The Analysis Of The Stability Of Bedding Slope Under The Effect Of Frequent Seismic

In recent years,Three Gorges Reservoir Region induced earthquake frequency has maintained at a higher level.The frequent seismic activity will be in the bad geological body sustained impact.Bedding rock slope is the main type of landslide instability in the Three Gorges reservoir area.Compared with other types of slope,its overall stability is relatively poor and deformation is bigger.Moreover,the stability of the slope is more prone to degradation under the influence of external forcings.Therefore,it has very important theory value and practical significance studying the deformation law of development and its stability of bedding rock slope under the action of frequent tremors. This paper is based on the National Natural Science Fund Project 41372356 by theoretical analysis and numerical simulation method.The stability of the bedding rock slope and its influence factors are systematically studied under the action of frequent microquake.This article main research content is as follows:① With FLAC3 D,the dynamic stability of a bedding rock slope is analyzed under seism action.As well as,based on safety coefficient curve,dynamic stability index are obtained under IV~VII degree of intensity of earthquake.In addition,dynamic stability index are obtained through dynamic strength subtraction under V degree of intensity of earthquake;② According to the structural plane degradation mechanism under the action of cyclic shear,structural plane stress-strain relationship which was considering rolling angle wear was deduced.Combining with the slope dynamic time history curve analysis method,it was achieved that the structure of the strength parameters could be updated in real time for each dynamic calculation steps.And then,the stability of the bedding rock slope was analyzed in the five IV degree of intensity of earthquake action.The results show that the wear degree of structure on the surface of the ups and downs also was increasingly serious with the increase of earthquakes.Thus,it leads to the equivalent friction Angle decreases and slope stability decline.As a consequence,it is necessary to consider frequent seismic impact on the long-term stability of the slope.③ Using dynamic strength subtraction,stability analysis was complete of bedding rock slope with a set of parallel planes.Mainly from the slope Angle, slope height, strata dip Angle, spacing and structural surface seismic wave frequency five aspects,the dynamic stability of the slope change rule was discussed.④ According to the bedding rock slope geological prospecting data which is one of slope in the three gorges reservoir,three-dimensional finite element numerical model was established.Considering water by 145 m to 175 m and 175 m to 145 m two kinds of working conditions,the slope dynamic response and deformation characteristics was got under two different working conditions in the five IV degree of intensity of earthquake action.Results are as follows:①The slope deformation is mainly controlled by weak intercalated,and main show bedding down along the weak layer.The trend of slope deformation are convergence under two different working conditions.②Dynamic response of the slope exists obvious hysteresis characteristics.Acceleration and speed of response is very strong in the weak intercalations,showing obvious amplification effect.③Environmental and microseismic seepage coupling effect on the slope that nots allow to ignore. Under the action of five times earthquake,the deformation of the water from 175 m to 145 m is bigger than the deformation of 145 m to 175 m. It turned out that the imbalance of seepage vector when water levels fall adverse to the deformation of the slope.