位移调节器用于端承型桩筏基础的模型试验研究

位移调节器是用于调节物体支承接触点之间位移的特殊装置，可用来保证端承型桩筏基础桩–土的变形协调和共同作用。为研究端承型桩筏基础中位移调节器的设置对桩–土–筏相互作用的影响，进行了位移调节器设置前后端承型桩筏基础的室内模型对比试验。试验测量了桩身轴力、筏板沉降及桩间土反力，分析了不同荷载级别下端承型桩筏基础的荷载传递规律、整体沉降与差异沉降分布特征以及桩土荷载分担比等内容，结果表明：与常规端承型桩筏基础相比，位移调节器的设置改变了桩筏基础的荷载传递规律，顺利实现了桩土的共同作用，同时适当支承刚度的调节器可优先且充分地发挥筏底土体承载能力，优化桩土荷载分担比。结论可为进一步理论研究提供试验依据。

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.