为了探究左权五里堠煤业上组煤老空区富水性及其对下组煤首采工作面突水的危险性，以下组煤首采面为研究背景，系统分析了研究区上下2组煤层顶底板岩性组合及水文地质条件；根据物探探测结果，在下组煤首采面巷道先后施工了20个探放上组煤老空水钻孔，发现上组煤老空水存在局部水量大、水压高、富水性分布不均的特点。在此基础上，建立了上下组煤层开采顶底板的工程地质数值模型，采用数值模拟方法对上组煤和上下组煤开采完毕后的应力场及塑性区场变化特征进行了对比分析，得到上组煤层开采后底板破坏深度为11 m，下组煤开采后导水裂隙带高度为112 m，没有波及上组煤底板破坏深度范围，与首采面实测涌水量反映的规律是一致的。根据首采面及附近2个钻孔的资料，采用2种相关经验公式类比计算了下组煤开采导水裂隙带高度，优选了可靠性较高的经验公式。

In order to research the water abundance in the goaf area of the upper coal group and the risk of water inrush to the first mining face of the lower coal group, the first mining face of the lower coal group is taken as the research background, and the lithologic combination and hydrogeological conditions of the top and floor of the upper and lower coal groups in the research area are systematically analyzed. According to the results of geophysical exploration, 20 goaf water boreholes of the upper coal group have been constructed in the roadway of the first mining face of the lower coal group. It is found that the goaf water of upper coal group has the characteristics of large local water volume, high water pressure and uneven water richness. On this basis, the engineering geological numerical model of upper and lower coal seams mining roof and floor is established. The stress field and plastic zone field variation characteristics of upper and lower coal seams after mining are compared and analyzed by numerical simulation method. It is obtained that the floor failure depth of upper coal seam is 11.0 m after mining, and the height of water-conducting fracture zone of lower coal seam is 112.0 m after mining. It does not affect the failure depth range of the upper coal floor, which is consistent with the measured water inflow by in situ of the first mining face. Finally, based on the data of the first mining face and two boreholes nearby, the height of the water-conducting fracture zone in the lower group is calculated by analogy using two relevant empirical formulas, and an empirical formula is proposed with high reliability.