, which is approximately 440 feet long and changes to 14" diameter in the vicinity of 1101 Connecticut Avenue. This line changes vertical and horizontal direction several times by various degree bends in the line. One of the lines experienced a leak, which resulted in the shut down of the air conditioning system to the Farragut North Station.

The need to protect the environment has created many new challenges for pipeline engineers, particularly for rehabilitation of aging pipelines. The development of trenchless rehabilitation technologies presents many new options, but determining the most suitable rehabilitation method is a challenge. This paper describes the process used to define the rehabilitation program for the Barker Gravity Pipeline, and the lessons learned in the first phase of work.

Early in the conceptual design stages of a water transmission main design project, areas where standard open-cut installation would be difficult or costly were identified and trenchless methods to install segments of the proposed 400 mm (16-inch) diameter main were evaluated. Three areas along the proposed route were identified as conducive to trenchless installation: a major street crossing which has traffic impact considerations and requires numerous concrete encased utility crossings; a brook-box culvert adjacent to a reservoir and a railroad track crossing. Trenchless methods were also considered for crossing Interstate Highway Route 95. However, it was determined during design that sufficient space inside the existing bridge utility bay would eliminate the need to install the main by trenchless methods at this location. Trenchless technologies considered included horizontal directional drilling, jacking, microtunneling and boring. The use of a single method of trenchless technology was the design objective. This would allow for one contractor to perform the three installations and minimize costs. Space and construction impact considerations resulted in the selection of horizontal directional drilling to install the proposed transmission main in the three locations. The necessity of installing a sleeved main under the railroad right-of-way resulted in an innovative design in which the sleeve would be installed by horizontal directional drilling and the main will be placed inside by traditional installation methods. The sleeve would be shorter than the actual length of directional drill required to install it under the track. However, upon review of the proposed installation by railroad authorities, directional drilling was not allowed at this location and installation by jacking was utilized in final design. This paper will present the methods evaluated, the design issues encountered, utility survey and geotechnical investigations.

Baldwin Borough, a 5.5 square mile municipality located in Greater Pittsburgh with a population of 22,000, is undertaking a comprehensive sanitary sewer rehabilitation project to reduce inflow and infiltration systemwide. Rehabilitation activities include internal televising, pipe lining, bursting, and replacement as well as manhole repair and replacement. Chester Engineers has developed the sewer rehabilitation data management system (SRDMS) to assist in the planning and design phases of the ongoing rehabilitation project. This system was successfully implemented through the bidding phase in association with the internal inspection of over 200,000 feet of sanitary sewers and 3,000 manholes. The GIS-based system utilizes digital map data compiled during a sewer mapping effort initiated in 1996. Chester Engineers field-verified the sewer network data based on TV inspections conducted during a 3-month period in 2001. Concurrent with this effort, a Microsoft Access^TM database was developed to capture conditional information for each surveyed sewer feature, apply unit costs for all necessary repair work, and generate a variety of reports for use in bid document submittals. A GIS interface was also developed using Environmental Systems Research Institute (ESRI) ArcView^TM desktop GIS software to link repair information contained in the Access^TM database to corresponding map features. This interface was implemented as an ArcView^TM Extension and enables the system to symbolize damage extent and type for all sewer line and manhole defects. Recommended rehabilitation data related to each damaged line or manhole is also symbolized in the GIS environment. This data is completely integrated into the municipality's GIS. The SRDMS provides the end-user with digital mapping of problematic areas within a sewer pipe network, associated system repair activities, and the ability to output a series of reports detailing system damage, recommended remedial action, and cost estimations for the repair of damaged features.

The City of Greeley, Colorado is applying newly developed Geographic Information System (GIS) -based decision modeling capabilities to plan for the future of its water distribution facilities. This paper describes the City's use of a GIS model to identify critical locations where existing land development will hamper the future installation of new water distribution pipelines. The GIS model will serve as the City's primary tool for determination of suitable alignments for new pipelines and for timely acquisition of necessary easements.

A custom Web-based Geographic Information System (WebGIS) allows for the integration of the maintenance management system (MMS), engineering drawings and geographical information system (GIS) at the Vallejo Sanitation and Flood Control District. WebGIS allows all staff (including O&M, engineering, and management) to access District databases and maps of its sanitary sewer system using a web browser. Ultimately, the WebGIS may be available to the general public via the Internet and through s kiosk located at the District's headquarters. In addition, the architecture of the WebGIS has the flexibility to integrate with other databases and maps layers used by the District and the City such as billing databases and potable water and storm drain system maps. WebGIS developers collaborated with the District to understand business processes before development started (Figure 2). By integrating existing processes, the custom WebGIS compliment business practices without creating new work. The MMS is still run by the O&M staff, and the engineering department maintains records of improvements to the system. Now, however, the O&M and engineering staffs are working from a shared source of information that allows each of them to perform their functions more efficiently. WebGIS integration positions the District well for early compliance with portions of the proposed Capacity Management, Operations and Maintenance (CMOM) regulations. The system provides maps and asset/condition assessment data required by CMOM. GIS maps and databases might also be integrated with hydraulic model of the District's system. Engineering staff can visually identify areas subject to Sanitary Sewer Overflows (SSOs), frequent corrective maintenance, and odor complaints. Capital planning can then be targeted to maximize results.

