Study on the Key Technology of Controlling the Instability of Deep High-Stress Coal and Rock Mass and Relieving the Danger

<div>Fracture expansion range. (a) The distance between the two hole making holes is 3 m, and the cracks are completely connected. (b) The diameter of a single hole is 0.7 m, and it has collapsed after coal cutting.</div>

Advances in Civil Engineering

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Figure 10

Figure 10: Study on the Key Technology of Controlling the Instability of Deep High-Stress Coal and Rock Mass and Relieving the Danger 