Water inrush mechanism of roof bed-separation and surface-underground combination treatment technology in Yuanzigou Coal Mine

Abstract

Yuanzigou Coal Mine belongs to Yonglong Mining Area of Huanglong Jurassic Coalfield, which is located in the south-central part of the Ordos Basin, and the main water hazard type is bed-separation water inrush. Using the borehole flushing fluid leakage and borehole television observation methods, the cracking and production ratio of the No.2 coal seam fully mechanized mining face was determined by designing the pre-mining and post-mining comparison boreholes. In order to ensure the safe mining of the 1012102 working face, according to the measured results of mining overburden failure and the characteristics of the geological structure of the rock layer, based on the key layer theory and the thin plate theory, the bed-separation development position, the risk of the water inrush and the mud and sand collapse of the bed-separation were evaluated. In view of the characteristics of this kind of bed-separation water inrush with hysteresis, periodicity, accompanied by secondary disasters such as sand collapse and roof pressure, a layered water treatment technology based on the combination of surface through-type drainage hole and underground dredging hole well was proposed. The research results show that the crack-to-mining ratio is 23.68 under the geological and mining conditions, and the conditions for the formation of bed-separation in Luohe Formation, Yijun Formation and Anding Formation are all available, and the volume of the separation cavity is large, and the mine is mainly threatened by the roof separation water hazard, and the sediment will be carried once the water inrush occurs. The change of water level data and the supplementary detection of ground electric method in the mining process realize the all-round monitoring of the overlying rock separated layer water, form a pre-control technology system for the separated layer water, and ensure the safe mining of the mine.

Keywords

• mine water disaster control
• water inrush mechanism of bed-separation
• hazard assessment
• surface relief hole
• electrical exploration
• underground dredging hole