Table 5 Formula table for the calculation of the permeability coefficient.
From: Study on parameter optimization of deep hole cumulative blasting in low permeability coal seams
Flow rate Y | Time criterion | Permeability coefficient | Coefficient A | Coefficient B |
|---|---|---|---|---|
\(Y = aF_{0}^{b}\) \(Y = \frac{A}{\lambda }\) | 10–2 to 1 | \(\lambda = {\text{A}}^{{{1}{\text{.61}}}} {\text{B}}^{0.61}\) | \(A = \frac{qr}{{p_{0}^{2} - p_{1}^{2} }}\) | \(B = \frac{{4 \times p_{o}^{1.5} }}{{\alpha r^{2} }}\) |
1 to 10 | \(\lambda = {\text{A}}^{{{1}{\text{.39}}}} {\text{B}}^{0.39}\) | |||
10 to102 | \(\lambda = 1.10{\text{A}}^{{{1}{\text{.25}}}} {\text{B}}^{0.25}\) | |||
102 to 103 | \(\lambda = 1.83{\text{A}}^{{{1}{\text{.14}}}} {\text{B}}^{0.14}\) | |||
103 to 105 | \(\lambda = 2.10{\text{A}}^{{{1}{\text{.11}}}} {\text{B}}^{{{0}{\text{.11}}}}\) | |||
105 to 107 | \(\lambda = 3.14{\text{A}}^{{{1}{\text{.07}}}} {\text{B}}^{0.07}\) |
