Abstract
An earthquake-proof pile composed with a main pile and a short outer sheath pile has been proposed by the authors. This outer sheath pile is isolated from the main pile. In this study, a roller and a pin mechanism are inserted between the main pile and the outer sheath pile in the tip position of the latter pile, in order to secure clearance between both piles during construction and also in an earthquake. This paper presents the calculation result of the earthquake-proof pile, which is composed with a PHC-pile (main pile) and a steel pile (outer pile). These results suggest that the bending moment in the main pile and the horizontal deformation of the earthquake-proof pile with a roller and a pin coupling could be decreased remarkably in comparison with an isolated main pile, even if the outer sheath pile length is so short as 2.5m.
