Abstract: 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.

Key words: Spatial Characteristics of Deep Excavations, Excavation Unloading, Mindlin Solutions, Residual Stress