Pipelines 2020: Utility Engineering, Surveying, and Multidisciplinary Topics

Surge Control is vital to the design of water transmission systems. If surge control methods are not properly implemented, surge pressures can have devastating effects on pumps, valves, pipe fittings, or pipelines—sometimes causing line breaks and service interruptions. A hydraulic transient can be caused by any number of events that cause the flow in the pipeline to be disrupted, including starting and stopping of a pump, an instantaneous closure of a delivery valve or a power failure at a pump station. When a reflected surge wave reaches the pump station, it must be dissipated through some open flow path to a lower pressure region. Failure to dissipate this reflected surge wave will cause a sudden pressure rise, due to the conversion of kinetic energy to potential energy. If the momentum energy and pressure energy of the reflected wave is not relieved, high surge pressures will result. There are several accepted approaches to surge control in the water industry. Many pump stations rely on check valves to prevent water from back-flowing through the pump, requiring an open path through a surge anticipator valve, pressure relief valve, or a lateral to a surge accumulator tank to dissipate the energy. The purpose of this paper is to provide the background and details for a distinct surge control methodology developed by Logan Kerr, chairman of the ASME’s Hydraulic Division Water Hammer Committee from 1933 to 1956. This methodology was later adopted and put into practice by Lee Freese in the late 1960s and implemented on dozens of water transmission systems across Texas. The main difference in this surge control philosophy centers around allowing the water to backspin through the pump after a power failure and using an accumulator system to slowly close the pump control valve after several cycles of the surge wave have passed through the system. This paper will provide additional details of the surge control methodology and its key components.

An accurate estimation of energy losses caused by pipe friction is important for the analysis and design of forcemain systems. Friction losses in a forcemain are primarily dependent on the hydraulic roughness of the pipe; which is a function of the material, age, size, condition of the pipe, and characteristics of the wastewater. One of the most common approaches used to estimate the friction losses in a pipe is the Hazen Williams Equation, where the Hazen Williams roughness coefficient (C-Factor) is used to represent the roughness parameter and consequently friction losses. Therefore, appropriate selection of C-Factor is critical to hydraulic calculations of a pipeline, as it would impact pipe sizing and can have a significant impact on pump selection. As a best practice, most engineers consider a range of C-Factors in the hydraulic calculations, representing new and aged conditions of the pipe. Hydraulic analyses performed by the Author of more than 14 municipal wastewater forcemains located in the United States and other available literature determined that C-Factors from in-service forcemains are much lower than typical values used in practice. Approximately 60% of forcemain systems evaluated are operating at C factors less than 100. Results suggest that the wastewater slime layer affects forcemains in a similar manner regardless of pipe material. Nearly all lift station pumps evaluated were found to be operating to the left of the design point which increases operational costs due to longer pump run times at lower efficiency. In many cases the actual capacity of the lift station was found to be significantly less than the original design capacity. This paper will compare the actual C-Factors calculated from in-service forcemains to the C-Factors used in the original design and identify the increased energy consumption and operational costs resulting from underestimating friction losses (i.e., over-estimating C-Factors). In addition, the paper will provide recommendations to identify ranges of in-service C-Factor values and proper selection of C-Factors to be used for wastewater forcemain design.

Across the United States (U.S.), a large number of corrugated steel pipes, installed three or four decades ago, are approaching the end of their useful service life. However, information for minimum soil cover (less than or equal to three feet at the crown) and the applicability of previous methods to assess a pipe’s load rating factor is limited. To obtain such a load rating factor, measuring structural responses of several metal culvert structures in the field under in-service live loads during controlled load tests are required because neither Federal Highway Administration (FHWA) nor American Association of State Highway and Transportation Officials (AASHTO) has a comprehensive procedure on load rating of large-span culverts and multi-pipe system. In this study, a triple circular culvert was instrumented and tested under in-service live loads during controlled load tests to investigate the culver performance and calculated the pipes’ load rating factor. Because of the symmetry of the construction, only two pipes were instrumented with strain gauges and string potentiometers, the outside Pipe-1 and the center Pipe-2; Pipe-3 might react in a manner similar to Pipe-1. Eleven positions for static loading, where the positions indicated the location of the load from the tandem axle, which was heavier than the other axle, were applied to measure the strains and deflections and calculate the stresses, thrusts, and bending moments. For Pipe-1, the highest longitudinal strain recorded was 919 με located at gauge 1-3AL when the load was in Position 5. The maximum deflection was 0.395 in. recorded at location 4 when the load was in Position 3 (on the crown). The Pipe-2 of the culvert responded to the load with fewer strains, deflections, and thrusts/moments than Pipe-1 results except for transverse strain with 472 με located at gauge 2-2AT. The anecdotal field evidence of a load rating factor for cover less than minimum suggests a guide to stability design criteria for metal structures method proposed by ODOT is too conservative.

Large diameter pipelines in Japan are commonly buried in open-excavation using sheet piles because of the limited work sites and poor ground conditions. However sheet pile extraction is likely to cause significant damage to buried flexible pipes. In the Japanese current design guidelines for irrigation pipelines, influences of the sheet pile conditions have been ignored. In this study, model experiments were conducted to clarify the influences of ground density and sheet pile characteristics (the friction of the sheet pile, and the scale of the voids after sheet pile extraction) on the mechanical behavior of the buried pipes. Moreover, PIV (particle image velocimetry) analyses were carried out to evaluate the displacement of the backfill material around the pipe. The experimental results revealed that the deformation of the model pipe became large when the ground density decreased, and the sheet pile characteristics influenced the buried pipe during sheet pile extraction.

