Study on development law of water conducting fracture zone in coal seam mining under burnt rock aquifer

Abstract

In order to study the development law of water conducting fracture zone in coal seam mining in A’ai Mining Area, Xinjiang, 1013 working face of a coal mine is selected as the research object. The development height of water conducting fracture zone in coal seam mining is analyzed by the combination of numerical simulation, underground segmented water pressure detection and theoretical calculation. The results show that the stress concentration phenomenon appears around the working face after coal seam mining, and the stress is mainly distributed on the coal pillar 0-20 m away from the coal wall. A pressure relief zone is formed in the roof rock mass above the goaf, and the maximum pressure relief zone is located at the center line of the goaf. With the increase of mining distance, the stress gradually increases, and the development height of water conducting fracture zone gradually increases. The maximum development height of water conducting fracture zone obtained by numerical calculation is 53.50 m, and the fracture mining ratio is 16.72. The development height of water conducting fracture zone in 1013 working face is detected by underground segmented water pressure method. The maximum height of water conducting fracture zone is 50.08 m and the fracture mining ratio is 15.65 times. According to the empirical formula, the development height of water conducting fracture zone is 42.30 m and 45.78 m respectively, and the fracture mining ratio is 13.22 times and 14.31 times respectively. The development height of water conducting fracture zone obtained by the three methods is close, which proves that the results are reliable.

Keywords

• xinjiang a’ai mining area
• burnt rock
• numerical simulation
• segmented water pressure
• water conducting fracture zone