ABSTRACT
ABSTRACT: The security of local people and normal operation of highway are directly threatened by Yanjiagou developed rockfalls. Based on the scene investigation of Yanjiagou 56 rockfalls, the paper statistically analyzed formation mechanism and feature of those rockfalls, found the features of rockfalls included monomer rockfall with colonial development, local chain laws, massive structure, smaller scale, multipoint and wide area, leaded to the formation of raindrops style disasters, realized that the discrepancy of formation mechanism and shape of rock cell, developmental feature of rockfalls were caused by construction and combinations of rock, classified rock cell into two types as smooth rock cell and rough rock cell, studied the major controlling structural plane consisted of ledger rock and high-angle planar X-type conjugate shear joints, finally concluded the formation of rockfalls mainly influenced by four factors as topography, interbedded sandstone and mudstone, surface water, plant roots split role, and failure mechanism involved slip-tensile, bending-tension.
