Stress Characteristics and Ground Support Application in the Short-Distance Mining Face Under a Loose Aquifer

This study investigates the impact of weak water-rich aquifers overlying shallow-buried thin bedrock coal seams on mining support systems. By applying Terzaghi’s theory to the evolutionary characteristics of the overburden structure in loose aquifers, a mechanical model for load transfer from the aquifer is established, and a calculation formula for the maximum working resistance of the support is derived. The results are validated using field mine pressure data from the 1010–1 working face of Wugou Coal Mine. The findings show that the overlying load of the key stratum is positively correlated with the water pressure in the aquifer; the higher the water pressure, the greater the overlying load, which leads to increased instability of the key stratum and a higher likelihood of support crushing. Additionally, the thickness of the bedrock is negatively correlated with the aquifer water pressure load transfer coefficient, meaning that a thicker bedrock layer reduces the impact of the aquifer’s water pressure on the key stratum, with a critical thickness of 50 m. Moreover, the working resistance of the support is positively correlated with the water pressure, and the pressure intensity at the working face in the aquifer-covered area after grouting reconstruction is about 33% higher than in non-aquifer-covered areas. The results provide a theoretical basis for safe mining in similar geological conditions and offer guidance for the selection of support systems.