연약지반의 압축성이 성토지지말뚝의 거동에 미치는 영향

초록

Recently pile-supported embankments have emerged as an optimum method when the rapid construction of railways and roads are required on soft soils. Arching effect which concentrate the embankment load to the stiffer piles is the key mechanism of the method and very dependent on the relative displacement between stationary and moving regions. However, in the existing design method the arching is assumed to be fully mobilized without any consideration on the relative settlement between the piles and the soft subsoil. In this paper, six design methods were applied to an existing Korean site and their adequacy was discussed. The settlements of subsoils among piles are calculated for the representing compression indices of Korean soft clay. By comparing the settlement difference between pile head and soft subsoil with the relative displacement for maximum arching suggested by Iglesia et al (1999), the significance of the stiffness rather than the strength of geogrids which are generally included to share the embankment load transferred to soft subsoil are emphasized.