基坑空间特征对开挖卸荷条件下残余应力的影响

Spatial Influence of the Residual Stress in the Deep Excavation under the Unloading Conditions

基坑形状及尺寸效应对开挖卸荷条件下残余应力的影响主要通过数值分析、模型试验或现场监测等方法进行研究,但这些方法均缺少严格的数学理论依据。基于土体附加应力Mindlin解,分析基坑空间特征对开挖卸荷条件下残余应力的影响,为市政工程基坑设计与施工提供指导与参考。研究表明,基坑开挖卸荷条件下的残余应力对宽深比较小的基坑安全稳定性起到有利作用。

Currently,the influence of dimensional effect of the residual stress in the deep excavations under the excavation unloading condition is evaluated mainly through the numerical analysis,model test and field monitoring,all these approaches are lack of strict mathematical basis.Based on the Mindlin solution of soil incremental effective stress,this paper analyzes the influence of the spatial characteristics of the residual stress in the deep excavation under the excavation unloading condition so that the results can be used to provide guidance’s and reference for the design and construction deep excavations in the municipal engineering.The results show that the residual stress under the excavation unloading condition is beneficial to the stability of the deep excavation with a small ratio of width to depth,this needs to be further verified and optimized in the future practices.