Abstract
A newly developed dynamic compacting method (DCOM), in which a cylindrical steel pile of 60cm(D) was driven into ground to a depth of 10m and then pulled 2m upward placing gravel into the bored hole, was tested in three patterns of pile driving pitch at a loose fill site of coarse gravel. It was found that the improved area in the trial fill extended to a range of ±3.5D from the center of the pile, and 4D from botom of the pile. An increase of over 30 blows by SP-testing was observed in the 2D and 3D pitch drivings of the pile, and one of 10 blows for the 5D pitch driving. Model tests in a laboratory were also carried out in order to compare ground movement, and found a similare deformation pattern as that observed by tilting meter tests for the horizontal displacement in the ground.
