The bored piles 2.0 m in diameter is adopted in the foundation under Fujin-Suibin Songhua River Bridge. The in-situ static loading tests using conventional testing method and self-balanced method have been carried out on the test piles which are 45 m long and 70 m long for the latter one with upper shaft upon the load cell. By comparing the data of the testing piles from such two methods
the load-pile head settlement relationship and the vertical load-transfer behavior have been studied as well as the shaft friction resistance. It is indicated that
in the limit state
the displacement difference between the two is 14.97 mm; the side resistances difference is 7.30%; the side frictions of the two test pile meet the requirements. In the pile-soil system before destruction
under the same load conditions
the difference between the displacements gradually becomes larger. The pile skin friction in the same soil layer is consistent each other.