Flow monitoring data is useful for more than billing, modeling, and developing I/I removal programs. Long-term and temporary flow monitoring data provides specific information about the capacity and performance of the collection system. When flow monitoring is appropriately targeted it can address many aspects of a comprehensive program like the EPA's Capacity, Management, and Operations and Maintenance (CMOM) program. This paper first describes what is required to develop an effective monitoring and reporting program. This paper then presents case studies of operational and maintenance issues identified through analysis of flow monitoring data. Silt and debris build-up in sanitary sewers can be identified with flow monitoring data and used to schedule cleaning and maintenance activities to proactively address these issues before the public is impacted. Vandalism, blockages, pump station failures, and illicit discharges are identified in flow monitoring case studies. Techniques for identifying and locating elusive sanitary sewer discharges from surcharged manholes are also presented in case studies. These techniques not only help in the documentation of a comprehensive O&M program but also provide the necessary proof of effectiveness for those programs. This paper also presents a capacity reporting system based on flow monitoring data. This reporting system evaluates key points within the collection system to determine if adequate capacity is available to convey normal and peak flows. This is a key directive within the CMOM program. Collection systems must be evaluated for existing capacity. Programs for improving efficiency and planning for future development must take the available capacity of the system into consideration. This capacity reporting system provides the essential evaluation of current capacity. It also provides proof of results for long-term rehabilitation programs.

Many sewer system managers today are faced with managing both their routine Sewer Maintenance Programs and comprehensive Infiltration/Inflow (I/I) Reduction Programs. As a result, enormous amounts of data are generated relative to these programs. Furthermore, there is a need to compile, process, and analyze an assortment of data related to these programs, and summarize the conditions of assets such as pipe and manholes. Investigation activities typically include cleaning, root cutting, televising, manhole inspections, smoke testing and building inspections. The impending program known as CMOM — Capacity, Management, Operation and Maintenance - will have far-ranging impacts upon sanitary sewer system owners and operators. Federal regulatory officials are developing regional response plans for sanitary sewer overflows (SSOs). The regional plans will include enforcement and compliance assistance targets. Region 4 of the U.S. Environmental Protection Agency (EPA) has already instituted a CMOM-Municipal Self-Audit Program as an initial step. In support of the ongoing need, we will discuss GIS based software designed to manage both Sewer Maintenance and I/I Reduction Programs. The asset management tool includes inventory, public system, private system, and reporting components. The program is useful primarily to sewer managers as a tool for managing day-to-day activities relating to sewer system tasks such as issuance of work orders and responding to customer complaints, but can also be utilized in conjunction with system modeling needs by engineers. Pipeline assessment is based upon a modified WRc-type rating system for categorizing the condition of sewers. Based upon the results of internal televisual inspection of sewers as part of routine annual maintenance or an I/I program, a grading system is applied for specific defects identified and an overall rating is applied to each sewer segment. Prioritized rehabilitation programs can then be implemented in a systematic fashion. Appropriate case study data will be presented as an example of specific communities implementing and utilizing a data management tool as part of daily sewer system activities.

Like many of the sanitary sewer systems in the United States, Churchill Borough had an aging sewer that was in generally poor condition. However, most of the systems in the Churchill's system was laid under and through abandoned mine drainage seeps and discharges. For a construction cost of $88,000, the Borough removed over 70,000 gallons per day of continuous infiltration.

This paper stresses the importance of sewer records, computer usage, communications and training to provide acceptable customer service and asset management for sanitary sewer systems. It also emphasizes the need for civil engineers to acquire knowledge pertaining to the maintenance, evaluation, rehabilitation and replacement of older sewer systems.

CONSOER TOWNSEND ENVIRODYNE ENGINEERS, INC. (CTE) was retained by the Erie Sewer Authority (Authority) of Erie, Pennsylvania to plan, design and provide construction management services for modifications to the 50 million gallons per day (mgd) annual average day flow Erie Wastewater Treatment Plant (WWTP). The project consists of headworks improvements, an overflow retention facility (ORF), a new parallel lake outfall, and ancillary modifications. The goal of the project is to maximize secondary treatment capacity at the WWTP during wet weather events. Achievement of the goal will provide significant water quality improvements to Presque Isle Bay in Lake Erie by eliminating wet weather plant bypasses and flooding. The secondary treatment capacity is 105 mgd. Flows above 105 mgd will be diverted to the ORF for storage and subsequent pump back to the WWTP when the wet weather event subsides. Flows in excess of the capacity of the ORF will overflow, be disinfected, mixed with the secondary effluent, and be discharged to Lake Erie via the existing outfall and the new parallel outfall. Malcolm Pirnie, Inc., as a subconsultant to CTE, is providing design services for the ORF facilities. Additionally, Malcolm Pirnie, with assistance from CTE, completed the Pennsylvania Act 537 Plan that serves as the planning document for the improvements described above. This article will focus on the detailed design of the new parallel lake outfall. This outfall, as will be discussed, was the first outfall in Pennsylvania to be reviewed and receive approval and permits under the Great Lakes Initiative (GLI) requirements. The project construction was completed in late 2000.

