地震作用下回填砂地基沉入式钢圆筒防波堤变形机理分析

为分析沉入式钢圆筒防波堤变形机理，通过振动台试验和数值模拟研究了回填砂地基沉入式钢圆筒防波堤的动力响应影响。研究结果表明当地震波加速度峰值为3.2 m/s2时防波堤筒外回填砂产生明显的液化滑移现象，且由于液化导致筒外回填砂对防波堤的侧向力改变，防波堤试验模型发生倾斜现象，建议优先对筒外回填砂进行改良；通过数值模拟对防波堤抗震性能设计极限值进行分析，当设计地震动为3.2 m/s2时，由于钢圆筒屈服强度高，钢圆筒处于弹性阶段，损伤程度主要由水平残余位移决定。通过数值模拟研究了钢圆筒应力影响规律，发现了防波堤钢圆筒的薄弱环节，可为工程设计提供参考依据。
Abstract：The dynamic responses of embedded steel cylinder breakwaters with backfill sand foundation were studied by shaking table tests and numerical simulations in order to comprehend its deformation mechanism.The results show that the slip phenomenon of the backfill sand outside cylinder becomes obvious under seismic waves of the peak ground acceleration 3.2 m/s2 in shaking table tests,and the tested breakwater model tilts by reason of the lateral force change due to liquefaction,so it is advised that the backfill sand outside cylinder should be improved in priority.The design limit of the seismic performances of breakwaters was analyzed by numerical simulations.When the design ground motion is 3.2 m/s2,the steel cylinder is still in an elastic stage on account of its high yield strength and the damage degree is mainly determined by the residual horizontal displacement.The effects of the stresses in the wall of steel cylinder were studied by numerical simulations,and the weak points were found out,which can provide reference to practical engineering designs.