EARTHQUAKE PERFORMANCE EVALUATION OF PVC PIPELINES WITH RESTRAINED JOINTS

Abstract

Full-scale test results to evaluate the earthquake performance of 6-in. (150-mm) PVC pipelines with restrained bell-and-spigot joints under water pressure of at least 80 psi (550 kPa) are summarized for material properties, axial joint tension and compression, four-point bending, and axial pullout and fault rupture in dense sand. Notable findings include the pipeline’s ability to compress axially through spigot penetration into adjoining bells, elongate axially through joint slip and pipe barrel extension, and joint deflection as high as 52 degrees. The compressive pipe joint axial stiffness is independent of loading rate for 1, 10, and 100 in./min. (25, 254, and 2540 mm/min., respectively). The pipeline was able to sustain 1.9% elongation during the fault rupture test, enough to accommodate the great majority (approximately 95%) of liquefaction-induced ground strains measured by high resolution LiDAR after each of four major earthquakes during the recent Canterbury Earthquake Sequence (CES) in Christchurch, NZ.