Research On Dynamic Response And Stability Of Layered Rock High Slope Under Earthquake

Earthquakes are multiple natural disasters in China.In the slope of highway engineering,earthquake action is often an important factor inducing slope instability,which will pose a serious threat to the normal operation of roads and the safety of people’s lives and property.Therefore,the topic of analyzing the effect of earthquake action on slope stability has also received more and more attention.Because of the particularity of the rock layer shape,the bedding rock slope is different from the general soil slope or homogeneous rock slope in the stability analysis,and it usually has different performance when the failure occurs.This paper mainly analyzes the dynamic response and stability of the bedding rock high slope under earthquake action through the combination of theoretical analysis and numerical simulation,and the working conditions of a slope in a southwestern region.The main research content and results include:(1)Starting from the failure state of bedding rock slopes under earthquake action,according to the different damage forms and failure reasons,several types of failures are summarized,such as lateral expansion,bedding slip,wedge failure,dumping failure,buckling failure,Sliding splitting destruction,etc.And the stress and mechanical characteristics of the rock mass under the action of earthquake are analyzed,and the destruction of the rock mass is composed of two forms of shear and tension.(2)Analyze several theoretical methods and applicable conditions commonly used in the analysis of the stability of rock slopes,and analyze the deformation characteristics,shear strength and the effect of weak interlayers of the bedding slope structural surface under earthquake action.It is proposed that the instability judgment of bedding rock slope under earthquake action can be analyzed by means of slope safety factor criterion,stress level criterion,displacement level criterion,etc.,combined with the corresponding dynamic time history curve to analyze whether the slope has lost its stability(3)Use the FLAC3 D software to establish the numerical model of the slope,and use the control variable method to simulate the key factors such as the height of the bedding rock slope,the slope of the slope,the position of the weak interlayer,and the dip angle of the rock layer,and analyze the impact of their changes on the slope stability.At the same time,according to the shear stress distribution inside the rock mass and the displacement time-history curve of the monitoring point to determine the failure mode of the slope instability,it is compared with the damage types summarized above.(4)Taking the example of a bedding rock slope in a field slope project as a calculation model,for a bedding rock slope with a weak interlayer under earthquake action,according to the relevant regulations in the "Road Engineering Seismic Code"(JTG B02-2013),the 0.30 g peak acceleration for simulation analysis.Taking the "safety factor of 1.15 when the slope is higher than 20 m and 1.10 as the safety factor of less than 20m" as the control index,calculate the critical safety height and slope that the site should meet when designing the excavation slope.At the same time,it is concluded that when the dip angle of the rock layer is slow and the lower part of the slope contains a weak interlayer,the failure is mostly in the form of bedding slip.The maximum displacement is concentrated at the intersection of the weak layer and the upper rock layer on the slope surface.Most of the slope instability is the result of weak layer failure and rock mass self-weight.