Evaluation of polyethylene pipe–sandy soil interaction subjected to strike-slip faulting

Abstract

Pipelines are simulated in the form of a continuous beam resting on a collection of linear springs. The relationships put forth by the American Society of Civil Engineers (ASCE) guidelines are commonly used to derive the specifications of the spring elements. Some recent studies have suggested that these relationships are accompanied by a certain degree of inaccuracy. In this study, two full-scale tests were carried out on polyethylene pipes (with diameters of 120.5 and 214 mm) buried in sandy soil. The displacement of the pipe along its length was recorded throughout the entire test. Then, using the Abaqus finite-element software package and an optimisation algorithm developed in the Matlab software, a modelling approach was adopted so that the properties of the equivalent linear springs simulating the soil could be determined. In this way, the displacements obtained from the experiments would have the highest level of congruence with the values derived from the numerical simulations. Using this approach, the initial stiffness and the maximum force resulting from the pipe–soil interaction were computed and compared with the values given by the ASCE and American Lifelines Alliance (ALA) guidelines. The results showed that for a polyethylene pipe at the condition of strike-slip faulting, these values were much smaller than the values put forth by ASCE and ALA.