某超高层办公楼两阶段变刚度复合桩基础监测数据分析

Analysis on monitoring data of two⁃stage variable stiffness composite pile foundation of a super high⁃rise office building

两阶段变刚度复合桩基础的工作机理与常规桩筏基础以及天然基础具有一定差异,为了解桩和地基土在建筑施工及使用过程中的应力以及变形情况,对某超高层办公楼两阶段变刚度复合桩基础的地基土压力、桩顶内力、弹性支座变形、钢筋应力、沉降变形等现场监测数据进行了统计分析,研究上述监测数据在逐层施工加载过程中的发展、变化规律,并与理论计算结果进行了对比。结果表明,基础反力实测结果小于理论计算值,验证了两阶段变刚度复合桩基础设计的合理性,从而验证了桩筏基础变刚度调平的理念。

The working mechanism of two⁃stage variable stiffness composite pile foundation is somewhat different from that of conventional pile raft foundation and natural foundation.In order to understand the stress and deformation of pile and foundation soil during construction and use,field monitoring data such as foundation soil pressure,pile top pressure,reinforcement stress,elastic support deformation and settlement deformation of two⁃stage variable stiffness composite pile foundation of a super high⁃rise office building were statistically analyzed.The development and change law of the above data in the process of layer by layer construction loading were studied,and compared with the theoretical calculation results.The results show that the measured results of the foundation reaction are less than the theoretical calculation value,which verifies the reasonableness of the design of the two⁃stage variable stiffness composite pile foundation,thus verifying the concept of variable stiffness levelling of pile raft foundation.