This paper provides a comparison of basic features of the three most popular numerical techniques that are utilized to solve differential equations, by computer software to conduct hydraulic surge analyses of liquid pipeline systems. These three numerical techniques are comprised of the method of characteristics (MOC), the wave method (WM), and the Galerkin method (GM). While MOC and WM are most popular for hydraulic transient analysis software utilized within the water industry, GM is most popular for hydraulic transient analysis software utilized within in the petroleum industry. However, surge analysis software based on GM can be used in the water industry as well.

With the rise in the intensity and frequency of extreme weather events, short- and long-term planning have become more necessary to enhance the capability of sanitary and combined sewer networks to cope with potential disruptions in their serviceability. Based on the previous reports and observations, separation of pipe joints, leaks, breaks, and collapses are among the most frequent failures in buried wastewater and storm water pipelines. Moreover, many cities experienced uprooting trees as a result of high winds during hurricanes and tornadoes, which caused damage to shallow buried sewer pipes. Besides the immediate consequences, extreme weather events may have long-term impacts such as formation of voids around the pipes, exacerbation of the structural integrity of corroded pipes, and acceleration of the degradation of pipes. These immediate and long-term consequences can lead to severe environmental issues, health problems, and economic losses. These consequences as well as critical factors such as aging, deterioration, and population growth highlight the need for enhancing the resilience of these infrastructure systems. In this study, a brief review of several case studies related to the resilience of existing and future sewer pipe networks is presented. Subsequently, a resilience assessment framework is proposed that consists of four models: (1) hazard models; (2) component and system fragility models; (3) response models; and (4) restoration models. This comprehensive framework can be used to analyze and enhance the resilience of sewer pipe networks in the face of extreme weather events.

For a slow valve closure, compression waves and reflection waves interact resulting in flow reduction and creation of a transient less than Joukowsky’s pressure. This phenomenon has not been accurately defined and described. This paper provides plots of dimensionless maximum transient pressures versus dimensionless valve closure times obtained from transient, parametric simulation results for four valve inherent characteristic curves that are quick open, linear, parabolic, and equal percentage. These results match the published experimental data. The plots showed that dimensionless maximum transient pressures are less than 1 if dimensionless valve closure times are larger than 3. The dimensionless maximum transient pressures are 0.5 (or half of the Joukowsky’s pressure) when the dimensionless valve closure times are 14 for the equal percentage curve, 22 for the parabolic curve, 70 for the linear curve, and 150 for the quick opening curve. The plots provide quick references how to reduce magnitudes of transient/surge pressures by designing valve closure times for a valve type in a given pipeline system.

The American Iron and Steel (AIS) provision, introduced in the consolidated appropriations act of 2014, requires clean water and drinking water state revolving fund (SRF) assistance recipients to use iron and steel products produced within the United States. This requirement applies to the construction, alteration, maintenance, or repair of public water systems or treatment works. To date, several thousand water infrastructure projects have successfully implemented the AIS requirement, and after conducting hundreds of informal site visits and trainings, the Environmental Protection Agency (EPA) understands that there continues to be unfamiliarity with the AIS requirement. This paper provides a brief overview of the AIS requirement as well as a discussion of the top things to know regarding compliance. The goal of this paper is to help those involved with SRF water infrastructure projects—state staff, assistance recipient personnel, consulting engineers, construction contractors, suppliers/distributors, and manufacturers—better understand and comply with the AIS requirement.

As infrastructure ages and projects become more complex, addressing the unknown variables of subsurface utilities is becoming ever more integral to project success. History has proven the value to a project for performing subsurface utility engineering (SUE) done in accordance with the ASCE 38 standard but this only provides the foundation, the base knowledge, and information, to build a robust utility management plan for an individual project assignment. This presentation will present practical tools and processes for outlining such a project specific utility management plan (UMP). Effective use of an UMP mitigates the unknown variables associated with subsurface utilities and allows for scoping early on in the project lifecycle to realistically identify costs and schedule impacts and facilitates a reasonable assessment of associated risks. Not dissimilar to Project Management Plans, Utility Management Plans are living, breathing documents that are started at the project planning phase and carry through to project completion. The UMP provides for a systematized approach to address all utility unknowns encountered in various phases from route assessment to design, through construction and into operations and maintenance. The elements of the UMP vary depending on project requirements and conditions but all are built on the premise of focusing the knowledge base of Utility Engineering into one unified document that is founded on a professional level of understanding of SUE, Utility Coordination, Condition Assessments, Land Survey, Project Management, and the fundamentals of utility design. Instrumental in the creation of an UMP is a solid understanding of the multitude of variables inherent to subsurface utilities and the impact that these variables may have on any given project or phase of a project. ASCE has published or is in the process of publishing standards that can aid in qualifying certain requirements that would be set forth in the UMP. These standards and how to effectively implement them on a UMP will be presented in this discussion as well. This presentation will take a deeper dive into the utility management life cycle in relation to the project lifecycle and provide the necessary guidelines for managing utilities and help define the concepts related to the Utility Management Process and its physical guidance document, the Utility Management Plan.

