桩-沙土相互作用地震分析研究

Study on Pile-sand Interaction under Seismic Vibration

沙土强震后场地液化会产生重大的灾害,在历次地震中已有所呈现.利用Opensees程序对单桩在沙土中的地震反应进行计算分析,模型土中,顶部2m为粘土,以下10m为沙土,利用集中质量模拟上部结构,El Centro和正弦波作为模拟地震动输入.计算结果显示:沙土在强震下的孔隙水压力和液化规律与地震波的类型有关,液化后桩身位移和弯矩迅速增大,桩的承载能力下降,表明液化后上部结构可能破坏.

Some serious damages were presented as sand liquefaction under strong earthquake in previous years. Single pile with concentrated mass on the top loaded by seismic vibration was simulated by Opensees pro- gram. 2m below the surface is clay while lOre below the clay is sand for the model. E1 Centro and sine wave were inputted as seismic vibration. The results show that the types of earthquake have effect on pore water pres- sure and liquefaction. The amplitude of displacement and bending moment increase heavily, which may cause the bearing capacity degenerated owing to the sand liquefaction.