Coal Engineering ›› 2024, Vol. 56 ›› Issue (10): 90-99.doi: 10.11799/ce202410010

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Study on mine pressure manifestation in the working face of large-depth “Three-soft” thick coal seams with consolidation

  

  • Received:2024-09-09 Revised:2024-09-15 Online:2023-10-20 Published:2025-01-16

Abstract: Under the condition of ‘Three-soft’(soft immediate roof, soft coal, and soft immediate floor) in large depth of burial, Xinhu Coal Mine,Huaibei City,the applicability of hydraulic support in No. 818 longwall top coal caving face is analyzed, and the hydraulic support automation system of the No.818 intelligent mining face is introduced. Through theoretical calculation, the max working resistance of the hydraulic support is 9940 KN. By analyzing the measured data in the field, it can be seen that the working resistance of the hydraulic support in the middle is the highest, followed by the Headgate part, and the Tailgate part is the smallest. The working resistance of the front column of the working face is larger than that of the rear column, when the working face is under pressure, the working resistance of the front column of the hydraulic support is 44.5% larger than that of the rear column on average, the ratio of the working resistance of the front column to that of the whole frame is roughly in the range of 0.57 to 0.74, and the average working resistance of the hydraulic support in the working face is 28.11 MPa. The method of calculating dynamic load is more suitable for calculating the working resistance of the hydraulic support in the working face of 818, and the calculation of the working resistance of the hydraulic support is more suitable for the calculation of the hydraulic support in the working face. The dynamic load calculation method is more suitable for the calculation of working resistance of No.818 working face, and the reasons for the bottoming of hydraulic support were analyzed, and the control measures of hydraulic support were proposed. Through numerical simulation, the influence range of the working face over-support pressure is 110 m in front of the coal wall, the peak stress in the middle of the working face is the largest, followed by the lower part, and finally the upper part, and the peak stress occurs 12 ~ 19 m in front of the coal wall, and it can be seen that in the range of 105 m outward of the coal wall, the bottom of the roadway dropsy and the deformation of the two gangs are relatively large, and the top of the roadway plate sinking and the bottom of the dropsy are more obvious, based on which the prevention of roadway bottom dropsy is proposed. On this basis, the relevant measures to prevent the dropsy of the roadway are proposed, in order to provide reference for the working face in Huaibei mining area and similar conditions.

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