Risk assessment of roof water inrush in No. 8 coal seam of Jurassic system Yan'an Formation in the first mining area of Xinzhuang Coal Mine in Ningzheng Mining Area

The unclear understanding of the hydrogeological conditions of Xinzhuang Coal Mine, especially the water source and mechanism of mine water inrush, directly affects the safety, efficiency, and green mining of Xinzhuang Coal Mine.This time, through water quality analysis and calculation of the development height of the water conducting fracture zone, it is determined that the water source of the roof of the No.8 coal seam in Xinzhuang Coal Mine is water inrush; At the same time, based on the analysis of aquifer water abundance based on six main control factors: aquifer thickness, unit water inflow, geophysical exploration aquifer water abundance anomaly area, borehole consumption, core recovery rate, and formation brittleness plasticity ratio, and based on the safety analysis of caving under fully mechanized top coal caving mining conditions, the risk of water inrush from the roof of No. 8 coal seam in the first mining area was evaluated through multiple results superposition.The results show that the source of water inrush from the roof of the mine is the sandstone pore fissure aquifer of the Luohe Formation of the Lower Cretaceous Zhidan Group and the composite confined aquifer of the upper and middle sandstone of the Middle Jurassic Zhiluo Formation and Yan'an Formation (above the roof of the 8th coal seam). The sandstone pore fissure aquifer of the Luohe Formation of the Lower Cretaceous Zhidan Group is the main source of disaster.The development height of the water conducting fracture zone of the No. 8 coal seam in the first mining area can communicate with the sandstone aquifer of the Luohe Formation, and the entire area of the first mining area is a risk area of cracking.In the roof water inrush danger zone of Coal Seam 8, Zone I is mainly distributed in the north and central west of the first mining area, Zone II is mainly distributed in the middle and central west of the first mining area, Zone III is mainly distributed in the middle and south of the first mining area, and Zone IV is mainly distributed in the east and south of the first mining area. © 2023 Coal Science and Technology. All rights reserved.