The pile bearing capacity

base resistance and shaft resistance development of open PHC pipe pile can be confirmed through the interval re-pressed test of jacked pile with FBG sensors. It is indicated that the ultimate-bearing capacity shows logarithmic growth with elapsed time in the certain time after installation; and the magnitude is 140% after 284 hours with timeliness coefficient of 0.52. The increase magnitude of base resistance and shaft resistance is respectively 6.28% and 475.37% with time

which indicates that ultimate bearing capacity growth derives from shaft resistance in the test condition. The results show that the development of pile ultimate bearing capacity and shaft resistance accord with three-phase increase model and the time points are respectively 21.5 hours and 279 hours. respectively. The research results can provide evidence for timeliness coefficient and relevant design.