Prediction of the Height of Water-Conductive Fractured Zone under Continuous Extraction and Partial Backfill Mining Method—A Case Study

Longwall backfill mining effectively mitigates the height of water-conductive fractured zone (HWCFZ), preventing it from reaching overlying aquifer and thus preserving groundwater. However, has disadvantages insufficient filling time space as well mutual constraints between mining. A novel continuous extraction partial (CEPB) water-preserving method was therefore proposed. The analytic hierarchy process (AHP) employed to identify factors affecting HWCFZ CEPB, five main factors, namely, hard-rock lithology ratio, depth, width Wongawilli protective block, were determined based on weight distribution. UDEC software used establish a numerical model simulate under factors. By using multiple linear regression analysis simulation results, for predicting established. It applied in colliery Yu-Shen area, 57.7 m, 9% higher than that borehole television logging 53.1 m field measurement, indicating its rationality. Subsequently, generalized whole thematic map thickness CEPB longwall caving obtained. criterion equivalent permeability coefficient is then proposed, which can provide guidance parameters optimization CEPB.