Burj Khalifa - Every Civil Engineers dream

Burj Khalifa - Civil Engineers Dream Project

Introduction:-

Being the tallest building in the world and its beauty attracts anyone in the world.
The edifice is located in Dubai, United Arab Emirates.
With a total height of 829.8 m, the Burj Khalifa has been the tallest structure in the world since 2010.
The building was built within a period of 6 years.
The construction began on 6 January 2004 and ended in the year 2010.
The building was earlier known as Burj Dubai but was renamed in honor of the ruler of Abu Dhabi and the president of the UAE, Khalifa Bin Zayed Al Nahyan.

Burj Khalifa Structure

The world’s tallest building, Burj Khalifa took 6 years for its construction and was inaugurated on 4^th January 2010. The structure is 828m tall and the whole system is a reinforced concrete tower structure. This was the first attempt in world history to have such a large height for structures. This reason made the designers to employ one of the best and latest technology and innovative structural design. The structural features of Burj Khalifa is explained in the following section.

As the skyscraper has a floor plan of” Y” shape, this plan gives higher performance and provides a full view of the Persian Gulf.
Due to the integration of aerodynamic shaping and the plan, the structure can reduce the effect of wind forces. The central core has a higher resistance to torsion.
The total floor area of the building is 460000 sq meters.
The whole structure is designed as a reinforced concrete building with High-Performance Concrete up to level 156 and up to the top it is designed as a structural steel braced frame.
The C80 and C60 cube strength concrete is used with fly ash, portland cement, and the local aggregates.
A Young’s Modulus of 43800N/mm2 is said to be granted by C80 concrete. The largest pumps in the world were used to pump concrete up to a height of 600 m at a single step

Burj Khalifa Project - height, storey, floors etc.

The structure is located in Dubai, United Arab Emirates. The structural features include:

160 + storey tower
Podium structure adjacent
Have a six story office adjacent
A two story pool facility near

The tower comprises 2,80,000 m² area. This area is utilized for 700 residential apartments located from 45 to 108 floors. Remaining spaces is till the 160^th floor is occupied by the corporate officers. The total project cost is estimated to be US$20billion. The tower construction itself costs $4.2billion. The structural elements used and their amount is mentioned below:

Concrete Used = 250000 cubic meter
Curtain Walls = 83,600sq.m of glass and 27,900 sq.m of metal
Steel Rebars Used = 39,000 tones
Man-Hours = 22million man-hours

Burj Khalifa - shape of the tower

Adrian Smith is the man behind the structural and the architectural design of Burj Khalifa. The basic structure is a central hexagon core with three wings, which is clustered around it, as shown in figure-2. While moving up along the tower, one wing at each tier is set back. This makes decreasing cross section when moving up. The structure consists of 26 terraces.

Burj Khalifa - Cross section

Cross Section plan of Burj Khalifa

Burj Khalifa - Structure system

The Burj Khalifa employs a ‘Y’ shaped floor plan. This plan provide higher performance and provides a full view of the Persian Gulf. The shape and the upward setbacks help the structure to reduce the wind forces that is acting on the structure. The shape was finally fixed based on the series of wind tunnel tests. The structural system employed for Burj Khalifa can be called as the Buttressed Core System. The whole system is constructed by using high performance concrete wall. Each wing buttresses the other through a hexagonal central core as shown in figure-2. The central core has a higher resistance towards the torsional resistance. The structure is more designed for wind force and related effects. There are corridor walls that extend from the central core to the end of the wing. At the end, these walls are thickened by means of hammer walls. These walls resist the wind shears and moments by acting like the web and the flanges of the beams. There are perimeter columns which are connected to the mechanical floors. The connection between the perimeter columns and the mechanical floors is provided by means of outrigger walls. This help to resists higher wind loads laterally. The outrigger depth is three storey heights. There is periodic encounter of outrigger system through the height of the tower.

Burj Khalifa - Concrete used in projects

The high-performance concrete used in Burj Khalifa guarantee low permeability and higher durability. The C80 and C60 cube strength concrete is used incorporating fly ash, Portland cement, and the local aggregates. A young’s modulus of 43800N/mm² is said to be granted by the C80 concrete. The largest concrete pumps in the world were used to pump concrete to height up to 600 m at a single stage. Two numbers of this type of pump was used. As the temperature of the location (Dubai) is very high, there were chance of cracks due to shrinkage. So, the concrete pouring process was carried out at night at a cooler temperature. Ice was added to the concrete mix to facilitate the desired temperature. To withstand the excessive pressure caused due to the building weight, special concrete mixes were employed. Every batch was tested before placing.

Burj Khalifa - Foundation pile and raft

The superstructure of Burj Khalifa is supported over a large reinforced concrete raft. This raft is in turn supported by bored reinforced concrete piles. The raft has a thickness of 3.7m and was constructed in four separate pours. The grade of concrete raft is C50 which was self-consolidating concrete. The concrete volume used in the raft is 12,500 meter cube. The number of piles used were 194. The piles were 1.5m in diameter and have a length of 43m. Each pile has a capacity of 3000 tons. The concrete grade used in piles where C60 SCC concrete which were placed by tremie method. This utilized polymer slurry to carry out the process. To reduce the detrimental effects of chemicals, cathodic protection where provided under the raft.

