Performance of rigid-flexible-pile foundation with cushion.

Rigid-flexible-pile composite foundations are a newly developed method for resisting vertical load in deep soft soil. Flexible piles are used to strengthen shallow soft soil, and rigid piles are used to reduce settlement of the foundation. A cushion below the foundation caps is used to redistribute and adjust stresses on the piles and subsoil. The soft soil can also share part of the applied load in the foundation system. This enables the rigid-flexible-pile composite foundation to resist much larger load with less settlement. This paper examines the performance of such a foundation under vertical load. The results show that the stress and load-sharing ratio of the two kinds of pile and subsoil varies with the applied loading, but most of the applied load is shared by the rigid and flexible piles. Settlement of the composite foundation is controlled well, and can satisfy the performance requirements of buildings on deep soft soil. [ABSTRACT FROM AUTHOR]