| Road transportation is related to the development of a country’s national economy.In order to promote economic development,China continues to increase the scale of highway construction and regards it as a key direction for infrastructure construction.In many mountainous areas in our country,many mountainous is high and steep,and the geological conditions are very complex.The core problem of highway construction is to accurately evaluate the stability of cutting slope and check the protective measures.Reasonable and effective excavation and support measures for tall road cutting slopes are the key to the success or failure of highway engineering construction.In this paper,through the analysis of many cases of slope instability in Guizhou,the failure mechanism and deformation failure mode of soil-like slopes in Guizhou are studied.The numerical simulation research uses the specific geological survey data and the geotechnical test data of the slope,with the help of FLAC3D numerical analysis software,focuses on the study of the stress,strain,deformation and stability of the high cutting slope during the excavation and support.This paper firstly focuses on the topography and geological conditions of the main roads in the Guizhou mountain area,combined with many high-grade soil slope instability cases,studies the failure mechanism,deformation failure mode and stability influencing factors of the common road slope.According to the actual working conditions of the high-grade soil slope on the left side of K27+200 slope,the safety factor is used as the evaluation index,and the influencing factors of slope stability are studied in detail by using the finite difference strength reduction method.Next,based on three excavation schemes,considering the graded excavation conditions,The paper simulates the stress,displacement and shear of the slope and calculate the stability safety factor,so as to comprehensively evaluate the stability of the slope.Secondly,the paper simulates and check the proposed supporting scheme,analyzes the supporting effects of different anchor length and angle,then,adopted the scheme of prestressed anchor cable to optimize the design.Finally,through the comprehensive comparison of the excavation deformation,support effect and cost of the three schemes,a more reasonable slope excavation construction scheme is selected.In order to analyze the influence of rainfall infiltration on the actual engineering slope,this paper analyzes and studies the change rule of the soil strength under different moisture content of the completely weathered basalt residual soil according to the experiment of the strength characteristics of the soil in the engineering area,based on the saturated-unsaturated theory,the program of rainfall infiltration is compiled by using the fish language of FLAC3D,so as to realize the simulation of saturated-unsaturated seepage in the actual high slope.Finally,the change of pore water pressure in the weathered basalt slope and t he deformation stability of the slope at different rainfall durations are obtained.The results can serve as a guide for similar highway slope projects. |
