| Different from the near horizontal and gently inclined coal seams,the characteristics of the roof breaking and the regularity of the mining pressure are determined by the large dip angle of the coal seam and the non uniform filling of the collapsed gangue after mining.This paper is based on the characteristics of S2611 test face in Fengchun Coal Mine adopting the steep inclined pseudo-skewed arrangement.The theoretical analysis,numerical simulation and on-site measurement of mine pressure in the working face of the working face of the stope are carried out and tested.The hydraulic support of the working face was subjected to adaptive analysis and evaluation of the operating characteristics,verifying that the ZJY2400/8.5/15.5 support can meet the requirements for controlling the top plate.The main research contents and conclusions are as folloes:(1)The beam model of the top plate of the steeply inclined and inclined plane was established to analyze the breaking characteristics of the top plate of the working face: along the direction of advancement of the working face,the upper roof would break first,and then the middle and lower roof phases would break,showing the spatiotemporal difference Features;Along the oblique direction of the work surface,after the two ends of the top plate break,the top middle plate will break first,and the top plate forms a relatively stable hinge structure along the oblique direction.(2)The suspended roof of steep inclined oblique stope is simplified to solve the rectangular plate subjected to uniform load.By solving the top plate of rectangular stope,the internal forces of the roof rock strata under uniform load before the initial collapse and periodic collapse are analyzed.According to the stress distribution law,the maximum principal stress cloud diagrams of the upper and lower slabs of the roof rock are calculated,and the broken patterns of the roof slabs are analyzed as "OX" and "CX" type damages.Based on this,it is predicted that the parallelogram roof of the steeply inclined and pre-diagonal mining slope exhibits the initial fracture of "O-X" and the cyclical fracture pattern of "C-X".(3)The FLAC3 D software was used to construct a numerical calculation model of S2611 steeply inclined pseudo-sloping face,and the strata pressure along the strike direction of the coal seam and the direction of the inclined face was studied.The simulation results analyze the vertical stress distribution characteristics along the advancement direction of the working face and along the inclined direction of the working face.Through the simplified model,the parallelogram square roof is simulated and analyzed under the conditions of uniform load and non-uniform load.Breaking features.(4)The monitoring results of the 10#,27#,and 44# supports on the S2611 working face show that the top working face of the working face has the smallest initial pressing step,the upper working face,and the largest middle working face;the top face of the working face undergoes segmentation cycle Spontaneous fracture,the average cycle pressure step is the top of the work surface,followed by the middle,the lower part of the largest,the cycle between the upper,middle and lower pressure step difference are 11%.(5)Based on the theoretical calculations and on-site measurement of the support resistance of the support,the ZJY2400/8.5/15.5 shielded hydraulic support is highly adaptable to moderately stabilizing the steeply inclined thin seam and the following roof;the operating characteristics of the face support are evaluated and the maximum work is performed.The resistance is less than the rated working resistance of the bracket.It shows that the new hydraulic support of ZJY2400/8.5/15.5 can be well adapted to the requirements of the control roof. |
PDF Full Text Request