Research On Rapid Excavation Technology Of Coal Roadway And Temporary Support

In China's coal mines,due to the continuous improvement of mining capacity and efficiency,a large number of fully mechanized mining faces of millions of tons or even 10 million tons have emerged,resulting in a significant increase in the number of new mining lanes.However,the rapid excavation,support technology and mechanical equipment of coal roadway are lagging behind the development of fully mechanized mining.The excavation speed of the roadway obviously does not reach the large demand of mining.The problem of the imbalance of mining scale is widespread in the national coal industry.In the coal mine safety accident,the roadway boring and the top-down accidents accounted for a high proportion.Through the analysis and research on the factors affecting the rapid excavation of coal roadway and the existing advanced temporary support technology,it is found that the rock breaking efficiency,drilling efficiency and transportation efficiency of the roadheader basically meet the requirements.However,there are still many problems in the construction technology and the excavation method.The reasonable maximization of the empty top distance is a way to effectively improve the speed of excavation.Temporary support is the bottleneck restricting the rapid excavation of coal roadway.The existing equipment is based on the roadheader to develop supporting equipment.In order to make a qualitative leap in the excavation,it is urgent to develop an integrated mechanical automation equipment with the support technology as the main body.In view of the shortcomings of the construction process and the way of excavation,the cutting process and the supporting process are studied and analyzed under the construction technology of the single anchor rig of the cantilever type boring machine.Through the limit shape analysis of the roadheader section and the numerical simulation analysis of three kinds of cutting paths of "snake shape","return shape" and "spiral shape" through finite element program,Obtaining the "snake-shaped" optimal cutting path from bottom to top is most beneficial to the stability of the surrounding rock of the roadway.It is proposed that the heading machine body will not move left and right,the coal roadway section will be cut once and quickly,and the temporary support and permanent support will be combined into one to improve the tunneling speed.Taking the 50110 return wind roadway of Wei bei Dong dong Coal Industry Co.,Ltd.as the engineering background,the effects of different air-top distance,section shape and roadway depth on the stability of roadway surrounding rock are studied by the Midas GTS NX finite element program.The displacement and plastic zone distribution of surrounding rock in rectangular roadway are obtained.The cross section of the straight wall archway can increase the air-top distance from 4m to 4.8m.In view of the defects of the existing temporary support equipment,the advantages and improvement ideas suitable for the temporary support equipment of the existing excavation process are proposed.A temporary support equipment structure for the construction of the cantilever type roadheader is designed.Two kinds local structure of support equipment are proposed,which are beneficial to rapid construction.The force characteristics of the main load-bearing members of the support equipment are analyzed by numerical simulation.