With the increase of various loads on the upper structure, bored cast-in-situ piles demand higher bearing capacity.
Consequently, the diameter and length of bored piles increase constantly. Unfortunately the bored piles in the traditional tech nique have some drawbacks，such as sedimentation on the bottom of piles and mud around the shaft，which weaken the pile end bearing and pile skin friction and limit its capability. This paper based on an engineering project，compares the bearing capacity of two kinds of piles by static loading tests of two normal bored piles and four post-grouted piles. The results show that using the post-grouting technology can significantly improve the bearing performance of a pile foundation.