Abstract: Deep foundation engineering is increasing in northwest China. The anti floating and durability for deep foundations problem research is a blank. This paper effectively solved the anti floating and durability problem by introduction of large diameter bag pile technology to comprehensive renovation project of Xining Railway Station. The 6 piles are selected to conduct on-site single pile load test; it is shown that the maximum load weight is 9 060 kN, Using MATLAB to fit out the three prediction function models of uplift ultimate bearing capacity curve; and using PLAXIS to simulate for different grades of pile soil load displacement. The study results show that the hyperbola and exponential function models to predict ultimate bearing capacity of uplift pile are appropriate; similar foundation prediction of large diameter corrosion deformation of uplift pile ultimate load corresponding standard limit displacement should be reduced from 0.030D to 0.025D. The ultimate friction based only on physico-mechanical characteristics of soil to determine the anti pulling pile surrounding soil is not enough; the influence of different buried depths of similar physico-mechanical characteristics of soil should be considered.

Key words: bag uplift pile, ultimate bearing capacity, prediction model, static test