Simulation Experiment Research On The Granite Residual Soil Slope Erosion Characteristics In Laboratory

This paper is based on the traffic science and technology project of Hunan province named "A Study on Rain Disaster Mechanism and Ecological Treatment Technology of Granite Residual Soil Slope under Complex Conditions".And the granite residual soil used in the test was took from a section of Yiyang-Loudi Expressway.In view of the different strength and permeability characteristics between the residual remolding soil and the original soil sample,madding the simulated undisturbed soil of granite residual soil by adding a certain amount of cement in the remolded residual soil to make the internal friction angle,cohesion and permeability of the simulated undisturbed soil be closed to the parameters of the undisturbed soil.Then study the erosion mechanism of granite residual soil cutting slope through indoor erosion test by using the simulated undisturbed soil.The main work is as follows:(1)Through the domestic and foreign literature reviews,summarized the properties of granite residual soil,and studied the erosion types of granite residual soil slope through the investigation of Yiyang-Loudi Expressway,discussed the causes of slope erosion types and its formation law,analyzed the stress characteristics of the erode surface soil particle.(2)Simulated soil samples was made by adding cement content of 0,2%,3%,4%,5%into remolding residual soil,the internal friction angle and cohesion value of the samples was measured by direct shear test with the condition of same compaction degree,different cement content and curing ages and obtained the basic conditions for the preparation of simulated undisturbed after comparing the experimental data with the field parameters.(3)The specimen of indoor variable head permeability test was prepared according to the basic conditions of simulated soil was obtained.The permeability coefficient of granite residual soil was obtained by field double ring seepage test.Compared the indoor test data with the field date to further ensure that the permeability of the simulated soil be near the site soil,so as to ensure the feasibility of indoor simulated soil samples in granite residual soil.(4)The slopes of simulated soil samples and remolded residual soil are simulated according to the basic conditions of indoor simulated soil.The erosion test of simulated undisturbed soil slope was carried out to study erosion phenomenon of simulated soil slopes with different cement contents and remolded residual soil slopes.The influence of cement content on the simulated slope could be studied,and the scouring mechanism of indoor simulation slope was studied according to the field investigation of slope erosion.