Owners, engineers, and operators that are involved with wastewater forcemain systems often neglect the importance and associated risks of intermediate high points. This paper outlines the hydraulic-related challenges with intermediate forcemain high points and provides examples of the full suite/range of typical design solutions that are often considered and/or employed during design. The potential solutions are discussed from the point of view of challenges and risks, with the ultimate conclusion being that intermediate forcemain high points are a significant design challenge that is often not solved in a clear or proven manner. Given that many wastewater forcemain systems with an intermediate high point experience operational challenges, the paper also presents an additional and seldom considered design alternative of inline booster pumping for wastewater. The paper outlines the benefits and risks of inline booster pumping and proceeds to present a case study for a conceptual wastewater forcemain system with four inline booster stations to address the associated high static head, long length, and challenging intermediate high points. The case study initially provides an example of the hydraulic-related differences between inline booster pumping and traditional design with wet wells, including pump selection and surge protection requirements. The paper then proceeds to demonstrate how proportional integral derivative (PID) control logic for inline booster systems can be optimized with hydraulic transient modelling of pump operation and flow control stability. Overall, the objectives of the paper are to re-emphasize the challenges with intermediate forcemain high points and to discuss the potential benefits and risks of inline booster pumping as to promote discussion.

Evaluation of pipeline infrastructure system resilience requires an understanding of pipeline risk of failure. Current methods for pipeline risk assessment are largely deterministic, and as such, do not explicitly represent the effect of uncertainties in the critical parameters. This limits the understanding of which parameters most significantly affect the accuracy and ability to quantify the confidence level of the produced outcomes. This paper presents a methodology to quantify the uncertainty on the risk assessment of structural systems. The methodology uses the separation of variables method, a systematic approach typically used in seismic fragility evaluation of nuclear facilities. The methodology is applied to two metal pipeline examples.

In large linear infrastructure projects under public private partnership (P3), one of the principal risk contributors are the subsurface utilities impacted that need to be either protected or relocated. In fact, utility relocation may be a significant factor in selecting a preferred construction methods or even dictating changes on design disciplines. The P3 model is designed share risk between private and public entities. This alternate delivery approaches have an accelerated nature with aggressive schedules, where minor utility conflicts can result in significant costs and schedule impacts. The utility coordination task is a key driver and sets the critical path on the schedule. Therefore, early engagement of utility agencies in the project will be crucial, even from the initial planning phase of the project. The use of Transportation Association of Canada (TAC) guidelines and utility relocation procedures are the key elements to a successful project win and delivery.

East Bay Municipal Utility District (District) has recently completed several challenging utility relocation projects for outside agencies with large roadway and transportation construction projects. From 2014 to 2019, the District has completed the planning, design, and construction inspection of three large utility relocation projects that were in various phases of construction within the same timelines. The projects include utility relocation for the: City of Oakland’s new 10th Street Bridge construction, AC Transit Bus Rapid Transit project, and Caltrans/ACTC Interstate 880 Improvements at 23rd and 29th Street in Oakland, California. Faced with a demanding workload of relocating miles of pipeline within a short timeline in a congested public right-of-way, the District utilized their Engineering, Construction, and O&M resources and experience to meet the challenges that lay ahead. This paper discusses the lessons learned in the planning, design, and construction phases of the project and the challenges and success in resolving operational constraints, permitting, installation challenges, and negotiating financial budget and agreements with multiple agencies.

Transient pressures can cause damage to force mains and pumping systems, leading to pump station down-time, sewage overflows, and costly repairs. In this case, the collection system owner detected that excessive surge pressures were occurring in a sewage force main system. The owner undertook a surge analysis study to determine the magnitude of surge pressures in the system, and to develop a solution for reducing surge pressures to acceptable levels. The surge analysis study included numerical modeling of the system and field measurements of transient pressures along the force main both before and after installing a surge tank at the pump station. This study provides convincing evidence for two conclusions relevant to managing transient pressures in pipeline systems: (1) numerical modeling can provide reliable data for sizing a surge tank to mitigate surge pressures, and (2) measured peak pressures may exceed modeling predictions by significant amounts when the system is subject to vaporous column separation. Modeling results will be most reliable when a surge mitigation strategy is in place that can fully prevent vaporous column separation within the system.

Current civil engineering practice bases planning, programming, and execution of projects to reduce sewer infiltration and inflow (I&I) levels on collection and analysis of flow rate, precipitation, and ground water level data in order to characterize the behavior of a sanitary sewer system flow as a function of rainfall. However, the cost of the installation of instrumentation and the collection of data for a period ranging from 4 to 6 months may constrain entities with limited resources from initiating and carrying out timely studies and effective remedial actions. This paper discusses how a public works operation, rather than wait until specific resources would be available for detailed flow monitoring, addressed the problem of limited resources by gathering and analyzing existing records of sanitary sewer flows and local precipitation as a preliminary method to: conduct an analysis of the effectivity of a current I&I reduction program; define and select the drainage area with the highest rate of I&I per inch of rainfall for further study; use an estimate of a range of acceptable levels of investment in I&I reduction, as a function of the expected percent of reduction, as a planning and programming tool.

Based on an internal energy concept an analytical approach is proposed to determine whether a pumped pipeline system needs surge protection during the loss of power to the pumping units and, if required, to calculate the additional energy that protects the system against the resulting transient pressures. The approach is then extended to calculate the required size of two conventional proactive surge control devices, air chambers, and flywheels. The accuracy of the proposed approach is then tested in the context of hypothetical examples with comparison to results obtained from a full transient analysis conducted using a numerical solution based on the method of characteristics (MOC). A very good agreement between the analytical and numerical results confirms the validity of the proposed energy approach.

