针对我国内蒙古、陕西、山东和甘肃等深部煤炭开采矿区面临水文地质条件复杂，导致顶板疏水量大，覆岩承压含水层疏水诱发的冲击地压灾害日益凸显的问题，开展了覆岩承压含水层疏水过程中煤层应力场演化规律研究。

通过实验室分级加载条件下的煤体电荷感应试验与煤矿现场顶板疏水前后的电荷参数监测相结合的方法，系统研究了不同应力水平下煤体感应电荷的变化特征，以及顶板疏水过程中应力场的动态转移规律。

实验室研究表明，随着加载应力的逐级增大，煤样感应电荷量呈现非线性增长趋势，有效反映了煤体所受的应力水平。现场监测则揭示了顶板疏水过程中，富水区内电荷量均值和变异系数减小，而富水区外一定范围内电荷量先增后减，出现峰值点，表明应力从富水区边缘向外动态转移，并存在转移范围阈值；此外，基于富水区外各测点电荷量峰值的出现时间，得出了不同疏水量下的应力转移特征，即缓慢转移–快速转移–缓慢转移三个阶段。最后，通过大直径钻孔卸压试验，验证了该技术在降低顶板疏水条件下应力集中、防治冲击地压方面的有效性。研究成果可为顶板富水矿井冲击地压的预测与防治提供了理论依据和技术支持。

Deep coal mining areas in regions such as Inner Mongolia, Shaanxi, Shandong, and Gansu in China feature intricate hydrogeological conditions, which lead to substantial water drainage from roofs and increasingly prominent rock bursts induced by water drainage in overburden confined aquifers. This study investigated the evolutionary patterns of the stress field in coal seams during the water drainage of overburden confined aquifers.

By combining the laboratory charge induction experiments of coals under graded loading with charge monitoring pre- and post-water drainage from a roof in a coal mine, this study systematically examined the variations of induced charge in coals under different stresses, along with the dynamic stress transfer pattern of coals during water drainage from roofs.

Laboratory experiments indicate that the induced charge in coal samples exhibited a nonlinear growth trend with a gradual increase of loaded stress, effectively accounting for the stress applied to coals. Field monitoring results reveal that during the water drainage from the roof, the average charge and its coefficient of variation (CV) decreased within the water-rich zone while the charge first increased and then decreased in a certain range outside the water-rich zone, peaking at a certain position. This finding suggests that the stress was dynamically transferred outwards from the margin of the water-rich zone, with the presence of a transfer range threshold. Based on the times when the charge peaked at various monitoring points outside the water-rich zone, this study determined the stress transfer characteristics under different water drainage quantities. Specifically, the stress underwent slow, fast, and slow transfer stages sequentially. The experiments of pressure relief through large-diameter boreholes verified the effectiveness of the proposed technology in reducing the stress concentration under the water drainage from roofs and preventing rock bursts. The results of this study provide a theoretical basis and technical support for the prediction, prevention, and control of rock bursts in mines with water-rich zones in roofs.