| Soil-rock mixture is a mixture of hard-strength rocks and low-strength soil,in which the rock particle size is larger,the shape is irregular and the hardness is higher.Because the physical and mechanical properties of the two materials(" soil " and " rocks")that make up this kind of geological body are quite different from those of ordinary soil,they show strong discontinuity and heterogeneity.Soil-rock mixture is different from ordinary soil in mechanics,deformation and failure.Based on a large number of research results of soil-rock mixture at home and abroad,the contact surface of soil-rock mixture and the random generation method of earth-rock mixture are studied in this paper.According to the test data,the strength,deformation characteristics and slope stability parameters impact of soil-rock mixture were analyzed.The main work of this paper is as follows:(1)Based on digital image processing technology,a method of random generation of earth-rock mixture model is proposed.This method combines the characteristics of random generation and digital image processing technology,and generates random shapes on the basis of actual rock block shape.This method overcomes the limitation of general random shape generation(convex polygon and ellipse)and avoids the singularity and difficulty of data acquisition in digital imaging technology.This method satisfies the randomness of space position and the diversity of block stone shape required by the random modeling of soil-rock mixture,and can directly generate the soil-rock mixture model that conforms to the real rock block shape.(2)Based on direct shear test method and the 3D printing,the strength characteristics of cohesive soil in contact with different JRC interfaces were studied.The variation trend of the contact surface strength with the JRC value is given.Based on test data,the relation between interface C?? and the interface roughness JRC value is given,and its applicable JRC range is given.(3)Based on the finite element software ABAQUS,a variety of contact models were used to simulate the contact characteristics of clayey soil-rock.The results showed that using smooth surface and coulomb-cohesive contact and setting the corresponding contact surface parameters could better simulate the contact surface models with different roughness,and the simulation results were more similar to the test results.(4)Based on the random model generation method of soil-rock mixture and the contact surface model,the influence of different contact surface models on the strength of soil-rock mixture was studied by means of direct shear test simulation and triaxial test simulation.The results show that the presence of contact surface has a great influence on the strength of soil-rock mixture,and the coulomb-bond contact surface model can simulate the deformation such as slip,extrusion or detachment between rock and soil.The influence of JRC on the strength and deformation of the model has a relatively obvious rule.The results calculated by this method are in good agreement with the experimental results.It has a good prospect of engineering application.(5)Based on the shape database of block stone and considering various geometric parameters of rock,the random generation of the slope model of rock-soil mixture was realized.The slope stability reduction calculation based on ABAQUS finite element software is studied in two aspects: 1).The influence of the reduction method,particle size parameters,rock spatial distribution and Shape characteristic parameters of rock on the characteristics of the soil-rock mixture slope was analyzed;2).The impact on the slope stability,deformation characteristics and failure characteristics of two calculation methods(ultimate bearing capacity and ultimate bearing capacity considering the slope stability)was analyzed.as well as the influence of rock content and particle size on the bearing capacity of the adjacent slope foundation. |
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