Research On Slope Stability And Reinforcement Measure Of Slope Under Rainfall Infiltration

There are always the phenomena occur in the slope engineering: the safety coefficient is greater than the critical safety factor,but landslides occur;And safety coefficient is less than the critical safety factor,the slope is still stable.This phenomena show there are some disadvantages in this method which evaluate the state of slope stability only depend on the safety coefficient,needing to be improved.Rainfall is one of the main causes of landslides,in the research of slope stability under rainfall infiltration,safety coefficient is dynamic,so the disadvantages of this method is more prominent.In this paper,the research of slope stability under rainfall infiltration,firstly,establishing an homogeneous slope model to explore the factors which influence the stability of slope,then combining with engineering example-a colluvial soil slope in Anhui section of Yue-Wu Expressway,the slope seepage analysis and sensitivity analysis of main factors are conducted respectively,and establish the binary evaluation index safety factor and slope reliability stability.Then the corresponding measures of slope protection and reinforcement are developed based on the analysis of seepage field,the sensitivity analysis,the results stability analysis.The specific research work mainly includes:(1)The saturated-unsaturated soil seepage theory,rainfall infiltration theory,saturated-unsaturated soil strength theory,the seepage theory of slope stability are summarized systematically.(2)Apply the Numerical simulation software-GeoStudio to explore the main factors affecting the slope stability through the establishment of the ideal model of slope,including soil parameters,slope geometry,external conditions(rainfall characteristics,seismic action,underground water level),research methods(whether considering the matrix suction).(3)Combined with engineering example,research the change of seepage field and stability of slope under three kinds of extreme rainfall conditions.And based on sensitivity analysis,research the impact on the slope reliability of soil parameter variation characteristics which is more sensitive to the slope stability.Combined with the safety factor,establish binary evaluation index of slope stability.(4)According to the above analysis results,formulate and conduct the corresponding drainage measures and reinforcement engineering,and effect of its protection and reinforcement is validated by numerical simulation.In this paper,the research results show that establish binary evaluation index of colluvial soil slope stability evaluation,combine qualitative judgment and quantitative judgment,can more accurately determine the stability of the slope under the condition of rainfall infiltration.At the same time,the method of horizontal drain hole and soil nails is effective and feasible for the protection reinforcement of colluvial soil slope,which has certain reference significance for the similar projects.