Numerical Simulation Of Stability And Support Scheme Of Expressway Soft Rock Slope Under Rainfall Condition

Relying on the soft rock slope of a highway in Hubei Province as the research background,this paper collects the basic geological data of the soft rock slope and combines the results of indoor experiments such as triaxial test and permeability test to obtain the physical and mechanical parameters of the soft rock slope.Finite element numerical analysis software is used to carry out numerical calculation and analysis of slope stability under rainfall infiltration conditions,and numerically analyze the influence of rainfall duration and rainfall intensity on the seepage and stability of soft rock slopes.Based on the results of seepage analysis,finite element numerical software was used to carry out numerical calculation and analysis of slope stability of different support schemes before and after rainfall infiltration,and to analyze the reinforcement effects of soft rock excavation slopes in two different support schemes.Choosing the reasonable slope excavation support plan will provide good suggestions for the construction of the supporting project.The main research contents and results are as follows:(1)The shear strength parameters,elastic modulus and permeability coefficient of soft rock sample soil are obtained through triaxial and permeability experiments;Then,the soil water characteristic curve of soft rock sample is fitted,and the relationship between volume water content of soft rock sample and matrix suction is obtained.(2)By using the finite element numerical analysis method,combined with the seepage stress coupling of rainfall infiltration,through the numerical calculation and analysis of slope stability under the condition of rainfall infiltration,the influence of rainfall duration and rainfall intensity on the seepage and stability of soft rock slope is analyzed,and the variation laws of pore water pressure,displacement,effective stress and safety factor of soft rock slope are obtained.(3)By using the finite element numerical analysis method,through the numerical calculation and analysis of the slope excavation and support stability before rainfall infiltration,the reinforcement effect of two different support schemes for the soft rock excavation slope is analyzed,and the variation laws of the sliding surface,pore water pressure,displacement and safety factor of the soft rock slope are obtained.(4)By using the finite element numerical analysis method,combined with the seepage stress coupling of rainfall infiltration,through the numerical calculation and analysis of slope excavation and support stability after rainfall infiltration,the influence of rainfall lasting for 72 hours on the stability of soft rock slope excavation and support is analyzed,and the variation laws of pore water pressure,horizontal displacement and safety factor of soft rock slope are obtained.Finally,through the comparative analysis of the reinforcement effect and construction technology of the two support schemes,the reasonable slope excavation support scheme is selected.