# Biot coefficient as function of porosity

Can the Biot poroelasticity coefficient $\alpha$ be approximated as a function solely of porosity $\phi$, and if so then how (and under what conditions)?

I've read (e.g. 2.02-3 here) that it can, specifically $\alpha=1-(1-\phi)^{m(\phi)}$ where $m(\phi)=\frac 3 {1-\phi}$ however I haven't found any explanation or derivation. Elsewhere I've simply read that $\phi < \alpha \leq 1$ (e.g. p33 here).