The Allegheny County Sanitary Authority (ALCOSAN) and its 83 service communities have a problem with their sewer infrastructure. The sewage collection systems need to be rehabilitated and regional measures must be taken to address wet-weather sewage overflows. The cost to achieve compliance with Clean Water Act and CSO Policy has been estimated at $3 billion under a Long Term Wet Weather Concept Control Plan developed by ALCOSAN. This concept plan was not well received by the Service Communities and a regional solution did not seem possible. The Regulatory Agencies needed to step in and facilitate a process to develop a Regional Long Term Control Plan that would be acceptable to all the various stakeholders in the region.

Nashville's sewer system consists of over 2,400 miles of sewer and includes over 42,000 sanitary sewer manholes. As in most cities, the trunk sewers lie along several tributary streams and rivers. Although the trunk sewers are subject to periodic inspection, manholes along the trunk sewer segments can often be damaged or covers removed because of wet weather or vandalism. The Department of Water and Sewerage Services has found water quality sample collection to be an invaluable source of information in their ongoing effort to ensure the sewer pipeline remains sealed to the fullest extent possible to prevent inflow as well as overflow. Water quality sample results can provide valuable information to "track" any possible sewer pipeline maintenance issues as well as other pollutant sources, such as illegal direct connections to the tributary streams.

The paper summarizes the technical and operating characteristics of seventeen trenchless construction methods and their subclasses. Information, compiled from industry surveys, expert opinions, analysis of over 40 case histories, and an extensive review of the technical literature, is divided into three categories: general information (summary of method; applications and cost range); performance parameters (installation parameters; accuracy and limitations); and constructability parameters (staging areas; potential for ground movement; short/long-term effects). The information presented can be used by pipeline designers and municipal engineers to perform preliminary screening of potential no-dig construction methods as well as to support the development of better estimating budget rules and project management practices. For researchers, the data can be used to support a "Method Database" for an automated decision support system for evaluation of competing underground construction methods.

Watertight pipe and structures have historically only been considered with sanitary systems. The cost, however, of construction, maintenance, roadway safety and stream and groundwater contamination have united previous construction industry adversaries. Federal, state and municipal agencies, contractors, pipe and precast concrete producers, and design engineers all want watertight storm drainage systems. The reasons may vary but their overall goal in the same. Government agencies are having significant problems with non-point stream pollution, groundwater contamination, and de-watering of wet lands via leaking storm drainage systems. These agencies are starting to institute regulations to address these problems with possible ramifications on project designs. State DOT's and municipalities are implementing new specifications to address the effects of underground structural failures related to the leaking and piping of backfill materials through open. Contractor's, for their part, are also investigating the cost savings associated with quicker and lower priced watertight construction techniques. The final advocating group, the concrete precaster, is arguing for the benefit of a higher precast quality watertight product, over cast-in-place structures, with no additional cost to the owner. Specific examples from federal agencies, DOT's and cities indicate there is an evolution to watertight storm drainage systems. Financial arguments from the consulting engineer's, contractor's and precaster's point of view demonstrate an alternate reasoning for this requirement. It appears we are on the crest of a new design philosophy regarding storm drainage systems.

Our underground piping infrastructure has done more to advance our health and quality of life than even modern medicine. The collection and containment of wastewater and the distribution and preservation of clean, potable water have been the primary means of preventing the spread of disease. In fact, the population concentrations necessary to fuel the industrial revolution would not have been sustainable without our modern plumbing systems. As one of the oldest and most vital portions of our modern infrastructure, it is unfortunate that our buried pipes tend to be "out of sight and out of mind." Pipes, like all structures, have limited design lives. A balance is understandably sought between initial construction and material costs versus the expected service life. The hostile sewage environment and occasionally aggressive soils tend to gradually corrode and degrade many of the widely available piping materials, thus limiting their service life to less than 100 years. In extremely aggressive environments, some piping materials have structurally deteriorated in less than 50 years. More commonly, the technological limitations of available jointing systems and inadequate workmanship during construction have reduced the functional service life of our buried piping systems. Favorably, technological advancements continue to improve the design understanding and the performance of our modern buried piping systems. Unfortunately, few notice as our older piping systems continue to deteriorate far beneath our feet. The health and environmental impacts generated by their deterioration, although significant, are gradual and almost imperceptible. Until documentation was required, how many agencies were really aware of the actual increase in the number of SSOs or the increased concentration of fecal coliform in the waterways? Fortunately, however, the proper functionality of our systems can be effectively extended with proper maintenance and cost-effectively restored through trenchless pipe renewal. Trenchless pipe renewal offers an affordable means of sealing and structurally renewing our buried piping systems, thereby ensuring their sustainability and protecting the quality of life to which mankind has become accustomed.

