Regional bridge risk assessment due to the combined effect of flooding and overloading events in Manitoba

The challenges experienced by Canada’s aging infrastructure require probabilistic methods to address the threats that bridge systems are exposed to. This study provides a framework to evaluate risk associated with two major bridge hazards such as flooding and overloading in Manitoba. The probability of failure of highway bridges due to overloading is assessed as a function of traffic volume and overweight percentages. The probability of failure due to flooding is obtained from a spatial analysis of the water levels. Finally, consequences of failure are established from the analysis of insurance exposure, including climate change effects. Historic data are projected ten years into the future through an ARIMA model. The results of the analysis show that the risk for bridges in the south-west regions of Manitoba is expected to increase by 2035 up to 40% for water levels of 3.0 m and up to 0.6% for a threshold of 12.0 m.