Analysis of the Stability of Mud Inrush Induced by Fillings Sliding Failure in a Karst Cave Based on the Simplified Bishop Method and Its Application

A simplified computational model used for the stability analysis of the fillings is proposed based on the simplified Bishop method. In this model, sliding soil, circular slip surface, exterior load, pore water pressure and boundary constraint is defined by simplifying the complex system which consist of tunnel, filling materials and karst cave. The global stability coefficient of fillings is got by solving the equilibrium equation of force for individual soil slice and moment for failure mass and by assuming that the direction of inter-slice forces is horizontal. By this way, the risk of mud inrush due to the filled-typed karst caves can be identified. Using this analytical method, this paper analyzes a case and conducts research on the influence of hydraulic effect, shear strength parameters, mud content in cave and boundary constraint on the global stability of fillings.