The concept of high-rise buildings has always combined innovation and modern techniques for the magnitude. From the Braced Frame to Rigid Frame Structure, from the Infilled Frame Structure to Shear wall structure, from the Hull core structure to Bundled tube structure innovations have been happening worldwide.
According to arch daily reports, the number of officially “tall” buildings (at least 656 feet or 200 meters) is set to double over the next ten years.The number of “megatall” buildings (at least 1,969 feet or 600 meters) is expected to jump from two to 10 by 2020, building construction around the world is literally reaching new heights. Indeed, next year alone 10 new skyscrapers of at least 1,110 feet (338 meters) will be completed.
Dilemma on actualisation of the definition
The correct assessment of the height of artificial structures has always been controversial. Different standards have been implemented by varied firms. This clearly implicates the segregation of specified tallest structure or building has changed overtime depending on which standards have been accepted.
The Council on Tall Buildings and Urban Habitat, (an organisation that certifies buildings as the “World’s Tallest”) have revolutionised their definition overtime. However, there is a dilemma on what is a tall building? How is a building’s height measured?
ctbuh.org, have analysed standard information in this regard.
– It is not just about height, but about the context and proximity.A 14-story building may not be considered a tall building in a high-rise city such as Chicago or Hong Kong, but in a provincial European city or a suburb,it isseen as so.
– A tall building is inclined with proportion. Numerous buildings are not particularly high but are slender enough to give the appearance of a tall building. Numerous big/large footprint buildings are quite tall, but their size/floor area rules them out as being classed as a tall building.
– If a building contains technologies which may be attributed to being a product of “tall”, then this building can be classed as a tall building.
– Although number of floors is a poor indicator of defining a tall building due to the changing floor to floor height between differing buildings and functions, a building of perhaps 14 or more stories (more than 50 meters (165 feet) in height) could perhaps be used as a threshold for considering it a “tall building.”
– The CTBUH defines “supertall” as a building over 300 meters (984 feet) in height, and “megatall” as a building over 600 meters (1,968 feet) in height. As of June 2015, there were 91 supertall and 2 megatall buildings fully completed and occupied globally.
– The Council on Tall Buildings and Urban Habitat (CTBUH) recognises tall building height in three categories:Height to Architectural Top, Highest Occupied Floor and Height to Tip.
Material analysis of high -rise buildings
The structures of these buildings are high& lead to higher vertical loads and higher lateral loads and mostly comprises of concrete and steel.
– A tall concrete building is defined as one where the main vertical and lateral structural elements and floor systems are constructed from concrete.
– A tall steel building is defined as one where the main vertical and lateral structural elements and floor systems are constructed from steel.
– A composite tall building utilises a combination of both steel and concrete acting compositely in the main structural elements, thus including a steel building with a concrete core.
– A mixedstructure tall building is any building that utilisesdistinct steel and concrete systems above or below each other.
Few of the outstanding high-structure models around the world are analysed below:
The Chenab bridge
Chenab Bridge is located in the Jammu and Kashmir area. It crosses the river Chenab near the village of Kauri. It is a part of the new Baramulla-Srinagar-Udhamptur railway connection. The construction of this bridge began at 2014 and is expected to be completed by 2018.It is deck-arch steel bridge model. When completed in 2018, the Chenab Railway Bridge will become the world’s highest railway bridge, with a height of 359 metres.
Design and material segmentation
WSP Consulting KORTES Ltd. is in charge of the design module of this bridge. Afcons Infrastructure Ltd. and Ultra Construction & Engineering Company are Co-contractor of the projects.
Wind tunnel testing has been done by FORCE Technology. They have 20 years experience in wind-tunnel tests of bridges. Their services include Section model tests, aeroelastic full bridge model tests and terrain model investigations. They operate five state of the art wind tunnels including several large boundary wind tunnels and a climatic wind tunnel.
Mageba group is in charge of bearings. Mageba has to date supplied bearings and expansion joints for more than 20,000 structures. Mageba is supplying 22 RESTON-SPHERICAL bearings for the construction of this remarkable bridge. All of the bearings are of type KA (free-sliding), meaning that they allow sliding movements in all horizontal directions. They are designed to carry vertical loads of up to 14,160 kN, and 12 of the bearings are also designed to resist uplift forces. The use of ROBO-SLIDE, mageba’s high-grade sliding material, the bearings are smaller than they would be if PTFE were used, with advantages for the bridge’s design and its construction. Thanks to ROBO-SLIDE’s far superior wear resistance, bearing durability is also significantly improved.
– Chenab Bridge is an arch bridge completely made of steel.
– The dimension includes total length of 1315 m and arch span is 480 m
– The bridge is founded on the bedrock.
– The foundations of the arch are approximately 40 m high and 50 m wide
– The total length of the bridge is 1315 m.
– The free span length of the bridge is 467 m when measured from the river below
– The height of the bridge deck is 350 m.
– It contains approximately 25,000 tonnes of steel.
– The deck of the bridge comprise of steel.
– The foundations and the approach viaduct piers comprise of concrete.
– The arch is erected using a cableway crane.
– The number of bolts used is around 600,000.
