Stability Analysis and Support Design Methods for Rock Foundation Pit with Combination of Structural Plane and Karst Cave

Abstract

In this paper, the failure mode of the “deep foundation pit slope with high dip angle structural surface and cave development” is analyzed by numerical simulations, and an innovative numerical calculation method for calculating the stability of foundation pit slope based on the principle of upper limit analysis and the prediction method of rock slope surface is proposed. The lateral earth pressure acting on the support structure is further deduced, which can be used more widely than the traditional earth pressure calculation equations. Based on finite element analysis of a pole system, we developed an improved numerical calculation method of the force, and deformation of retaining piles is proposed to carry out the analysis of the deformation of structures under force. Our method avoids the need to artificially place earth pressure on either side of the embedded portions of the piles. Compared with the measured horizontal displacement of the retaining pile, this improved numerical calculation method can reflect the force and deformation law of retaining piles at certain construction stages. In this paper, the upper limit analysis method based on the stability analysis of slopes and earth pressure calculation equations is proposed, taking into account the working conditions of the karst cave in different locations, and the minimum supporting force required can be calculated more accurately while predicting the range of slope sliding surface. An improved numerical calculation method of the retaining piles is proposed in this paper, and the calculation results can reflect the deformation law of the retaining piles during the excavation of the rock foundation pit, and the whole analysis and calculation process has certain advantages compared with the traditional method.