This presentation will trace the development of sewers from 3500 BC on through to the early 1900s. The early sewage infrastructure, which was almost always created primarily, and initially, for conveying stormwater away from populated areas, would evolve to early high point (of infrastructure, and manners) went downhill for the next 1600 years. With time and need, the early conveyance system became combined systems.

Conventional Horizontal Directional Drilling technology has reached serious limits vis-à-vis today's strict environmental regulations that impose a "zero" tolerance for drilling mud fracturing to the surface. An approach developed and patented nearly 25 years ago promises a viable solution by enhancing the ability to drill extended horizontal distances and in environmentally sensitive areas.

This paper summarizes published and unpublished work in the areas of design and construction, analysis and retrofitting, and security of pipeline suspension bridges in North America over the past 50 years. The published work of many prominent civil engineers and civil engineering researchers is discussed. The basic types of pipeline suspension bridges and articles that have been written on the design and construction of pipeline suspension bridges since 1952 are presented. The pipeline suspension bridge analyses that are described include wind and seismic analyses. The retrofitting methods presented include modifications made to pipeline suspension bridges to eliminate vertical wind oscillations and proposed retrofit methods for improving the earthquake performance of pipeline suspension bridges. The security measures used to restrict unauthorized access to pipeline suspension bridges are also discussed. Recommendations regarding the improvement of security for pipeline suspension bridges are also presented.

This paper presents the elements and findings of a study to establish the feasibility of renewal/renovation of about 63 km of freshwater and saltwater mains distributed across the whole New Territories in Hong Kong. The paper also provides an overview of trenchless rehabilitation techniques for water mains and presents the results of several pilot trenchless techniques which were executed to investigate their feasibility to Hong Kong conditions.

The current water supply network in the UK comprises over 372,000 km (233,000 miles) of mains pipes, delivering water directly to over 99% of households. The majority of the UK's water supply network is over 50 years old, with a significant percentage being more than 75 years old. For the past 10 years the UK Water Industry has invested massively to improve the condition and performance of the water network to meet increasing regulatory requirements and customer service expectations. This paper examines the drivers behind the water mains investment programme and reviews the various technologies that have been used to provide cost effective solutions for the different problems encountered. The paper concludes by describing new technologies that have recently been introduced on the UK water mains rehabilitation scene.

The new City of Ottawa, now composed of the Region of Ottawa-Carleton and 11 neighbouring communities has a water distribution system servicing a population base of over 750,000 people. The Region of Ottawa-Carleton had owned and operated the water distribution system in all 11 municipalities since 1969. The potable water systems inventory consists of approximately 2,500 km (1,600 miles) of watermains, 24,000 valves and 14,000 hydrants. The age of the system varies significantly from a very old system, dating back to the 1870s in the core area to relatively new piping in the communities of Kanata, Nepean and Gloucester. The replacement value of the potable system has been estimated to be in excess of $1.5 billion ($1 billion US). The new City's annual budget for conventional watermain replacement is approximately $40 million dollars ($26 million US). Through various methods of investigation, it has been noted that failure due to external corrosion is not as severe on the cast iron pipes. Nevertheless, as the older cast iron mains were unlined, the interior walls of the pipes have been subject to internal build up due to internal corrosion, known as tuberculation, which significantly reduces the hydraulic capacity of the watermains as well as creating "red" problems.

In the late 1940's the City of Los Angeles worked with Ameron to develop a plastic liner that could be installed in concrete sewers to protect them from corrosion. The result of this collaboration was the Ameron T-Lock product. One of the first City projects that used T-Lock to protect the concrete pipe was the La Cienega & San Fernando Valley Relief Sewer (LCSFVRS), which was constructed in 1953.

The behavior of a buried pipeline is significantly influenced by its interaction with the surrounding ground as well as the backfill material. The thrust force generated by the action of internal water pressure tends to move the bend of underground pipeline to the back side. This thrust force is supported by the passive soil pressure that affects the back ground. The concrete block is also used at the bend to minimize the thrust. There is a lack of study on the magnitude of passive soil pressure and distribution of a pipe bend. Such information are required for design. In the current design standard for irrigation pipeline in Japan, back passive soil pressure is assumed to increase in depth with a trapezoid distribution. In other words, when the bend is buried without the thrust block, a trapezoidal passive earth pressure is assumed by projecting it laterally. However, the earth pressure distribution is not readily known when the pipe moves laterally in the ground. In addition, it is not clear about the relationship between pipe intrusion resistance and the interface of the pipe and ground. In this paper, pit tests were conducted using a model pipe having a diameter of 260 mm that was equipped with 20 bi-axial load cells. In addition, similar tests were conducted using a plate with bi-axial load cells. As the pipe moved horizontally in the ground, the distribution of the back earth pressure acting on the bend and plate, and development of slip surface in the backfill sand were measured and investigated.

