Risk Prediction of Water Inrush from Roof of Ultra Thick Coal Seam Based on GIS

Abstract

To solve the difficulty of predicting the risk of water inrush from the roof of the main coal seam in the early mining area of Xiaozhuang Coal Mine, the analysis shows that the source of water inrush is the aquifer of Luohe Formation. Taking into account the importance of the indicators and the ease of data acquisition, four indicators are selected, such as aquifer thickness, brittle to plastic rock ratio, ratio of cores taken and lithology structure index. AHP method and entropy weight method are used to carry out the index weighting comprehensively, and a water-rich partition map is drawn on the GIS platform by linear weighting. It is verified that the zoning method is reliable. The ratio of the height of the fractured zone to the mining height is determined to be 18.8, and the safety evaluation map of roof overburden cracking is drawn. The water-rich zoning map is combined with the safety evaluation map of roof overburden cracking to obtain the prediction map for water inrush risk. The results show that the water richness of the aquifer in the Luohe Formation from the southeast to the northwest of the study area gradually increases, and the risk of water inrush alternately increases. In general, the water inrush risk of the aquifer in Luohe Formation of the study area is high.

Keywords

• water inrush risk in roof
• gis
• luohe formation aquifer
• water-rich zone
• cracking to mining thickness ratio