Innovative Method for the Integral Sliding Stability Analysis of Filling Media in Karst Caves and Its Applications in Engineering

Abstract

Instability of filling media in large-scale filled-type karst caves often induce mud inrush in tunnel construction. An innovative method is proposed for the integral sliding stability analysis of the filling media on the basis of the simplified Bishop method. A computational model and six assumptions were put forward to interpret the complex system of the tunnel, karst cave, and filled media. In addition, the stability coefficients of the filling media were obtained by solving equilibrium equations of force and moment. The method can be used for analyzing the influence of the hydraulic effect, shear strength parameters, and boundary constraints on the global stability of filling media in practical cases. The results agree well with numerical simulations. In addition, the assumption that the weakened contact interface was taken to be the critical failure surface was proven reasonable by the numerical simulations. The findings indicate that the analytical method is efficient and suitable for theoretical and engineering studies on integral sliding stability analysis of the filling media in karst caves.