Study On The Combined Control Technology Of The Surrounding Rock Of The Large Roadway Group Of No. 2 Well In Huangling

Huangling No.2 mine adopts the method of inclined well development,the mine adopts single level and split area mining,the roadway group of Huangling No.2 well(four large lane)are arranged along the coal seam,and the layer seam in the roadway is more stable and the structure is simple.Based on the support theory and the control technology of roadway surrounding rock,this paper analyzes in depth the disturbance law between large roadway of coal seam with the background of Huangling No.2nd well seam large roadway group by means of mechanical derivation,numerical simulation,laboratory experiment,drilling peep and field test.The support scheme of "anchor net spraying + length drilling grouting" has been formulated,and the test has been successful in No.2nd Auxiliary Lane and Tape Lane of Huangling No.2nd well,which effectively controls the influence between alleys and the deformation of roadway surrounding rock.The main conclusions available are as follows.1)Through the analysis of mechanics model of single roadway and multi-roadway group,it is concluded that the main factor affecting the stability of roadway is the roadway spacing(the width of coal pillar)under static pressure.Among various roadway layout modes,horizontal layout in the same level has greater advantages in economic benefits and roadway stability.Through theoretical calculation and numerical simulation,it is concluded that when the roadways of Huangling Coal Mine are laid out in the horizontal 40 m type,under the static pressure condition,the influence of the stress increase caused by roadway excavation is the least,so the optimal scheme is to arrange four roadways with the horizontal distance of 40 m.2)In staggered excavation of roadway,when single roadway staggered excavation,the area of 50 m and more than 150 m is the stable area between roadways.When staggered excavation is carried out,the heading support of back-driving roadway is strengthened in the range of 50 m to 100 m.Among the three tunneling schemes,the "concave" shape tunneling scheme is better than the other two,which meets the needs of alternating operation in Huangling Mine.When the staggered distance between the two side roadways and the inner roadway is greater than 50 m,the roof support strength of the inner roadway will be strengthened.3)Loose circle test was carried out in Huangling No.2 coal seam roadway group under mining disturbance and no mining disturbance.Loose circle ranged from 1m to 4m.The technology of yielding pressure anchor cable was used in the reinforcement scheme,and the idea of "anchor net shotcrete + long and short hole grouting" was put forward.4)The support scheme with anchor net cable and long-short borehole grouting as the core was developed for industrial test.The long-short borehole grouting effectively improved the properties of surrounding rock,improved the integrity of cemented cracks,improved anchorage capacity of anchor cable,effectively reduced the breakage rate of anchor cable,and effectively controlled the roof separation layer,the maximum separation layer is not more than 18 mm.The reinforcement scheme can effectively control the side wall,and within four months after construction,the two sides can move no more than 150 mm.The reinforcement scheme was more successful in the field test.