The influence of pipeline-trenchbed interaction intensity on lateral soil resistance and failure mechanisms

摘要

Buried offshore pipelines may be subjected to large lateral displacements caused by ground movements, landslides, etc. A proper estimation of lateral soil resistance against the moving pipeline requires a deep understanding of pipeline-backfill-trench interaction mechanisms. Recent studies show that pipeline-trenchbed interaction can significantly affect the failure mechanisms and the resultant lateral soil resistance, an important aspect that is currently neglected by pipeline design codes. In this paper, the effect of pipeline-trenchbed interaction intensity on lateral soil resistance was investigated by performing centrifuge tests. The soil deformations and failure mechanisms were obtained by Particle Image Velocimetry (PIV) analysis. Two experiments with horizontal and downward inclined pulling directions were conducted to simulate different intensities of bed interaction. It was observed that increasing the intensity of pipeline-trenchbed interaction results in a faster and full development of shear bands in the trench wall and reduction of the mobilized lateral soil resistance.