Values of side and tip resistances of piles in Shanghai area

The values of side and tip resistances of precast and cast-in-place piles of Shanghai 1999 foundation design code (Code-99) completely follow the values of Code-89. However, since the 1990s, pile engineering has had a rapid development in Shanghai area. Many practical projects show that the measured results of the ultimate bearing capacity are different from the computed results by Code-99. So, it is necessary and meaningful to study the values of the side and tip resistances of piles in Shanghai area based on the measured samples. The collected samples contain 50 precast piles from 17 projects, which are mostly located in soft soil and take the layer = 5 \* GB3 ⑤ as the bearing stratum, and 66 cast-in-place piles from 22 projects, which take the layers ⑦, ⑧ and ⑨ as the bearing strata. Firstly, the method of statistical analysis and the finite element method are used to determine the values of side and tip resistances. Secondly, according to the determined values, all samples are back substituted, and the comparisons between the results of the back substitution and the measured results show that the amendment values are reasonable.