Swelling Pressure of Double-Expansive Material and Its Active Support Effect for Coal Seam Gas Drainage Borehole

<table class="table-group" id="tab3"><tr><td><table class="table"><tr><td class="thead-hr" colspan="8"><hr/></td></tr><tr class="thead"><td class="align_left">Density (g/cm<sup>3</sup>)</td><td class="align_center"><i>G</i><sub>M</sub> (GPa)</td><td class="align_center"><i>G</i><sub>k</sub> (GPa)</td><td class="align_center"><i>η</i><sub>M</sub> (MPa·h)</td><td class="align_center"><i>η</i><sub>K</sub> (MPa·h)</td><td class="align_center"><i>c</i> (MPa)</td><td class="align_center"><i>ψ</i> (°)</td><td class="align_center"><i>φ</i> (°)</td></tr><tr><td class="thead-hr" colspan="8"><hr/></td></tr><tr><td class="align_left">1.38</td><td class="align_center">1.94</td><td class="align_center">3.26</td><td class="align_center">117.5</td><td class="align_center">10.2</td><td class="align_center">0.85</td><td class="align_center">17</td><td class="align_center">31.5</td></tr><tr class="table-tr"><td colspan="8"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>Parameters of the coal from Huangling no. 2 coal mine.</div>

Advances in Materials Science and Engineering

tab3

Table 3

Table 3: Swelling Pressure of Double-Expansive Material and Its Active Support Effect for Coal Seam Gas Drainage Borehole 