Network- and bridge-level management under uncertainties associated with climate change

Abstract

Bridges are strategic connection points within the transport network, underpinning economic vitality, social-wellbeing, and logistics of communities. Currently, most of the transport authorities are not able to identify bridges at higher risk of disruptions, due to limited data or lack of a risk-informed assessment, and this is particularly true for bridge scour. The situation is exacerbated with the distributed knowledge about the condition of bridges, constrained resources, and concerns about the risks of climate change. To be effective, the strategies designed to improve the reliability and resilience of bridge assets needs to account for the uncertainties associated with predicting the performance of the bridge, progression of scour depth, and the impact of climate change hazards. To this end, this paper sets the scene for establishing a rational and systematic approach to evaluate the factors that affect bridge scour risk and condition, identify, and prioritise appropriate measures, thereby improving the allocation of scarce management resources. The bridge-level decisions are optimised to provide a wide range of monitoring and maintenance options that the network-level subsequently uses to prioritise based on budget availability, scheduling, probability of disruptions and the associated wider impacts. The functional framework presented within this paper would provide a basis for the development of a scour-focused module within the bridge management systems. This chapter explains the scene for establishing a rational and systematic approach to evaluate the factors that affect bridge scour risk and condition, identify, and prioritise appropriate measures, thereby improving the allocation of scarce management resources. It provides a basis for the development of a scour-focused module within the bridge management systems. The chapter overviews current practices and challenges involved in bridge scour management, framing it within the infrastructure authorities’ preparedness to deal with risks of climate change. The current scour management practices follow a reactive approach where repair or maintenance interventions are carried out after the scour has formed or has reached an unacceptable threshold where bridge closures or weight restrictions are necessitated. An accurate evaluation of the bridge scour risk requires information regarding hydraulic, soil, structural and traffic engineering.