Nonlinear finite-element analysis is used to predict the performance of prestressed concrete pressure pipe with broken wires in a pipeline. A nonlinear finite-element model of the pipe is developed and subjected to combined effects of internal pressure, pipe and fluid weights and earth load as it loses prestress due to gradually increasing number of broken wires. The model incorporates a nonlinear stress-strain relationship for concrete that includes nonlinearities due to compressive crushing, tensile softening and cracking. The pipe model consists of shell elements with many integration points through the pipe wall to allow capturing of its non-linear behavior in pipe wall bending as the concrete cracks or crushes. The model first subjects the pipe to the combined effects of prestress pressure, pipe and fluid weights, earth load, and internal pressure, and then the prestressing is removed gradually. Analysis results show crack patterns, crack width, crack depth, pipe deflection, change in the stress in the wires, and concrete crushing as a function of prestress loss length. The results of analysis for a large diameter non-cylinder pipe with low internal pressure a fixed internal pressure and increasing prestress loss show that the final failure mode of the pipe is in fact in form of progression of wire breaks due to the increase in the stresses in the wires, rather than concrete crushing or major leakage. The results of analysis for a smaller diameter PCCP subjected to a prestress loss and increasing internal pressure show that interlocking strength of cracked outer core and steel cylinder ultimate strength, rather than progression of wire breakage, governs the strength of pipe. For pipe with large number of wire breaks, structural cracking can occur exposing the steel cylinder to corrosive soil environments. Corrosion of the steel cylinder can result in leakage and premature failure of the steel cylinder. The results of the nonlinear finite element analyses are used to validate engineering criteria and procedures used for risk analysis and repair priorities determination of pipes with broken wires and for comparison with confirmation testing of the pipe with broken wires.

Simplified equations to calculate deflections and circumferential strains in buried thermoplastic pipe have been developed for AASHTO based on soil-structure interaction solutions. These equations are evaluated here using measurements of HDPE and PVC pipe responses in full-scale laboratory tests. The comparison indicates that the equations are suitable design tools for standard flexible pipe installations. Structural stiffness of the pipes may have an influence on the performance of the deflection equation, since the method overestimated the deflections for a ribbed PVC pipe with high hoop stiffness. The methods for estimating hoop strain and vertical arching factor worked very well for both pipes, and the equation for bending strains provided somewhat conservative values. Recommended design values for constrained modulus of the soil lead to conservative but reasonable predictions in all cases.

Full-scale tests were conducted at the place of manufacture, during transportation to and at Rand Water's Brakfontein Reservoir site, to evaluate the behaviour of unstiffened and ring stiffened flexible steel pipe. These tests were conducted as part of the feasibility study into the preservation of quantity, quality and energy saving potential of water from the Lesotho Highlands Water Project. The pipes were 3 130-mm in diameter and 18-m long, one fabricated from 6-mm thick steel plate and fitted with fully welded trapezoidal ring stiffeners at 4.5-m centres, the other an unstiffened pipe with a 10-mm thick wall. Both pipes were protected externally with bitumen and fibreglass coating and internally with epoxy paint. Suitable instrumentation including a photogrammetry technique allowed a comprehensive comparison of pipe behaviour with pre-test predictions and allowed calibration of Rand Water's design approach to buckling. The handling tests included quarter and third point lifting and compared horizontal and vertical internal props in the unstiffened pipe with internal ring braces. The low stiffness and flexibility of the unstiffened pipe resulted in the pipe shell squaring and tenting over the horizontal and vertical props. Ring braces were chosen for the transportation and backfilling tests. Both pipes were installed on sandbags in 6-m deep trenches and soilcrete bedding was placed underneath them to provide a 90-degree angle of uniform support. The soil backfill on the sides and above each pipe was placed and compacted in layers to the specified densities before conducting live load testing with a tandem axle truck. Embankment soil layers were compacted above the pipes to induce buckling. A third trench was dug next to the buried unstiffened pipe and widened until the instrumentation installed around the pipe detected a loss of soil support. The paper discusses the costs of manufacture and installation of each type of pipe with reference to shape imperfections, buckling capacity, quality control and backfilling materials. The paper further describes a three stage approach developed by Rand Water over the years to prevent buckling of its large diameter flexible steel pipelines. It uses the empirically based European recommendations for the design of stiffened cylinders ECCS No. 56 : 1988, a finite element program based on CANDE-89 and the finite difference program BOSOR 4.

