An efficient numerical approach for simulating soil-pipe interaction behaviour under cyclic loading

Understanding soil-pipe interaction during cyclic axial displacement is essential for the design and evaluation of buried pipeline systems. This study introduces an efficient and practical numerical approach using beam-spring-interface elements to simulate soil-pipe interaction behaviour. Numerical predictions of the evolution of shear and normal stress distributions around the pipe are validated against full-scale experimental results for steel and high-density polyethylene pipes buried in sandy soils. Three different backfill cover depths and soil densities ranging between loose and dense were considered to allow a rigorous comparison between the numerical predictions and the experimental results. The results show that the proposed approach provides a high-fidelity representation of the complex soil-pipe interaction behaviour at the interface zones, including stress cyclic degradation, hardening and softening, cyclic accumulative contraction and stabilization. This numerical framework provides accurate predictions for a fraction of the computational cost of a full three-dimensional finite element analysis