A Pseudo-Dynamic Seisimic Slope Stability Analysis Method Considering Wave Propagation Effects

The number of natural and artificial slopes in China is extraordinarily large,so does the occurrence of seismic hazard.Owing to those two reasons,seismic slope instability occurs frequently,causing huge loss of life and property.In order to mitigate and prevent the damage of seismic slope instability,the stability analysis of seismic slope is crucial.At present,the evaluation indexes for seismic slope stability analysis are safety factor of slope stability and permanent deformation of slope.The former is mainly obtained by seismic force calculation combined with limit equilibrium theory,while the latter is characterized by the relative displacement of the sliding body and the sliding surface.In theory,it is more scientific to use permanent deformation of slope to evaluate slope stability.However,the calculation of permanent deformation of is based on seismic force calculation.Therefore,the calculation of seismic force is particularly critical in the stability analysis of seismic slope.Currently,the main method of seismic force calculation is Pseduo-Static Method,who is simple in assumption,and easy to understand.And due to the simplicity,Pseduo-Static Method is widely used and incorporated into many Industry standards.But yet,the limitations of PseduoStatic Method can not be ignored.For example,the rigid slope assumption of Pseduo-Static Method is inaccurate;there is no direct and effective method to determine the seismic coefficients,;the Pseduo-Static Method does not consider the characteristics of earthquake ground motion and so on.All these factors lead to the conservativeness of Pseduo-Static Method.Relatively speaking,the Pseudo-Dynamic Method takes the propagation characteristics of seismic waves into account,for which it can simulate the ground motion better,and calculate the seismic force more realistic.Moreover,combined with the limit equilibrium method,the stability analysis and calculation formula for seismic slope stability analysis applicable to engineering application can be obtained,providing great theoretical significance and engineering application value.Considering the propagation characteristics of seismic waves in slopes,based on the pseudodynamic method and the traditional limit equilibrium method(Felenius method)for static slope stability analysis,the present study derives the formulas for calculating the seismic force of slopes and the safety factor of seismic stability of slopes.On this basis,with the help ofMATLAB software,a program for the sliding surface searching and safety factor calculation is developed,which realizes a pseudo-dynamic slope seismic stability analysis method considering wave effect.By discussing the influence of seismic wave effect on the stability of seismic slope,the advantages and disadvantages of pseudo-dynamic method and pseudo-static method are evaluated,and the applicable scope of pseudo-dynamic method and pseudo-static method in practical engineering is given,which provides a new perspective for the stability analysis of seismic slope.