Study on the Retention of Large Mining Height and Small Coal Pillar under Thick and Hard Roof of Bayangaole Coal

<div>The variation of stress with distance at different measuring points (ΔP-L) graph. A: 2 m, B: 4.44 m, C: 6.44 m, D: 8.44 m, E: 10.94 m, and F: 13.44 m.</div>

Advances in Civil Engineering

fig7

Figure 7

Figure 7: Study on the Retention of Large Mining Height and Small Coal Pillar under Thick and Hard Roof of Bayangaole Coal 