Study on Pressure Relief Technology of High-Pressure Water Jet of Residual Coal Pillar in Overlying Goaf in Close Seam Mining

<div>Mechanical model of the hydraulic cutting of the residual coal pillar. (a) Before coal pillar failure. (b) In the process of coal pillar failure. (c) After coal pillar failure.</div>

Shock and Vibration

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Figure 11

Figure 11: Study on Pressure Relief Technology of High-Pressure Water Jet of Residual Coal Pillar in Overlying Goaf in Close Seam Mining 