Floating Foundations.
A foundation set into a deep excavation is said to be compensated or floating if the building load is significantly offset by the load of soil removed during excavation. The foundation is fully compensated if the structural load equals the load removed by excavation, partially compensated if the structural load is greater, and overcompensated if the structural load is less than the weight of the excavated soil. A compensated foundation requires a study of expected subsoil rebound and settlement, excavation support systems, means to maintain foundation subsoil or rock integrity during excavation, and allowable bearing pressures for the soil or rock.
