In order to understand PHC pile profoundly and extend its application, based on optimized fitting of actual measurement data of 11 field testing piles in 3 sites, some uplift characteristics of PHC pile were studied.. Aiming at the bearing characteristics of PHC pile, Weibull mathematical model was selected and optimized fitting analysis of uplift load versus uplift displacement curves was carried out. The fitting results of 11 field testing piles with the model showed that the fitting precision was high, the correlativity coefficients R was 0.98877~0.99963, the average value was 0.99861.The fitting effect with the model was better than the hyperbolic model and exponential model. The error between calculation value and field measure value of uplifting load of PHC piles based on fitting equations was ; the uplift displacement of PHC piles was 5mm~17mm in certain two engineering when uplift reach ultimate state based on fitting curves; comparison between uplift load and compression load of PHC pile, between PHC pile and steel pipe pile was carried out based on fitting results. The following conclusions can be drawn that the Weibull mathematical model is accurate and credible for fitting of uplift load versus uplift displacement curves of PHC piles and PHC pile is a excellent pile.
