Quantifying Residual Resistance of Light Pipelines during Large-Amplitude Lateral Displacement Using Sequential Limit Analysis

Abstract

The design of on-bottom pipelines regarding thermally induced lateral buckling requires a comprehensive understanding of large deformation lateral pipe–soil interactions to ensure that lateral buckles form as planned. This paper presents a numerical investigation into the lateral loading behavior of a pipe on undrained clay using sequential limit analysis. The lateral displacement experienced by the pipe is up to eight pipe diameters to capture the residual behavior. Validation against published centrifuge tests in terms of pipe invert trajectory and lateral soil resistance is achieved before a detailed parametric study is presented. Lower and upper bound estimates of the critical pipe weight that differentiates light from heavy pipe behavior are derived. Analytical equations are then developed to predict the lateral residual resistances, accounting for the influence of pipe weight, initial embedment, strength gradient, unit weight, and strain softening effect, and the predictions compare very well with a number of model test results.