August 2021 Vol.76 No. 8

Features

CUIRE Completes NCHRP Pool-Funded Project on Structural Design for Spray-Applied Pipe Liners

In April, the Center for Underground Infrastructure Research and Education (CUIRE) submitted the final report, fact sheet and design worksheet to Ohio Department of Transportation (Ohio DOT) project leader and six other Departments of Transportation (DOTs) including Delaware, Florida, Minnesota, North Carolina, New York and Pennsylvania. In addition, Dr. Mo Najafi, CUIRE director, made a national webinar to all state DOTs on the project findings. 

FIGURE 1. Macro-fibers used in concrete linings: (a) polypropylene fibers, (b) fiberglass, (c) polyolefin fibers, and (d) steel fibers.

The primary objective of this research project was to develop design equations and performance specifications for structural renewal of gravity stormwater conveyance culverts using spray-applied pipe linings for both cementitious and resin-based materials, and for circular and non-circular (arch) shapes. The developed design equations utilized loading as detailed in the AASHTO’s Load and Resistance Factor Design (LRFD)-Bridge Design Specifications, and will be applicable for round and arch shapes up to 120-inch diameter or span. 

FIGURE 2. Micro-fibers used in concrete linings: (a) acrylic fiber, (b) alkali resistant (AR) glass fiber, (c) PVA fiber, and (d) alkali resistant glass scrim. 

As illustrated in below sections, to achieve the objectives of this research project, 12 tasks were defined to provide essential components for different aspects of the objectives to prepare design equations and performance specifications. 

Survey of U.S. DOTs, Canadian Transportation Agencies 

A survey of U.S. DOTs and Canadian Transportation Agencies was conducted to identify advantages and limitations of sprayed-applied pipe liners (SAPLs). The survey sought DOT experiences in three stages of planning and design: pre-installation, during the installation, and after installation was completed. This survey was beneficial to identify the gap in the knowledge and identified the following: 

  • Which DOTs used or planned to use SAPLs
  • Design procedure
  • Existing SAPL specifications
  • Applicability of SAPLs for culvert renewal
  • Environmental and host culvert requirements for SAPL application.

 

A literature review was conducted to utilize findings of previous researchers and to identify gaps in the knowledge that previous researchers had confronted. The literature review provided significant understanding of the subject matter, through assessment of the past research projects, to develop research needs for this project. 

Additional reinforcement 

To evaluate structural application, first the SAPL material should be assessed to see if it is capable to structurally resist all the applied loads. Then, if needed, applicability of using reinforcements can be considered to further increase the mechanical properties of SAPL material. FIGURES 1 and 2 illustrate different types of macro-fiber and micro-fiber reinforcements that potentially can be used. 

Evaluation of need to till valleys of corrugated pipes 

FIGURE 3. Two common SAPL installation methods: (a) following and (b) filling the corrugation pattern. 

In absence of previous standard guidelines for application of SAPLs on CMPs, the objective of this task was to investigate two different installation approaches (filling corrugations or not filling corrugations) to come up with a preferred installation method. This task was accomplished by consideration of hydraulic and structural effects of each installation method. FIGURE 3 illustrates two common SAPL installation methods on inner surface of corrugated metal pipes. 

Comparison of construction, environmental cost of SAPL with CIPP, slip lining 

FIGURE 4. (a) and (b). Some samples of SAPL installation issues. 

The life-cycle cost of a project includes direct and indirect cost of construction, social and environmental costs, as well as planning, design, operation and maintenance costs. The construction and environmental cost analysis performed in this task evaluated construction as well environmental cost of SAPL, cured-in-place pipe (CIPP) and sliplining installations. This comparison can be useful during planning and design phase of a culvert renewal to select a method with lowest construction and environmental costs. 

Review of the CIPP design equations 

To evaluate all the parameters needed for development of new design equations, it was crucial to investigate applicability of current design methodologies to SAPLs, mainly CIPP (ASTM F1216 design Appendix X1). 

