Experimental Study On The Mechanical Properties Of Soil-Rock Mixture

Because of the complicated structure and complex of the material composition and structure,the deformation and stability of the slope is one of the most concerned and urgent solved problems in engineering construction.Taking a typical accumulation body slope in Three Gorges Reservoir Area as an example in this article,based on field investigation and sampling,researching the accumulation of shear strength characteristics under the different water content,rock content and the compactness by large direct shear test.The microstructure model was establishedto analyze the influence of stone content on the characteristics of soil-rock mixture by PFC2 D software.The research results not only provide the basic data for the deformation and stability analysis of the bulk,but also provide a reference for the similar engineering construction.The main contents and results are as follows:1.The three typical stone content(30%,60%,80%)at different water content(8%,12%,16%)of the direct shear test,a certain water content under the condition of different density(1.8,2,2.2)of the direct shear test and specific water content under the condition of different stone content(10%,30%,40%...80%)direct shear test were done.and the stress-strain relationship curve,the cohesion and friction angle,the cohesion and friction angle with water content,density and stone content change curve and fitting relationship can be obtained by direct shear test.2.The influence of water content,density and stone content on the strength characteristics of soil rock mixture was analyzed by the experiment results:(1)The influence of water content on the shear strength of the samples of the three typical rock samples was 30%>60%>80%.(2)The greater the dry density,the greater the the cohesion and the friction angle of the sample,and the cohesion was more obvious than the friction angle.(3)Along with the increase of the stone content,the cohesion and friction angle showed the increasing trend.When the rock content is over 70%,the shear strength increased sharply.3.Test results of stress-strain curve types were strain hardening,the curve type of overall stability type through fitting the shear stress-strain relationship curve using the exponential model,that was the shear displacement reaches a certain value,the shear stress was no longer changed greatly,and it was a strain hardening phenomenon,the fitting effect of the exponential model was better,and it can reflect the strain hardening phenomenon in the shear process.4.The discrete particle flow PFC2 D was used to establish the microscopic model of the samples with different stone content(0%,10%,20%,100%).Combined with laboratory tests,the influence of stone content on the characteristics of soil rock mixture was analyzed from the microstructure analysis...