A qualitative assessment of the effects of climate change on bridges

Abstract: Climate change is a fact and the potential climate change impacts on infrastructure are necessary to examine to ensure the safety and performance of societies. The evidence for climate change is overwhelming, the changes have been observed and the projected future based on models indicate further change. Several of the climate change impacts are predictable, though the magnitude of the changes is unknown. Bridges are a part of the infrastructure that have a substantially long service life, which make them important to consider when regarding the impacts of climate change. In this thesis a recently developed risk-based prioritisation method was reviewed. The method qualitatively assesses the impacts of climate change on bridges, aiming to address the two following question related to operation and management. Firstly, which climate change impacts should be prioritised for a single bridge? Secondly, which bridge should be given precedence when considering the potential impacts of climate change, for a group of bridges? The main components of the method are hazard, exposure, vulnerability and consequence. These components are assessed and aggregated into two ranking indices, level-I ranking index addressing the first question and level-II ranking index addressing the second one. The review was conducted to examine the practical feasibility of the method, evaluating its strengths, weaknesses and possible improvements. The potential climate change impacts selected for analysis of the method were increased deterioration rates and increased stress due to expansion. The bridge selection comprised out of seven roadway bridge located in different counties in Sweden. The relevant bridge information for the selection was obtained from the Swedish Transport Administrations database, BaTMan. The climate data used to evaluate the increase of the potential climate change impacts was acquired from the Climate scenario database created by the Rossby Centre at the Swedish Meteorological and Hydrological Institute. The result of the review is that the risk-based prioritisation method is applicable, it addresses the aforementioned questions and prioritisation for the bridge selection is obtained. The method requires access to extensive data, both climate data and bridge data. It is also important to acknowledge that several assumptions and simplification were adopted to enable the assessment process.