A major challenge in water pipe infrastructure asset management is to determine the deterioration process for water pipes. The deterioration processes are usually modeled with a decay curve, which describes how pipe performance changes with time. Decay curves can also be used to predict the future performance of a water pipe. The methodology used to develop decay curves should be interpretable, reproducible, and validated. Many studies have been conducted to apply survival analysis to pipeline data, but most of the existing studies ignore the left-truncation problems in pipe break history records. Instead, in the modelling process they assume the first recorded failure to be the real first failure. This assumption leads to incorrect inferences and systematic biases by ignoring missing truncated failure records (i.e., breaks and leaks). In this paper, we summarize the identified major gaps and challenges when applying survival analysis to pipeline data by examining the published literature, practices, and the water pipeline break history data we collected from utilities across the U.S.

Numerous water sector management practitioners have stated an urgent need to have a unified platform for the nation’s water pipeline infrastructure data, information, and knowledge that is universally accessible and useful. Pipeline infrastructure database (PIPEiD) a web-based secured platform is envisioned to provide access to the data sources, tools, and models that enable the analysis and estimation of pipeline useful life based on materials and environmental factors and ability to model risk and life-cycle economic analysis for renewal decisions. PIPEiD a web-based secured platform is envisioned to provide access to the data sources, tools, and models that enable the analysis and estimation of pipeline useful life based on materials and environmental factors and ability to model performance, risk, and life-cycle economic analysis for renewal decisions. The research presents the descriptive data analyses methodology for the water pipe field performance data obtained from around 500 water utilities in the United States. The analyses are categorized into material distribution, failure distribution and trends, and performance analysis. Various exploratory and statistical techniques have been employed to represent the data and analyze deeper relationships within the data and pipeline infrastructure systems. The research team has also conducted extensive literature and practice reviews along with interviews with asset managers in water utilities to formulate a list of hypotheses which are essential to verify and validate the mathematical models. The paper will provide robust data structure, centralized database, and model-driven methodologies to benefit water utility, researchers, and water pipeline infrastructure industry. Also, it will provide extensive capabilities in multi-system and multi-scale data analytics for advanced water pipeline data management techniques, statistical analysis, advanced mathematical methods, and machine learning algorithms for water pipeline performance prediction and estimating useful life.

Water utilities are finding it more cost-effective to practice a risk-based and data-driven proactive renewal planning to avoid extra costs from reactive repair and replacement. Risk is a function of the likelihood of failure (LoF) and the consequence of failure (CoF). This study conducted a comprehensive review of past studies on CoF and risk matrix, from both literature and practice to develop a better methodology for assessing CoF and developing risk matrix. The proposed CoF model enhances the triple-bottom line parameters and includes operational intelligence and renewal complexity in assessing CoF. Therefore, the model can overcome the limitation in the previous studies that considered only direct costs of a water pipeline failure. The proposed model develops a fuzzy inference system (FIS) to model system parameter interdependencies using IF-ELSE rules and incorporate heuristic knowledge in a “White-Box” approach, which is better than previous weighted approaches. The fuzzy logic approach is chosen due to better interpretability by decision-makers and the ability to capture water pipeline system uncertainty. This study also presents the limitations of traditional risk matrices developed previously and methods to overcome those limitations. The model and matrix will be verified and validated with multiple water utility datasets to check their robustness and accuracy in real-world conditions.

Fuzzy logic model or fuzzy inference system is effective in modeling heuristic expert knowledge which is delivered as inexact statements with uncertainty, ambiguity, and even contradictions. Compared with other statistical or machine learning models, fuzzy logic model has great advantages in the interpretability and transparency as it directly mimics the human thought process. Because the previous fuzzy inference models existing in literature were mainly limited in metallic water pipes, this paper extends the fuzzy logic performance rating system to incorporate not only metallic but also cementitious and plastic pipes. A comprehensive list of variables from various sources are compiled and incorporated. The implementation procedures are discussed in detail, and the model outputs are checked and verified as intuitive.

Water utilities are facing increasing costs associated with the management and renewal of the water pipelines. A water pipeline goes through various costs during its lifecycle and hence it becomes important to perform lifecycle economic costs analysis before choosing the water pipeline material for replacement. However, water pipeline materials vary in performance in different environmental conditions and hence the lifecycle costs can vary in different environmental conditions. This study focuses on developing a performance-based water pipeline lifecycle cost analysis model to help in replacement decisions. Different scenarios have been developed based on the varying performance of different pipeline materials in different ecological cohorts and the lifecycle costs will be compared in those scenarios to present as alternatives to help in replacement decision making for water utilities. The proposed model will be more comprehensive, in terms of parameters included to more accurately reflect the lifecycle costs associated with different scenarios and materials. Different approaches will be explored to capture parameters affecting lifecycle costs comprehensively along with the uncertainties in the lifecycle cost assessment process.

Infiltration and inflow (I/I) are common problems in sanitary sewer systems. While inflow typically gets most of the attention in wet weather, groundwater infiltration can also be a big problem in dry weather, silently stealing sewer capacity 24 hours per day, 7 days per week, 365 days per year. Groundwater infiltration cannot be measured directly but is often estimated from sewer flow monitor data using a variety of empirical methods. The authors provide an overview and comparison of four methods, including the % minimum method, the wastewater production method, the Stevens-Schutzbach method, and the Mitchell method. Examples of each method are provided using actual flow monitor data to further explore the performance of these methods and provide guidelines for proper application.

