Empirical Equation

Equation No.

Required Parameter

Reference

$E_m\left(GPa\right)=40\text{log}Q\left(Avg.\right)$

13

Q

[41]

$E_m\left(GPa\right)=8Q^{0.4}$

14

Q

[21]

$E_m\left(GPa\right)=2RMR-100\text{for}RMR>50$

3

RMR

[15]

$E_m\left(GPa\right)=0.1{\left(RMR/10\right)}^3$

7

RMR

[20]

$E_m\left(GPa\right)=5.6{\left(RMR\right)}^{0.375}$

15

RMR

[42]

$E_m\left(GPa\right)=0.0736{\text{e}}^{0.0755RMR}$

16

RMR

[22]