Developing Mechanics for Perilous Rock in Karst Area:Taking the Hailuo Bay in the Three Gorges as an Example

Study the mechanisms and laws of evolution of the perilous rock collapse of geological disasters in Three Gorges Reservoir Area, is helpful for us to take a more rational management and protection measures, more effective ensure human lives and property safety. Study the formation mechanism of unstable rocks in Hailuo Bay with Geomorphology and structural geology. Both the monomer and the colony perilous rock are developing, and the area of perilous rock in a total with 4.30×104m2. According to the unstable modes, two types of perilous rock at the source of Hailuo Bay are classified as the compression and shear sliding type and the fracturing-toppling type, with the percentage of 93.7% and 6.3% respectively. The study found, the Hailuo Bay perilous rock collapse, belongs to the formation of self-stabilizing the balance of the development process. In the fluvial digesting movement, flowing dredging and erosion the bottom of the bank slope constantly. The weathering and the Karst never stop to develop the fissure, which the four main fractures interaction, until the penetrative cranny presence, and the perilous rocks formed which is harmful to the surrounding environment of human life. It shows that the Karst and a numerous engineering activities contribute to the formation of perijous rocks actively in the limestone area.