This dialog allows to extend a template leg so that it ties with a surface (or surfaces) above. It is most commonly used to widen a leg to account for super elevation.
Example
Suppose their is a base layer on top of sub-grade. The width (w1) and slope (s) of the base layer is known. When the road is super-elevated the sub-grade need to be widened (w2) to account for the additional slope.
This can be done automatically by setting the length of the sub-grade leg to Base Wd (in the Template Leg Properties dialog). and then entering in the Base Ht. in the Surface Above Depth field and Slope in the Surface Above Slope Slope field.
Surface List Box
Use the Add , Remove buttons to add and remove surfaces.