Over the past years, there has been a sustained interest in developing machine learning (ML) models that are sophisticated enough to capture the failure trends of water distribution systems and that are able to predict future breaks of the pipeline system. Given the limited budgetary resources of water pipeline owners, coupled with the deteriorated state of water networks, there is a vital need to deploy such tools to prioritize inspection and replacement of vulnerable regions, as well as to mitigate the chance of having catastrophic failures within the system. This study extends several ML algorithms that analyze the historical failures of water pipelines, with the goal to predict future breaks. The performance of each algorithm has been examined using various water networks as different case studies with varying network size and configurations. The developed models are all aimed to estimate the future likelihood of pipe failure by exploring historical failure patterns, surrounding attributes (e.g., environmental and demographic), as well as pipe characteristics. To improve the predictive power of the learning algorithms, several engineered features have been also created from raw data and tested to facilitate the learning process of each algorithm. While developing such models is by no means an insignificant task, an equally, if not more important emphasis should be put on how precisely these models are predicting actual failures. Additionally, the model variables should be defined wisely enough to ensure the uniqueness of each network has been captured and incorporated into the analysis. Lastly, it is crucial to evaluate the precision of the developed predictive models to evaluate the level of reliability a utility can expect by deploying it, as well as the further improvement needs of the predictive algorithm itself. Accordingly, this paper will review the analyses performed, the outcomes of this study, and discuss plans to improve upon the analyses to ensure that maximum usefulness of the model can be achieved.

This paper presents results from an “Internet of Things” leak detection technology that remotely and non-invasively monitors pipelines at the scale of a distribution network. Findings are presented from the deployment of 10,000+ acoustic leak detection nodes with dozens of utility partners. The design and installation of the nodes, the type of data collected, and the approach to data analysis is outlined. A series of case studies are described where the technology has found leaks that failed to surface: large or significant leaks, leaks that were difficult to pinpoint, and unexpected signals found in the process. Both the data analysis and utility perspectives are shown, comparing remotely collected acoustic data to observations from field technicians. The successes and limitations of the technology are both discussed.

The City of Stillwater (City) has experienced explosive growth in the southwest portion of the City’s service area. The service area includes a wide range of development, from areas within the City to a large portion of City owned rural service areas and wholesale customers. This growth combined with prolonged drought led to operational water pressures of 6 pounds per square inch (psi) at customer meters during peak demands of 2011. This area of the city includes more than 9 square miles of land and six different pressure zones due to significant changes in terrain. The City envisioned a delivery program, “Water 2040,” to not only deliver water supply at the required pressure to meet current demands, but also to address the needs of customers through the year 2040. The City’s multiple objectives and constraints were established as: (1) ensure minimum pressure of 45 psi at all locations from 2015 through 2040; (2) limit phasing to $30 million (M) per loan to satisfy a Trust Indenture Limitation, with projected total program cost of $93.2 M; (3) maintain water quality throughout all phases; (4) incorporate risk and resiliency planning while limiting oversizing; (5) meet average day, maximum day, and fire flow (where applicable) requirements; (6) increase system storage from 0.5 million gallons (MG) to 2.5 MG; (7) meet Oklahoma Department of Environmental Quality (DEQ) consent order deadlines for water pressure improvements and unpermitted facilities. To identify the optimal approach for efficiently delivering the Water 2040 Program, the City incorporated all of the objectives and constraints into a decision matrix that was fueled by hydraulic modeling and prioritization. The City identified the phasing and has successfully constructed 3 pump stations, 9 miles of pipe, and 2 elevated water storage tanks to meet the goals of the Water 2040 Program. The program will continue to deliver an additional 7 mi of pipe and a new water treatment plant (WTP) finished water pump station.

Thousands of miles of pipe serve the Houston metropolitan area to millions of customers. As Houston has faced a number of challenges, pipeline management requirements tend to exceed available resources. Therefore, the City has implemented a risk-based decision strategy to assure maximum effectiveness of resources and be resilient to ever changing community needs. The City leverages multiple smart technologies providing near real-time data streams to an enterprise communication platform conveying information to City management. This presentation will provide both quantitative and qualitative insight into applied technology in response to this year’s ASCE pipelines conference theme: Resiliency in infrastructure.

The use of artificial intelligence (AI) is rapidly penetrating the water industry in several key areas including main break prediction. With sufficient quality data, AI can find patterns of pipe failures and accurately predict the likelihood of failure (i.e., main breaks) in the near future. As time passes, AI software continues to learn from data to predict future events and more data is added from multiple sources. This offers a powerful way to find solutions to the challenge of mitigating pipe failures and maximizing remaining pipe life. AI is an affordable, effective, and accurate way to assess pipes to monitor, repair, or replace. This paper will highlight elements of the process and then discuss how the findings can not only make the machine smarter but the operators as well. The process includes gathering data and improving data quality to make AI most effective. It will describe the processes of machine learning. It will describe how using likelihood of failure (LoF) can be overlaid with consequence of failure (CoF) to help make better asset management decisions about pipes in the system based on risk. Utilities have an increasing number of ways to manage assets. These include inspection, leakage monitoring, condition assessment, and an array of renewal options. A probability analysis enables prioritization that can avoid catastrophic breaks and premature replacement. This paper will highlight elements of the process and then discuss how the findings can not only make the machine smarter but the operators as well. The process includes gathering data and improving data quality to make AI most effective. It will describe the processes of machine learning. It will describe how using likelihood of failure (LoF) can be overlaid with consequence of failure (CoF) to help make better asset management decisions about pipes in the system based on risk. Utilities have an increasing number of ways to manage assets. These include inspection, leakage monitoring, condition assessment, and an array of renewal options. A probability analysis enables prioritization that can avoid catastrophic breaks and premature replacement.

