Method for calculating and processing inrushing destruction of excavation and depressurization coupling effect of foundation pit with confined water

Abstract

The invention relates to a method for calculating and processing inrushing destruction of an excavation and depressurization coupling effect of a foundation pit with confined water. The method comprises the following steps of: (1) selecting a calculation range for the depressurization seepage field and the excavation stress field model of the foundation pit; (2) defining the attribute of a soil material around the pit within the calculation range; (3) creating a geometric solid model by using a finite element program, and carrying out element discretization; (4) setting boundary conditions for the depressurization seepage field and the excavation stress field model of the foundation pit; (5) carrying out finite element analog calculation on the excavation and depressurization coupling effect of a foundation pit model; and (6) obtaining the inrushing plastic failure distribution diagram for the soil around the foundation pit with confined water according to the calculated result, and judging whether the foundation pit can inrush or not. Compared with the prior art, according to the invention, the action of the coupling of a foundation pit excavation effect and a depressurization seepage effect is considered, and the shear strength, the heterogeneity and the elastoplasticity of the soil around the pit are considered, thus the defects of the traditional foundation pit inrushing judgment method are made up, and the accuracy and the reliability for the judgment of the inrushing destruction of the foundation pit are enhanced.

Description

technical field [0001] The invention relates to a calculation and processing method for surge damage of a pressurized water foundation pit, in particular to a calculation and processing method for surge damage of the coupling effect of excavation of a pressurized water foundation pit and depressurization. Background technique [0002] With the large-scale development and utilization of urban underground space in our country, there are more and more deep foundation pit projects, and the geological and environmental conditions of deep foundation pit engineering excavation and construction are becoming more and more complex, and the engineering accident rate and loss are also increasing. According to relevant literature statistics, the success rate of foundation pit engineering construction in some areas is only 1 / 3, and the remaining 2 / 3 of foundation pits have more or less problems of one kind or another, and foundation pit accidents related to groundwater account for about 1 / ...

AI Technical Summary

Problems solved by technology

However, in these research methods, they all assume that the soil of the aquifer at the bottom of the pit is a homogeneous and continuous elastic body, and the influence of excavation and unloading of the soil in the pit on the stress state of the soil at the bottom of the pit is not considered in the analysis process, and the hydrodynamic pressure is not considered. Seepage interaction between pit subsoil and envelope

In actual engineering, the aquifer at the bottom of foundation pits containing confined water in soft soil areas is a heterogeneous elastic-plastic body distributed in layers, and the soil has no bending resistance, so it is simplified into a beam or plate element model with bending resistance The analysis is obviously unreasonable, and when the ratio of the thickness of the aquifer soil to the span of the foundation pit is large, the simplified beam or slab unit model analysis does not conform to the definition of the beam and slab; on the other hand, the excavation and unloading of the soil in the foundation pit and The seepage effect of the confined water between the bottom soil of the pit and the retaining structure will also accelerate the plastic failure of the bottom soil of the pit

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