Study On The Seismic Response Law And Stability Of Rock Slope With Underground Caverns

Problem of slope stability is a vital topic in the study of geotechnical earthquake engineering currently. The researches show that the distribution of global earthquake zone is consistent with the distribution of landslide zone. This phenomenon reflects the earthquake is a reason of geotechnical slope instability. There are so many researches about the stability of slope or underground caverns under earthquake, however, the studies about the stability of rock slope with underground caverns under earthquake are very few. Its failure mechanism is obviously different from general rock slope, the existence and excavation of underground caverns will aggravate the mechanical environment of the slope. Coupled with the effect of earthquake, its failure mechanism has its own characteristics certainly. Therefore, Based on the seismic response law and stability of rock slope with underground caverns, the main works are as follows:(1)Several analysis methods of slope stability from the angle of static and dynamic are explained. The suitable conditions of all the methods and features are illustrated. The methods are evaluated in details, and the advantages and disadvantages of each method are compared.(2)The computing theory of finite element method is clarified.In static analysis, the liner elastic theory and elastoplastic theory for analyzing the deformation and stability of the materials and structures are mainly used.In dynamic analysis, the eigenvalue method,the time history based on Newmark method and the strength reduction method for analyzing the dynamic response and stability of the materials and structures are mainly used.(3)By using the finite element software for static and dynamic stability analysis of the single tunnel and small clear distance tunnel under rock slope, the changing laws of surrounding rocks stresses and displacements are concluded.In static analysis, only considering the weight of model,the pictures of slope principal stress, displacement and the plastic deformation region are obtained,then the factors of slope are acquired. From the results, the stress of upper rock is different from lower rock,the displacement and plastic strain of slope foot is lager,and the slope may occur a landslide.In dynamic analysis,the gravity is converted to time-varying static load.By adding the earthquake accelerations of X-direction and XZ-direction, the time history figures of slope displacement, velocity and acceleration are obtained, the amplification factors of the three are acquired. The slope safety factors and plastic strain area of each condition are calculated.From the results,under X-direction earthquake,the slope is stable,and the increasing ratios of acceleration,displacement and velocity are the same to the load,the amplification coefficient are close,when the peak acceleration are 0.1 g and 0.15g. Much of the slope is into plastic state,when the peak acceleration is 0.2g.Under X-direction earthquake,the slope is stable,when the peak acceleration is 0.1g.And Much of the slope is into plastic state,when the peak acceleration is 0.15g.(4)The results of the analysis are concluded.The works that can be enhanced are pointed out. Some suggestions for later researches of dynamic stability of the tunnel under rock slope are given.