Additionally, this task included consideration of WRc Sewerage Rehabilitation Manual, the German Static Calculation for the Rehabilitation of Drains and Sewers Using Lining and Assembly Procedures (ATV-DVWK-M 127 E, Part 2), and the ASTEE 3R2014 Structural Design for Non-Circular Linings under Groundwater Pressure, as well as pending ASCE Manual of Practice for the Design of Flexible Liners (currently in press). 

SAPL field inspection and data collection 

In addition to property of material, performance of any trenchless renewal method and specifically SAPLs, is dependent on the quality of installation. Appropriately designed and properly installed liner systems will generally perform well throughout their design life. 

FIGURE 5. Design equation development methodology. 

Proactive maintenance strategies can be scheduled based on the structural condition and performance assessments of the existing structures through the field inspection and collected data. To identify the most common issues with SAPL installations, a comprehensive field inspection program was prepared and conducted. 

The objective of this task was to collect data through in-situ inspections of past SAPL projects. This information was used to prepare performance specifications and to identify and categorize installation issues. The data collected through this task will improve design and installation of future SAPL projects. FIGURE 4 (A and B) illustrates some samples of SAPL installation issues. 

Development of structural design equations 

This task produced design equations for both polymeric and cementitious types of SAPLs using data and information from other tasks of this project, mainly finite element modeling (FEM) and soil box testing. The equations addressed both circular and arch geometries. 

FIGURE 6. Finite element modeling of the soil box testing. 

When first existing design methods were evaluated and analyzed for their applicability to SAPLs, design loading, per AASHTO’s Load and Resistance Factor Design (LRFD) Bridge Design Specifications was used. Then limitations with existing design equations were considered and design thickness results were compared with the data obtained from the numerical and experimental studies. 

Once the applicable equation was identified, it was further calibrated using regression curves to conform with test results. FIGURE 5 illustrates the design equation development methodology. 

Performance construction specifications 

In the absence of standard installation guidelines, this task investigated and prepared performance construction specifications based on the outcomes of the previous tasks to ensure structural integrity of the SAPL is not jeopardized due to faulty installation. 

Finite element modeling of renewed corrugated metal pipes 

FIGURE 7. The CMPs’ burial configuration (control test set): (a) plan view, (b) profile view of the aligned CMPs in the soil box, and (c) cross sectional view of both circular and CMP arch samples. 

This task included preparation of finite element modelling (FEM) and simulation of the soil box test results for other similar conditions. Once the FEM models were validated with the results of the soil box, different conditions and situations were simulated, which were not considered in the soil box testing. ABAQUS was used to perform FEM simulations and analyses. 

The simulations included three CMP pipes without linings, three invert-removed circular CMP lined with a SAPL, and three invert-removed arch CMP lined with a SAPL. The three CMP pipes without linings are one bare intact circular CMP, one bare invert-cut circular CMP, and one bare invert-cut arch CMP. 

These three bare CMP pipes were used as the control tests to provide baseline results of the CMP pipes before lining. The FEM results simulated other conditions that were not considered during soil box testing FIGURE 6. illustrates finite element modeling of the soil box testing. 

Laboratory testing 

The laboratory testing of this study was designed to include both structural and material evaluations. The tests were conducted at the CUIRE laboratory facility located at the University of Texas at Arlington. The soil box is equipped with a 330-kips MTS actuator installed on a steel reaction frame designed for this type of experimental project. The material testing program included results of tensile and flexural resistance evaluations of polymer, as well as compressive and flexural strength of cementitious SAPLs. 

As stated previously, the experimental structural testing program consisted of five sets of full-scale laboratory tests, including (1) control test, (2) circular CMPs renewed with polymeric SAPL, (3) CMP arch pipes renewed with polymeric SAPL, (4) circular CMPs renewed with cementitious SAPL, and (5) CMP arch pipes renewed with cementitious SAPL. 

