Equivalent thermal resistance of the surrounding soil of a tunnel.

Symbol
$T_{\mathrm{4t}}$
Unit
K.m/W
Formulae
$N_{\mathrm{c}} N_{sys} \left(T_{\mathrm{s}} + \left(T_{\mathrm{e}} + T_{\mathrm{t}}\right) \left(- \frac{\left(T_{\mathrm{e}} + T_{\mathrm{t}}\right) e^{- \frac{L_{\mathrm{T}}}{L_{\mathrm{0}}}}}{T_{\mathrm{a}} + T_{\mathrm{e}} + T_{\mathrm{t}}} + 1\right)\right)$
Related
$L_{\mathrm{0}}$
$L_{\mathrm{T}}$
$N_{\mathrm{c}}$
$T_{\mathrm{a}}$
$T_{\mathrm{s}}$
$T_{\mathrm{t}}$
Used in
$\Delta \theta_{\mathrm{c}}$
$\Delta \theta_{\mathrm{d}}$
$I_{\mathrm{c}}$