New method to evaluate the polyethylene pipe-sandy soil interaction subjected to strike-slip faulting

Pipelines are simulated in the form of a continuous beam resting on a collection of linear springs. The relationships put forth by the ASCE standard are commonly used to derive the specifications of the spring elements. Some recent studies have suggested that these relationships are accompanied by certain degree of inaccuracy. In this study, two full-scale tests were carried out on polyethylene pipes buried in sandy soil (with 120.5 and 214 mm of diameter). The pipe’s displacement along its length was recorded throughout the entire test. Then, using the ABAQUS finite element package and an optimization algorithm developed in MATLAB, a modeling approach was adopted so that the properties of the equivalent linear springs simulating the soil could be determined. 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 resulted from the pipe-soil interaction have been computed and compared to the values given by the ASCE and ALA standards. The results showed that for polyethylene pipe at the condition of strike-slip faulting, these values were too smaller than the values put forth by ASCE and ALA.