| The unstable rock collapse is a kind of natural geological disaster which occurs frequently in mountainous area of China.Especially in chongqing area,rock damage is very frequent.Combined with the complex geological conditions,the erosion cutting of the two rivers,and the combined effects of human activities and meteorological activities,the stability of the unstable rock gradually becomes worse.Large and small unstable rocks are distributed in alpine areas,which are threatening the safety of life and property of surrounding residents.Once a disaster occurs,it may cause casualties,economic losses and greater social impact.Therefore,it is very important and urgent for the management of unstable rocks.In this paper,taking the unstable rock of the water distribution town in wanzhou district of chongqing as an example,three methods are adopted:site investigation,Ansys numerical simulation and rigid limit equilibrium.Further study on the development characteristics,instability mode,stability,reinforcement and treatment of the unstable rock in FenShuiji town of Wanzhou district,Chongqing.Finally,some reasonable Suggestions for preventing and controlling unstable rock masses with different collapse modes are put forward.Main research contents include:(1)based on detailed field investigation and detailed investigation,the overall characteristics of the development of unstable rocks in the study area were determined,including 62 of various types of unstable rocks,with an overall volume of 56243.8m~3.The largest and the largest of the major rock monomers;The unstable rock is mainly from the middle to the low.The instability mode of unstable rock is mainly inclined,followed by the fall mode and the slip mode.(2)study on stability calculation methods of unstable rocks.Based on the morphology,deformation and structural surface characteristics of unstable rocks,calculation and analysis were conducted by using the stereographic projection map and the rigid limit equilibrium method.According to the actual situation of the stability of the unstable rock in wanzhou district of chongqing,the analysis results of geological conditions,the failure mode of unstable rock and the stability of unstable rock are comprehensively considered,and it is concluded that most unstable rock bodies are in the basic stable state and stable state.At the same time,a large amount of data analysis also confirmed the close relationship between rock stability and structural surface characteristics,structural surface combination state,initial stress state and rock mass strength.(3)adopt Ansys finite element numerical simulation method,and select sliding and dumping unstable rocks as representative unstable rocks.The elastoplastic constitutive model is adopted to simulate rock-threatening reinforcement according to actual boundary conditions.The simulation results show that the maximum displacement before the slip rock reinforcement is 5.88mm and the maximum displacement after the reinforcement is only 1.1mm.The maximum displacement before the reinforcement is 8.76mm and the maximum displacement after the reinforcement is only 3.0mm.It is concluded from the analysis of the displacement after reinforcement that the reinforcement effect of the unstable rock is quite obvious.The negative effects of dead weight,fracture water pressure and seismic load are effectively prevented,and the safety of the surrounding areas is guaranteed.Through the simulation analysis of the project,the correctness,feasibility and effectiveness of the selected design scheme are also verified.This provides a new theoretical basis for the implementation of this design scheme.(4)prevention and treatment of unstable rocks is a systematic project,which is affected and restricted by various aspects in the process of governance.Based on a large number of projects for preventing and controlling unstable rocks,this paper established a set of principles for preventing and controlling unstable rocks based on the actual situation of unstable rocks in FenShuiji town of Wanzhou district,Chongqing.taking into account various factors such as the importance grade of the project,the size of unstable rocks,the stability of unstable rocks and the construction conditions.In order to ensure the practicability of this principle,this principle is applied to the actual treatment of unstable rock in the water distribution market town of wanzhou district of chongqing city.It is expected to achieve the optimal treatment effect of unstable rock that takes into account the requirements of technology,safety,economy,application and environmental protection.Meanwhile,it can be used as a reference for the prevention and treatment of unstable rock in chongqing city in the future. |
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