Thickness of the uppder layer of a three-layer backfill.

Symbol
$s_{\mathrm{1}}$
Unit
m;
Used in
$a_{\mathrm{T}}$
$H_{\mathrm{T}}$
$R_{\mathrm{q11}}$
$R_{\mathrm{q12}}$
$s_{\mathrm{3}}$