Burj Khalifa | The Secrets of its incredibly Strong Foundation

the Magnificent Burj Khalifa is resisting a

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sand storm of 100 kilometers per hour a quick tour under the beautiful petals you will find its

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s a structure with an enormous depth of a 10-story building surprisingly the

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s of the Burj Khalifa have to withstand electricity 24 7. any small problem with the flow of electricity will weaken its foundation and the result could be catastrophic on a windy day. Interestingly, the base of the foundation is as thick as two human beings even though the raft looks like a simple building structure. It was a huge task, this is mainly because a large amount of concrete had to be poured in a single volume.

The construction of this raft began with the placement of steel bars. The next step was to pour the concrete, which was no easy task in the 40-degree heat in Dubai which is why the engineers executed this job overnight. They also mixed the concrete with ice cubes while pouring it. The concreting process of the entire pond was carried out in four separate parts, each over a period of 24 hours. There are many more. challenges present in front of Burj Khalifa chief design engineer Mr. Bill Baker, let's first solve the biggest challenge: ground settlement, this is what would happen if your design calculations for settlement went wrong in normal building construction.

Engineers always find something called hard strata, a hard ground where the building can rest during the construction phase the weight of a building increases and it is normal for the building to settle a few centimeters let's observe the settlement of the building once again during this process the Soil beneath the foundation is compressed and settled now the soil can produce the proper reaction force and balance the weight of the building. However, this settlement should be within a safe limit. Now let's take a cross section of the ground of Dubai. It's just loose sand and weak sedimentary rock.

Even after digging 140 meters deep, the engineers failed to find

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, hard strata. Burj Khalifa engineers had built a normal raft foundation on this site, it would settle too much and a catastrophe would inevitably have occurred. Chief Engineer Bill Baker came up with a simple solution to a problem as big as the frictional force of the surrounding soil here. Mr. Bill Baker is trying to pierce the sand using a thin, sharp rod. It is a common observation that after a distance the rod does not lower, this is due to the increase in friction force provided by the surrounding sand as the rod descends. generate the friction force, he added several piles under the raft base, the depth of these RCC piles is equal to 10 floors of Burj Khalifa.

He now immerses the foundation into the soil and takes a cross section. Let's try this base that these piles generate. friction force against the weight of the building with the help of ground reaction force and additional friction force, the raft pile would settle much earlier and within safe settlement limits. When construction of the Burj Khalifa was completed, it had a settlement of only about five centimeters. which is quite sure, the next big challenge is how to build these piles perfectly, making the design for the construction of the piles a reality. They started by drilling a hole with an auger excavator.

The blades of this device perfectly remove soil. However, Mr. Baker. He faced a problem: Dubai's groundwater due to the heavy machinery around the well would collapse and be filled with salty groundwater. The solution was quite clear when the ground was excavated. They simultaneously poured a drilling fluid through the shaft of the bit, which creates a slurry. The slurry is denser than water and exerts hydrostatic pressure on the walls of the well, so it resists soil collapse. Now the pit is ready, the workers placed a temporary hollow steel cylinder to keep the soil intact for concreting and then put welded steel reinforcement bars into the pit as a long cylinder in normal concreting, the workers must use vibrators of concrete to make the concrete compact.

The use of these machines is impossible in such deep wells, that is why SCC C60, a special type of concrete that flows like a liquid, is used for concrete piles. it was poured with the help of a tremi tube the construction of the foundation only took two years the entire sequence of foundation construction for the Burj Khalifa is illustrated here now we have achieved a good foundation design to support the world's tallest building in loose soil of Dubai although this stacked raft is against the gravitational pole Dubai's strong sand storms are yet another test the design of the stacked raft we developed will fail during a strong sand storm Do you have any design suggestions to overcome this problem if You want to strengthen this tower to prevent it from falling over, would you add glue to the center of the base plate or to the edges?

When the Burj Khalifa is stuck in the center, it falls down due to the force of the wind. When the building is glued on its edge, it stands firm on the original Burj Khalifa Design, we can also apply a similar technique to the pile design, simply increase the number of piles in the wing area. Due to this elegant design change, the Burj Khalifa is capable of withstanding wind speeds of up to 240 kilometers per hour. To analyze this optimal pile location, engineers performed rigorous pile loading tests that involved applying a heavy load on a temporary test pile and studying settlement.

These tests lasted more than six months and occurred at 23 points in this Burj Khalifa location. Now you have the answer. I have been waiting why the Burj Khalifa Foundation has to transport electricity continuously if this is not done. Salt water seeping in from the Persian Sea will corrode the reinforcing bars inside the piles. To overcome this problem, they use the physics behind battery electrolysis. They made these rebars as cathodes. and used a titanium mesh as a sacrificial anode when direct current from the rectifiers is applied between them, the electrons are deposited on the cathode, this prevented corrosion of the reinforcing bars, but severely corroded the anode metal after years , the anode would need to be replaced, one thing is clear.

From here, to avoid corrosion completely, we have to supply the optimal amount of current flow; However, if we supply too much, this will lead to a phenomenon known as hydrogen embrittlement. This phenomenon causes the bars to become brittle and crack quickly. That is why the cathodic protection system developed must be precise. There is no excess or shortage of electricity supply, of course, any failure of electricity supply in the cathodic protection region would weaken the foundation over the years. Before you leave, become a Lasix member and enjoy our exclusive civil engineering videos. Thanks for watching.