DEVELOPING FRAGILITY CURVES AS AN EFFICIENT METHOD FOR ASSESSING COMMON RETROFIT METHODS OF PILE-SUPPORTED WHARVES

The aim of this study is proposing fragility analysis as an efficient method to evaluate common retrofit methods (FRP and batter pile) for pile-supported wharves damaged by aging effect in harsh environment of sea. In this study, fragility curves are developed for the concrete pilesupported wharf located in Persian Gulf by Capacity Spectrum Method (CSM) [1]. To compare retrofit methods, the wharf is modeled in ABAQUS 6.12. Then, results are shown in four different conditions i.e. before aging effect (initial condition), after aging effect (damaged condition), and retrofitted conditions (FRP without batter pile and FRP with batter pile). The damaged condition is considered for the splash zone having the highest corrosion rate among the other zones. In this zone, the behavior of damaged concrete is modeled according to the physical modeling carried out for concrete material in Persian Gulfenvironment [2], and for rebar, the corrosion rate proposed by OCDI is considered [5]. To retrofit the damaged model, at first, FRP layer is wrapped around damaged areas. Then,the batter pile with the degree of 43º is attached by rubber isolator (Figure 1). CSM is a Pushover (SPO) based method which measures performance points of structures under scaledselected spectrum. Here, this method is performed by choosing 8 records (Table 2), and the probability of the responses exceeding from the damage states, defined byPIANC [6], is obtained. The cross section of the wharf and property of soil layers are respectively displayed in Figure 1 and Table 1 [3]. The soil layer is modeled by MohrCoulomb theory.