2019 CSCE Annual Conference - Laval (Greater Montreal) Conference
Dr. Luaay Hussein, Ryerson University
Dr. Lamya Amleh, Ryerson University (Presenter)
Climate is changing. Extreme weather phenomena are now obvious, Global temperature increased by more than 2°C leading to the melting of the ice-pack at the North Pole. Moreover, The intensity and frequency of both precipitation and hurricanes have been changed dramatically over the last few years. These changes are substantially significant in the regions lies high latitudes compared to the rest of the world, including Canada, when compared with global trends. The rate of warming in Canada as a whole has been more than double that of the global mean, and that warming in northern Canada (i.e., north of 60°N latitude) has been roughly three times the global mean. Canada’s infrastructures could be at risk if actions are not taken to consider or adapt the climate change. The transportation networks, especially bridge infrastructures, can be considered as one of the most systems that will be affected by changing climate. The service life of such infrastructures is typically in the order of the time frame of the expected climate change scenarios (50 to 100 years).
Several parameters are considered in the design standards that depends either directly or indirectly on the climatic data, including: temperature, relative humidity, ice accretion, wind, and water loads. It should be pointed out that most current design climatic parameters are derived from historical data that goes back to the 1970’s time horizon. Thus, the existing and future infrastructures might face higher extreme climatic events than loads considered in the current practices.
This paper investigates the applicability of the current design climate loads of the Canadian Highway Bridge Design Code (CHBDC) to model current and future climatic actions. The studied climate loads include: daily temperatures (maximum, minimum, and mean) and hourly mean wind pressures (for return periods of 25, 50 and 100 years). First, the climatic design loads of CHBDC are compared with the current loads estimated based on homogenized climatic data from Environment Canada’s national archives for ten main Canadian cities. Thereafter, the future climate data are estimated for two different time horizons 2050 and 2100 use multi-model ensemble of projections, ranging from low to high emission pathways and compared to CHBDC values. The results showed that daily temperature parameters of CHBDC represent the current and future temperatures reasonably well. However, wind pressures that estimated based on actual climate data showed a significant difference in comparison to CHBDC, especially for coastal and north cities of Canada.