我国西部生态脆弱区受煤矿开采影响巨大，在开采扰动下采空区上覆含水岩层遭到破坏，易导致水资源流失、土地荒漠化等问题，为此人工引导裂隙自修复进而保护或恢复地下水位至关重要。

以内蒙古布尔台煤矿22108工作面为工程背景，采用物理相似试验、数值计算与理论分析等方法，深入研究开采扰动和裂隙水渗流耦合作用下生态脆弱矿区煤层覆岩裂隙渗流演化规律，并对覆岩裂隙自修复效果进行表征分析。

结果显示：(1)基于位移差值系数，裂隙发育总体表现为采空区两侧高度发育、中部压实的“双峰”状分布。(2)工作面推进78 m时，导水裂隙已发育至第Ⅱ含水层，此时位移差值系数为0.25，并出现突变现象，渗流演化分布与覆岩裂隙发育开始呈现强相关性，位移差值系数由0.25增大至0.40时，覆岩隔水层含水率平均增加2.0%，且开采边界附近裂隙导流能力大于其采空区中部覆岩裂隙导流能力。(3)开采结束后，第Ⅱ含水层水位较开采前有所下降，平均水位下移13 m，由于采空区压实及覆岩采动裂隙闭合形成新的含水层，地下水流场实现自身演替。(4)经长期残余沉降、应力压实等多因素耦合影响，覆岩裂隙岩体表现出隔水层降渗的自修复现象，根据模拟开采完毕8.3 a后自修复结果显示，基于导水裂隙渗流速度求得采空区中部覆岩区域自修复率为45.5%~55.6%，开采边界区域自修复率为6.3%~25.0%；基于覆岩含水率求得采空区中部区域自修复率为33.3%~35.7%，开采边界区域自修复率为10.0%~18.2%。研究成果为揭示西部生态脆弱矿区覆岩裂隙渗流演化规律及其自修复特性的定量表征提供了理论依据。

The ecologically vulnerable areas (EVAs) in West China have been significantly affected by coal mining. In these areas, aquifers overlying goaves have been damaged under mining disturbance, being prone to cause water resource loss and desertification. Hence, it is crucial to guide the self-sealing of fractures artificially to preserve and further restore the groundwater level.

This study investigated mining face 22108 in the Buertai coal mine in the Inner Mongolia Autonomous Region. Based on the physical simulation experiments using similar materials, numerical calculations, and theoretical analysis, this study delved into the seepage evolution patterns of fractures in the overburden of coal seam 2-2 in the ecologically vulnerable mining area under the coupling effect of mining disturbance and fracture water seepage. Moreover, this study characterized and analyzed the self-sealing effect of overburden fractures.

The results indicate that the overall fracture development, derived using displacement difference coefficients, exhibited a bimodal distribution characterized by highly-developed fractures on both sides of the goaf and compaction in its central part. As the mining face advanced for 78 m, hydraulically conductive fractures propagated to the No.Ⅱ aquifer, corresponding to a displacement difference coefficient of 0.25 and an abrupt change in moisture content. In this case, the evolution and distribution of seepage began to correlate passively with the development of overburden fractures. As the displacement difference coefficient increased from 0.25 to 0.40, the average moisture content of aquicludes in the overburden increased by 2.0%. Concurrently, fractures near the mining boundary exhibited higher conductivity than overburden fractures in the central part of the goaf. After coal mining, the groundwater level in the No.Ⅱ aquifer declined by 13 m on average, and new aquifers were formed by the compaction of the goaf and the closure of mining-induced overburden fractures, suggesting the succession of the groundwater flow field. Under the long-term influence of multiple factors like residual subsidence and stress-induced compaction, the fractured rock masses in the overburden showed a self-sealing phenomenon as evidenced by seepage reduction in aquicludes. According to the simulation results of self-sealing 8.3 years after coal mining, the fracture self-sealing rates, calculated using the seepage velocity of hydraulically conductive fractures, ranged from 45.5% to 55.6% in the central part of the goaf and from 6.3% to 25.0% in the mining boundary areas. In contrast, the self-sealing rates calculated based on the moisture content of the overburden ranged from 33.3% to 35.7% in the central part of the goaf and from 10.0% to 18.2% in the mining boundary area. The results of this study provide a theoretical basis for revealing the evolution patterns of seepage in overburden fractures in ecologically vulnerable mining areas in West China and quantitatively characterizing the self-sealing capacity of fractures.