Availability function as bridge element’s importance weight in computing overall bridge health index

Abstract

Extensive research has been conducted over the past two decades to evaluate the condition and bridge health index (BHI) of bridges using different performance measures. The International Association for Bridge Management and Safety (IABMAS) has stressed on the growing need to assess the condition state of the bridges by integrating new functionalities and methodologies into bridge management systems (BMS) for better monitoring outcomes. This article presents the development of bridge element importance weight using availability metric computed from element failure time distribution parameters and repair rates. This study investigates the following issues: the availability of bridge elements and subsystems, the evaluation of the criticality rank of bridge components and subsystems using failure and downtime criticality indices and the effect of deterioration of critical elements on the overall operability of the bridge system. The availability index and failure criticality output of selected elements showed that superstructure elements, reinforced concrete column, metal bearings, piling, pile cap/footing and reinforced concrete cap were of more importance (critical) to the bridge system deterioration compared to decks, railings and expansion joints. At the component level, it was observed that movable bridge elements (hydraulics, operator facilities, etc.) were less available based on their downtimes and operational characteristics.