基于有限元法的隧道荷载模型位移反分析

Back Analysis of Tunnel Displacement on FEM Load Model

介绍了一种以荷载模型为求解对象的位移反分析法。它是以通用有限元软件为实验平台,利用隧道位移实测值建立荷载灵敏系数方程,根据最小二乘法原理反求隧道模型的荷载,再将正分析结果和实际值进行对比分析并重新调整隧道荷载模型,最终获得较为符合实际的隧道荷载模型。该方法的优点是既考虑了岩土松动荷载效应又能体现支护结构与周围岩土体的共同作用,且具有较好的操作性。

This paper introduces a new method to acquire a FEM load model by back analyzing the measured displacements of tunnel. A general FEM software is used as the analysis tool to work out the sensitvity values of load, which are then combined with the measured displacements of tunnel to create a equation group. By applying the least square principle to solve the equation group, a FEM load model of tunnel can be acquired. Through the comparison of the actual displacements and the calculated displacements, the model is eventually adjusted and optimized. One advantage of the method is that both the effect of the loosening soil （or rock） load to tunnel and the interaction effect of tunnel and soil are taken into consideration; the other advantage is its easy application.