考虑土体空间变异性的管廊基坑开挖过程中变形及能量演化特征分析

基坑开挖工程的稳定性受所在区域土体参数的空间变异性影响较大，其施工过程伴随着基坑内部能量的相互转化，为研究复杂多层土基坑开挖过程中土体参数的空间变异性影响及能量演化特征，依托佛山市某综合管廊基坑项目，基于中心点法建立了多层土的弹性模量随机场模型，结合FLAC软件构建了复杂多层土的随机场-有限差分耦合计算基坑开挖的数值模型。研究结果表明：基于随机场参数的统计分析及位移实测对比分析验证了所建立模型的准确性；基于均质模型与随机场模型的测点变形趋势一致，但不同测点处位移的变异性存在显著差别，基坑总体变形可控；基坑开挖过程中，弹性应变能的一部分转化为塑性应变能，开挖完成后基坑处于稳定状态。

Study on Deformation and Energy Evolution Characteristics During Pipeline Gallery Foundation Pit Excavation Considering Soil Spatial Variability

The stability of a foundation pit excavation project is greatly affected by the spatial variability of the soil parameters in the area. The construction process is accompanied by the mutual transformation of the internal energy of the foundation pit. In order to study the spatial variability and energy evolution characteristics of soil parameters during excavation of complex multi-layer foundation pit, a foundation pit project of a comprehensive pipe gallery in Foshan is taken as the research object of this work. Young''s modulus random field model of multilayer soil is established based on the midpoint method. Then, the numerical model of foundation pit excavation with random field and finite difference coupling is build using FLAC. The research results show that, the accuracy of the numerical model is verified by the statistical analysis of random field and the comparative analysis of displacementactual measurement. The deformation trend of the measuring points is the same between the homogeneous model and the random field model, and the deformation of the foundation pit is controllable. Part of elastic strain energy is converted into plastic strain energy during the excavation of the foundation pit, and the foundation pit is in a stable state after the excavation is completed.