%0 Journal Article
%T Enhancing Seismic Capacity of Pile-Supported Wharves Using Yielding Dampers
%A Seyed Amin Mousavi
%A Khosrow Bargi
%J Journal of Structures
%D 2013
%R 10.1155/2013/329130
%X This paper presents a numerical study on the seismic response of pile-supported wharves equipped with metallic yielding dampers. Using 20 ground acceleration records, the contribution of the yielding damper is examined, and its main parameters are optimized through a parametric study. In the current study, considering coupling effects of different parameters, a new optimization procedure is proposed. The obtained results indicate that the stability condition of the retaining wall (quay wall) behind the wharf, period of the soil-wharf system, and also maximum allowable ductility ratio of the damper are the key factors affecting the optimum damper parameters. A simplified design guideline is proposed for either the design or the retrofit purposes followed by a numerical assessment to evaluate the contribution of the proposed damper on the seismic behavior of a typical pile-supported wharf. The obtained results show that yielding dampers, through their nonlinear behavior, can dissipate a large portion of seismic input energy and mitigate piles damages which have been observed in earlier earthquake events. 1. Introduction During an earthquake event liquefaction of saturated loose sandy soils and excessive piles drifts make the most common causes of damages to pile-supported wharves. Therefore, in absence of liquefaction conditions, pile drift can be considered as a suitable indicator in order to evaluate performance of wharves under seismic events. Some techniques, which rely on stiffness increasing, such as inclined piles, have been investigated in earlier studies by Gerolymos et al. [1] and Poulos [2], as a method to reduce lateral displacements of pile-supported wharves. Inclined piles have two main drawbacks, high construction costs and punching failures in their connections. As reported by Oyenuga et al. [3], however, the punching failure problem can be moderated using a new design approach for pile-deck connections. Lehman et al. [4] have also improved performance of pile-wharf connections. In another study a novel stone column has been proposed by Mageau and Chin [5] to improve seismic behavior of wharves. Using passive control techniques, this study tried to improve the seismic behavior of pile-supported wharves. Nowadays passive control methods have gained more attention in order to mitigate natural or man-made structural vibrations. Some of these passive techniques have been briefly described by Soong and Dargush [6]. Earlier studies on passive control techniques have been commonly restricted to long period structures, such as tall buildings,
%U http://www.hindawi.com/journals/jstruc/2013/329130/