Optical Fiber Frequency Shift Characterization of Overburden Deformation in Short-Distance Coal Seam Mining

<div>Impact pressure identification curves during the mining of coal seam 1<sup>-2</sup> (the abscissa is the face excavation distance, and the ordinate is the variation degree of the optical fiber frequency shift). (a) Face excavation distance of 37 cm. (b) Face excavation distance of 58 cm.</div>

Geofluids

fig8

Figure 8

Figure 8: Optical Fiber Frequency Shift Characterization of Overburden Deformation in Short-Distance Coal Seam Mining 