Behavior of Large Bored Piles in Fuzhou

Large bored piles are popularly used in south‐east coast of China. Pile foundation design is based largely on empirical method. However, the behavior of these piles is not well understood. Generally, end bearing capacity of these piles is regarded as a dominant factor in design. This paper describes a group of static loading tests on instrumented large bored piles in Fuzhou city. All test piles were installed by slurry displacement method. Strain gages and telltales were mounted in the shafts of the piles. Load transfer behavior of the piles was studied under static axial compressive load condition. The results of the tests show that all of the piles carry a significant portion of the applied load through skin resistance although the surrounding soils are very weak. This fact contradicts the traditional understanding of large bored piles by local engineers. The ultimate skin resistances of predominant soils in Fuzhou are presented in the paper.