# Study on Surface Damage Induced by High Heavy Layer Movement and Mining-Induced Earthquakes
## 3 Results
### Comparative Analysis of Subsidence Patterns with and Without Mining-Induced Earthquakes  
The settlement cloud diagrams of the model with applied seismic stress waves are shown in Figure 11. Specifically, Figure 11 depicts the settlement during excavation from 600-650 m with seismic stress waves, Figure 11 shows the settlement during excavation from 650-700 m with seismic stress waves, and Figure 11 shows the settlement during excavation from 700-750 m with seismic stress waves. As shown in Table 5 compared to the simulation without applied seismic stress waves, the settlement of the heavy conglomerate layer and the top stratum in the model increased further. In order to quantitatively assess the impact of mining-induced earthquakes on subsidence displacement, a paired \(t\)-test was conducted on the displacement data of six simulation scenarios. The \"subsidence with mining-induced earthquakes\" and \"subsidence without mining-induced earthquakes\" were designated as Variable 1 and Variable 2, respectively. The results showed a t-statistic of 22.21 (df = 5) and a two-tailed \(p\)-value of 3.44 \(\times\) 10\({}^{-6}\). Clearly, since the \(p\)-value is much smaller than the conventional significance level of 0.05, this statistical evidence confirms that mining-induced earthquakes significantly increase subsidence displacement of top stratum and heavy layer. To some extent, the heavy layer-type mining-induced earthquakes ex  
Figure 11: Cloud diagrams of the model displacement induced without mining-induced earthquakes: (**a**) excavation of 600–650 m; (**b**) excavation of 650–700 m; (**c**) excavation of 650–700 m.  
The displacement data from the monitoring points were processed, and the results are shown in Figure 12. The subsidence of the heavy layer caused by coal seam excavation exhibits a characteristic where the slope along the excavation direction initially increases and then decreases. The slope increases until the maximum subsidence is reached, leading to a similar settlement process in the top stratum, and the surface settlement is less than that of the heavy layer. As shown in Figure 12a,b, during the 600-650m excavation stage, the heavy conglomerate layer remained intact, exhibiting only elastic bending deformation without fracture. Under non-mining-induced earthquakes conditions, both the top stratum and heavy layer showed minor subsidence, with maximum displacements of 0.5841 m and 1.13232 m, respectively. This subsidence resulted primarily from gradual bending of the heavy layer, with no visible fracturing. When subjected to mining-induced earthquake, localized settlement troughs developed, increasing maximum displacements to 0.73861 m and 1.34192 m, respectively, indicating seismic waves amplified bending deformation while maintaining structural integrity. Figure 12c,d demonstrate that during 650-700 m excavation, the conglomerate strata fractured completely, causing catastrophic collapse of both the heavy layer and overlying weak strata. Maximum displacements surged to 5.02025 m (top stratum) and 7.95331 m (heavy layer). Mining-induced earthquakes further increased these values to 5.18006 m and 8.13513 m, respectively, confirming that seismic waves exacerbated fracture propagation while reducing overburden porosity. As shown in Figure 12e,f, during 700-750 m excavation, the fractured heavy layer formed articulated rock blocks, stabilizing subsidence trends. Maximum displacements reached 5.73751 m (top stratum) and 8.14228 m (heavy layer), increasing marginally to 5.91752 m and 8.31716 m under mining-induced earthquake influence, showing continued porosity reduction in fractured zones. Figure 12g systematically compares subsidence magnitudes across all stages, demonstrating consistent seismic amplification effects.