Skyscrapers, wonders of engineering. Or, one of the most dashing expressions of human desire to reach for the sky. In recent years, 70 skyscrapers were built in the districts of Levent and Maslak in Istanbul, Turkey. The latest of these towers is rising in the very same area. A 261-meter-high Sapphire. At the top floor, you can enjoy a panoramic view of Istanbul’s skyline. Of course, you should never forget that when you open a window at the 56th floor, the wind might knock you against the wall. Soon we will see what precautions have been taken to prevent it from happening.
Sapphire, with a height of 261 meters, is currently the tallest building in Istanbul, and the 15th tallest building in the world. The tower has an overall total construction area of 165,000 m2, meaning a huge foundations pit had to be excavated. Considering the first 10 floors were built into the rocky soil of the area, it is not surprising that engineers had to excavate a huge pit to a depth of 43 meters. First, the 10 floors below ground were built, and then the other 56 floors, using some special reinforced concrete.
Sapphire architect said: “We wanted it to be as resistant as the Imperial Hotel in Tokyo which had survived a 9.0 magnitude earthquake. But we chose a very different method than many other earthquake-resistant buildings. In this building, you can’t see any columns 50-60 cm thick, which you used to see in other structures.”
The columns separating apartments were embedded into the walls in such a way that they would form a rectangle, thus making the walls themselves carry the load. Another feature of Sapphire is that a second facade made of steel was attached to the main structure built of concrete. Now, hold tight! The second facade is a self-supporting steel frame which does not lean against the main structure, therefore is not a load to be carried. It is, in fact, a steel armor. But how come?
You can do many things at a height of 261 meters above the ground, expect for one thing; You can’t open a window. The function of the second facade, or the shell, is to create a buffer zone between the building and weather conditions at this height. All the balconies and gardens in the building are in this buffer zone. The shell both breasts the harsh winds and makes them moderate with the help of ventilation louvers, thus taking a moderate air in. Therefore, a natural atmosphere is obtained inside the building.
This system is based on one of the most important rules of physics: The heated air rises. On a signal coming from the wind and temperature sensors, the vents at both sides of the building let the air out. When the air inside is heated too much, the temperature sensor steps in and sends signals to the vents to open. If the wind sensor that detects the strength and direction of the wind outside confirms the vents fling open. This way, you get a natural air-conditioning and can breath oxygen naturally at the 56th floor. So, there is only one problem left: To reach the 56th floor. But with express elevators at high speed, it is not really a problem.