Inspection of Existing Bridges – Moving on from condition rating

Abstract

<p>It is widely accepted that safety and serviceability are primary concerns in bridge design. However, for the most of bridges’ service life, these concerns are addressed indirectly by a qualitative meas- ure, defined herein as condition rating, which is based upon observable damages recorded during inspections. Condition rating is at best, only loosely correlated to safety and serviceability. It would be more reasonable to address safety and serviceability in an inspection process directly, using the information on bridge performance obtained during the design and construction.</p><p>To address this issue, the reliability was chosen as a Key Performance Indicators (KPI) for existing bridges and a novel practical solution is proposed. It is based on survey of observation types (visible defects, measurements, etc.) used in Europe, which were examined with regard to their potential impact on reliability regarding safety and serviceability. The impact of these observations on relia- bility is also dependent on their type, location and intensity/extent as well as on bridge structural systems. The paper presents a methodology to assess reliability, which heavily relies on data from design and construction phase. It also proposes a set of data elaborated in design and/or construc- tion phase that need to enter current bridge data bases to allow a rough reliability assessment of existing bridges.</p>

Reliability-Based Bayesian Updating Using Visual Inspections of Existing Bridges

“…This is why a time-dependent management approach developed within a framework of structural reliability is required. Moreover, there are different guidelines for infrastructure inspection practices, which differ considerably from country to country [1].…”

“…Even after maintenance interventions, where there is relevant information on safety and serviceability, it is not stored either. Hajdin et al [1] mention that the optimal procedure would be to change from condition rating to reliability index, (i.e., moving on from a qualitative measure to a quantitative key performance indicator). Since condition rating is not a measure that can easily be correlated with bridge safety, serviceability, or reliability, another option should be considered for integrating both measures.…”