State-of-the-Art of Floating Foundations

For a floating foundation the soil must have weight but need not have shear strength. The foundation must be able to resist pressure on its base and sides and if the weight or level of the soil varies, the pressures will not be uniform and shear and bending forces will act on the foundation. In practice nearly all foundations are partly floating and nearly all so-called floating foundations are only partly floating because a small residual pressure is usually left on the soil. After a history of their development and the reasons for their use are given, the problems to be considered in using floating foundations are examined. Among the most important problems are excavation, bottom heave, settlement and tilting, and structural problems.