RESEARCH ON LONG-TERM EFFECT OF LARGE-DIAMETER ROCK-SOCKETED PILES AND FIELD MEASUREMENTS

Shenzhen Ping’an Financial Center is a super-high-rise building in China. The pile foundation of the project is rock-socketed end-bearing piles with a super large diameter. Due to the creep and shrinkage of concrete materials, the compression of pile body and the settlement of pile top caused by the creep and shrinkage of concrete should not be ignored. In order to explore the influence of non-load factors on the long-term settlement of super-large diameter piles in this project, the settlement of pile foundation in the whole construction process of this project was analyzed and predicted by using SAP 2000, a finite element software. During the analysis some time-dependent volume varying models of concrete were adopted to reflect the time-varying characteristics of the concrete in the super-large diameter piles. To check the rationality of the calculation results, comparison was made between the calculation results and the measured results. The results showed that it was reasonable and necessary for large diameter end-bearing pile to predict the settlement of pile foundation considering the creep and shrinkage property of concrete. The frequently used models, such as CEB-FIP 90、ACI 209R-92 and GL2000, could give a correct prediction closed to the measuring results.