目前，矿山生态保护修复迫在眉睫，大规模的开采遗留下了土地损毁、地下水系统破坏等诸多生态环境问题。为了给生态保护修复提供可行的建议，本文以韩城矿区桑树坪煤矿为例，运用相似材料模拟物理实验、三维地质建模及数值模拟分析等研究手段，对覆岩移动破坏特征、开采沉陷对地表的损伤效应和“覆岩破坏—地表沉陷—土体破坏”传导驱动机制进行了综合分析探究，得到了以下主要结果：

（1）覆岩破坏特征表现形式为开采条件下，水平方向和垂直方向的拉应力共同作用于采空区上覆岩体，移动变形从下至上传导，先以离层形式体现出来，纵向离层发育较多，横向裂隙发育较少。而后伴随垮落体的产生，破碎岩体以非紧密接触形式堆积，其周围覆岩持续性压实。覆岩破坏沿着上行裂隙依次传递，岩体内应力得以释放，为下沉盆地的形成提供了条件，同时引发了裂隙的开闭现象。

（2）覆岩破坏是地表沉陷的基础，起伏地形中变化的坡体产状和黄土垂直节理是地表沉陷的影响因素。三者共同作用下，加剧地表沉陷现象的发生。土体在拉伸作用和剪切作用下，超过对应的临界值发生破坏，地表受到损伤，研究区地表发生拉伸变形的水平变形临界值为1.4mm/m。最大剪应力随着开采的进行，从0.19MPa增大到0.3MPa，剪切破坏主要分布于采空区上方地表低山丘陵区及黄土台塬区。拉伸破坏产生地裂缝，这些破坏形式使植物根系受到错断、拉出、皮裂等损伤，根系固土能力减弱，短期内损伤不明显，后期植被损伤显著。形成了“覆岩破坏—地表沉陷—土体破坏”的传导驱动机制。

（3）裂缝发育最明显位置处的水平应变与温度的拟合相关系数的平方（P0点的R²=0.647、P1点的R²=0.672、P5点的R²=0.634）表明裂缝与水分赋存情况存在相关性。开采过程中产生的裂缝会改变表层土壤水分的赋存情况，裂缝形成初期会对水分起到汇集的作用，导致土壤营养物质随着裂缝发生渗流，裂缝经过“开闭”之后，处于稳定期时，对水分起到加速蒸发的作用，增大了蒸发面积。最大下沉量所处位置位于切眼与沉陷区中央之间，比较植被生长形态的分形维数，切眼处从开采前1.587下降到1.288下降了0.299；沉陷区中央从1.515下降到1.413，下降了0.102；停采线从1.419下降到1.32，下降了0.099。由此可以看出，裂缝较发育周围的植被生长状况比其它位置的较差。植被在开采过程中受影响较小，在开采结束后随着时间的推移受影响程度大。开采初期的物理损伤将直接影响到地裂缝周围植物，后期土壤理化性质的改变会间接影响整个植被，且影响程度大大增加。因此生态修复应该先处理地裂缝，防止其引发土壤理化性质的改变。

At present, the ecological protection and restoration of mines are urgent, and large-scale mining has left many ecological and environmental problems such as land damage and groundwater system damage. In order to provide feasible suggestions for ecological protection and restoration, this article takes the Sangshuping coal mine in Hancheng mining area as an example, and uses research methods such as similar material simulation physical experiments, three-dimensional geological modeling, and numerical simulation analysis to comprehensively analyze and explore the characteristics of overlying rock movement and damage, the damage effect of mining subsidence on the surface, and the transmission driving mechanism of 'Overburden failure - surface subsidence - soil failure'. The following main results are obtained:

(1) The characteristic manifestation of overlying rock failure is that under mining conditions, the horizontal and vertical tensile stresses jointly act on the overlying rock mass in the goaf, and the movement and deformation are transmitted from bottom to top, first manifested in the form of separation layers. Longitudinal separation layers are more developed, and transverse fractures are less developed. Subsequently, accompanied by the occurrence of collapse, the fractured rock mass accumulates in a non close contact form, and the surrounding overlying rock is continuously compacted. The failure of the overlying rock is transmitted sequentially along the upward cracks, and the stress inside the rock mass is released, providing conditions for the formation of a sinking basin and triggering the opening and closing of cracks.

(2) The failure of overlying strata is the foundation of surface subsidence, and the changing slope occurrence and vertical joints of loess in undulating terrain are the influencing factors of surface subsidence. Under the joint action of the three, the occurrence of surface subsidence is exacerbated. Under the action of tension and shear, the soil fails beyond the corresponding critical value, causing damage to the surface. The critical horizontal deformation value for tensile deformation on the surface of the study area is 1.4mm/m. The maximum shear stress increases from 0.19MPa to 0.3MPa as mining proceeds, and shear failure is mainly distributed in the surface low mountain and hilly areas above the goaf and the loess plateau area. Tensile damage produces ground fissures, which cause damage to plant roots such as dislocation, pulling out, and skin cracking. The soil fixation ability of the roots is weakened, and the short-term damage is not significant, while the later vegetation damage is significant. A conduction driving mechanism of "overburden failure surface subsidence soil failure" has been formed.

(3) The square of the fitting correlation coefficient between horizontal strain and temperature at the most obvious location of crack development (R²=0.647 at point P0, R²=0.672 at point P1, and R²=0.634 at point P5) indicates a correlation between cracks and water occurrence. The cracks generated during the mining process will change the occurrence of surface soil moisture. In the early stage of crack formation, they will play a role in collecting water, causing soil nutrients to seep along with the cracks. After the cracks pass through the "opening and closing" process and are in a stable period, they will accelerate the evaporation of water and increase the evaporation area. The maximum subsidence is located between the cut hole and the center of the subsidence area. Comparing the fractal dimensions of vegetation growth morphology, the cut hole decreased by 0.299 from 1.587 before mining to 1.288; The central subsidence area decreased from 1.515 to 1.413, a decrease of 0.102; The stopping line decreased from 1.419 to 1.32, a decrease of 0.099. From this, it can be seen that the vegetation growth around the well-developed cracks is worse than that in other locations. Vegetation is less affected during the mining process and is more affected over time after the mining is completed. The physical damage in the early stage of mining will directly affect the plants around the ground fissures, and the changes in soil physicochemical properties in the later stage will indirectly affect the entire vegetation, and the degree of impact will greatly increase. Therefore, ecological restoration should first deal with ground fissures to prevent them from causing changes in soil physical and chemical properties.

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