Wind load refers to the force exerted by wind on a structure, including its walls, roof, and other components. This force varies depending on factors such as wind speed, direction, and the building's shape and height. Engineers and architects must carefully calculate and accommodate wind loads to ensure the stability and safety of buildings. The calculation of wind load is guided by standards and codes that consider local wind conditions, building height, and exposure.
Modern approaches to managing wind forces became more sophisticated with the advent of skyscrapers and high-rise buildings in the late 19th and early 20th centuries. The development of building codes and standards, such as those by the American Society of Civil Engineers (ASCE) and the International Building Code (IBC), has been essential for guiding the design and construction of buildings to withstand wind forces effectively.
EXAMPLES IN CHICAGO:
- 150 North Riverside: Completed in 2017 and designed by Goettsch Partners, 150 North Riverside features a distinctive design with a narrow base that expands as it rises, creating a "bow tie" shape. This design helps manage wind forces by reducing wind pressures on the lower levels and allowing for effective load distribution. The building incorporates advanced wind engineering techniques, including a robust core and perimeter columns, and mass tuned dampers to ensure stability against high wind loads.
- St. Regis Chicago: Completed in 2020 and designed by architect Jeanne Gang, the St. Regis Chicago is another significant example of addressing wind loads in modern architecture. The building’s unique design features a series of tapering, curved glass facades that create a dynamic and aerodynamic form. This design not only provides a striking visual appearance but also helps to manage wind forces by reducing wind pressures on the building’s surface. Additionally, the building contains “blow through” floors which allow the wind to blow through the structure, thereby reducing the stress on the building.
- Willis Tower (Sears Tower): Completed in 1974 and designed by Bruce Graham and Fazlur Rahman Khan, the Willis Tower employs a bundled tubular structural system that effectively manages wind loads. The building features a central core and surrounding perimeter columns that provide the necessary strength to withstand high wind forces, making it a prominent example of wind load management in tall buildings.
