Seabed Liquefaction around Pipeline with Backfilling Trench Subjected to Strong Earthquake Motions

As an indispensable part of the lifeline for offshore gas and oil industry, submarine pipelines under long-term marine environmental loadings have historically been susceptible to earthquakes. This study investigates impact trench backfilling on residual liquefaction around a pipeline induced uplift combined action earthquake, ocean wave current loading. A fully coupled nonlinear effective stress analysis method, which can consider hysteresis large deformation after seabed soil, is adopted describe interaction between soil pipeline. Taking typical borehole in Bohai strait as site condition, seismic response loading carried out. The numerical results show that has significant existence reduces accumulation excess pore water pressure, so mitigated also decreased.