Uplift Capacity of Belled Pile in Weathered Sandstones

摘要

The coastal development on the Persian Gulf has increased recently with the development of Abu Dhabi, the United Arab Emirates. To ensure the stability and serviceability of the coastal structures, the resistance against the horizontal and uplift forces should be considered in the design process of the foundations supporting those structures. Unlike the resistance against compression and lateral forces, however, the pullout resistance of piles has not yet been fully investigated; also, belled piles are known to be very effective against pullout forces, but research on their pullout behavior has been limited. Hence, in this study, pullout load tests of belled tension piles were performed at 4 sites in Abu Dahbi, and subsequently the bearing capacity, characteristics of load-displacement of piles and load distribution considering skin friction were investigated. Based on the numerical simulation analyses, proved to capture the ultimate uplift capacities from the load tests, the shape and size of the bell has influence on the load-displacement behaviors of belled piles rather than the ultimate uplift capacity of the belled piles in the weathered sandstone ground conditions. In addition, the limit pullout bearing capacity calculated by 3D finite element analysis and theoretical methods were compared. The theoretical methods overestimate the ultimate pull out capacity regardless of the bell-shape considerations.