Welded lap joints are commonly used in large-diameter steel pipelines for water transmission. Their structural performance constitutes a key consideration for safeguarding pipeline integrity with no loss of pressure containment, required after a severe seismic or geohazard event. Full-scale experiments are presented, which are part of an extensive ongoing project related to structural performance of welded lap joints under severe ground-induced (seismic) actions. The paper describes a series of large-scale physical experiments on 24-in. diameter steel pipes with welded lap joints subjected to axial compression and tension. The axial loading experiments under consideration complement the series of large-scale bending tests performed in 2017, and presented in the ASCE 2018 Pipelines Conference (paper entitled: “Experimental Results of Steel Lap Welded Joints in Seismic Conditions”, authored by Keil et al.). The specimens tested under axial loading are first pressurized to 40% of yield pressure, and subsequently subjected to large amount of compression or tension. Measurements of the axial load, characteristic displacements, and local strains at the joint area have been obtained. All specimens exhibited the capability of sustaining high axial loads with significant axial deformation, without loss of pressure containment. In support of the above experiments, advanced finite element models have also been developed, for the purpose of simulating the experiments and elucidating some pertinent topics on the structural response of welded lap joint behavior. The results of the present study demonstrate the remarkable strength and deformation capacity of lap welded joints under consideration, supporting the argument that those joints can be used in steel pipelines crossing seismic and geohazard areas, where severe and permanent ground-induced actions are expected.

Located in North Texas, this project required navigation through over 20 mi of sloping 72-in. raw water prestressed concrete cylinder pipe to install internal bonding wires at each joint. The work required demolition and removal of the 2.5-in. of interior concrete to expose the steel cylinder and spigot ring of the pipe, installation of three bond wires across each joint via thermite welding, application of coating to the wires and welds with 100% volume solids epoxy, testing electrical resistance, and grouting the concrete cutout. The 72-in. diameter pipeline provides raw water for treatment and distribution to 1.7 million people, as well as water required at a local power generation plant, so project timelines were extremely tight. The total project consisted of approximately 4,325 joints, requiring approximately 13,000 bond wires, 26,000 thermite welds, cases of epoxy and pallets of cement and sand, and it was all completed in 44 working days.

The mechanical performance of lap welded joints is essential for safeguarding the structural integrity of steel water pipelines, after a severe earthquake or other geohazard loadings. Over the past 4 years, an extensive experimental project was launched to determine the structural performance of lap welded joints under the most severe ground deformations. The research consisted of full-scale physical experiments, supported, and validated by rigorous numerical finite element simulations. The experimental results have indicated a remarkable strength and deformation capacity of the standard lap welded joints without loss of water containment. In addition questions related to local lap weld joint deformation were elucidated and the corresponding strains developed under extreme tensile or compressive loads at critical locations were quantified, demonstrating the ability of those joints to sustain a significant amount of local strain at critical locations. The latest phase of the research focuses on the behavior, analysis, and design of a new seismic resistant lap welded joint. Results of a series of additional full-scale experiments, supported by finite element numerical simulations, on the mechanical performance of the new lap welded joints under severe structural (axial and bending) loading conditions are presented herein. The new lap weld joint comprises the standard lap weld configuration but contains a small geometric projection introduced at a specific location near the field applied fillet weld. Based on current research results, a modification of the standard lap welded joint is proven to result in consistent buckling of the steel pipe cylinder and not the lap weld joint, during severe or extreme loading. The proposed joint, referred to as “Atlas Seismic Resilient or ATLAS SR-joint”, effectively allows steel pipe to not be limited by the capacity of the standard lap welded joint during strong seismic or geohazard events, and offers an efficient, reliable, yet economical solution for welded joints in steel water pipelines in geohazard areas.

The Second Edition of AWWA Manual M55 PE Pipe—Design and Installation is expected to be published in late 2020. In this edition, there are significant updates to the design and installation recommendations that users of HDPE water pipe should be aware of. For design, the new manual will include PE4710 compounds that have been added in the ANSI/AWWA C901 and C906 standards. Design updates also include higher E’ (modulus of soil reaction) values, use of composite E’ values, use of uniform soil classes, and terminology. For installation, M55 contains revised information on trench width, flowable fill, inspection and soil testing, and compaction requirements. These changes reflect the recent revisions to ASTM D2774 Standard Practice for Underground Installation of Thermoplastic Pressure Piping> The second edition of M55 encourages the use of basic installation and engineered installation. The basic installation is for HDPE pipe stiff enough to not need special bedding and embedment, for shallow burial with no live load, and for stable trench wall support. In this case, the HDPE pipe can be laid on the trench bottom and backfilled with soil from the excavation. This covers the majority of HDPE pressure pipe installations. For other conditions, the engineered installation means selecting an HDPE pipe and corresponding installation details to meet deflection and buckling requirements. In addition, the second edition of M55 has a new chapter describing trenchless technology and has new appendices on model specifications, seismic performance, marine applications, case studies, and PE4710 pipe data. This paper will focus on HDPE external load design and commensurate installations.

Underground thermal distribution pipelines are common at institutional facilities where thermal energy is generated at a central utility plant and is distributed to various buildings (otherwise known as district energy or district heating and cooling). Chilled water, hot water, or steam is created and distributed through a network of underground pipelines to provide building heating or cooling. The high range of pressures, temperatures, fluid properties, and other design considerations observed in these underground thermal piping systems can present many technical challenges. There are many factors to consider in selecting and specifying the appropriate underground thermal piping system including service pipe material, insulation material and thickness, corrosion protection and jacket material, expansion and contraction considerations, field-insulated versus factory-insulated, and constructability/cost considerations.

