contribution of excitation action triggered by collopse of perilous rock to the stability of perilous rock

The mechanism failure must consider the interaction of perilous rock. Study on stability of perilous rock by excitation action triggered by collopse is an important question. In this paper, focused on the falling perilous, a physical model was established considering falling excitation action; Analyzed the dominant fissure's mechanic characteristics under the vertically incidence of excitation waves; Based on the fracture mecheanics, a method to calculate the combined stress intensity factors of dominant fissure under falling excitation action of perilous rock was established. As the instance results showed, two cites of nature and rainfall, the stability coefficient are both reduce, specially in the horizontal, stability coefficient reduced by about 10%, while in vertical about 2%. The results provided some scientific foundation for disasters prevention and mitigation of perilous rock.