Study On Rapid Excavation And Optimization Of Bolt-Mesh-Cable Support Parameters In Large Section Coal Roadway

With the development of high-efficiency fully mechanized mining technology in modern mines,the scale of coal mining has increased significantly,and the engineering geological conditions are complex and changeable,which has brought about poor stability of surrounding rock of coal roadway and high difficulty in supporting large-section coal roadway.The support technology of large-section coal roadway has become an urgent problem to be solved.In this thesis,theoretical analysis,numerical simulation,field measurement and other research methods are used to systematically carry out rapid excavation of large-section coal roadway and optimization of bolt-mesh-cable support parameters,and the bolt-mesh-cable support parameters of W3303 working face in Gaohe Coal Mine are determined and successfully applied.The research results of this thesis mainly include the following aspects:（1）Through on-site coring,three kinds of coal rock samples,including coal,mudstone and sandstone,were processed and prepared.The uniaxial,triaxial and Brazilian splitting tests of coal rock mass were carried out using MTS 815.02 and MTS 816 rock mechanics test systems.The basic physical and mechanical parameters of large section coal roadway were obtained,and the strength characteristics and deformation laws of roadway surrounding rock mass were revealed.（2）According to the practical experience and actual working conditions of coal mine,seven indexes of roof strengthσ_t,coal seam strengthσ_c,direct bottom strengthσ_b,buried depth H,roadway width b,top mining ratio N and coal pillar width X are selected as the classification indexes of surrounding rock stability of coal roadway.Based on the analytic hierarchy process,the weight distribution of the seven indexes is carried out,and the stability grade of the surrounding rock of the roadway in W3303 working face is comprehensively evaluated by fuzzy clustering.At the same time,the displacement of the roof and floor of the surrounding rock of the roadway is predicted.（3）A BP neural network model was constructed based on MATLAB software,and the network model was programmed to build and run.After testing,the network performance was good.Based on the trained network,the working conditions of the W3303 working face were tested and verified,and the recommended support parameters for the W3303 working face along the coal roadway were obtained.（4）Based on FLAC^3D simulation of the deformation characteristics of surrounding rock under different cutting methods,the selection of a regular S-shaped cutting method is determined.Multiple orthogonal comparative simulation experiments were conducted to optimize tunnel support parameters,analyzing and comparing the characteristics of tunnel surrounding rock under different support conditions,and optimizing the anchor mesh and cable support parameters.There are 50 figures,25 tables and 99 references in this thesis.