Model tests on a caisson-pile composite foundation in sand subjected to lateral static and cyclic loadings

Model tests are carried out using a lateral cyclic loading rig developed by the authors in order to investigate the bearing capacity and deformation characteristics of a simple caisson foundation and a caisson-pile composite foundation in sand under lateral static and cyclic loadings. Test results reveal that the lateral stiffness of the caisson-pile composite foundation couples the stiffnesses of caisson and group piles compared with that of the simple caisson foundation, and it improves the deformation response of the foundation under lateral loading. The bearing capacity of the caisson-pile composite foundations is significantly higher than that of the simple caisson foundation. Meanwhile, the lateral stiffness and bearing capacity of foundation increase after the application of lateral bidirectional and symmetric cyclic loading, and the bearing capacity of the caisson-pile composite foundations is higher than that of the simple caisson foundation after cyclic loading. The caisson-pile composite foundation is a more effective solution to increase the capability of the foundation in resisting the lateral cyclic loading.