Analysis of Dynamic Evolution of Surrounding Rock Movement and Stress-Fracture in the Upward and Repeated Mining of Close-Distance Coal Seams

<div>Fracture development and expansion of upper coal seam with different face advance of lower coal seam: (a) 70 m; (b) 90 m; (c) 130 m; (d) 180 m.</div>

Advances in Civil Engineering

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Figure 16

Figure 16: Analysis of Dynamic Evolution of Surrounding Rock Movement and Stress-Fracture in the Upward and Repeated Mining of Close-Distance Coal Seams 

Figure 16 | Analysis of Dynamic Evolution of Surrounding Rock Movement and Stress-Fracture in the Upward and Repeated Mining of Close-Distance Coal Seams 