New Technical Guide Helps Engineers Design HDPE Water Mains for Seismic Fault Crossings
Key Highlights
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New engineering guide details HDPE water main design for seismic fault crossing hazards
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38-page technical publication includes formulas, calculations and charts for pipeline wall thickness requirements
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Free resource for engineers and utilities, developed by the Municipal Advisory Board and Plastics Pipe Institute
IRVING, TX — The HDPE Municipal Advisory Board (MAB) has released a new technical document outlining design requirements for high-density polyethylene (HDPE) water mains crossing seismic faults. The 38-page publication, MAB-10 2025: Design of HDPE Water Mains for Crossing Seismic Hazard, provides formulas, calculations, charts and analysis describing how pipelines respond to strike-slip seismic events.
The document complements the previously released MAB-9: Design of HDPE Water Mains for the Lateral Spread Seismic Hazard, with both publications available free through the Plastics Pipe Institute website.
Engineering Guidance for Seismic Pipeline Design
“As requested by multiple owners and consultants, the Municipal Advisory Board developed this document to assist in the design of HDPE for the expected fault crossing seismic event,” stated Camille George Rubeiz, P.E., F. ASCE, Co-Chair, HDPE Municipal Advisory Board, and Vice President for the Municipal & Industrial Division of the Plastics Pipe Institute.
The MAB serves as an independent, non-commercial adviser to the Municipal & Industrial Division of the Plastics Pipe Institute, the major North American trade association representing the plastic pipe industry.
“In MAB-10 2025, simple relations are developed for the required wall thickness for an HDPE water main subject to the fault crossing seismic hazard,” he continued.
Understanding Seismic Hazards Affecting Buried Pipelines
According to the report, two primary seismic hazards affect buried pipelines: wave propagation (WP) and permanent ground deformation (PGD). The fault crossing hazard described in MAB-10 focuses on conditions where ground movement directly affects a pipeline.
Design requirements outlined in the report show that wall thickness is influenced by site conditions such as burial depth and soil unit weight, as well as the allowable pipe strain and geometric characteristics of the fault. These include the amount of fault displacement and the angle at which the pipeline crosses the fault.
HDPE Pipe Performance and Installation Advantages
HDPE pipe is often selected for water infrastructure in challenging conditions due to its flexibility and ductility. Heat-fused pipe sections create a leak-free, monolithic pipeline that can better accommodate ground movement compared with rigid pipe materials.
The material also resists corrosion and is not subject to tuberculation, helping maintain long-term water flow capacity. HDPE water mains can be installed using a range of trenchless and open-cut construction methods, providing flexibility for municipal infrastructure projects.
Industry Collaboration in Developing the Guide
Development of MAB-10 involved a volunteer task force of engineers, utility professionals, contractors and industry specialists. The effort was led by Michael O’Rourke, Professor Emeritus of Civil Engineering at Rensselaer Polytechnic Institute.
The publication is intended to provide engineers, utilities and infrastructure planners with practical guidance for designing HDPE pipelines capable of withstanding seismic fault crossing hazards.
MAB-10 plus other documents can be found at www.plasticpipe.org/MABpub.