关键词: 陕北矿区, 烧变岩含水体, 风化基岩含水层, 顶板突(涌)水, 富水性评价指标

Abstract: There are many layers of burnt rock aquifers with extremely uneven water abundance which is interbedded and overlapped with fissure developed weathered bedrock aquifers in the coal seam roof of the northern Shaanxi mining area. It is of great significance for mine safety to accurately evaluate the water abundance of both and scientifically predict the water inrush hazard of coal seam roof. This paper takes 5-2 coal in Zhangjiamao mine field as an example. The evaluation indicators of water abundance are selected based on the hydraulic characteristics, aquifer thickness and lithologic difference of weathered bedrock and burnt rock of 2-2 coal, 3-1 coal and 4-2 coal. To improve the method of weight determination, comprehensive weighting method based on AHP and the entropy weight were adopted to accurately characterize the spatial water-abundance characteristics of the target aquifers. The calculation method of the guided height based on the correction coefficient is put forward and the thickness data of the guided fractures entering the aquifer are drawn into the partition diagram of the roof cracking stability. By superimposing two kinds of geospatial information, the classification and zoning prediction of roof water inrush risk of 5-2 coal in Zhangjiamao coal mine are realized. The research result provides a new method for prediction of roof water inrush risk under the complex geological conditions of multiple aquifers discontinuous interbedded and an important basis for roof water hazard prevention and control.