Xdisp – How do I enter volume loss for an inclined tunnel?
Xdisp takes the volume loss to be volume loss per unit horizontal length. However, the user generally inputs volume loss per unit length of tunnel which means that for inclined tunnels total volume loss, and hence settlement, are underestimated. Without modifying the Tunset code it is possible to divide the volume loss per unit length of tunnel by the angle of inclination of the tunnel to get the volume loss per unit horizontal length and input this into the program. The Xdisp calculation will then be correct.
It is not possible to apply this correction to vertical shafts since the horizontal length is zero so settlements are always calculated as zero. The workaround is to make the shaft almost vertical (say 89 degrees) and apply the corrected volume loss.