Overburden Thickness

The Overburden Thickness is measured from the surface of the pillar. This is the absolute value of the Overburden Thickness, and is NOT measured from the base of the pillar. The overburden contributes to the deadload magnitude, and therefore the normal forces on the abutments when the abutments are non-vertical. However, the weight of the overburden has no impact on the computation of the lateral stresses.