Load Transfer by Soil Arching in Pile-Supported Embankments

Abstract

Piles have been used to support unsymmetrical surcharges due to embankments or backfills on soft grounds. The unsymmetrical surcharges can be transferred by embankment piles to a firm layer below soft grounds according to mobilizing soil arching in pile-supported embankments or backfills. Two kinds of model tests such as the soil arching test and the load transfer test were performed to investigate, respectively, the configuration of the soil arch and the loads transferred on piles in pile-supported embankments. In these model tests, model piles were installed in several rows below sand fills, and the heads of piles in each row were connected with cap beams. The soil arch showed a configuration of a semi hollow cylinder, whose diameter was equal to the space between the outer edges of two cap beams and thickness was equal to the width of the cap beams. Based on the configuration of the soil arch defined by the soil arching test, a theoretical analysis was carried out to predict the loads transferred on the piles according to mobilizing soil arching in pile-supported embankments. The equation presented by the theoretical analysis could consider the effect of various factors affecting on the loads transferred on the cap beams; the loads depended on space between cap beams, width of cap beams, height and strength parameters of embankment fills, etc. The loads predicted by the presented equation showed good agreement with those measured in not only the presented test but also the previous test. Finally, the presented theoretical analysis was compared with the previous theoretical analyses on soil arching and its differences from the previous theories were discussed.