Dynamic Response Analysis Of Dual Structure Slope With Anchor-Frame Reinforcement

China's mountainous area is wide,and the area is about 2/3 of the land area.China's earthquake disaster prone,and the earthquake is to promote the stability of the slope,induced landslide,collapse,debris flow and other secondary geological disasters,one of the main reasons.Fujian is a mountainous area,and the dual structure slope by the rock formation and overlying loose deposit composed of loose sediments are widely distributed in the mountainous area.So it has important theoretical significance and engineering value to study the slope stability problems of soil rock dual structure.The large scale shaking table model test of the soil rock dual structure slope is designed and made,and the numerical simulation of the soil rock dual structure under the prestressed anchor frame supported by the FLAC3D numerical platform is carried out.In this paper,the seismic dynamic response of the the soil rock dual structure with anchor frame supported is studied in detail.The conclusions are listed below:(1)The numerical simulation results are in good agreement with the experimental results,which indicates that the numerical simulation is reasonable and reliable;it can provide certain basis for subsequent analysis study.(2)Numerical simulation and model test results show that the earthquake on the slope of the acceleration response generated amplification,and the acceleration response of the monitoring of the slope height effect,lash effect and epistrophe effect is obvious;the peak acceleration of the slope of each monitoring point amplification coefficient(PGA coefficient)increased by ground motion intensity decreased.(3)Horizontal displacement of the monitoring of slope have the same change trend,the permanent horizontal displacement value increases with the increase of elevation;With the interface of the soil rock interface as the boundary,the change rate of the permanent horizontal displacement of the monitoring points below the interface is less than that of the above interface;The effect of ground motion intensity on the permanent horizontal displacement of each point is large,the ground motion intensity is small,the permanent horizontal displacement of measuring points changed little,and the local vibration intensity is bigger,the horizontal displacement of the measuring point permanent change is obvious.(4)The horizontal earth pressure relative amplitude(PEP shock coefficient)decreases with the increase of buried depth under the earthquake;the monitoring points of the earth pressure by peak ground motion intensity increased significantly,increased the intensity of ground motion,it increases with the increase of the intensity of vibration.(5)The cable axial force response performance significantly,using the sliding average method to decompose the axis force time history into "baseline" and "shock",the "baseline" section has a similar trend of change under different seismic waves;Due to the slope deformation,axial stress of anchor "baseline" part of the relative variation of "small earthquake”is positive,"big earthquake" is negative;The axial force variation of the upper row anchor cable on the same grade slope is greater than that of the lower row.The dynamic response of the cable is represented by the"shock",and the dynamic response peak and amplitude of the same monitoring point increase with the increase of the earthquake intensity;Different types of seismic waves make the dynamic response peak of anchor cable axial difference,but its trend along the elevation and the law is similar.