FIGURE 8. (a) The 330-kip actuator used for this project and (b) SAPL installed for testing as well (c) a sample of Digital Image Correlation (DIC). 

The control test consisted of one intact circular CMP, one invert-cut circular CMP, and one invert cut CMP arch. The SAPL liner thickness for the polymeric circular and arch pipe samples was 0.25, 0.5, and 1-in. The circular and CMP arch cementitious SAPL test series consisted of three separate invert-cut CMP samples each, renewed with 1, 2, and 3-in. thick cementitious SAPL. 

To acquire the structural capacity of  
the SAPLs, the invert section of the  
CMPs were cut and detached after backfilling. Therefore, no ring compression existed in the CMP sample and the load was resisted by the SAPL only. The soil-pipe structure was subjected to statistical vertical load, applied at the soil surface, simulating a truck load. 

The outcomes of the soil box testing can reveal the true renewed pipe-soil structural capacity and failure modes, which were crucial for design equation development. FIGURE 7 illustrates  
CUIRE soil box testing setups. 

FIGURE 8 illustrates the 330-kip actuator used for this project and SAPL installed for testing as well a sample of Digital Image Correlation (DIC). 

The full report, fact sheet, and the presentation files are available for download on the Ohio DOT’s website at https://lnkd.in/gZaV2R7 or https://tinyurl.com/kb8apcrs. 

 

CUIRE Industry Advisory Board 

Abu Abraham, P.E. 

Director of Engineering 

Insituform Technologies, LLC 

Robert A. Carpenter 

Editor-in-Chief 

Underground Construction/UCT 

Bruce Hollands 

Uni-Bell PVC Pipe Association 

Aaron Houming Ni 

Asoe Hose Manufacturing Inc. 

Julia J. Hunt, P.E. 

Formerly Assistant Regional Manager/Operations Trinity River Authority of Texas 

Bruce Jameson 

Regional Manager 

Ace Pipe Cleaning, Inc. 

Dr. Jey K. Jeyapalan, P.E. 

President 

Civic Enterprises, LLC 

Therese R. Kline, P.E. 

Flexible Pipe Specialist 

Michigan Department of Transportation 

David Marshall, P.E. 

Former Director of Engineering and Operations Support 

Tarrant Regional Water District 

Lynn Osborn, P.E. 

Principal 

LEO Consulting, LLC 

Camille George Rubeiz, P.E. 

Director of Engineering 

Plastic Pipe Institute 

Jim Rush 

Editor 

Benjamin Media Inc. (Trenchless Technology) 

Dr. Larry Slavin 

Principal 

Outside Plant Consulting Services, Inc. 

Dr. Niranjan Swarup 

Director General 

Indian Society for Trenchless Technology (IndSTT) 

Richard Williammee Jr., P.E. 

Formerly Materials Engineer Fort Worth District 

Texas Department of Transportation 

Sanaz Ghalambor 

Polymer Engineer | MBA | VP of Specifications  
and Testing 

Nukote Coating Systems International, LLC 

 

CUIRE Names New Program Manager 

Roz Javadi Zadeh joined CUIRE as a Program Manager and Graduate Research Assistant in January. She has a bachelor’s in civil engineering degree from Isfahan Azad University in Iran and is currently working on her master’s in construction management at UTA. 

Before joining CUIRE, Zadeh had more than five years of work experience in the field of construction, as sales and trade manager, quality control specialist and laboratory technician. In a short time since joining CUIRE, she has excelled at managing conferences and workshops, and working with CUIRE members and other graduate students to conduct research and testing at the CUIRE laboratory. 

