The higher is the building, the more it experiences wind pressure. This is the so-called "sail effect", which in turn must neutralize engineers. Besides, each additional floor adds weight, which means that the structure should not permeate like the Leaning Tower of Pisa, or collapse under its own weight. During the design process it is necessary to consider the corresponding soil type. An interesting fact is that despite its strength all skyscrapers are quite plastic which allows buildings to fluctuate.

Steel skeleton

New York is considered to be the alma mater of the world's skyscrapers. It seems to be created for being built up with high-rise buildings. At the end of the XIX century engineers began to use steel frames in the construction of industrial buildings and stations, and at the beginning of the XX century urban high-rise buildings were erected with the use of those frames. Metal "skeleton" provided the stability of the first skyscrapers. For example, the Empire State Building consists of hundreds of steel profiles and weighs 59,000 tons. Another interesting fact is that the metal beams of the legendary New York skyscrapers were joined together by means of riveting.

The pyramid effect

Technologies of skyscrapers were being developed rapidly. During that period engineers and architects developed new technologies for damping buildings (artificial suppression of mechanical vibration of the building). In particular, again and again the designers turned and continued to refer to the pyramidal form of the buildings, since the conical construction itself is very strong. For example, the Transamerica tower in San Francisco is stable precisely because of its shape. Besides, an additional fortress is attached to it by an elevated base in the form of a grid of triangular beams, which, in its turn is one of the types of earthquake-resistant construction. The fact is that in case of an elevation, the main load from underground vibrations and tremors falls on the base reducing the pressure on the upper part of the building. Roughly speaking, the raised base extinguishes some part of oscillations.

By the way, the tallest building in the world – “Burj Khalifa” tower in Dubai is also built on the pyramid principle, asymmetrically-stepped. This makes it possible to weaken the "sail effect": the sections of the tower destroy the wind flow in such a way that it traverses the tower instead of crashing on it with the whole wind power.

The backbone of the building is reinforced with concrete and metal with an artificial stone embedded in it. Especially for the construction of "Burj Khalifa" was developed a special concrete, to withstand high temperatures, and during the process of construction was enriched with added ice. Another interesting fact is that the construction of the building is mobile - the steel frame bends. However, the wall panels themselves are rigid. This also ensures the stability of a skyscraper, which literally "transforms" into atmospheric differences.

The pendulum balance

Modern engineers are using dampers (treasures, which extinguishes the mechanical vibrations of the building) to balance the skyscrapers. And sometimes the damper turns into a work of art that one can admire.

For example, the inertial damper of the tower "Taipei 101", which is located in the capital of the Republic of China (Taiwan), Taipei, turned into a real attraction for tourists. Anyone can climb and look at this miracle of engineering - a steel spherical pendulum weighing 660 tons, placed inside the building between 88 and 91 floors.

The pendulum oscillates, compensating the movement of the building caused by strong gusts of wind. Because of that, the building is considered to be the most stable in the world, despite the fact that it is located in an earthquake-prone region. By the way, in the process of construction it has perfectly transferred a 6,8-point earthquake. The sphere of the pendulum is considered the largest in the world, it consists of 41 steel plates, each 125 mm thick, which together makes up 5.4 m in diameter.

Singapore hotel Marina Bay Sands became famous all over the world for its stunning rooftop pool, which connects three towers of the hotel. Vacationers do not even suspect that they are sweeming, in fact, in a huge damper.

The author of the project of the hotel is the Israeli architect Moshe Safdi. He developed this pool not only as an architectural highlight, but also to ensure the stability of the design in case of earthquakes. The water in the basin compensates fluctuations during the tremors.