ABSTRACT: A hybrid foundation for buildings consisting of a mat slab and a small number of complementary bearing piles has been developed. In order to secure the subgrade reaction force against the mat foundation, the building itself must subside together with the soil. A reaction control device having a special kind of slide system is necessary in the hybrid foundation in order to deliver a certain magnitude of load from the mat slab to a pile head, because the settlement characteristics of bearing piles are different from those of shallow foundations. The static and dynamic behaviors of the hybrid foundation including reaction control devices are investigated through both experiment and numerical analysis based on a full-scale foundation model without soil. It was confirmed that the reaction control device smoothly absorbed the relative vertical displacements between piles and the mat slab while keeping the pile bearing forces constant, and the hybrid foundation transferred the lateral force of the mat slab to piles effectively.

Key words: hybrid foundation, numerical analysis, pile foundation, reaction control device, shallow foundation, static and dynamic load test (IGC: Hl)