Water Hazard Assessment in Active Shafts in Upper Silesian Coal Basin Mines

Since 1976, there have been six inrushes of water into shaft mine workings in the Upper Silesian Coal Basin in Poland, with two of the more serious events occurring during the last 3 years. A safety assessment was conducted, considering inflow intensity, the amount of suspended material contained in the water flowing into the shaft, the proportion of water-bearing formations in the vertical profile, the condition of the shaft lining and safety pillar, and the history of the shaft. A risk assessment system is proposed to classify mine shafts with respect to the risk of a water hazard occurring, based on these factors. Each of the risk factors was assigned a weight, based on their relative significance, and then a method of evaluating each of these factors was developed. The proposed approach may be the basis for a more detailed, expert system for timely assessment of water hazard risk analysis. It may also be possible to adapt it to different geological and mining conditions.