Study on Dynamic Evolution of Roof Crack and Support Timing of Secondary Tunneling for Large Section Open-Off Cut in Deep Mines

<div>Distribution, damage, and failure modes of roof cracks in three support schemes, (a) Scheme 1; (b) Scheme 2; (c) Scheme 3. (The green cracks represent tensile cracks, and the red cracks represent shear cracks.)</div>

Advances in Civil Engineering

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Figure 12

Figure 12: Study on Dynamic Evolution of Roof Crack and Support Timing of Secondary Tunneling for Large Section Open-Off Cut in Deep Mines 