Pile Raft Foundation in Burj Khalifa. Photos From the Construction Stage

Did you know about :- Burj Khalifa facts

Burj Khalifa World Records

At over 828 metres (2,716.5 feet) and more than 160 stories, Burj Khalifa holds the following records:

Tallest building in the world
Tallest free-standing structure in the world
Highest number of stories in the world
Highest occupied floor in the world
Highest outdoor observation deck in the world
Elevator with the longest travel distance in the world
Tallest service elevator in the world

Tallest of the Supertall - Burj Khalifa

Not only is Burj Khalifa the world's tallest building but it has also broken two other impressive records: tallest structure, previously held by the KVLY-TV mast in Blanchard, North Dakota, and tallest free-standing structure, previously held by Toronto's CN Tower. The Chicago-based Council on Tall Buildings and Urban Habitat (CTBUH) has established 3 criteria to determine what makes a tall building tall. Burj Khalifa wins by far in all three categories.

Height to architectural top
- Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the architectural top of the building. This includes spires but does not include antennae, signage, flagpoles or other functional-technical equipment. This measurement is the most widely used and is used to define the Council on Tall Buildings and Urban Habitat rankings of the Tallest Buildings in the World.
Highest occupied floor
- Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the highest continually occupied floor within the building. Maintenance areas are not included.
Height to tip
- Height is measured from the level of the lowest, significant, open-air, pedestrian entrance to the highest point of the building, irrespective of material or function of the highest element. This includes antennae, flagpoles, signage and other functional-technical equipment.

Amazing facts about Burj Khalifa

The skyscraper holds 900 apartments,3004 hotels, and 35 floor offices.
The curtain wall of the whole building is equivalent to 17 football fields. It takes 3 months to 36 employees to clean the windows of the building from top to bottom
It has 54 elevators which move with a speed of 40 miles per hour equivalent to 10 meters per second.
Burj Khalifa is three times taller than Eiffel Tower and two times taller than the Empire State Building.
It holds the World’s highest outdoor observation deck at about 452 meters above the ground.
The skyscraper can be seen from a distance of 95 kilometers away from it.
At the highest point of Burj Khalifa, visitors can enjoy the temperature different to 15 degrees lower.
The skyscraper with 163 floors is constructed within a period of 6 years.No one would have thought that the World’s tallest skyscraper would be built within a short period of time.

Burj Khalifa - Technology Used

The tower is consisted of 163 floors and followed a very tight schedule of a 3-day cycle. The key construction Technologies are-

Auto Climbing formwork System(ACS)
Rebar prefabrication
High-performance concrete provides high strength, high durability, and high pumping
Advance concrete pumping technology
The formwork system can be dismantled and assembled quickly with minimum labor work
Column/Wall proceeding method.

for More detail about burj khalifa visit following sites

source :

https://civilengineeringbible.com/article.php?i=281

https://theconstructor.org/structures/structural-details-burj-khalifa-concrete-grade-foundations/20512/

BRICKS - SIZE, SHAPE, CLASSIFICATION, DEFECTS, MANUFATURE, TYPES, STRENGTH, TESTS, ALL TOPICS CIVIL ENGINEERING ORIENTED

TIMBER- TIMBER, TYPE, CLASSIFICATION, DEFECTS, SHAKES, TESTS, DRY ROTS, WET ROTS-ETC, SEASONING, CONVERSION, ALL TOPICS CIVIL ENGINEERING ORIENTED

MASONRY & TUNNEL - STONE MASONRY, RUBBLE MASONRY, QUAINS, KING CLOSER, QUEEN CLOSER, D.P.C., POINTING- ( STRUCK, TUCK, WEATHERED, BEADED, RECESSED ) , TUNNEL, OFF -SPUR TUNNEL, BASE TUNNEL, SLOPE TUNNEL, SPIRAL TUNNEL, TUNNEL JACKING, TUNNEL LINING, SHIELD TUNNELING, GROUTING, TUNNELING METHODS, TYPES OF TUNNEL SECTION,

10. Lake Pontchartrain Causeway
9. Burj Khalifa
8. English Channel Tunnel
7. Golden Gate Bridge
6. Hoover Dam
5. Itaipu Dam
4. Brooklyn Bridge
3. The Colosseum
2. Great Wall of China
1. Great Pyramid of Giza

10. Lake Pontchartrain Causeway

Lake Pontchartrain Causeway

The Lake Pontchartrain Causeway in Louisiana (U.S) spans the entirety of Lake Pontchartrain and is 23.83 miles (38.35km) in length. Despite it being opened decades ago in 1959, it is still the longest continuous stretch of bridge over water in the world. The causeway is supported by 9,500 pilings and is so stable that it has suffered a minute amount of damage from major hurricanes and storms when compared to any other causeway worldwide.

