HORIZONTAL BEHAVIOR OF AN EARTHQUAKE-PROOF PILE GUARDED WITH OUTER SHEATH PILE : Part 1 Model test and calculation method

Abstract

An earthquake-proof pile composed with a main pile and a short outer sheath pile is proposed in this study. It is expected that the outer sheath pile shears the most part of the horizontal load in an earthquake whereas the main pile is against the vertical load mainly. This paper presents the experimental result of model earthquake-proof piles done by changing the outer sheath pile length, and also a calculation method for the pile system of this type. These results suggest that the horizontal deformation of the pile and the bending moment in the main pile could decrease remarkably, even if the outer sheath pile length is set up comparatively short.