Feasibility analysis of gob-side entry driving technology with flexible molded concrete in 52607 working face in Daliuta Coal Mine
In response to the problems of large deformation of surrounding rock,large amount of trimming work,and poor stability of surrounding rock when using gob-side entry retaining technology with flexible formwork concrete for thick coal seam working face,it was proposed to adopt flexible formwork concrete gob-side entry driving with roof cutting and pressure relief technology.The feasibility of this technology in 52607 working face was analyzed through theoretical calculation and numerical simulation.The results showed that when the flexible form work concrete wall was 1.2 m thick and 4.3 m high,the maximum load acting on the wall in the vertical and horizontal directions by the overburden self-weight was 5 740.36 kN/m2 and 101.20 kN/m2,respectively,which were significantly lower than the comprehensive bearing capacity of the wall,and the safety factor was 2.25;considering the lateral pressure caused by the collapse of gangue on the wall,the anti-slip coefficient was 31.56,which was much higher than the standard value;dring the mining of 52607 working face,the plastic zones of the wall lagging behind the working face were located at both the top and bottom,with a relatively small impact range and a maximum of only 0.74 m;When advancing the working face,the peak value of the advance support pressure was located 10 m in front of the working face,at 10.24 MPa,and the stress peak inside the wall was located at the bottom of the roadway side,with a maximum of 9.25 MPa.The maximum deformation value between the roof and floor and between the two sides of the transportation roadway was 107.2 mm and 69.4 mm,respectively,both within a reasonable range.The results indicated that the application of gob-side entry driving technology in similar geological conditions of the 52607 working face and the No.52 coal seam had certain feasibility.
gob-side entry drivingflexible formwork concreteroof cutting and pressure reliefsurrounding rock stability
NETL
NSTL
万方数据
