Construction and performance of FRP-concrete composite piles

The objectives of this thesis were: to develop a technology suitable for the construction of FRP and thin-walled piles; to investigate the performance characteristics of FRP self-consolidating concrete (SCC) composite piles; and to develop procedures for the design of tapered piles under different loading modes including axial, uplift and lateral loading. A toe driving mechanism was developed for the efficient installation of empty FRP shells and thin-walled piles. FRP empty shells, FRP-SCC composite piles with different taper angles ranging from 0.0° to 1.13°, and steel piles were installed in dense sand enclosed in a pressure chamber using both the toe-driving and the conventional head-driving. The results showed that toe driving could be used for efficient installation of FRP piles. Interface shear tests on small FRP samples and uplift load tests on large-scale model piles were conducted to evaluate the FRP/dense sand interface characteristics. The results showed that the interface friction for FRP piles compares favorably with that of conventional steel piles.; The load transfer mechanism of tapered piles in compression was investigated and the results of twenty-six axial compressive pile load tests are presented. The model piles were tested at different confining pressures to represent pile segments at depths of 4.0 and 8.0 m. The load distribution along the pile shaft was measured and the results were compared with an analytical solution in terms of the taper coefficient Kt. The measured toe resistance of tapered and cylindrical piles was compared to available analytical solutions. A simple rational approach was proposed for the design of tapered piles in compression.; The uplift performance of tapered piles was evaluated relative to that of straight-sided wall piles. The results showed that the uplift capacity of tapered piles is slightly higher than that of cylindrical piles having similar average diameter and length. The taper effect on the pile uplift performance was evaluated using the uplift taper coefficient. (Abstract shortened by UMI.)...