Full-scale buried pipe tests were conducted on two large diameter thin-walled steel pipes to evaluate pipe-soil interaction during backfilling and to determine pipe buckling strength. The full-scale buried pipe testing forms part of a study into the preservation of quantity, quality and energy saving potential of water from the Lesotho Highlands Water Project for supply of water to South Africa. Water is to be piped some 250 km from Lesotho to a point south of Johannesburg using two 3 130 mm O.D. thin-walled steel pipelines. Two prototype steel pipes of 3 130 mm O.D. were fabricated and tested. The stiffened steel pipe was externally fitted with fully welded trapezoidal stiffeners spaced at 4.5 m centres. The stiffener dimensions were 150 x 90 x 6 mm (top width x overall height x plate thickness). The stiffened pipe was manufactured from 6 mm thick steel plate. The plain wall unstiffened pipe was manufactured from 10 mm thick steel plate. The unstiffened steel pipe was temporarily stiffened with internal ring-braces to prevent excessive shape distortions during backfilling. The internal ring-braces were removed after 0.3 m of soil cover was placed. The plate thicknesses translate into pipe diameter-to-thickness ratios of 522 for the stiffened pipe and 313 for the unstiffened pipe. A total of three buried pipe tests were conducted and one adjacent trench was excavated to determine the minimum safe spacing between test trenches. Test 1 was conducted on the stiffened steel pipe. Test 2 was conducted on the unstiffened steel pipe. Test 4 was also conducted on the stiffened steel pipe although backfill material for this test was placed loosely. Test trenches were excavated in undisturbed in situ soil conditions. Both steel pipes were subjected to vehicular loading followed by earth loading to the maximum practical soil cover. For Test 1, earth loading continued up to 4.22 m of cover and was stopped because significant soil arching was occurring from the well compacted backfill material. The stiffened pipe was then uncovered and the backfill was replaced in a loose state (Test 4) to induce negative soil arching and therefore, increasing the soil loading on the pipe. Earth loading stopped at the maximum practical soil cover depth of 8.0 m. Signs of approaching buckling instability were noticed at this deep soil cover. Test 2 was stopped at a soil cover of 8.13 m. Pipe and soil behaviour were extensively monitored. Measurements were taken to assess stiffened and unstiffened pipe behaviour, soil behaviour and soil-pipe interaction during backfilling and during live load testing. Measurements were made of pipe shape, pipe and stiffener strains, pipe-soil interface pressures, soil density, soil stresses and soil penetration resistance. Pipe shape changes were measured with a custom built profilometer, while buckling deformations were measured by photogrammetry. All instrumentation performed as expected. The paper presents detailed testing procedures and selected results from the buried pipe tests.

The downtowns and business districts of the metropolitan areas are characterized by high-density population, soaring volume of electronic data transfer, congested underground space, and aesthetic paved or landscaped ground surface. In recent years, many of these communities installed fiber optic networks to supply the required broadband. Consequently, trenchless solutions were sought to provide economical construction methods that diminish disturbance to the community. HDD and in-sewer fiber installations provide economical trenchless solutions. The in-sewer fiber technology uses robots in no-man entry gravity sewers and drains to install fiber optic networks. University campuses share the same above characteristics of downtowns and business districts. The universities need to transfer high volume of data for education, research and development, and administrative activities. It is imperative that every classroom, lab, office, and dorm on the university campus has a fast Internet connection. Also many universities are converting to distance learning (teaching classes via the Internet). Economical and efficient communication between the universities and research institutions amplifies the return on the limited funds allocated for research and development. This study evaluates the hypothesis that trenchless installation of the fiber optic network is more beneficial than open cut installation on university campuses. In the last five years, many universities installed their fiber optic network using the open cut technique, which has caused numerous inconveniences to their campuses. Bowling Green State University (BGSU) just completed the Supernet project where BGSU replaced its old copper backbone and main rings with fiber optics cables. The study uses the BGSU campus as a guide to simulate an average size campus. The simulated model was used to quantify and estimate the cost of the HDD, in-sewer fiber, and open cut solutions and to discuss the advantage and disadvantage of each solution. The research indicates that trenchless techniques are viable alternative construction methods for installing fiber networks on university campus.

The increasing demand for high speed data communications and providing fiber optic network connectivity in inner city cores proved to be more challenging than previously though. Disruptive and expansive methods of digging up the streets and placing multiduct structure delayed many service providers in delivering their services to end users and created havoc in the cities. The sewer system has been designed and built as a network. Revolutionary idea to utilize that network, that is the most extensive open-access conduit network in any city, and place fiber optic cable attached to the top wall of the pipe started a new trend. This has become a preferred method of installations for cities that want to leverage their existing infrastructure, minimize disruptions and create additional revenue. Also, necessary maintenance, inspection and rehabilitation are done on behalf of telecoms further benefiting the owners of ROWs and sewer pipes. How it is done, technical challenges and solutions.

The Horizontal Directional Drilling (HDD) installation industry is one of the fastest growing industries in the North American underground construction sector, representing a commanding share of utility services installed in urbanized areas. The growing need for renewal of the buried municipal infrastructure in urban areas focused much attention on HDD as a technically viable and cost effective method for the installation of water distribution systems and pressurized sanitary sewers with minimum surface disturbance. Consequently, there is a growing need for a variety of pipe products that meet relevant AWWA and CSA standards and are suitable for installation using the HDD method. The paper describes the development and testing of a new restrained joint for rigid pipes that enables the installation of standard C-900 bell-and-spigot pipes using the HDD or Pipe Bursting (PB) construction methods. In particular, the paper will cover the design concept, and laboratory testing for tension and bending, finite element modeling of the new joint and the results of a full-scale field test. The latter involved the installation using a HDD rig of an 110m long, 100mm diameter, bell-and-spigot C-900 PVC pipe column that utilized the new restrained joint. The pull-head as well as the two leading joints were instrumented to measure the tensile and shear stains that developed in the pipe during the installation.

