External radial stiffeners to improve seismic capacity of pile supported wharves
Abstract: Most steel piles suffer from low ductility because of their non-compact cross sections. In this study, ductility of steel piles is improved through external radial stiffeners (ERS) placed in a radial pattern around the external wall of the pile. The ERS would be placed close to the plastic hinge regions. Hysteretic behaviors of piles with and without the proposed stiffener are numerically investigated and compared with each other. Obtained results indicate that ERS would delay local buckling of the steel piles and in this way strength degradation would be alleviated. In other words, ductility capacity of steel piles with ERS would be greatly improved. A parametric study is also carried out to explore optimum geometry and number of required stiffeners. Finally, using a nonlinear static analysis, efficiency of the proposed technique is investigated for a pile-supported wharf located at the Port of Sirik in south of Iran. The proposed technique can be used either in the case of new designs or for retrofit purposes. It turned out that the external stiffeners are substantially beneficial for seismic rehabilitation of highly corroded steel piles.