Factor for characteristic diameter

The factor for characteristic diameter by Dorison $q_x$ is used to calculate the characteristic diameter.

Symbol
$q_x$
Formulae
$\sqrt{\frac{2\pi}{\tau \delta_{soil}}}$General case
$\sqrt{\frac{2\pi}{86400\delta_{soil}}}$for daily transient load variations
$\sqrt{\frac{2\pi}{604800\delta_{soil}}}$for weekly transient load variations
$\sqrt{\frac{2\pi}{31557600\delta_{soil}}}$for yearly transient load variations