Up until the rapid increase in urbanisation, superstructures such as 100-floor+ buildings were a luxuriant sight. Today, fuelled by a dearth of land area and the demands imposed by multi-millionaires and billionaires for high-rise buildings that offer the experience of being “on top of the world,” 100-floor skyscrapers are commonplace structures. One can find super-tall, skinny buildings in almost every metropolitan city in the world. But designing such colossal edifices means overcoming several challenges of which wind load seems to be the most predominant.
Wind Resistance: A Vital Consideration in Constructing 100-Floor Super-Structures
Notwithstanding the demand for buildings with beanstalk proportions, a major architectural challenge in constructing such structures is that the taller a building, the more likely it is to sway at the top owing to high wind loads.
For instance, on a standard breezy day, a building that has 100 floors may sway a couple of inches at the top, according to consulting engineers Rowan Williams Davies and Irwin, but once each year can be experienced strong wind forces that travel 50 miles per hour and can move a superstructure with 100 floors about half a foot. But that’s not all, at least once every 50 years, winds with even greater velocities, around 100 miles per hour, are capable of making the tower deflect as much as even two feet!
Now, not only can such swaying movements prove to be a safety hazard, but they can also make the occupants of such superstructures woozy. This is especially a serious matter of consideration if the 100-floor building in question is a residential one. After all, not many people want to feel like they’re living on a giant pendulum!
As a result, architects and construction engineers include dampening and enveloping systems onto such superstructures that can act as shock absorbers and keep the occupants safe from the high velocity of wind forces that blow at such enormous heights – weight per square unit area of a building decreases with increasing height.
While designing buildings that have 100 floors and above, three kinds of wind load need to be taken into account – Uplift Wind Load or the upward pressure of the wind forces on horizontal structures such as the roof, Shear Wind Load or horizontal pressure on the walls and vertical structures, and Lateral Wind Load or horizontal wind pressure that can overturn the building by affecting its ballast.
Overcoming the Wind-Load Challenge with Glazed Glass Facades
One construction material that has gained popularity as the protective shield of 100-floor edifices has been glass. However, it is important to keep in mind that all glass structures and installations should be designed to offer a wind resistance of at least 0.5kN/m² (500 Pa). Glass glazing systems; triple-glazing systems to be precise are designed to withstand the forces of the wind.
Glass envelopes or glazed glass facades are strong enough to withstand some of the harshest weather elements, be it the sun’s heat, rain, or high-velocity winds. Moreover, since such glass facades do not rust or weather, environmental effects will not damage the aesthetics of huge structures such as 100-floor buildings.
The load-bearing capabilities of such glazed glass facades depend on various components – required thickness of the glass, framing members, and size of brackets – all of which will be dictated by the wind loads in the area. For this, advanced engineering methods such as wind tunnel testing and Computational Fluid Dynamics (CFD) are used. These methods help in accurate prediction of the wind pressure – critical in designing complex 100-floor superstructures.
If the inter-story drifts are high owing to high wind and seismic loads, the façade systems may require customisation, such as wider vertical joints or stiffer façade profiles.
Let’s consider the example of two such 100+ floor superstructures optimised using glass facades for wind –resistance. The Port Baku Tower 2 is located in Azerbaijan, where each of the two towers measures 240m and 100m in height respectively. This super-huge shopping facility is constructed using complex facade geometry – a unitised curtain wall that is curved in the southern face of the building, creating a spectacular skylight over the entrance area. In total, 12 different façade typologies have been included for protection against wind forces. The bespoke façade designs had to be created owing to differential wind pressure in the podium area (4.0 kPa) and the main tower areas (-7.5 kPa). Accommodations for even inter-story drifts were made.
Wind-proofing 100-Floor Buildings with AIS
For providing a strong foundation for 100-floor superstructures, AIS provides a comprehensive range of glass facades solutions that are multi-functional – providing resistance against the sun’s extreme heat and harmful UV rays, rains, and high-velocity wind forces. They also provide optimal natural lighting and maintain ideal indoor temperatures throughout the year. Discover the benefits of in an architect’s guide to glass facade with AIS Glasxperts. So, what are you waiting for? Enveloping 100-floor buildings against the impact of high-velocity wind forces is easy with AIS ! Get in touch today and get an expert consultation.