The Leaning Tower of... ABU DHABI? #OnlyinDubai

In terms of architecture, Abu Dhabi and Dubai are some of the most innovative places in the world, always pushing things a step further in order to stay one step ahead and we can see proof of this in their skylines, taking inspiration from classic or iconic buildings from around the world and bringing them up a level. Marina Bay Sands in Singapore, The Gate Towers in Abu Dhabi. Twisting torso, Sweden, Cayan Tower, Dubai. The Gherkin, London, Damac Park Towers, Dubai. Sydney Opera House, Australia, Zayed National Museum, Abu Dhabi. Elizabeth Tower, London, Al Yaqoub Tower, Dubai. Chrysler Building, New York, Business Central Towers, Dubai. and The Leaning Tower of Pisa, Italy, Capital Gate, Abu Dhabi. Capital Gate is almost 3 times taller than the Tower of Pisa and whereas the Tower of Pisa’s top overhangs its base by around 13ft (4m), Capital Gate’s top overhangs it’s base by a whopping 108ft (33m)! In order to achieve this, and to do it safely, required some incredibly innovative engineering that may not only change the future of Abu Dhabi but the future of skyscraper engineering worldwide. Foundations. One of the main problems occurring due to the immense overhang is the one side of the building is pushing down on the ground but the other side is actually pulling up. To overcome this problem they used a total of 490 concrete piles, (1m) in diameter. On the overhang side, 245, 66ft (20m) long piles were sunk into the ground these piles push the overhang’s forces into the ground, on the other side, 245, 98ft (30m) long piles sunk deeper into the bedrock to resist the stretching forces trying to rip the foundations out of the ground. All these pilings were then unified by a (2m) thick, heavily reinforced concrete slab containing around 247,000 cubic ft (7000m3) of concrete. Core. The next problem to overcome was the core, a normal skyscraper uses a solid core to keep it upright, but on the Capital Gate the core would be compressed on one side and in tension on the other and would therefore just sheer and crumple under the stress, so once again they had to discard the conventional and innovate. Structural engineers came up with an ingenious solution, they built the reinforced concrete core to lean in the opposite direction to the building, as the building grew in size its lean pulled the core straight compressing the core rather than trying to sheer it off. Using a technique called jump forming, the crew would set up the steel bar reinforcement work and the shuttering on a 13ft (4m) high section of the core during the week and then pour the concrete on the last day, due to the intense temperatures this concrete had to be poured at night to stop it drying out too quickly, then the whole platform and form could be hydraulically lifted up another 13ft (4m). External Structure. The external structure didn’t just have to lean, it had to twist and bend, mimicking the contours of a wave and desert sand dunes. It also had to be strong and as thin as possible to maximize internal floor space. So engineers were looking for something thin, curved, and strong, and the humble chicken egg is what came to mind, however, engineers couldn’t replicate an eggshell for the Capital Gate, but they could replicate the principles of how it works by using a diagrid. Glasswork. It was clear from the start that the curvy facade of the Capital Gate could not be clad in curved glass, it would be too complicated and too expensive to get all the curves exactly right, so they use triangles. Every 26ft by 26ft (8m*8m) diamond shape of the diagrid was clad with a module of 18 hinged triangular glass panels making a grand total of 26000 individual panels. The building’s shape and construction method meant that as they continued to build and add weight, the building itself continued to move, this meant that the glass modules had to have a tolerance built-in to allow for this movement and to also allow for thermal expansion and contraction whilst at the same time remaining watertight. The tolerance that was needed was huge in terms of glazing systems, 20mm! Internal Diagrid. In order to reduce the toppling effect, architects wanted to reduce the weight at the top of the building, they did this, by adding a funnel-shaped atrium to the top 18 floors, this lessened the eccentric weight, and also brought in extra sunlight to the upper floors, however, the unconventional design of the Capital Gate uses the floors to join the core to the Diagrid and dissipate the load, by cutting a hole in 18 floors, they were definitely reducing weight, but they were also reducing strength. Do you like Capital Gate’s aesthetic or not? Do you think it’s a new wonder of the world or a waste of money? Comment Below! Get more Tips here!