基于随机介质理论的土体融沉预测及其参数敏感性分析

为预测人工冻结法施工引起的地表融沉,以广州某地铁为研究背景,考虑土体压力的变化,运用随机介质理论建立马蹄形水平冻结融沉计算模型,分析对地表融沉有影响的各参数的敏感性。由计算结果得出,水平冻结引起的地表竖向融沉呈正态分布,在隧道中心处达到最大值;参数敏感性分析得出各参数敏感度从大到小依次为冻结壁厚度、土体主要影响角正切值、隧道埋深、融化与压密系数;最大竖向融沉随着冻结壁厚度、土体主要影响角正切值、融化与压缩系数的增大而增大,随着隧道埋深的增大而减小。

Prediction of Surface Thawing Settlement Based on Stochastic Medium Theory and Parameter Sensitivity Analysis

To predict surface thawing settlement caused by artificial freezing,the horseshoe horizontal freezing calculation model on a subway in Guangzhou is established. Stochastic medium theory is employed to calculate the thawing settlement in view of the change of earth pressure and the analysis of the sensitivity of parameters that have influence on the surface frost heave is conducted. The calculation results show that the surface vertical thawing settlement caused by horizontal freezing tends to be in normal distribution,and the largest values are in the center of the tunnel. The sensitivity of the parameters from high to low are the frozen wall thickness,the tangent value of main influencing angle,the buried depth of tunnel,the coefficient of thaw,the coefficient of thaw compression. The maximum vertical displacement increases with the increasing of frozen wall thickness,tangent value of the main influencing angle,coefficient of thaw and coefficient of thaw compression, but decreases with theincreasing of the depth of tunnel.