Experimental Research On Similar Materials Of The Slope Bottom Friction Model Of Red Bed In Guizhou

In the road construction in the red bed area,slope excavation and differentially weathered dangerous rocks will induce slope collapse,landslides and other geological disasters.In order to control and prevent the occurrence of such geological disasters,this paper adopts the bottom friction physical model test to Research on the failure mechanism of slope deformation.The key to the success of the model test lies in the reasonable selection and ratio of similar materials.At present,the similar materials in the bottom friction model test have a low degree of similarity with the original rock in terms of physical and mechanical properties.In order to obtain similar materials that meet the requirements of the bottom friction model test of the red bed slope in Guizhou,this paper takes the red bed slope in Guizhou as the research object,and determines the similar mechanical index of the similar material and the original rock through the discrete element numerical simulation.Based on the uniform experimental design method,the physical and mechanical parameter values of similar materials under different ratios are obtained,and the experimental data is subjected to regression analysis to obtain the regression equations of physical and mechanical indicators on the components of similar materials.Finally,an engineering case verifies the reliability of the similar material ratio model.The main research content and the results obtained are as follows(1)Based on discrete element numerical simulation,the numerical simulation study of the influence of rock mechanics parameters on slope deformation and failure.According to the numerical simulation results,the similar mechanical indexes of similar materials in soft rock are determined to be cohesion,internal friction angle and density,taking into account the similarity of elastic modulus and Poisson’s ratio.Similar mechanical indicators of hard rock similar materials are cohesion,internal friction angle,density and tensile strength,taking into account the similarity of elastic modulus(2)Based on the selection principle of similar materials,combined with previous research experience,select quartz sand,barite powder,fly ash as aggregates,gypsum as the cementing material,and red clay as the adjustment material to simulate the soft rock in the red bed area.Quartz sand,barite powder and iron fine powder are selected as aggregates,gypsum is the cementing material,and fly ash is the adjustment material,and the hard rock in the red bed area is simulated and studied.(3)Based on the uniform test method,the uniform test design of the red-bed mudstone is carried out,the multiple regression model is established through the test data,and the influence of various factors on the mechanical properties of similar materials is studied.The empirical equation of cohesion and internal friction angle on the influencing factors.A uniform test design with upper and lower limits is carried out on the red sandstone,a Scheef regression model is established through the test data,and the influence of various factors on the mechanical properties of similar materials is studied,and the density,compressive strength,tensile strength,elastic modulus,The empirical equations of cohesive force and internal friction angle on various influencing factors.(4)Taking the Dashigou slope in the red bed area of Guizhou as an example,based on the bottom friction model test,the deformation and failure mechanism of the slope in the red bed area is studied.The deformation and failure evolution process of the red bed slope is divided into three stages: Slope excavation unloading crack expansion stage → differential weathering stage → concave rock cavity continues to retreat into the slope deformation and failure stage.Compare and analyze the model test process of traditional paraffin oil materials and new similar materials to verify the reliability of the new materials...