White Paper on Thrust Restraint Design of Buried Pipelines: Part 1—Current Practice

Abstract

The practice of thrust restraint design within the water/wastewater pipeline industry has continuously evolved over the years, benefiting from both theoretical and experimental research. Many of these research activities have primarily been originated by the pipe manufacturing industry, thus the research and the resulting practice changes have essentially been reflected in the design practice of these pipe materials. Widely varying material properties and joint configurations have made it difficult to have coordinated practice changes, which have resulted in a lack of consensus on a common design approach amongst different pipe materials. This results in not only significantly different guidance from AWWA design manuals for different pipe materials and agency requirements, but also widely varying design practices and company specific best practice approaches amongst the consulting engineering community. Recognizing the need to develop consensus amongst practicing engineers, the members of the ASCE Technical Committee on Pipeline Installation and Location have formed a special task committee "Thrust Restraint Design of Buried Pipelines" to prepare a white paper on the subject. The objective of this task committee in preparing this white paper is: 1) To document current design practices of thrust restraint systems for various pipe materials; and compare current practices with theory. 2) To document the historical evolutions of the different design approaches, collect and compile field tests completed for different pipe materials. 3) To explore improvements to current practice, develop consensus, and propose recommendations for the development of a manual of practice. Preliminary findings of this white paper are presented in a series of three companion papers: Part 1, Current Practice; Part 2, Historical Development; and Part 3, Roadmap for Unified Approach. This is the first paper presenting current practice. This paper documents the various methods currently used to calculate and mitigate thrust for common pipeline materials including concrete, ductile iron, fiberglass, polyvinyl chloride (PVC), polyethylene (PE), and Steel. Also, this paper utilizes the current design approaches to quantitatively summarize the similarities and differences in the thrust calculations for each material and provide tabular and graphical comparisons of each design approach.