She is president of the North American Society for Trenchless Technology-UTA Student Chapter and a student member of the American Society of Civil Engineers (ASCE). She can be reached at (817) 272-9177 or cuire@uta.edu 

 

Recent CUIRE Graduates 

Dr. Amin Darabnoush Tehrani graduated in August 2020. He is currently a project manager at ASFI Construction (Sanger, Texas) and a Post-Doctoral Research Associate at the CUIRE. He is experienced in development, structural testing, evaluation, and design of pipes and their rehabilitation using Spray Applied Pipe Liners (SAPL). He served as a Co-Principal Investigator (CO-PI) of multiple funded research studies and is a voting member of multiple technical committees, including AWWA’s M28, M81, and M77, as well as ASCE’s Younger Member Engagement Committee (YMEC). Dr. Darabnoush Tehrani has co-authored more than 18 peer-reviewed journal and conference papers. He is a recipient of the International Society for Trenchless Technology’s (ISTT’s) Academy Award in 2019 for his endeavors in SAPL structural design development. 

Ukendran Gopi graduated in May 2021 with a master’s in Construction Management. As a graduate research assistant, he worked at CUIRE on the SAPL project conducting testing operations. He is currently a construction estimator at Bluenative Landscape and Irrigation, Key West, Fla. 

Dr. Vinayak “Vinny” Kaushal, PACP, M. ASCE, graduated in Summer 2019 with his Ph.D. in civil engineering and a focus on construction engineering. He is currently an assistant professor of instruction in the civil engineering (CE) department at the University of Texas at Arlington (UTA). Dr. Kaushal conducts trenchless technology research and has previously served as a post-doctoral research associate and an adjunct professor at CUIRE and UTA. 

Dr. Zahra Kohankar Kouchesfehani graduated in August 2020 with a Ph.D. in civil engineering, focused in Construction Engineering. She currently serves as an Engineer at Hazen and Sawyer, Dallas, Texas, and is an active member of ASCE, NASTT and American Water Works Association (AWWA) Standard Committees. She serves as the Chair of the Publications Subcommittee of AWWA’s Water Main Condition Assessment Committee. Her expertise is trenchless technology, pipe rehabilitation, inspection, and condition assessment. She has co-authored more than 18 peer-reviewed journal and conference papers. In 2019 she received the International Society for Trenchless Technology’s (ISTT’s) Academy Award for her role in SAPL structural design methodology development. For this award, Dr. Kohankar Kouchesfehani was recognized by ISTT as an expert who has made exceptional contributions to trenchless technology. 

Dr. Reza Malek graduated in July 2019 with a Ph.D. in Civil Engineering and a focus in Construction Engineering. He has been with Plummer Associate Inc., (Fort Worth, Texas) as an Engineer in Training III on the Water Planning team since October 2019. He has been involved in several projects such as, Texas Regional Water Planning; TMCRWS (Ten Mile Creek Regional Wastewater System) Corrosion Management Plan; Fort Worth and North Texas Industrial, Commercial, Institutional (ICI) Program Implementation; and North Texas Municipal Water District (NTMWD)-Long Range Water Supply Plan. 

Suhas Patil received a master’s oinConstruction Management at the University of Texas at Arlington in May 2021. During his graduate studies, he worked as a Graduate Research Assistant on several research projects at CUIRE and served as president of the NASTT Student Chapter at UTA. He is currently working as a project engineer at Stacy and Witbeck constructing a transit station in Salt Lake City, Utah. 

Dr. Ramtin Serajiantehrani graduated with a Ph.D. in civil engineering (construction engineering) in December 2019. He works as a project manager/estimator at Reyes Group Ltd., in Dallas, Texas. Earlier he served as an adjunct professor and a post-doctoral research associate at CUIRE. He has published more than 20 papers in high-impact factor journal and conference proceedings and is involved in industry research projects on underground utility and infrastructure, water technology, wastewater treatment, stormwater management, pipelines, and trenchless technology methods. A member of ASCE and NASTT, he is a reviewer of several journals, including ASCE’s Journal of Pipeline Systems-Engineering and Practice and Journal of Performance of Constructed Facilities. 

