Research On The Formation Mechanism And Stability Analysis Of The Simianshan Toudaohe Perilous Rock In Jiangjin District Of Chongqing

Perilous rock means a steep slope which constituted by multiple sets of structural planes that cut by multi-faceted group structure, and gradually separated from a complete rock under the force of gravity, weathering, crustal stress, earthquake and water effect. Then, it develop to be an unstable or less stable or limit equilibrium state rock. Simianshan dangerous rock band distributed in the rear upper of Simianshan county. It directly threat to the security of the town, in the same time, it may resulting in a standstill of the4A scenic travel in Simianshan.This paper considered the Simianshan Toudaohe perilous rock as a typical example. On the basis of the reconnaissance, design, construction materials of Simianshan Toudaohe perilous rock, we have in-depthed and systematic studied on the formation, failure mechanism and stability analysis by choose one typical body of the dangerous rock band. Also the research make an in-depth study on the formation conditions, deformation and failure mechanisms, all of these study are based on the reconnaissance work, also in full use of the reconnaissance, construction and monitoring materials which obtained by use the measures like surface survey, drilling and geophysical prospecting. Under the above work we have defined the failure mode of perilous rock, and in use of limit equilibrium method and numerical analysis method we have made a systematic analysis and evaluation on several conditions for perilous rock. In the stability analysis of the perilous rock we are depending on the failure mode and select a different load combination under different conditions to determine the geotechnical parameters. We have obtained the following basic conclusions:(1) The perilous rock are distributed in the steep edge of old landslide area. There are major8single unstable rock. One of the single unstable rock is distributed in the south steep crag of the bedrock. And all of these rocks are belong to the super-huge high perilous rock.(2) The dangerous rock band originally is an ancient flat push rock slide, and the groove in the back of the landslide is originally a rear edge tension crack. Then the tension crack gradually buried by the rock and soil of collapse that accumulated in both side of itself. The front of dangerous rock band gradually collapsed by the erosion and cutting of river.(3) Numerical simulation analysis on the deformation of slope shows that the maximum horizontal displacement value and the maximum horizontal stress values are located in the block which form cliffs. When the strength reduction factor F=2.9, the solution does not converged, in this time the slope model have been damaged. Based on the above date, we determined the slope model stability factor as2.8.(4) Limit equilibrium analysis of the overall stability of the Toudaohe dangerous rock shows that each profile is stable in the working condition I; profile3-3’is generally stable and profiles1-1’、2-2’、4-4’are stable; profile3-3’is unstable and profiles1-1’、2-2’、4-4’are limiting stable.