Rooftop based hospital heliports represent critical infrastructure, providing rapid access to emergency medical care while reducing the impact of helicopter downwash and outwash on pedestrians and nearby urban spaces. Effective heliport design requires a comprehensive understanding of the reciprocal interactions between helicopter operations and the surrounding built environment. Addressing these interactions during the early design phases enables designers to anticipate, evaluate, and mitigate potential adverse effects.
Most building codes have assumed stationary historical climatic data that can be statistically extrapolated to the future. However, nonstationarity has been shown in projections of future climatic data relevant to the design of buildings. For climate adaptation and resilience for Canadian buildings, recent studies proposed methods to integrate future climates into determining the climatic design loads and transitioning from the uniform hazard design approach to the uniform risk design approach in the National Building Code of Canada (NBCC). This study summarized these proposed changes to NBCC and derived the corresponding design scenarios for buildings in 17 cities across Canada. Three prototype building geometries with various construction materials and design schemes were developed to assess the impacts of the proposed changes on the climatic design loads and associated costs. The results showed that the proposed code updates incorporating climate change impact can increase or decrease the climatic design loads geographically. The associated cost impact on the structural design is minimal and mostly within the range that engineering design can accommodate with small to negligible initial cost increases.
This paper proposes a methodology to distinguish true measurement uncertainty from aerodynamic effects when comparing load coefficients from different atmospheric boundary layer wind tunnels. It considers the similarity of the wind field through profiles of mean velocity, turbulence intensities, and gust factor, along with the distribution of fluctuating flow properties, especially at small scales of turbulence. To ensure consistency, peak wind velocities and responses are estimated from time-histories matched in full-scale sampling time, hence longer records are truncated to match shorter ones. A test case involving a pressure model of a medium-rise building is proposed. It was independently tested by RWDI, CPP, and Western University under five different conditions. Time-histories of wind velocity and integrated aerodynamic base shear force, overturning, and torsional moments are analyzed and compared for nominally similar exposures. The trends in two comparisons are qualitatively consistent, with discrepancies in mean and peak coefficients not exceeding 7 % and 14 %, respectively. The analysis of the alongwind response reveals even smaller differences, especially in the mean coefficients, even across all five conditions. These findings suggest that current wind tunnel testing standards could potentially be relaxed, particularly by incorporating Partial Turbulence Simulation concepts, without compromising the reliability of aerodynamic load predictions.
Ferreirinha Bridge over the Douro River waters is currently under construction in Porto, Portugal. The bridge will carry two metro rail lines as well as pedestrian and bicycle traffic along a total span of 838 m, with a main span of 428.6 m and a nominal elevation at midspan of 76 m. The bridge was designed by Arenas & Asociados, Edgar Cardoso and Noarq for Metro do Porto. RWDI provided the design team with wind engineering consulting during the design process including aerodynamic stability review, optimization and verification for the bridge during its critical construction phases and completed stage.