9. Burj Khalifa

Burj Khalifa Project Details

The structure is located in Dubai, United Arab Emirates. The structural features include:

160 + story tower
Podium structure adjacent
Have a six story office adjacent
A two story pool facility near

8. English Channel Tunnel

The English Channel Tunnel links the shore of Kent in the UK with Pas-de-Calais in France. It has the longest undersea portion of any tunnel in the world, at 23.5 miles (37.9km). At its deepest point, it is 75 metres (250ft) below the sea bed and 115m (380ft) below sea level. It is designed to carry high-speed Eurostar passenger trains, international goods trains and a shuttle for road vehicles, making it the largest transport system of its kind in the entire world. When it opened in 1994, it was the most expensive project of all time, with the final cost of an astounding £9 billion. Despite other construction projects being more expensive in recent years, it still considered to be one of the highest-value engineering feats ever.

7. Golden Gate Bridge

The Golden Gate Bridge is considered by many to be one of the most beautiful bridges in the world. This $27 million project is a mile-long suspension bridge that spans a strait, connecting the city of San Francisco to Marin County. It opened in 1937 and was the longest suspension bridge in the world for almost three decades. The bridge is one of the most recognised and influential symbols of the United States and has been declared a Wonder of the Modern World by the American Society of Civil Engineers.

6. Hoover Dam

Constructed during the Great Depression, the Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River. The construction of the Hoover Dam impounds Lake Mead, the largest reservoir in the United States. It was such a large project that several temporary towns were built during its construction to house the thousands of workers who made it. The dam is named after President Herbert Hoover, cost the equivalent of over $660 million to build and was completed in five years, two years ahead of its schedule.

5. Itaipu Dam

On the Parana River, bordering Brazil and Paraguay lies the Itaipu Dam. This mega-dam produces more hydroelectric energy than any other dam in the world – measuring in at an immense 103,098,366-megawatt-hour (MWh). The energy produced by the dam is split evenly between Paraguay and Brazil, although it generates so much electricity that there is surplus energy for Paraguay which is transferred back to Brazil.

4. Brooklyn Bridge

The Brooklyn Bridge is one of the oldest bridges in the United States and was the first steel-wire suspension bridge in the world. Completed in 1883, it connects the boroughs of Manhattan and Brooklyn by spanning the East River. The bridge was designed and completed by two generations of engineers, John August Roebling and his son Washington Roebling, who took charge of the project when his father became ill. It cost $15.5 million to build. Originally called the New York and Brooklyn Bridge, as well as the East River Bridge, its name officially changed to Brooklyn Bridge after 30 years of being called that by locals. Since its opening, it has become a historic icon of New York City and is one of the city’s most visited tourist attractions. It was designated a historic landmark in 1964.

3. The Colosseum

The Colosseum is one of the most recognisable structures in the world and is the largest amphitheatre ever to be built. This structure is almost 2,000 years old and has a capacity of between 50,000 and 80,000 people, making it as large as many modern stadiums. This construction sits at the heart of Ancient Rome, Italy and was used for the entertainment of the Roman citizens. It has featured in countless examples of popular culture and is still studied and written about today.

2. Great Wall of China

With a history of more than 2,000 years, the Great Wall of China is one of the greatest wonders of the world, and one of the most visited tourist attractions globally. Whilst it is known to Western cultures as the ‘Great Wall’, Chinese people refer to it as Chéng which means both ‘wall’ and ‘city’. The intrinsic connection between settlements and walls in China means that they share the same term, so the ‘Great Wall’ to us, is the ‘Long City’ and the ‘Long Wall’ to the people of China. The Great Wall stretches from Dandong in the east of the country to Lop Lake in the west. The entire wall with all its different branches, measures out at 13, 171 miles in length. It isn’t possible to know exactly how much the wall would have cost to build, but modern calculations say it would be somewhere between $13billion and $65 billion.

1. Great Pyramid of Giza

The Great Pyramid of Giza is one of the Seven Wonders of the Ancient World, and despite being the oldest, it remains largely undamaged. It is the largest of the three pyramids in the Giza pyramid complex and was the tallest construction in the world for over 3,800 years. It is believed that the pyramid was built as a tomb for the fourth Dynasty Egyptian pharaoh, Khufu and was constructed over a twenty-year period. Many experts estimate that 5.5 million tonnes of limestone, 500,000 tonnes of mortar and 8,000 tonnes of imported granite were used to make it. Experts also estimate that it would cost around $5 billion to build a replica today.

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Across the history of mankind, we have used our intelligence to create large, impressive structures and buildings. There have been many great civil engineering projects that have become historic landmarks and icons, but we consider these to be amongst the greatest. They showcase our ability to design and construct our own unique vision.

Every engineer will have a different opinion on the most impressive creations. Honourable mentions include: the Millau Viaduct, which is the tallest cable-stayed road bridge in the world and the Shanghai Tower skyscraper in China, which is now the second-tallest building in the world. It is clear that the future of engineering is bright, and as technology advances, we will get to see even more incredible creations.

source - https://www.cobaltrecruitment.co.uk/blog/2017/03/top-10-most-impressive-civil-engineering-projects-of-all-time

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Burj Khalifa - every civil engineers dream