This paper describes how the hazard resilient ductile iron pipe (HRDIP) withstood permanent ground deformation caused by natural hazard. The HRDIP was mainly targeting developed performance under earthquake-induced ground deformations in Japan and have been no documented failure in the event of big earthquakes for 45 years. Also, HRDIP had no failure under other ground deformation natural hazards such as landslide, ground subsidence, and tsunami. We investigated the behavior of the pipelines in landslide area caused by heavy rain, and tsunami-stricken areas caused by 2011 Great East Japan Earthquake. The results concluded that HRDIP accommodated to the ground deformation caused by the landslide and tsunami because of the pipe's joint flexibility and pull out resistance. In addition, in tsunami-stricken area, it seemed that exposed pipeline and debris clashed against each other from the tsunami. This confirmed that the ductile iron pipe has enough strength which endures clash of debris and loaded stress on pipe by debris.

This paper provides the background for a new method in fatigue life calculations for polyvinyl chloride (PVC) pipe developed by Utah State University that is simple to use and is the recommended practice by the PVC pipe association. Design engineers must select an appropriate pipe wall thickness (or DR) that will accommodate both maximum pressure and repeated surge pressure events. Methods for assessing the number of cycles to failure have been developed for PVC pipe over the past 50 years. The AWWA C900-16 standard has a procedure in appendix B for assessing the number of cycles to failure for PVC pipe, which is based off of testing done at Utah State University’s Buried Structures Laboratory in 2004 and additional research prior to that. The current approach requires input of a mean stress and a stress amplitude and typically requires a root finding approach to calculate a number of cycles to failure. Experience has shown that this method can be difficult and time-consuming for most design engineers to use. This paper looks at a new method that will be used as a design standard in North America to calculate fatigue life in PVC pipes subjected to repeated pressure surge events.

This paper reviews the water main break research and findings from Utah State University, Purdue University, Louisiana Tech, which have formed the new foundation to help utilities to better understand what future trends of water main breaks may look like nationally. International main break data from Australia is also available to be used to contrast results from the U.S. The next generation of water main pipe performance research will include advanced analytics and predictive analysis using machine learning taking into consideration hundreds of potential pipe performance variables such as climate and environmental corrosive soil variables. Private digital pipe condition assessment firms are amassing huge predictive data sets not based in survey results but GIS main break files. Another effort includes the development of national pipe inventory and pipe performance database called the PipeID project at Virginia Tech. This federally funded project while offering direct benefits to over 500 participating water utilities can also provide regional insight to utilities and the aggregate data will be used for federal policy making on regarding water pipe performance standards.

As the world is moving to provide a better and cleaner environment for future generations, there is a critical need to reduce the environmental emissions footprints. Underground utility installation, especially in the development of residential communities in the urban area, is one of the largest construction projects across North America and, consequently, one primary source of emissions. This study focused on optimization of the CO₂ emissions during the life cycle of one of the commonly used pipe materials: pre-stressed concrete cylinder pipe (PCCP). The study focused on a large-diameter 36-in. sewer pressure pipe operating at 100 psi internal pressure for 100-years life operation. The study compared and analyzed the CO₂ emissions during fabrication, operation, and disposal phases for PCCP pipe, and give recommendations to how to reduce the CO₂ emissions during the life-cycle of the pipe. The results of the study show that the CO₂ has been reduced by 75% on the fabrication phase, 7% on the operation phase, and by 43% on the disposal phase of PCCP.

For pressure pipe applications, the American Water Works Association (AWWA) publishes manuals that provide design and installation guidelines for PVC, HDPE, fiberglass, steel, ductile iron, and concrete pipe. Unfortunately, there is little uniformity in these manuals for flexible pipe design and installation and that creates uncertainty, confusion, and wasted time. Consistency and simplicity will promote practices that will result in better pipeline projects and save money. While based on the early theoretical and empirical basis as presented by Merlin Spangler, and later modified by his student Reynold Watkins in the modified Iowa equation, the method of calculating deflection of flexible pipe has evolved somewhat independently for the different pipe types. As a result, representatives for each type of pipe material developed different guidelines specific to that pipe which then made their way into the various AWWA manuals. Consequently, this has resulted in nonuniformities that include varying schools of thought on the factors that affect E’, differences in E’ values, use of the deflection lag factor, D_L, differences in basic terminology, use of the constrained soil modulus, M_s, acceptance or rejection of composite E’, and use of multiple classification systems for the same soil types. Pertaining to installation, the differences include trench section terminology, trench widths, and bedding thicknesses. This paper will provide an in-depth review and comparison of buried flexible pipe design and installation as addressed in each of the AWWA manuals of water supply practice for the six previously mentioned pipe materials: M23 (PVC), M55 (HDPE), M45 (GFRP), M41 (DIP), M11 (steel), and M9 (Bar-wrapped CCP). Revisions to create uniformity and consistency in the manuals are suggested. A single manual dedicated to external load design and installation may be a solution. It could then be referenced in the current manuals.

Showing utilities in three-dimensional (3D) models has helped provide designers with valuable information on how to clear utility conflicts in transportation projects. Placing the realistic image of a utility feature into a 3D model helps provide scope detail for a replace in-kind relocation and what details need to be considered to clear a utility conflict. This helps to avoid schedule delays and/or scope misunderstanding that could lead to unforeseen utility relocation costs and overruns.

