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| Adrian smith said about the kingdom tower |
Smith said, would be at least 3280ft (1000m) tall, and about 50 storeys taller than the Burj Khalifa (164 floors). The building will have three sky lobbies, with the most prominent situated at the 157th floor. The viewing platform disc that juts out from the side of the building was originally designed as a helipad and is 25 metres across.
“We designed it in to the building and liked it but most pilots said it could be risky to land on, so we’ve convinced the prince, at the moment at least, that it is a pretty cool feature.”
Smith said the main challenge in designing the tower was incorporating structural, mechanical and architectural systems in to the tower.
“Getting everything to fit and still having room for the use of the building is a challenge.”
Smith said the main lessons learned from designing the Burj Khalifa that transferred over to the Kingdom tower design were the three legs around the core design; the nature of a stepped and sloping or tapered tower design.
“The advancement here is that the stepped design is not as high performance as the sloping design at wind mitigation.” “Wind forces are significant in a tower of 1km.”
"When the wind moves around a building, it creates negative pressure areas behind the building, which creates little tornados or vortices, which push the tower from side to side. It’s the acceleration of this movement that we are concerned about.”
“One of the ways to mitigate that is to step the tower, or slope it. Sloping is more effective but it is a little more expensive." The aspect ratio - the footprint to height ratio - of the two buildings is about the same, Smith said.
One of the limiting factors in skyscraper design, Smith said, was elevator design. At present, elevators can reach a maximum height of 550-570m – due, primarily, to the weight on the cable and the load placed on motors that were currently available. As it stands, the elevators don’t quite reach the highest occupied level of the Kingdom Tower, so a second tier of elevators has been designed in to the building. Smith didn’t elaborate further
Smith also said that skyscraper design had changed considerably post 2001, with thicker concrete walls required, larger stairwells and better security systems in place on all supertalls.
