Study On The Technology Of Gob Side Entry Retaining Along The 13165 Air Return Way In Tucheng Coal Mine

Tucheng Coal Mine belongs to coal and gas outburst mine.The 13165 working face is located in the mining area of NO.13.The mining coal seam is NO.16,the coal seam dip angle is 15°,and the average coal seam thickness is 3.5 m.It adopts comprehensive mechanized coal mining method and all slumping method management about the roof,13165 return airway section shape is a straight wall semi-circular arch,the wall height is 0.6 m,the arch height is 2.5 m,the roadway width is 5.0 m,and the surrounding rock control is carried out by the integrated support method of the anchor cable.In order to realize the reuse of the roadway,the13165 return airway is implemented with the roadway retaining technology.The stability of the roadway along the empty roadway is affected by the immediate roof and the basic roof collapse.At the same time,it is related to the two-way breaking of the roof during the graded up-and-down expansion of the fallen layer and the secondary collapse.The long-term stability of the roadway can be divided into four stage: the excavation deformation stage,the pre-harvest deformation stage,the gradual deformation stage of the retaining lane and the deformation stabilization stage.The stresses affecting the stability of the roadway mainly include immediate roof pressure,fracture pressure and stratified slump pressure.According to the numerical simulation of different cutting heights and supporting schemes,the cutting top pre-cracking can play the role of blocking the mining surface stress transmission and controlling the joint movement of the roadway roof and the working face roof,from the construction convenience and cutting top Based on the analysis of the effect,it is determined that the appropriate cutting height is 5.0 m.The surrounding rock support of the 13165 working face is: bolt type ?20 mm×2500 mm,spacing between rows is 800 mm×800 mm,and the bottom angle is bolt type is ?20mm×1800 mm,which is at an angle of 15° to the horizontal direction,and the rest is perpendicular to the surface of the roadway;the anchor cable type is ?21.6 mm×8000mm,and the spacing between the rows is 1600 mm×3200 mm.The 13165 working face returning wind road adopts pre-splitting blasting cutting technology to carry out the roadway along the empty road.The roadway has a net width of 2500 mm and a net height of 2500 mm,and a set of anchor cables with a spacing of 800 mm is arranged on the roof.Gas highlights the mine,and the process of retaining the lane should pay attention to gas and ventilation management.The displacement monitoring along the roadway shows that the deformation of the top and bottom of the roadway is generally 160 mm,the deformation of the two sets is 240 mm,and the amount of the roof is 9 mm.During the roadway,the average value of the top bolt support is 85 k N,the average stress of the top anchor cable is 210 k N,and the average force of the anchor bolt is 45 k N.The surrounding rock of the roadway is well controlled,which can meet the normal safety production requirements of the working face.