## 4 Analysis of Test Results
### Spatial Distribution Characteristics of Goaf Pressure
#### 4.2.2 Goal Pressure Inversion Analysis  
The deformation data acquired via the distributed optical fiber sensing (DOFS) system correlates well with the strain profiles detected by the digital image correlation (DIC) instrumentation deployed on the key stratum surface. Both monitoring methodologies reveal concurrent dome-shaped patterns, characterized by progressive rightward migration of peak magnitudes during face advancement, as illustrated in Figure 11. The comparative analysis demonstrates exceptional conformity between these two independent measurement techniques. Figure 11: Fiber and DIC strain curves. (**a**) Advance to 108–124 cm, (**b**) Advance to 148–164 cm, (**c**) Advance to 192–232 cm. According to the failure mechanism observed in the analogous model, the geological formations initiate destabilization along the excavation boundary at the model's left section. With the continuous advancement of the mining front, the formations posterior to the working surface progressively achieve stability; meanwhile, the rock mass on the opposite flank undergoes progressive fracturing and disintegration, accompanied by dynamic variations in the maximum strain magnitude throughout the deformation process. Based on the mechanical mechanism analysis of strata failure, the phenomenon of peak value movement with working face advancement reflects the dynamic evolution process of the mining-induced stress field. When the working face advances to 108-124 cm, the initial failure of the rock strata begins to occur above the cut-hole position. As the working face continues to advance, the mining-induced stress gradually transmits forward through the rock strata. During this period, the elastic deformation in the unfailed zone continues to accumulate, and the stress concentration effect intensifies, leading to a continuous rise in the peak value on the right side. When the working face advances to 148-164 cm, large-scale fragmentation begins to occur in the rock strata, resulting in stress release and gradual dissipation of deformation energy, causing the peak value on the right side to decrease. Finally, when the working face advances to 192-232 cm, the mining-influenced zone tends to stabilize, the stress field reaches a new equilibrium state, the failure zone morphology becomes basically fixed, and the peak value stabilizes accordingly. From the perspective of the overall strain process, the left-side strain peak value ultimately stabilizes at approximately 45 cm from the model, while the variation process of the right-side peak value at different positions also reflects the degree of fragmentation of the key stratum as the working face advances. The strain peak moves to the right at a speed of 4 cm per step. This comprehensive study examines the correlation between distributed optical fiber sensing (DOFS) and digital image correlation (DIC) monitoring systems in analyzing critical stratum deformation during mining operations. This research reveals a distinctive saddle-shaped strain pattern that migrates rightward as the working face advances, with both monitoring systems demonstrating remarkable consistency in their measurements. This study identifies key deformation stages tied to specific face advancement distances: initial failure occurs at 108-124 cm, followed by progressive stress transmission and elastic deformation accumulation, leading to peak strain values on the right side. At 148-164 cm advancement, large-scale fragmentation triggers stress release and deformation energy dissipation, resulting in decreased peak values. The system achieves stability at 192-232 cm advancement, with the left-side strain peak stabilizing approximately 45 cm from the model. This dynamic evolution pattern reflects the complex interplay between mining-induced stress fields, rock mass failure mechanisms, and structural stability, providing valuable insights for predicting and managing mining-induced deformation in practical engineering applications.