Analysis Of Slope Stability Based On Residual Soil Structure

Granite residual soil is widely distributed in Fujian Province.It is a special soil with special engineering characteristics.Taking the granite residual soil in Fuzhou as the research object,the paper carried out the indoor experiment based on the residual soil structure,analyzed the change law of the residual soil structure potential under different dry and wet cycle times and moisture content conditions,analyzed the impact of granite residual soil on the slope stability using the simplified Janbu method,and discussed the relationship between structural quantity parameter m,and the slope stability safety factor Fs of granite residual soil under different conditions.The main research works is as below:1)Natural soil is alternatively dry and wet for a long time.The dynamic expansion or shrinkage of soil results in the constant change of its shear strength.Based on the comprehensive strain structure potential,it is advised to define the structural quantity parameter m? of granite residual soil from the shear strength change of residual soil,and carry out research using the simply direct shear experiment directly.2)Indoor experiment was carried out on granite residual soil.The result indicates that the defined structural quantity parameter m? of granite residual soil reflects the structural difference of granite residual soil sensitively and the structural quantity parameter m? of granite residual soil declines with the increasing of the number of dry-wet cycle and the declining amplitude is obvious;the higher the moisture content is,the lower the structural potential of granite residual soil.The higher the moisture content is,the higher the disturbances strength is.Thus,the more serious the structural failure is,the lower the structural potential is.3)The research analyzes the stability of slope based on structural potential of granite residual soil to explore the change rule of slope stability coefficient Fs of granite residual soil,times of alternation of wetting and drying and stress structural parameter m? and establish the empirical formula between structural potential m? for granite residual soil and earth slope stability coefficient Fs in southeast Fujian,finding that:the structural property produces an important influence on the stability of granite residual soil,and soil slope stability coefficient FS and structural parameter m? are in a positive linear correlation;the stronger the structural potential of residual soil is,the stronger the stabilizability is,i.e.the soil mass has stronger safety stock;contrarily,for the soil mass with weak stress structural potential,the stabilizability is lowered and variability increases,i.e.the earth slope shows lower stability factor.The established empirical formula can provide significant references for the analysis on structural slope stability of granite residual soil and the research on long-term and short-term macromechanics performance of earth slope.