黄土沟谷区浅埋煤层开采地表非连续性的开裂损害，不仅引发了许多生态环境问题，也加大了生态修复难度，严重威胁着矿区生态安全。浅埋煤层开采地表非连续变形是特殊地质条件下覆岩破坏移动的结果，为更加系统地研究覆岩破坏对地表非连续性损害的影响规律，以陕北安山井田125203工作面为地质原型，采用离散元数值模拟与物理相似材料模拟相结合的方法，模拟分析了覆岩及地表破坏、岩块尺寸分布及力链演化等特征，揭示了覆岩力链演化对块体分布和地裂缝发育的影〖JP2〗响规律，阐明了覆岩破坏块体对地表非连续损害的控制效应。研究结果表明：黄土沟壑缓坡地带浅埋煤层开采覆岩垂向变形与水平移动受地形影响较大；覆岩破坏形成双分层块体结构，分层界面距煤层底板11.0 m，下分层块体平均长度小于5.0 m，上分层大于5.0 m，覆岩块体平均长度随岩层至煤层底板距离的增大呈幂指数增长特征，地表块体平均长度由坡底至坡顶逐渐增大；下分层垮落压实的岩块结构和应力集中的力链结构，影响着上分层块体和力链的分布及地裂缝的发育，地裂缝平均间距与上分层应力集中点平均间距基本一致，主沟段顺坡、沟底和逆坡地裂缝平均间距分别约为下分层应力集中点平均间距的1.10倍、0.75倍和1.95倍，分别约为下分层岩块平均长度的2.93倍、

2.00倍和5.18倍；“砌体梁”位移模型可以很好地描述下分层底部岩块的下沉移动过程和特征，进而反映覆岩块体的双分层结构特征和地表的损害效应。该研究结果可为黄土沟谷区浅埋煤层开采条件下沉陷控制与修复提供新的科学依据。

The discontinuous cracking damage on the surface of the shallow-buried coal seam mining in loess gully area not only caused many ecological and environmental problems,but also increased the difficulty of ecological restoration,which seriously threatened the ecological security of the mining area. The discontinuous deformation of the surface of shallow coal seam mining is the result of overlying strata failure movement under special geological conditions. In order to more systematically study the influence law of overlying strata failure on surface discontinuous damage,taking No.125203 working face in Shanbei Anshan minefield as the geological prototype,by using the method of combining discrete element numerical simulation and physical similar mate-rial simulation,the characteristics of overlying rock and surface failure,rock block size distribution and force chain evolution were simulated and analyzed. The law of influence of the evolution of the overlying force chain on the distribution of the blocks and the development of ground fissures was revealed,and the controlling effect of the overlying broken blocks on the discontinuous damage of the surface was clarified. The research results show that the vertical deformation and horizontal movement of the overlying strata in the shallow-buried coal seam mining in the gentle slope area of the loess gully area are greatly affected by the terrain. The failure of the overlying strata forms a double-layered block structure. The stratified interface is 11.0 m from the coal seam floor. The average length of the lower stratified block is less than 5.0 m,and the upper stratified block is more than 5.0 m. The average length of the overlying strata block increases exponentially with the distance between the rock strata and the coal seam floor. The average length of the surface blocks increases gradually from the bottom of the slope to the top of the slope.The rock block structure of layered caving and compaction in the lower strata and the force chain structure of stress concentration affect the distribution of blocks and force chains in the upper strata and the development of ground fissures,and the average spacing of ground fissures is basically consistent with the average spacing of upper stratified stress concentration points.The average spacing of ground fissures along the slope,ditch bottom and reverse slope in the main ditch is about 1.10 times,0.75 times and 1.95 times the average spacing of the stress concentration points in the lower strata,respectively,which is about 2.93 times,2.00 times and 5.18 times the average length of the rock blocks in the lower strata. The displacement model of

“block voussoir beam” can well describe the subsidence and movement process and characteristics of the rock block at the bottom of the lower strata,and then reflect the double-stratified structure characteristics of the overlying strata block and the damage effect on the surface. The research results can provide a new scientific basis for subsidence control and restoration under the condition of shallow coal seam mining in loess gully area.