Pipelines are vulnerable to earthquakeshaking (ground motion) and permanentground deformation (PGD) resulting fromliquefaction landslide and fault movement.Pipe performance during an earthquakedepends on four parameters: ruggedness,resistance to bending, joint flexibility, andjoint restraint. Pipe materials are rated inthis article for each of these parameters tohelp utilities select the appropriate pipe forthe job. New pipelines installed in regionswith high seismic activity should use continuousor restrained-joint pipe, includingsteel pipe with welded joints, high-densitypolyethylene pipe with fused joints, orductile-iron pipe with restrained joints.These guidelines are applicable to pipelinesinstalled in both competent soils (i.e., thosecapable of providing competent foundationperformance) and soils subject to PGD.Additional mitigation measures are recommendedfor critical pipelines. In regionswith moderate seismic activity, pipe withsegmented joints such as ductile iron andpolyvinyl chloride, can be used in competentsoils, but in soils subject to PGD continuousor restrained-joint pipe similar tothat used in areas of high seismicity shouldbe used.For existing systems, replacement ofexisting pipe is not cost-effective based onearthquake vulnerability alone, unless thepipe is critical for maintaining systemoperation. Vulnerable pipe should bereplaced over the long-term, with prioritizationbased on both seismic vulnerabilityand other asset management parameters.In the short-term, system owners shouldfocus on system control and emergencyresponse mitigation approaches.Includes 12 references, tables, figure.
