Study On Surrounding Rock Control During Fully Mechanized Mining Face Crossing Abandoned Roadway Of Yushupo Mine

Based on the engineering background of 1207 working face abandoned roadway in Yushupo Coal Mine,this paper systematically studies the stress evolution characteristics and surrounding rock deformation and migration law of the fully mechanized working face when crossing the abandoned roadway according to theoretical analysis and numerical calculation.The research is as follows:?1?According to the redistribution of stress in roadway excavation and the superposition effect of advanced abutment pressure in face mining,the stress distribution of coal pillar in abandoned roadway is analyzed theoretically.With the decrease of coal pillar,the stress evolution process presents the changing trends of saddle-shaped,single hump-shaped and cusp-shaped.The stress concentration of coal pillar is increasing.There is an empty Lane in front of the work,and the basic roof may break in advance.In this way,it will cause safety accidents such as pressure rack and roof fall.Based on the catastrophe theory,the evolution law of elastic-plastic zoning of coal pillars is analyzed,and the causes of catastrophic instability of coal pillars with decreasing width are explained.Based on the structure of masonry beam,a three-dimensional mechanics model of basic roof breakage of abandoned roadway is established,and the lowest supporting resistance is 3.62 MPa,which can make the working face pass through the abandoned roadway safely by mathematical calculation.?2?Through the numerical simulation software FLAC^3D,the law of surrounding rock movement,stress evolution and plastic zone change in the abandoned roadway are simulated and studied.It is concluded that the width of coal pillar should be greater than 10m when the filling body of abandoned roadway reaches the final strength.Then the deformation law of filling body with different strength is analyzed,and the final strength of filling body is 4 MPa,which can make the working face pass through the abandoned roadway.?3?According to the actual water temperature in the field,the final solidification strength of high-water material can be greater than 4 MPa when the water-cement ratio of high-water material is 2:1.Then,through comparative analysis,it is determined that the field filling scheme uses"segmented barrier filling method".Finally,according to the monitoring data of mine pressure and the actual effect of the site,the scheme can make the working face pass through the abandoned roadway quickly and safely.Compared with the traditional scheme,it has great advantages.There are 41 figures,7 tables and 85 references in this paper.