Sensitivity Analysis of Pile Supported Wharves against Directional Uncertainty of Earthquakes Using Fragility Curves

Abstract

Article History: Received: 18 Feb. 2018 Accepted: 13 Mar. 2018 This paper aims to tackle an important uncertainty which extremely affects seismic performance of wharf structures in earthquake events. According to previous studies performed for structures on land, it is shown that structures on land are highly susceptible to unknown orientation of earthquakes called as the directional uncertainty. However, for marine structures, especially pile supported wharves, research efforts are rare to assess the effect of directional uncertainty of earthquakes on structural responses. Therefore, to show this effect on seismic performance of pile supported wharves, fragility analysis is performed based on methodology suggested by Pacific Earthquake Engineering Research Center (PEER) for the modeled pile supported wharf located in Maah-shahr port as a case study. As the first phase of this methodology, nonlinear static pushover analyses are performed for randomly chosen incident angles in order to quantitatively measure damage states suggested by marine design code. After damage states are obtained, IDA analyses are conducted in the selected incident angles to obtain nonlinear structural responses which are supposed to be used for fragility analysis as inputs. Finally, once fragility curves have been developed according to the last phase of PEER methodology, the more vulnerable direction(s) of wharf from those incident angles is represented.