Abstract: The interface mechanics theory was used in the numerical simulation of the process of karst rock cavern collapse in the soil, rock and void system. It is concluded that the interface had a significant influence on the subsidence in the karst geotechnical materials. A stress concentration and the stress discontinuity are encountered at the interface between the soil cavity and the void. And the progressive failure was initiated at the interface of soft soil-rock. These numerical analysis results are consistent with a collapse encountered in the Guixng Development.

Key words: Karst Collapse, Finite Element Method, Interfacial Mechanics