Potential Analysis of Fault Hydraulic Conductivity During the Mining of Two Very Close Coal Seams

Accurate evaluation of fault water conductivity potential is the key to water disaster prevention and control during coal mining. In this study, we identified seven primary controlling factors of fault hydraulic conductivity. The multi-factor coupling prediction model of fault conductivity potential was constructed using a combination of IFAHP and CRITIC, and a new concept of fault hydraulic conductivity index (FHCI) was proposed. The model was successfully applied to the quantitative and fine evaluation of the water conductivity potential of the Wangzhuang and Xiaonsonglou Faults in the Jiangzhuang Coal Mine, and the accuracy of the model was verified by field investigation. The fluid–solid coupling numerical simulation was used to analyze the seepage evolution rules and activation patterns of fault bundles under repeated disturbance of the 13^–1 09 and 13^–2 21 working faces. The results showed that the water conductivity of the fault bundle was weak near the working face. Notably, there was no obvious disturbance in the two faults when only the 13^–1 09 working face was mined. Although localized failure was experienced when the mining of both the 13^–1 09 and 13^–2 21 working faces was simulated, there was no connection with the mining-induced rock failure zone. Therefore, mining of the two very close coal seams should not lead to fault activation and water inrush.