Study on the Characteristics of Top-Coal Caving and Optimization of Recovery Ratio in Steeply Inclined Residual High Sectional Coal Pillar

<table class="figure-group"><tr class="fig-image" id="a"><td><object data="https://static-preview.hindawi.com/articles/geofluids/volume-2020/8883784/figures/8883784.fig.003a.svgz" name="8883784.fig.003a" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(a) </b>Damage state of the borehole wall</td></tr><tr class="fig-image" id="b"><td><object data="https://static-preview.hindawi.com/articles/geofluids/volume-2020/8883784/figures/8883784.fig.003b.svgz" name="8883784.fig.003b" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(b) </b>Crack state of the borehole wall</td></tr><tr class="fig-image" id="c"><td><object data="https://static-preview.hindawi.com/articles/geofluids/volume-2020/8883784/figures/8883784.fig.003c.svgz" name="8883784.fig.003c" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(c) </b>Intact state of the borehole wall</td></tr></table>

<div>Typical borehole images of the top-coal structure.</div>

Geofluids

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Figure 3

Figure 3: Study on the Characteristics of Top-Coal Caving and Optimization of Recovery Ratio in Steeply Inclined Residual High Sectional Coal Pillar 