台阶级数对加筋土挡墙地震动力响应影响研究

Study on the effect of step series on seismic dynamic response of reinforced soil retaining wall

为了优化加筋土挡墙的结构设计,研究了台阶级数对加筋土挡墙抗震性能的影响程度。基于Flac3D软件建立了加筋土挡墙数值模型,探讨了不同地震峰值加速度(peak ground acceleration,PGA)下不同台阶级数加筋土挡墙的侧向位移、竖向沉降、加速度响应和水平土压力的变化规律。结果表明:4 m/s^(2)峰值加速度下,增加台阶级数,侧向位移减小了61.9%,竖向沉降减小了20.5%;PGA放大系数随着台阶级数的增加而增大,其中加筋区PGA放大系数略大于面板处PGA放大系数;1级加筋土挡墙最大水平土压力位于墙脚处,2,3级加筋土挡墙最大水平土压力位于台阶分级处;水平土压力在台阶分级处大于规范计算值。增加台阶级数能够提升加筋土挡墙的抗震性能,可为实际工程中加筋土挡墙的分级设计提供理论参考。

In order to optimize the structural design of reinforced earth retaining wall,the influence of step series on the seismic performance of reinforced earth retaining wall was studied.Based on Flac3D software,a numerical model of reinforced earth retaining wall was established,and the lateral displacement,vertical settlement,acceleration response and horizontal earth pressure of reinforced earth retaining walls with different step series under different peak ground acceleration(PGA)were discussed.The results show that under the peak acceleration of 4 m/s^(2),the lateral displacement decreases by 61.9%and the vertical settlement decreases by 20.5%with the increase of step series;The PGA amplification factor increases with the increase of the step number,and the PGA amplification factor in the stiffened area is slightly larger than that at the panel;The horizontal earth pressure of the one-stage retaining wall is maximum at the bottom,and the horizontal earth pressure of the two-stage and three-stage retaining walls reaches the maximum at the grading;The horizontal earth pressure is greater than the calculated value of the specification at the grading.Increasing the number of steps can improve the seismic performance of reinforced soil retaining wall.The research can provide theoretical reference for the classification design of reinforced soil retaining walls in practical engineering.