遮帘式板桩码头地基地震液化破坏机理
Destruction Mechanism of Covered Sheet-pile Wharf Foundation under Seismic Liquefaction

遮帘式板桩码头作为一种新型的板桩结构型式,其抗震性能研究是设计建造过程中的重要环节。在FEM-FDM水土耦合计算的平台上引入循环弹塑性本构模型,借助FORTRAN编程软件形成饱和砂土动力液化分析的数值方法,可有效模拟饱和砂土在地震动力作用下的非线性及大变形特性,同时也可模拟砂土液化流动对遮帘桩和前墙的动土压力。研究表明:地震作用下可液化土层超孔隙水压力比增长并发生较大的水平流动变形,对前墙的水平破坏大于竖向破坏;前墙剪力最大值位于海床与前墙交界处;遮帘桩剪力最大值位移与前墙底平行的位置;后拉杆拉力逐渐变大,前拉杆拉力逐渐变小。通过对板桩码头地震液化灾害的分析,可为抗震和抗液化设计提供参考依据。
The all-covered type of sheet-pile wharf is a new type of sheet-pile structure,and research into its seismic performance is important for its design and construction.In this study, based on the FEM-FDM soil coupling calculation platform,the cyclic elastic-plastic constitutive model is introduced.The FORTRAN dynamic programming software is used for saturated sandy soil liquefaction numerical analysis.This software can effectively simulate saturated sand under earthquake dynamic nonlinear and large deformation and can also simulate sand liquefaction flow at the barrier of the pile and the front wall.The results are:under the action of earthquakes,the excess pore water pressures of liquefiable soils increase and there is large deformation due to horizontal flow;the horizontal damage to the front wall is greater than the vertical damage.The maximum shear wall is located in the seabed and before the wall at the junction.The barrier pile is the location of the maximum shear displacement parallel to the bottom of the front wall. The rod tension in the back increases gradually,while that in front reduces gradually.Through the analysis of sheet-pile wharf disasters caused by seismic liquefaction,the results of this study provide a reference for seismic and liquefaction resistance design.