Research On Slope Stability Based On Seismic Wave Principle

Numerical simulation technology is mostly used to researche on dynamic time-history analysis of slopes under earthquakes use at present.And the relationship among slope dynamic safety factor,and slope angle,and slope height is less studied,especially the problem of slope stability,which is rarely reported when the slope angle is close to the critical angle of seismic SV wave.For this purpose,this paper carries out research on seismic slope stability based on the theory of seismic wave propagation.It is expected to more accurately reveal the relationship among slope angle,and slope height changes,and dynamic safety factors.This article assumes that the problem of slope dynamic field under earthquake action is a problem of seismic wave propagation inside the slope.All propagation paths through a point in the slope are determined according to the geometric characteristics of seismic wave propagation.,The relationship among propagation travel time,vibration displacement,and dynamic stress along time of seismic waves down each path is derived.The mathematical expressions of the time history of vibration displacement and dynamic stress at any point in the slope body by means of the principle of vector field superposition can be obtained by calculating.Then the most dangerous slip surface is obtained according to Swedish slice method and the minimum static safety factor.The limit equilibrium principle is applied to establish the calculation expression of the dynamic safety factor of the seismic slope under the combined action of dynamic and static stress.Based on this,a research of dynamic stability of slope under the action of the seismic P wave and SV wave is developed.The research shows:(1)Under the action of seismic P waves,the dynamic safety factor has trend of decreasing with increasing slope angle.But when the slope angle is 45°?50°,the dynamic safety factor changes slowly and its rate of change is close to zero.(2)Under the action of seismic SV waves,the dynamic safety factor decreases monotonically with increasing slope angle.However,when the slope angle is a critical angle,the dynamic safety factor will suddenly reduce and a steep drop will occur.This situation does not appear in the calculation results of the quasi-static method,which indicates that the dynamic safety factor calculation method proposed in this paper is more suitable to deal with the slope stability problem when the slope angle is close to the seismic SV wave critical angle.(3)No matter under the action of seismic P wave or SV wave,the dynamic safety factor will gradually decrease along the increase of slope height.Among them,whithin the range of slope height less than 20m,the dynamic safety factor under the action of seismic SV wave changes seriously especially with the slope height;when the slope height is greater than 20m,the safety factor gradually decreases with the slope height.