Influence And Control Of Deep Seam Crossing Mining On Deformation And Failure Of Underlying Roadway In Weijiagou Coal Mine

As the depth of coal mining increases,the support of roadways becomes more and more difficult.As a main roadway serving the entire production level,the transportation roadway's stability is critical to the normal production of the mine.Affected by the deep coal seam mining,the deformation and surrounding rock control of the coal mining roadway are more complicated.Aiming at the problem of deformation and destruction of the undermining roadways in deep coal seam mining,the on-site monitoring,numerical calculation simulation and theoretical research Combined with the method,the scope of the loosening ring and the deformation and displacement law of the roadway under the coal floor across the mining floor are studied;the roadway loosening ring is measured by the geological radar and the roadway deformation is monitored by3 D laser scanner;The numerical simulation method is used to analyze the stress distribution,displacement change characteristics and roadway stability of surrounding rock under the condition of cross mining,which provides a theoretical basis for roadway stability control.The main research results and conclusions of this article are:(1)Through on-site investigation and analysis of the coal roadway with cross-mining and undercutting,the roadway collapses,bottom drums,and roadway watering are affected by the cross-mining of the overlying working face;the use of geological radar on-site detection methods and analysis to obtain the roadway surrounding The thickness of the rock loosening ring is between 3.0m-6.0m,the range is large and the distribution is irregular,and there are obvious crack fracture zones at the shoulder angles of the two sides;combined with the deformation and damage of the underpass pedestrian stone gate under the coal seam,it can be seen that-320 m transportation It is difficult to maintain the stability of the main roadway during the cross-mining by the first anchor-shotcrete support in the roadway,and it is necessary to strengthen the support of the roadway across the mining section.(2)Numerical simulation calculation analysis was used to determine the stress distribution,displacement change characteristics and roadway stability characteristics of surrounding rock under the influence of cross mining in coal seam under mining.The results of numerical calculation show that: under the influence of cross mining in the upper coal seam,work The strata of the floor and floor produce advanced supporting pressure and gradually shift to the deeper part.At the same time,after the coal seam is mined,the goaf generates pressure relief,which causes the vertical stress of the roadway to be released,causing the overall uplift of the roadway to move and deform.The most severely affected by mining face.(3)Through the comparative analysis of the field measurement and numerical simulation calculation results,the cause of the destruction of the transportation roadway under the condition of cross mining is determined;the analysis shows that the normal stress along the coal seam is released under the influence of the cross mining in the upper working face of the floor roadway,resulting in the floor The roadway moves along with the coal floor floor rock towards the mined-out area,so that the displacement of the right side of the roadway is greater than that of the left side.At the same time,the floor rises upwards,and a serious bottom drum occurs in the roadway;The swelling in water exacerbates the deformation and destruction of the roadway,which eventually leads to the destruction of the original support system of the roadway and the instability and destruction of the surrounding rock of the roadway.(4)Based on the analysis of the mechanical deformation mechanism of deep cross mining roadway,combined with the engineering geological conditions of coal seam undermining transportation roadway,the secondary strengthening support technology for coal seam undermining transportation roadway is proposed by using "U" steel telescopic support The scheme determines the supporting parameters such as the supporting resistance of the secondary support of the roadway and the spacing between the supports.(5)Through the use of three-dimensional laser scanning technology to monitor the deformation and displacement of the roadway under the condition of cross mining,and record the change of the support pressure of the roadway during the process of mining through the installation of a pressure box;the analysis of the monitoring results shows that: It maintains good stability under the protection conditions,and verifies that the U-shaped steel telescopic support support scheme can effectively control the deformation of the surrounding rock of the roadway under the cross-mining condition,and has certain reference significance for the roadway support under similar conditions.