Abstract: The DX pile is a new proprietary type of bored reinforced cast-in-place concrete pile with multiple enlarged shaft sections. This paper presents a case history of the installation, analysis, and load testing of long bored DX piles in Guangdong coastal area. The coastal project site is characterized with soft peaty soils and thick silty fine sand with gravel. The commercial finite difference software, FLAC3D, was used to simulate performance of the DX pile under failure load. The stress field distribution, development of settlement at pile, development of plastic zone in the surrounding soils, axial force in the pile and the stress changes in the enlarged shaft sections are evaluated. The loading transfer mechanism and failure mode under axial loading are discussed in the paper. The results are also compared with the test results.

Key words: DX columns, FLAC3D software, numerical simulations, axial capacity