Study On Shear-tension Failure Mechanism And Evolution Law Of Surrounding Rock In Deep Roadway

For the tension-shear failure mechanism and evolution law of deep roadway surrounding rock,this subject plans to carry out research in the following two aspects:the first aspect is the analysis of the characteristics of shear slip line of roadway surrounding rock under high stress conditions.The unsupported roadway with plane strain as the model is established by using the self-developed similarity simulation test bench and FLAC^3D finite element numerical simulation software,at the same time,when the vertical load and horizontal load are applied on the model boundary to reach the set stress conditions,the laws of initial position,length change,density,occurrence and direction of sliding shear failure are explored in surrounding rock.The second aspect is the analysis of failure characteristics of roadway surrounding rock under different stress and lithology conditions.The formation mechanism of tension-shear failure of roadway surrounding rock is analyzed and discussed by means of laboratory similar material simulation test,numerical simulation test and theoretical analysis,and the stress effect and lithology effect of shear slip failure evolution are revealed by changing the stress level and rock properties of surrounding rock.The main conclusions are as follows:(1)In order to realize the biaxial loading of similar material model,a biaxial loading plane strain test bench was developed.The underground excavation process can be truly simulated by the designed loading system and excavation system,which lays a foundation for the simulation experiment of similar materials.(2)Through the similar material simulation experiment of rock roadway under different lateral pressure coefficients and different buried depth,and semi coal rock mass and coal seam roadway under different buried depth,the failure characteristics and development law of deep roadway surrounding rock under different stress conditions and lithology conditions are obtained.(3)Through the numerical simulation experiment,the tensile-shear failure characteristics and development law of rock mass roadway,under different lateral pressure coefficients,different internal friction angle and different buried depth and semi coal rock mass roadway and coal seam roadway under different buried depth are revealed.(4)Through the comparison between similar material simulation experiment and numerical simulation experiment,the conceptual figure of roadway surrounding rock fracture under different stress conditions and different buried depth conditions is established.The research results have great practical value and will provide an important theoretical basis for accurate targeted control of deep roadway surrounding rock.