Water-preserving coal mining method for multi-seam mining of ecologically vulnerable area

Abstract

The invention discloses a water-preserving coal mining method for multi-seam mining of an ecologically vulnerable area. According to statistics of average measured values of ratios of heights of collapsed zones to the mining height and ratios of heights of fractured zones to the mining height of mining areas of the same kind, the ratio of the height of the collapsed zone to the mining height and the ratio of the height of the fractured zone to the mining height are 5.7 and 17.5 respectively, maximum heights of the collapsed zone and the water-diversion fractured zone which are formed after mining of four seams are predicted under the comprehensive mechanical high-intensity mining condition, results indicate that if the upmost 2<-2>th seam is mined firstly, formed water-diversion fractures of the 2<-2> seam enable precious ecological ground water to seep underground and be discharged out of a well field; however, if 5<-2>th, 4<-2>th and 3<-1>th seams are firstly and sequentially mined from bottom to top and the 2<-2>th seam is mined finally, the ecological ground water can enter a reconstructed water-bearing layer formed after coal mining, so that the purpose of water-preserving coal mining in the range of the well field is achieved.

Description

technical field [0001] The invention relates to a multi-coal seam mining method, in particular to a water-preserving coal mining method for multi-coal seam mining in an ecologically fragile area. Background technique [0002] The Jurassic coalfield in northern Shaanxi is located in the border zone between the Mu Us Desert and the Loess Plateau in Northwest China. The surface of this area is the Mu Us Sandy Land with a fragile ecological environment, and the widely distributed Salawusu Formation (Q 3 s) Underground water is the coal resource formed in the Jurassic period, which constitutes an organically connected ecological environment-water resource-coal resource system in the vertical space. Diving in the Salawusu Formation is the main source of domestic water for local residents, and it is also an important guarantee for the local ecological environment, so it is called ecological diving. Underground coal mining will inevitably form caving zones and water-conducting fiss...

AI Technical Summary

Problems solved by technology

For example guide, mine 2 -2 The height of the water fissure zone in the coal seam shall not be greater than 45.6m, mining 3 -1 The height of the water-conducting fissure zone in the coal seam shall not be greater than 81.38m. -2 The height of the water-conducting fissure zone in the coal seam shall not be greater than 123.17m. -2 The height of the water-conducting fracture zone in the coal seam cannot be greater than 195.03m

Images