Risk assessment of roof water disaster due to multi-seam mining at Wulunshan Coal Mine in China

In the case of multi-seam coal mining, the earlier mined coal seam affects the engineering geological conditions of the subsequently mined coal seam, which increases the risk of mine water inrush during the subsequent coal seam mining. Previously developed evaluation methods are incapable for the risk assessment of roof water disaster due to multi-seam coal mining. Taking the first mining area of Wulunshan Coal Mine in Guizhou Province, China, as the study area, and based on the deformation and failure characteristics of the overlying strata in the coal seam during mining, an engineering geological model has been developed. There are eight controlling factors in the model, which can be used to evaluate the roof water disaster in multi-seam mining. Applying the fractal theory to quantify the geological structure, and using the AHP-EM method to determine the weights of the multiple factors, a model for the prediction and evaluation of the risk of water inrush from roof in multi-seam coal mining has been developed. A new method for the prediction and evaluation of water disaster in multi-seam coal mining has also been developed, and the risk of water inrush in the first mining area has been evaluated. The 1601 # coalface and 1603 # coalface of Wulunshan Coal Mine have been selected as the verification areas, and the results calculated by the new method have been verified as accurate and reasonable. The method can therefore provide the basis and guidance for the prevention of roof water disaster in multi-seam coal mining. © 2021, Saudi Society for Geosciences.