Study On Calculation Method Of Falling Rock Stability In The Three Gorges Reservoir Zone

In the calculation of falling rock stability, gravity is one of the most important factors. The gravity depends on the volume of falling rock directly. How to calculate the rock volume accurately is an urgent problem to be solved of investigation. At present, thr analysis of falling rock stability is based on Code for investigation of Geological Hazards Control Engineering in Chongqing city (DB50143-2003). But the specification without considering the double sliding faces of the wedge failure, only the two-dimensional plane coordinates of falling rocks is calculated and analyzed, so the calculation model exists problems.it is necessary to supplemented and modified the specification..Aiming at the problem that the geometric size of falling rock mass in the high-steep slope is difficult to be measured directly, the paper design and assemble a field measuring device.which is used to measure the geometric size of falling rock mass. According to the measured data, theoretical formulas which can calculate the rock volume accurately are establishedby analytic geometry method. Taking falling rock in the Three Gorges reservoir zone for research objects, the paper makes the mechanical analysis on various kinds of falling rock. On the basis of local code of Chongqing and falling rock studies, the calculation formula of the stability of unstable rock is deduced in three-dimensional coordinate system.In this paper, the geometric data of a falling rock mass in the Three Gorges Reservoir zone was measured. And the exact volume is calculated by the volume formula, which is verified the accuracy of the size measurement device. According to the diversity of perilous rock mass morphology in three-dimensional coordinate system, the paper establish different failure modes. Meanwhile, the paper revise and perfect the calculation method in Code for investigation of Geological Hazards Control Engineering in Chongqing city (DB50143-2003) of falling rock mass, and verified by an example. This paper also analyses the influence of wedging effect on the stability result, and verify the rationality of the hypothesis.