As part of the Metro Vancouver (MV) Annacis Island Wastewater Treatment Plant (AIWWTP) expansion, two new Gravity Thickeners are to be designed and constructed. The area of this planned construction is in an older area of the plant and understanding of the presence and position of underground utilities and other features here is incomplete. Surveys with electromagnetic-based (EM) technology (e.g., Ground Penetrating Radar or GPR) have been unsuccessful due to soil conditions at the plant. Brown and Caldwell utilized an emerging acoustic technology, developed by Cartacoustics, LLC, to detect, locate, and map the position of underground utilities and other features in the area of the planned construction. These results will be included in design and construction efforts and will help prevent unwanted strikes and costly change orders.

Aging stormwater infrastructure is one of the biggest challenges facing communities today. With portions of the City of San Antonio’s (City’s) stormwater collection system approaching 100 years old, a comprehensive understanding of the condition and location of the existing system was needed. This paper will provide an overview of the multi-year Stormwater System Televising, Mapping, and Condition Assessment project initiated by the City in 2015; the Stormwater CCTV Master Plan development; and information about technologies used to complete the project, including: (1) mobile LiDAR for above ground survey; and (2) InfoMaster Sewer to transform the asset condition data and defect codes into GIS, conduct the system defect analysis, and develop a City-wide CCTV Master Plan for San Antonio This 6-year project provided a procedure to accurately inventory the system and understand the condition of the assets. The use of these advanced data collection and analysis technologies made it possible to complete the project according to the accelerated timeline and provided the City with detailed and useful data deliverables.

The collection and depiction of comprehensive and accurate information about subsurface utilities’ locations and attributes—also referred to as utility surveying—has been a priority in the planning, design and monitoring of construction projects for many years. Where internationally comparable utility surveying standards have established (e.g., the British PAS 128, the American ASCE 38-02, the Australian AS 5488, and the Malaysian Standard Guideline for Underground Utility Mapping), this has not occurred in the Netherlands. Given the lack of a utility surveying standard, this study examines how the Dutch utility surveying practice is arranged, specifically looking at the localization of utilities prior to excavation works. Our findings show that the Netherlands primarily benefits from utility plans, verified trough trial trenches, while seemingly neglecting the commissioning of geophysical methods. This practice mainly originates from the availability of a regulated central utility data-exchange platform and the obligation by law to precisely determine the location of utilities prior to excavation. After qualitatively comparing the Dutch utility surveying practice with the practices as outlined by the international utility surveying standards, we argue that two fundamental differences may provide lessons for both the Dutch and international surveying practices. In specific, Dutch practice may learn from international practices that geophysical detection methods provide a complementary means to reduce excavation risk besides utility plans and trial trenches, whereas the international context, in turn, may learn that having a regulated central utility data-exchange platform helps to enhance the availability of utility plans.

Quality site survey data is a key component to all water and wastewater design projects, which can become quite costly and time consuming as the scale of the project increases. For Alliance Regional Water Authority’s (Alliance Water) phase 1B program, which includes approximately 90 mi of water transmission lines, aerial surveying is a great fit to achieve cost savings and reduce schedule risk. For the treated pipeline segment A of the phase 1B system, which consists of approximately 17 mi of 48-in. water line, a fixed wing aerial survey is performed in conjunction with traditional surveying methods to optimize efficiency. Various aerial surveying vehicles are discussed in addition to available instrumentation that can be utilized for data collection.

Thousands of damages to underground utilities, including gas, water, and sewer, occur every year. Damages to underground utilities have a significant impact on national and local growth, as well as citizens’ wellbeing. It is crucial to reduce damages to underground utilities. Currently, damage prevention effort consists of three-steps: (1) construction firms must contact state notification centers (one-call centers); which in turn (2) notify utility owners who must locate their utilities on the ground; and (3) construction firms (i.e., excavators) must respect marks and exercise care around marked utilities while excavating. This study investigates the perspectives of utility locators regarding current practices. Among other findings, the study reveals that the lack of clear communication between locators and excavators negatively impacts the current damage prevention process. The findings will contribute to better damage prevention processes and a lower number of strikes to underground utilities.

The Northeast Transmission Line is a joint project between the City of Houston and several major regional water authorities. It is a series of 120- and 108-in. water transmission lines, with 96, 84, 66, and 54-in interconnections which will convey water from the currently expanding Northeast water purification plant across the north of the City and to the wider region. Although the waterline will be buried, it still provides ample opportunity for the use of drones during construction. They have been used to capture preconstruction conditions, to track construction progress, and to document milestone steps in the construction progress. Additionally, drones have been utilized by the City to document existing conditions at two of its main repump facilities in order to provide useful training and reference tools to plant staff.

It is well recognized that utility conflicts pose one of the top risks on complex infrastructure projects. Subsurface utility engineering (SUE) is often used as part of the design process to provide utility coordinators and design engineers with valuable data needed to complete project designs. That same SUE data can also be used by other disciplines on the project. The geotechnical team is one of those disciplines that can use SUE data to improve the efficiency and effectiveness of the geotechnical programs. This paper will explore the use of SUE on large infrastructure projects and identify how it can be integrated into other disciplines focusing on the geotechnical inspection program and generation of the geotechnical baseline report (GBR). Ontario has been a leader in the use of private public partnership (PPP) projects and has made use the use SUE as standard practice at the preliminary design stage of most large projects funded by the government. Megaproject, the Hamilton LRT will be used as an example of how SUE data was used on a large-scale urban PPP project.