Analysis Of Seepage And Stability Of Meizhou Granite Residual Soil Slope Under Rainfall Conditions

The topographical features of the hills in Meizhou City have caused a large number of slopes to build houses.Due to the abundant rainfall characteristics of Meizhou and the special engineering properties of granite residual soil,the unreasonable slope cutting method is very easy to cause slope instability in the rainy season.Therefore,it is of great significance to study the seepage characteristics and stability variation of granite residual soil slope under rainfall conditions.In this paper,the effects of rainfall intensity,rainfall duration and slope ratio on seepage characteristics and stability of slopes are studied by soil test and numerical analysis.The main research work is as follows:(1)Induction and analysis of the basic theory of slope saturated-unsaturated seepage and stability analysis.Based on the conservation of energy and Darcy's law,the saturatedunsaturated seepage differential equation is derived,and the soil water characteristic curve and the basic theory of rainfall infiltration are introduced.Finally,the unsaturated shear theory and the Morgenstern-Price method are analyzed.(2)Overview of artificial slopes in Meizhou and engineering properties of granite residual soils.The geological survey of Meizhou was analyzed by means of literature survey and data statistics,and the distribution of slope height and slope of artificial slope and unstable slope in Meizhou were summarized.Further selected two test sites in Meizhou for related indoor and outdoor tests for analyzing the mechanical properties such as permeability coefficient,cohesion and internal friction angle of granite residual soil.Finally,the distribution law of slope moisture content with depth was studied by field moisture content test(3)Analysis of slope seepage characteristics under rainfall conditions.The SEEP/W section of GeoStudio was used to study the seepage characteristics of the slope under different rainfall intensity,duration of rainfall and different slope ratio design schemes,focusing on the spatial and temporal variation rules of volumetric water content,pore water pressure,seepage velocity and permeability under different working conditions.(4)Slope stability analysis under rainfall conditions.Based on SEEP/W seepage analysis results,the stability of the slope under different rainfall conditions and slope ratio design scheme was analyzed,and the slope safety coefficient and the change law of critical sliding surface under different rainfall intensity,rainfall duration and slope ratio was studied.finally,the influence of slope height on slope stability under rainfall conditions is analyzed.