| For stable support of soft rock roadways under the influence of multiple disturbances,the biggest problem is that the support is difficult and the surrounding rock has a large amount of deformation.The stress environment of the surrounding rock under certain complex stress conditions is further deteriorated,and the stable support of the roadway is more difficult..The Jurassic 3-1 coal seam is mined in the Mataihao Coal Mine with a burial depth of about 400m and is found in mudstone strata.The roadway is affected by comprehensive factors such as burial depth,multiple disturbances in the working face,overlying rock movement,and hydraulic properties.The environment is complex.According to the actual situation on the site,the return flow of the 3106 working face in Mataihao Coal Mine is taken as an example to analyze.After the 3104 working face and the 3106 working face are successively mined,the roadway support system is difficult to meet the softness under the condition of multiple disturbances.The stability control of the rock roadway is particularly reflected in the serious deformation of the roadway as a whole,and the failure of the support system to varying degrees,which seriously affects the normal production of the coal mining face.Taking into account the fact that the rock strength at the top and bottom floors of the mining roadway in the Mataihao Coal Mine is low,and the mudstones are disintegrated and muddy in contact with water,the situation of the mine pressure in the roadway is taken as the research object.Research on control technology of surrounding rock in rock roadway was carried out to reform the support system of the original roadway.It was proposed to adopt high-strength prestress to allow the pressure equalizing anchor system to carry out the support reform test of surrounding rock control technology of "combination of resistance and concession",and worked in 3116.The surface return wind was successfully applied.The main research contents of the paper are as follows:(1)Three different phases of the surrounding rock stress distribution law and the influence of the backflow trough of the 3110 working face affected by the disturbance of the double roadway excavation,the first mining stop of the 3108 working face and the second mining of the 3110 working face Rock deformation law,combined with the characteristics of deformation and failure of the original support roadway,explore the main causes of roadway deformation and damage.(2)From the perspective of improving the initial support efficiency of surrounding rocks,numerical simulation methods are used to analyze the effect of different pre-tightening forces on controlling surrounding rocks,and explore the role of pre-tightening forces in controlling deformation of surrounding rocks.(3)An on-site test method is used to analyze the effect of different anchor fittings on torque conversion rate,and to explore effective ways to increase the conversion rate between torque and preload.(4)The structure function,characteristics and action mechanism of the pressure-stabilizing anchor are explained,and the load-deformation curves of different types of pressure-stabilizing pipes are obtained through a series of experiments on the pressure-bearing uniaxial load.The mechanical characteristics and key parameters of the stage are based on the actual site selection of reasonable parameters for the pressure tube.(5)Based on the theoretical analysis and numerical simulation research results,field industrial tests were carried out.Through the observation of the underground pressure of different support methods and the comparison of economic benefits,the rationality of the surrounding rock control technology in soft rock roadways under multiple disturbance conditions was verified.. |
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