Model tests on end-bearing pile foundation by use of settlement adjustor

Settlement adjustor is a special device used to adjust the displacement between contact points of structures. The installation of the settlement adjustor can ensure the deformation coordination and the interaction for pile-soil of end-bearing piled raft foundation. In order to study the influence of the settlement adjustor on the interaction with pile-soil-raft of end-bearing piled raft foundation, laboratory model tests are performed before and after the installation of the settlement adjustor. The axial forces of pile ， the settlement of raft and the raft-soil contact pressure are measured. Then, the pile-soil load transfer mechanism, the settlement and difference settlement of raft and the pile-soil load sharing ratio of end-bearing piled raft foundation under different load levels are analyzed. The results show that, as compared with the conventional end-bearing piled raft foundation, the installation of the settlement adjustor has changed the load transfer rule of piled raft foundation and achieved the interaction of pile-soil. Suitable bearing stiffness of the settlement adjustor can give priority and full play to the bearing capacity of the soil beneath the raft and optimize the pile-soil load sharing ratio. The conclusions can provide the experimental basis for further theoretical researches.