降雨作用下黄土引水隧洞安全性分析

Safety Analysis of Loess Diversion Tunnel Under Rainfall Action

以某引水隧洞为工程背景,基于试验得到的黄土含水量与抗剪强度的关系,借鉴有限元强度折减法的思想,通过数值模拟方法得到降雨作用下隧洞不同时间的安全系数。通过不断设置不同时间(不同含水量)土体的抗剪强度参数,使黄土隧洞围岩塑性区不断扩展,直至塑性应变或位移发生突变时,即表明隧洞发生剪切破坏,此时即为降雨作用下剪切破坏临界时间。尝试找到一种降雨后隧道安全系数变化预测的方法。

Based on the relationship between loess moisture content and shear strength obtained from experiments,and drawing on the idea of the finite element strength reduction method,the safety factor of the tunnel at different times under the action of rainfall was obtained through numerical simulation.By continuously setting the shear strength parameters of the soil at different times(different water contents),the plastic zone of the surrounding rock of the loess tunnel continues to expand until a sudden change in plastic strain or displacement occurs,indicating that shear failure of the tunnel occurs,and rainfall occurs at this time.Critical time for shear failure under action.