During the last ten years the advantages of CLSM-CDF as a structural backfill for flexible pipe were mentioned occasionally in technical publications. However, the use of CLSM-CDF is still not widespread in underground pipeline technology due to a lack of reliable technical data available to support the cited advantages of CLSM-CDF. A team at Ohio University recently completed a comprehensive research project on the application of CLSM-CDF as a pipe backfill. The project consisted of three phases: Phase 1 concentrating on laboratory characterization of CLSM-CDF, Phase 2 involving two field demonstration tests at the load frame site, and Phase 3 focusing on analytical predictions of HDPE pipe performance installed in CLSM-CDF. This technical paper summarizes the key findings made in Phases 2 and 3 of the Ohio University project. Overall, the project results showed that CLSM-CDF could be a high-quality backfill material for flexible pipe.

DOTs are interested in developing guidelines for use of large diameter corrugated HDPE pipe buried under roadways with shallow fill, but this application has not been studied extensively. A pooled fund study consisting of full-scale field tests and computer modeling has been initiated to address this matter. The objectives of the project are to improve understanding of the behavior of large diameter thermoplastic culverts under low fill heights, and develop design and installation procedures for inclusion in DOT and AASHTO specifications. The field tests are being conducted at the MnRoad Research Facility, which maintains a two-lane test road traversed only by test vehicles, a truck with a maximum axle load of 107 kN (24,000 lb) travels in one lane and a truck with 80 kN (18,000 lb) maximum axle load travels in the other. Ten 20 m (65 ft) runs of 1,500 mm (60 in.) diameter test pipe were installed. Test pipe consisted of eight runs of thermoplastic pipe, and one run each of reinforced concrete and corrugated steel pipe. Nominal installation depths were 0.3 m and 0.6 m (1 ft and 2 ft) to the top of pavement. Backfill materials were A-1 and A-2 soils per AASHTO M145. Backfill compaction effort was minimal. Pipes were instrumented with strain gages, displacement transducers, soil pressure cells, and thermocouples. All instruments are connected to dataloggers that are remotely accessed via an internet connection. This paper reports on the installation of the test pipe and early results on pipe performance. Deflections and strains are small. There has been some settlement in the backfill due to the low compaction levels.

The pipe autopsy confirmed that Remote Field Eddy Current/Transformer Coupling non-destructive testing of the pipeline is effective. Prior to the RFEC/TC test, the City had no reason to suspect the presence of highly distressed pipe at this location. The RFEC/TC test indicated the presence of a structurally significant number of broken wires (40 wraps), and while the actual number of breaks was 52, this discrepancy does not alter the overall effectiveness of the method. Confirmation of the effectiveness of this test method has served two important purposes.

Current design standards for concrete pipe bedding in Canada utilize the Indirect Design Method for the design of backfill and bedding. This approach does not fully account for the strength of the pipe and does not take into account the nature of the native soil, as every installation is considered to be the same. Consequently, the Indirect Design Method is overly conservative in many cases where the pipe is installed in competent ground and the anticipated level of live loads is minimal. The Standard Installation Direct Design (SIDD) system for design and installation of concrete pipes was developed through the American Concrete Pipe Association's (ACPA) long-term research program. The method takes into account the inherent strength of the concrete pipe as well as insitu soil conditions. The SIDD design minimizes the use of imported material while making maximum use of native soils. This paper describes the design, installation, long-term monitoring and Finite Element Modeling of full-scale SIDD Type 4 installations. Type 4 installations do not use any imported material and require minimal backfill compaction. Pipe diameter is selected to be 600mm with a burial depth of 1.8m. The test sections are located in heavy traffic areas and simulate the worse case scenario for pipe installation. The results from a 16-month monitoring period are reported and compared with predictions from the ASCE 15–93 specification, Marston-Spangler theory and two finite element analyses. It was concluded based on nearly 40,000 data points that the SIDD method illustrates well the stress envelope around a buried rigid pipe installed using the cut-and-cover construction method.

Internal sealing of large diameter pipelines to repair joint leaks has been utilized in municipal, industrial and power applications for over 25 years. This process consists of an ethylene propylene diene momomer (EPDM) rubber seal that is positioned over the affected area and is locked in place with two hydraulically expanded retaining bands, located at each end of the seal. Typically installations of internal seals have been limited to straight runs of pipe or in areas with minor offsets in radial configurations. However, field conditions have often identified that areas that are most vulnerable to deterioration are at tees and elbows. In general these type fittings are subject to flow induced turbulence, that result in accelerated erosion/corrosion and at a significantly greater deterioration rate than the remainder of the piping system. Recent developments in the internal sealing process have led to the creation of continuously formed seals for branch, tee and elbow configurations. In addition, specially designed seals have been installed in expansion joints in lieu of component replacement. These new type of seals are capable of providing a corrosion/erosion barrier with an operational life of 50 years and are installed in less than 24 hours with minimal impact on cost.

