Experimental study on gasketed bell-and-spigot joint behaviour of lined-corrugated HDPE pipe subjected to normal fault

Although the structural response of pipelines has been studied in relation to different geohazards, few studies have focused on the behaviour of flexible pipeline joints. In this paper, the response of a bell-and-spigot joint in a 600 mm dia. lined-corrugated high-density polyethylene (HDPE) pipe was investigated under differential ground movements imposed using a facility that simulates a normal fault. Two experiments were undertaken in this facility. In the first experiment, the kinematic responses of the pipe joint (i.e. axial, shear displacements and rotational angles) were measured using particle image velocimetry and string potentiometers. Strains were also monitored using optical fibres. In the second experiment, the pipe was sealed and leakage of the joint was captured through monitoring the internal vacuum pressure of the pipe. The results show that axial shortening, rotational angle and shear displacement of the pipe joint increased with increasing fault offsets. The joint began to leak when axial shortening, rotational angle and shear displacement of the pipe joint were 0·65 mm, 0·44° and 3·40 mm, respectively, and the joint clearly lost its functionality when those values reached 0·85 mm, 0·58° and 4·32 mm.