Life-cycle cost analysis of pile-supported wharves under multi-hazard condition: aging and shaking

Abstract

Investigating the economic consequences of the natural hazards on the infrastructures is a crucial task in any risk-based decision-making process. Life-cycle cost (LCC) analysis is an important tool in both design (to choose the most economic configuration) and analysis (to estimate the future cost of ownership) stages. The pile-supported wharves, as one of the main parts in a marine harbor system, may experience significant deterioration (i.e. strength reduction) and seismic shaking during their life time. In this paper, damage cost in multiple limit states of a deteriorated pile-supported wharf due to chloride corrosion is calculated. A precise finite element model is developed to account for structural aging and the simultaneous seismic shaking. Aging-dependent seismic fragility functions are first developed using incremental dynamic analysis. Next, the LCC analysis is conducted considering the crane damage, as well as, inspection and maintenance costs. The results are calculated for three seismic hazard levels. The findings confirm significance of corrosion on LCC of pile-supported wharf. It is observed that corrosion may increase the LCC of the structure and system (i.e. structure and cranes) by 15% and 8%, respectively. Finally, a set of analytical formulations are proposed for performance index as a function of age, damage state, and seismic hazard level.