Static vertical loading tests and stress tests of four types of piles
that is
the normal cast-in-place pile
the cast-in-place pile with post-grouting
the cast-in-place pile with expanded-base
the cast-in-place pile with expanded-base and post-grouting
are performed in the same site. Based on the field experiments
compares the bearing capacity behavior
the distribution of axial force and lateral friction of the four types of piles. And transmission rule of axial force and the action of lateral friction of the piles is analyzed. The results of researches prove that the cast-in-place piles with expanded-base and post-grouting possess the characteristics of low settlement and high bearing capacity.