Dr. Amir Tabesh, P.E., graduated in 2018 with a Ph.D. in civil engineering (construction engineering) and, since then, has been working with DAL-TECH Engineering in Dallas, Texas. He received his professional engineering license last April and was promoted to an engineering manager position. Currently, he is working on his MBA at the University of North Texas and is expected to graduate in Summer 2022.   

 

CUIRE Holds 19th Annual Certification Schools at UCT 

The 19th Annual Trenchless Technology Certification Schools were held on Monday and Tuesday, July 12–13, 2021, at Music City Center, Nashville, Tenn., in conjunction with the Underground Construction Technology (UCT) International Conference & Exhibition. 

This year’s program included three, full-day courses: Advanced Horizontal Directional Drilling School, Geotechnical Schools for Pipelines and Trenchless Technology, and Pipe School, as well half-day Pilot Tube and Microtunneling School and Spray Applied Pipe Lining (SAPL) School – offered for the first time and was well-attended. 

More than 50 professionals and graduate students attended these courses, which were taught by expert instructors from industry with at least 20 years of experience working in the trenchless technology field. 

Attendees received a complimentary copy of Trenchless Technology: Planning, Equipment and Methods, up to 1.2 CEUs and 12 PDHs, and a PDF copy of all presentations. 

 

CUIRE Schools’ Speakers Information 

Advanced Horizontal Directional Drilling Schools 

  • Jeff Puckett, P.E., President, J.D. Hair & Associates, Inc.
  • AbhinavHuli, Senior Technical Specialist, Haley & Aldrich, Inc.
  • Mike Whitehouse, Technical Sales/Fabrication Specialist, ISCO Industries, Inc.
  • Marv Klein, Vermeer Corporation
  • Peyton Boyle, Vermeer Corporation
  • Michelle L. Macauley, PE, LEG, President and Principal Engineer, Macauley
  • Mark Gallucci, Customer Insight, Digital Control Incorporated

Geotechnical Schools for Pipelines and Trenchless Technology 

  • TennysonMuindi, P.E., McMillen Jacobs Associates
  • Nicholas H.Strater, P.G., Brierley Associates Corporation

Pipe Schools 

  • JeffBoschert, P.E., National Clay Pipe Institute
  • Rich Mielke, P.E., Northwest Pipe
  • Al Hogan, P.E., American Concrete Pipe Association
  • Paul H. Hanson, P.E., DIPRA Regional Director
  • Camille GeorgeRubeiz, P.E., Plastic Pipe Institute
  • AmsterHoward, P.E., Consultant
  • Shah Rahman, MBA, Practice Leader – North Texas, KCI Technologies Inc.
  • GabrielCastelblanco, P.E., HOBAS Pipe USA

Pilot Tube and Microtunneling School 

  • Troy Stokes,Akkerman, Inc.
  • JeffBoschert, National Clay Pipe Institute

Spray Applied Pipe Lining (SAPL) School 

  • SanazGhalambor, Polymer Engineer,Nukote Coating Systems International 
  • Dr. MoEhsani, P.E., SE,QuakeWrap Inc. 
  • MarioTamezJr., Standard Cement 
  • Dr. Amin Tehrani, CUIRE/UTA – ASFI Construction
  • Dr. Zahra (Ellie)Kohankar, CUIRE/UTA–Hazen and Sawyer
  • Chip Johnson, P.E., Director, Technical Services

CURE Exhibit Booth at UCT 

On Tuesday through Thursday July 13–15, the CUIRE research team had a booth at the UCT Exhibition Hall to introduce latest testing and development at CUIRE, such as structural design methodology for Spray Applied Pipe Liners (SAPLs) in gravity storm water conveyance conduits and pressure pipe applications through soil-box testing and finite element modeling (FEM). 

CUIRE will continue its educational schools next year in January 2022 in Fort Worth, Texas in conjunction with the next UCT. For more information call CUIRE at 817-272-9177 or email cuire@uta.edu or visit www.cuire.org.

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