Value of strain-based structural health monitoring as decision support for heavy load access to bridges

Abstract

Bridges are frequently subjected to permit loads. While deciding on permitting such loads, bridge owners usually adopt a tiered approach for structural analysis, assessment, and measurement. Under these complexities of decision-making, the owner can decide to adopt structural health monitoring (SHM) strategies in guiding the issuance of permits. A value of information (VoI) framework can be utilised by the owner to estimate the benefit of various SHM strategies. This study proposes a novel VoI framework which incorporates tiered assessments common in engineering practice. The proposed decision framework utilizes a generic approach to incorporate the successive tiers of measurement, analysis, and assessment. A real-world inspired case study of a reinforced concrete bridge pier crosshead subjected to high shear is used to demonstrate the proposed framework. Using a novel and practical tiered-assessment and multi-intervention option strategy, the potential monetary benefit of strain-based SHM strategies is quantified. It is found that the potential benefit of SHM is particularly high when high risks are involved. SHM is also found to be highly beneficial when slight changes in structural assessment could trigger different intervention actions by the stakeholder. The study also identifies the significant role that low-cost low-accuracy SHM strategies can play in decision guidance by providing adequate information for decision-making at a cheaper cost.