The Stability Analysis Of Rockslope With Weak Interlayerunder The Unloading Influence

The stability problems of rock slope are always the major problems on affecting the development and utilization of mineral resources and slope protection engineering.because of actual rock mass actual rock mass generally containing joints,cracks,discontinuous structural planes and other weak interlayer,and simultaneously being externally disturbed by tectonic stress field,earthquake,artificial blasting,groundwater,excavation unloading,bringing about rock mass damage and destabilization failure process more complex.On the basis of consulting a large number of domestic and foreign relevant research materials,this paper used synthetically theoretical analysis,numerical simulation,site deformation monitoring and other methods to make in-depth study on slope stability containing weak interlayer.1.This paper detailedly analysis the concept,composition,classification and engineering characteristics of weak interlayer,summarized the characteristics of topography,rock mass structure,tectonic action,natural weathering,vibration effect and water action on the stability of weak mezzanine slope,generalized some common failure types of slope including weak interlayer,discussed the influence mechanism of weak interlayer on slope stability.2.In connection with multi-step slope for excavation step by step,analyzing unloading effect of rock mass respectively about three aspects: slope stress field,rock mechanics parameters,unloading deformation range.Summarizing four stages from initiation to expansion and finally to the formation of a sliding through surface rock mass crack under excavation conditions.Simultaneously integrating geometrical characteristics of multi-step slopes on the basis of limit equilibrium method,and obtaining the minimum safety factor formula of multi-step slope failure is given.3.By combining orthogonal test with numerical simulation,chose the six factors:inclination,thickness,numbers of weak interlayer,position of weak interlayer,cohesion,internal friction angle.Using the strength reduction software RFPA-SRM to establish 28 numerical models,to get the change regulation from the maximum displacement in the X and Y directions and slope safety factor of each model.The results showed that inclination of inclination and the distance of the bottom of the weak sandwich from the foot of the slope had the influential influences on slope displacement and safety factor,is the most important factor affecting slope stability,besides thickness,cohesion and internal friction angle also have influences on slope stability,but not particularly significant.4.According to Jinchuan quartz quarry project,establishing the model of slope including weak interlayer with geologic structure.It is analyzed that the temporal and spatial evolution of stress field,displacement field and acoustic emission of open pit slope,on the basis of the continuous mining unloading.At the same time,the numerical simulation results are analyzed and validated with site deformation monitoring data.