Stability Analysis And Reinforcement Of Mountain Slope Based On Earthquake And Rainfall

Earthquake and rainfall are two common causes of slope instability.In order to deeply analyze the mechanism of slope instability under rainfall earthquake and rainfall-earthquake coupling.In this paper,Geostudio software is used to simulate and analyze the slope stability under rainfall infiltration,earthquake action and rainfall-earthquake coupling action,and the horizontal displacement,total stress and stability coefficient of slope under different working conditions are studied.On this basis,the slope reinforcement scheme is put forward and the reliability is analyzed.Specific research results are as follows:(1)The physical and mechanical parameters are obtained through indoor tests,and according to local meteorological and hydrological data,different rainfall intensity conditions are simulated.It is found that the greater the rainfall intensity,the greater the horizontal displacement and pore water pressure near the top of the slope,but the less obvious in the middle and lower part of the slope.The variation amplitude of pore water pressure and safety factor of slope at each time is positively correlated with rainfall intensity at that time.When the rainfall intensity is constant,the longer the rainfall duration,the more rainwater infiltration,the higher the groundwater level rise,the larger the saturation area,the smaller the matrix suction in the slope,the weaker the shear strength of the slope,the increasing displacement,the more obvious the loading effect of rainwater and the softening effect on rock and soil,and the decreasing the stability of the slope.The influence of rainfall on slope stability is mainly concentrated in the slope surface and slope toe area,and the probability of unstable landslide is relatively high.(2)Under the action of earthquake load,the sensitivity of seismic horizontal coefficient to safety factor is analyzed by using quasi-static method,and it is found that horizontal inertial seismic force has severe influence on slope stability;The dynamic response analysis of the slope shows that the displacement field of the slope,the maximum total stress and the peak earthquake acceleration are in direct proportion.The larger the earthquake acceleration,the more obvious the stress concentration phenomenon,the more obvious the cumulative effect and hysteresis effect of horizontal displacement;Through the Newmark analysis method,the permanent displacement is studied,and the failure degree of slope is understood,which provides a new basis and reference for the evaluation of slope stability.The slope instability is the result of the interaction of many factors such as external geological environment.(3)Under the coupling action of earthquake and rainfall,the excess pore water pressure will be produced instantaneously by earthquake,and the pore water pressure of soil will continue to increase by rainfall.When the two kinds of pore water pressures are superimposed,the matrix suction will further decrease,and the coupling action of earthquake and rainfall is more likely to cause slope damage than single rainfall or earthquake.When the rainfall intensity is constant,the distribution of permanent displacement,excess pore water pressure and maximum shear strain of slope all increase with the increase of peak acceleration;It is also found that the impact of earthquake on slope is more obvious than that of rainfall.When the earthquake acceleration is constant,with the increase of rainfall intensity,the permeability increases,the groundwater level line rises,the water content of slope increases,the horizontal displacement increases,and the stability of slope decreases.(4)The reliability analysis method is used to analyze the slope,and the contingency of the effect of rainstorm and earthquake load on the slope is fully considered.It is found that the slope safety factor is the lowest and the failure probability is high under earthquake-rainfall conditions,and the slope is at medium risk at this time;Adopt the new bolt support structure to control,can not only to rainfall downhill drainage,but also can effectively reinforce the slope,to ensure the stability of the slope.There are 87 figures,23 tables and 144 references in this paper...