On the Mechanism of Collapse and Slide of the Rockmass at Lianziya Precipice in Three Gorges and Its Remedial Measures

摘要

The mechanical analysis of mechanism of collapse and slide of the rockmass at Lianziya Precipice is made based on the measured results of acoustic wave character and mechanics tests in dangerous rockmass, geologic structures and observed data of rockmass deformation at Lianziya Precipice. It is indicated that the main factor to rockmass crack is cantilever-beam-effect of the rockmass as a result of underground mining and great disparity in elastic moduli between complete rock layer and coal layer, four soft layers and broken rock layer. The basic reason causing collapse and sliding of the rockmass is that geologic structure, which is multilayer and hard in the upper and soft in the deeper, is possessed of steep inclination sloped outward. Some suggestions for reinforcing the dangerous rockmass at Lianziya are put forward according to mechanism forming the dangerous rockmass.