Cut-fill transition. A cut-fill transition occurs when a building pad has some rock removed
(the cut portion), with a level building pad being created by filling in with soil the remaining
portion. If the cut side of the building pad contains non-expansive rock that is hard and sound,
then very little settlement would be expected for that part of the building on cut. But the fill
portion could settle under its own weight and cause damage. For example, a slab crack will typ-ically open at the location of the cut-fill transition as illustrated in Fig. 7.22. Damage is caused
by the vertical foundation movement (settlement of fill) and the horizontal movement that man-ifests itself as a slab crack and drag effect. One option is to use deepened footings or deep foun-dations to underpin that portion of the structure located on fill such that the entire foundation
is anchored in rock. This option would be the preferred method, especially for heavily loaded
foundations.