A condition assessment of the Muskegon County Wastewater Management System's 1676 mm (66 in.) diameter PCCP wastewater forcemain that failed 4 times since its installation in 1972, indicated that a 3.2 km (two-mile) long portion of a 17.7 km (11-mile) long pipeline had an unacceptably high risk of additional future failures. It was decided to replace the portion of the pipeline with the highest risk of failure and to monitor the remainder of the pipeline. The pipeline had no backup and its flow could not be interrupted or diverted to facilitate the construction and connection of the new portion of the pipeline. The transition from the old to new pipeline had to be accomplished with no spillage of sewage. This paper presents the pipeline replacement design process, including route selection, pipeline design, surge analysis and pressure monitoring, thrust restraint, corrosion protection design, and two 914 mm (36 in.) diameter live taps and 1676 mm (66 in.) diameter line stops designed to keep the pipeline in continuous service. The live tapping and line stopping required modification of equipment to accommodate defects in the cylinder and inner core and control of pressures produced by three pumping stations to minimize the risk of pipe rupture. The paper includes the owner's perspective on the design and construction processes.

This paper discuss the design criteria, tunneling method, social impact and construction utilizing the pilot tube microtunneling method of microtunneling in urban areas. The pilot tube microtunneling method is also known as guided boring.

Over the last decade, pneumatic pipe bursting has emerged as one of the most preferred environmental sensitive, trenchless pipeline and service line replacement methods. The success rate of pneumatic pipe bursting in challenging situations has also increased dramatically over the past few years. Much has been learned about the capabilities of the method as well as what is needed for the method to succeed under a wide range of conditions.

A parametric study is undertaken using axisymmetric cavity expansion theory to investigate the effect of soil parameters on ground movements in the vicinity of the static pipe bursting operations. Comparisons are made with experimental results reported by other workers, and these indicate that cavity expansion theory has the potential to be a valuable design tool. The parametric study shows that ground movements are controlled by soil strength and dilation angle, rather than the elastic soil properties.

Horizontal directional drilling (HDD) methods involve steerable tunneling systems for both small and large diameter lines. HDD is a two-stage process. The first stage consists of drilling a small diameter pilot hole along the desired centerline of a proposed line. The second stage consists of enlarging the pilot hole to the desired diameter to accommodate the utility line and pulling the utility line through the enlarged hole. The HDD methods have the ability to track the location of the drill bit and steer it during the drilling process. The result is a greater degree of precision in placing the utilities. HDD has traditionally been used for cable and pressure pipeline installations. In recent years, there have been innovative applications for HDD, such as, gravity pipe installations, pipe removal, pavement stabilization and environmental applications such as horizontal wells and gas extraction applications in sanitary landfills. Ground displacements and borehole stability are always of prime concern during HDD installations under pavements, in close proximity to existing buried utilities and structures. Stable boreholes also relate to successful completion of the projects. The Trenchless Research and Development Center (TRDC) at University of Missouri — Columbia, is conducting research concerning ground displacement monitoring and borehole stability in cooperation with Missouri Department of Transportation (MoDOT) and several industry participants. The objective of this research is to study the cavity expansion within the soil caused by the HDD process and to study the displacements of the soil in the vicinity of the cutterhead, reamer and at the ground surface.

The South Tahoe Public Utility District (District) in California owns and operates a mechanically complex, high-pressure, wastewater reclamation system in one of the most highly regulated regions in the United States. Working pressures in the force main range from 10.5 to 42.2 kgs/sq.cm. [150 to 600 pounds per square inch (psi)]. The District is now replacing deteriorated reaches of this 45-kilometer (28-mile) long pipeline. One reach involved the installation of a new 76.2-cm diameter [30-inch diameter (ID)] welded steel pipeline with 1.27-cm (1/2-inch) thick walls under environmentally sensitive Trout Creek and the associated meadow. Installation of the new pipeline using horizontal directional drilling (HDD) was the chosen method to satisfy agency environmental concerns. However, the District had experienced significant problems with the use of HDD in the past on much smaller diameter pipelines 25.4 cm through 45.7 cm (10 inch through 18 inch, ID) and had misgivings about using this method.

This paper presents the results of three field installations of high-density polyethylene (HDPE) using the Horizontal Directional Drilling (HDD) process. One each of 114 mm (4 in.) diameter standard dimension ratio (SDR) 17 HDPE pipe, 219 mm (8 in.) diameter SDR 17 HDPE pipe, and 324 mm (12 in.) diameter SDR 17 HDPE pipe were installed in a cohesionless soil medium. Various testing parameters were captured during the pullback phase of these three installations. These testing parameters consisted of utilizing pressure transducers to capture the pullback and rotational pressures on the drilling rig, linear potentiometers installed inside the HDPE pipe to measure the axial strain on the pipe, and the application of an external load cell to quantify the loading on the pipe during the pullback phase. Comparisons of the pullback and rotational pressure on the drilling rig, loading on the HDPE pipe, and average and maximum strain experienced by the HDPE pipe are presented with respect to the installed pipe diameter.