Multiple hazard incidents lifecycle cost assessment of structural systems considering state-dependent repair times and fragility curves.

Fereshtehnejad, Ehsan; Shafieezadeh, Abdollah

The performance and serviceability of structural systems during their lifetime can be significantly affected by the occurrence of extreme events. Despite their low probability, there is a potential for multiple occurrences of such hazards during the relatively long service life of systems. This paper introduces a comprehensive framework for the assessment of lifecycle cost of infrastructures subject to multiple hazard events throughout their decision-making time horizon. The framework entails the lifecycle costs of maintenance and repair, as well as the salvage value of the structure at the end of the decision-making time horizon. The primary features of the proposed framework include accounting for the possibility of multiple hazard occurrences, incorporating effects of incomplete repair actions on the accumulated damage through damage state-dependent repair times, and requiring limited resources in terms of input data and computational costs. A dynamic programming procedure is proposed to calculate the expected damage condition of the structure for each possibility of the number of hazard incidents based on state-dependent fragility curves. The proposed framework is applied to a moment-frame building located in a region with high seismicity, and lifecycle costs are evaluated for six retrofit plans. The results displayed variation in the ranking of the retrofit actions with respect to decision-making time horizon. Furthermore, the sensitivity analyses demonstrated that disregarding repair time in the lifecycle cost analysis can result in false identification of unsafe retrofit actions as optimal and reliable strategies. Copyright © 2016 John Wiley & Sons, Ltd.

STRUCTURAL analysis (Engineering); EARTHQUAKE engineering; BUILDING repair; EARTHQUAKE resistant design; EARTHQUAKE damage

Earthquake Engineering & Structural Dynamics, 2016, Vol 45, Issue 14, p2327

0098-8847

Academic Journal

10.1002/eqe.2764