# Study on Surface Damage Induced by High Heavy Layer Movement and Mining-Induced Earthquakes
## 1 Introduction
[PERSON] et al. [14; 15] using microseismic monitoring to identified four overburden spatial structures. These included the supported \(\theta\) type, which forms arc-shaped hinges; the unsupported O type, consisting of closed-loop fractures; the S type, exhibiting sinusoidal bending; and the C type, displaying circular arch-like deformation. Their research emphasized that dynamic structural changes significantly influence seismic and rockburst occurrences. [PERSON] et al. [16] monitored surface subsidence at Yingpanhao Coal Mine and found that under insufficient mining conditions, ultra-thick weakly cemented overburden exhibits small-magnitude but widespread subsidence with an asymmetric profile along the main cross-section. [PERSON] et al. [17] studied the mechanisms of mining-induced earthquakes under multiple goal conditions, including instability and shear sliding of the lower and upper sub-key layers, respectively, and ultimate fracturing of the main key stratum. [PERSON] et al. [18] investigated mine-induced earthquakes under ultra-thick weakly cemented Jurassic coal seams in the Ordos mining area. Using multiple technical approaches, they revealed overburden fracturing mechanisms and seismic source characteristics, identifying tensile and shear rupture as the primary causes of seismicity at Shilawusu Coal Mine. [PERSON] et al. [19] analyzed the mechanism of a static stress concentration-induced rockburst in a western coal mine roadway cluster. They proposed an ultra-long horizontal staged hydraulic fracturing technique, which weakens stress transfer by inducing plastic failure in thick-hard roofs, significantly reducing microseismic events. [PERSON] et al. [20] observed that during the \"O-X\" fracturing of hard heavy layer, both the frequency of high-energy mining-induced earthquakes and the rate of land Subsidence significantly increase. [PERSON] et al. [21] investigated the heavy conglomerate layer, which consists of densely packed conglomerate rock, focusing on its delamination and fracturing behavior. Their study revealed that both initial and periodic collapses of the upper and lower layers can induce high-energy mining-induced earthquakes. [PERSON] et al. [22] proposed that the elastic energy released during the fracturing of heavy layer is the primary factor triggering high-energy mining-induced earthquakes. [PERSON] et al. [23] suggested that the cooperative fracturing movement of multiple key stratums in the roof leads to frequent strong mining-induced earthquakes during deep coal mining. [PERSON] et al. [1] found that both the initial fracturing and periodic structural adjustments of heavy layer induce high-energy mining-induced earthquakes. [PERSON] et al. [24] noted that mining-induced earthquakes is primarily driven by the bending deformation energy and rotational kinetic energy of hard heavy layer. [PERSON] et al. [25] discovered that the fracturing, rotation, and sliding instability of hard heavy key stratum induce mining-induced earthquakes, with those caused by overburden movement being the primary type in deep coal mining in China. In China, many mines are affected by heavy layers. Notable examples include the Dongtan Coal Mine in Shandong Province, where a 180 m thick heavy layer overlies a working face; the Tengdong Coal Mine, also in Shandong, where a 90 m thick heavy layer is located 70 m above the coal seam; and the Qianqiu Coal Mine in Henan, where a 410 m thick heavy layer sits approximately 210 m above the coal roof. These mines commonly experience surface damage due to such geological conditions [5; 6]. Heavy layers are characterized by resistance to fracturing and tendency to induce high-energy mining-induced earthquakes, resulting in differences in fracturing intervals compared to other hard rock layers. During their fracturing process, strong mining-induced earthquakes are frequently induced. In this paper, mining-induced earthquakes caused by the fracturing or movement of heavy layers is referred to as heavy layer-type mining-induced earthquakes.