抄録
Since it was disclosed that the piles and pile caps of some buildings in Japan were damaged by an earthquake in 1978, many studies on substructures have been made in order to establish a rational design method for substructures. In part 1 of this paper, we explained the results of experiments in which it was found that the currently used PHC piles had limited deformability. We also showed analytically that concrete fill in the hollow part of PHC piles could possibly improve the deformaility of these piles. In this paper, we report on the results of experiments in which it was found that a combination of concrete fill in the hollow part of PHC piles and high strength spiral hoop cast into the piles to confine the conrete was very effective for improving the deformability of PHC piles even under the limit magnitude of axial load. We also describe the effectiveness of concrete fill in the hollow part of PHC piles on the basis of the results of three dimensional analysis by Finite Element Method.
