Interaction Between The Surrounding Rock And Anti-shear Gallery In The Right Bank Slope Of Dagangshan

With the rapid development of national economy, construction of large-scale projects and the launch of Western Development, lots of high-steep rock slope stability problems appear in many major projects which located at mountains and canyons. Especially at the west part of China, the geological structure of slope is complex. Under the influence of artificial unloading and a series of engineering disturbance, the stability of slope deteriorate furtherly. Then the study of the analysis of stability problem and the choice of a reasonable strengthening measure of high-steep slope after excavation unloading is imminent.In this article, in order to study the key problem of the stability analysis and reinforcement of high-steep rock slope under the condition of unloading, we take the right bank slope of Dagangshan as an example, which has complex geological condition. According to the result of miroseismic monitoring, which combined with the on-site geological exploration data, we confirm the big weak structural plane. In the light of the actual situation, we use anti-shear gallery to reinforce the slope. By numerical simulation, through analyzing the calculation results of rock-gallery interaction, we choose an available section form of anti-shear gallery and economic and reasonable concrete materials that will be used to make anti-shear gallery. At the same time we build 3D slope numerical model, combining the microseismic monitoring date and the result of numerical simulation, to analysis the problem of slope stability and the strengthening effect. The result verify the anti-shear gallery has a good strengthening effect and give some reference to similar slope problems. The main study conclusions of this article are shown as follows:(1) Square, round and city gate hole are the most common sectional form of anti-shear gallery. But which kind of sectional form is best or is most reasonable from the mechanical point of view, does not have conclusion yet. Through numerical simulation we find the city gate hole sectional form is most reasonable from the point of mechanical.(2) By analyzing the rock-gallery interaction with the numerical simulation result, combined with engineering economy, we select the most reasonable material that will be used to make anti-shear gallery. And the material we choose is consistent with the concrete we use in the actual project.(3) According to the microseismic monitoring date we located the big weak structural plane which consisted by unloading fracture XL-315 and fault f231. Through the numerical simulation of 3D slope model, we analyze the change of stress, displacement, deformation and safety factor before and after the reinforcement. Compared with the microseismic monitoring date we can see clearly that before reinforcement the slope appear apparent slippage along the whole weak structural plane under the condition of unloading, after reinforcement the slippage was inhibited by the anti-shear gallery obviously. After reinforcement around the anti-shear gallery appears apparent stress concentration. The microseismic deformation reveals that the deformation of the rock around anti-shear gallery is apparently bigger than other area. The safety factor of the slope before reinforcement is 1.27, while after reinforcement the safety factor become 1.73, improving 36.2% which compared with the safety factor before reinforcement. Microseismic monitoring and numerical simulation verify each other mutually and prove the reinforcement of the anti-shear gallery is effective.