– All the bridge structures have been 3D modelled.
– Temporary cables and related anchoring towers are used to install the cantilever were modelled.
– The design of the bridge has been made keeping severe seismic loading and possible blast loads.
– The model was created in an undeformed shape including camber.
– The design speed of the railway was set to be 100 km/h and the design life had to be 120 years.
– To facilitate production on site, the chords of the trusses and the diagonals are added
– In the arch portion, the superstructure is supported on steel piers with a height of up to 120 metres.
– Expansion joints are also incorporated at the end abutments
– The superstructure is a plate girder with a closed deck
The Chenab Bridge will be the biggest railway arch bridge ever built in the world.
At the forefront of worldwide skyscraper activity, Jeddah Tower represents an unprecedented exercise that dares to go beyond the one-kilometer threshold, a height that seemed only to exist in fantasy just years ago. Jeddah Economic Company is the developer of the project. The design has been done by Thornton Tomasett, and peer review has been done by Magnusson Klemencic Associates.
The Jeddah Tower is located in Saudi Arabia. The skyscraper is intended to be the centrepiece of the Kingdom City development.It is estimated to cost $1.23bn.
– It would be 568 ft (173 metres) taller than Dubai’s Burj Khalifa tower
– It will be at least 3,280 feet tall,
– It will be the first structure in the world to reach the one-kilometer-high mark
– It will have 200 floors
– The structure will have a separate, 98-foot-diameter outdoor balcony
– The foundation piles of the structure are about 10 feet in diameter
– The structure will be constituted with “three petal” plan which allows separate extrusions to nudge against one another
– It has 59 elevators and 12 escalators, and five of these elevators will be double decker.
– A high-performance exterior wall system, including low-conductivity glass, have been installed which will minimise thermal loads.
– The gigantic structure will inhibit 80,000 tonnes of steel.
– The parts of the core will contain concrete that is several meters thick.
– The project is estimated to be completed by 2020
Burj Khalifa in Dubai, United Arab Emirates, is the “Tallest Building in the World”. It is over 828 metres (2,716.5 feet) and more than 160 stories. This high-rise structure is the tallest free-standing structure in the world.
Dubai is synonymous to ‘high-rise’ structures and also leads by example viz; the 828m Burj Khalifa, the 355mJW Marriott Marquis Dubai Hotel (tallest hotel in the world), Dubai Marina – the tallest residential skyscraper cluster in the world, the Burj Al Arab which rests on an artificial island constructed 280m off shore, the 80 storey Cayan Tower (twisted by 90 degrees from top to bottom), the 101 storey Princess Tower in Dubai – the world’s tallest residential building,to name a few.
– The construction practices of the structure inhibit an established approval of Project Quality Plan (PQP) and Inspection Test Plans (ITPs) with well-narrated method statements and definite objective checklists/formats.
– Project Management Information System was effectively and efficiently used in day-to-day construction activities for ensuring an advanced information on construction activity.
– The tower foundations subsist of a pile-supported raft. The solid reinforced concrete raft is 3-7 m (12 ft) thick and was streamed utilising C50 (cube strength) self-consolidating concrete (SCC).
– In addition to the standard cube tests, the raft concrete was field tested prior to placement.
– DOKA Auto-climbing formwork was used for the Tower cores and Hunnebeck Table formwork for the Podium slabs and FRP shuttering for walls of circular Car parking ramps.
– Aluminum shuttering is implemented for tower slabs. C80 grade concrete was used in tower columns and shear walls and C50 grade concrete for beams and slabs. Podium rafts were cast with C50 grade concrete.
– The composite link beams were used to connect core walls and nose columns.
– The architectural design concept was derived from Blue Dick, the flower of the desert.
– The structure system is supported by a big reinforced concrete mat.
– The mat is 3.7 meters thick, and it was architected in four separate pours totalling around 12,500 cubic meters of concrete.
– The podium provides a base which anchors the tower to the ground. This allows grade access from different sides of the building
– The exterior cladding is made of reflective glazing with aluminium and elongated with stainless steel spandrel panels and stainless steel verticals
– The tower has adopted the most stabilised Y-Shape, which provides stability by building weight shifts to the end of the wings.
– Fire safety and speed of evacuation were prime factors in the design of the structure
– The concrete surrounds all stairwells of the structure
– The telescopic spire comprises of around 4,000 tonnes of structural steel.
– The system consists of centre hexagonal reinforced concrete core walls which enable the torsional resistance of the structure
– The wall concrete specified strengths range from C80 to C60 cube strength.
– Local aggregates were utilised for the concrete mix design.
– The top section of the tower consists of a structural steel spire which uses a diagonally braced lateral system.
– The system’s structural steel spire is designed for gravity and seismic activities
– To analyse the wind loading on the main structure, wind tunnel tests were undertaken early in the design. Force-balance technique was used for analyzation.
Burj Khalifa is a fantastic example of progress and dynamic design.
The developer of the tower is SOCAR (The State Oil Company of The Azerbaijan Republic).The architect is Design Heerim Architects & Planners Structural Engineer Design has been created by Thornton Tomasetti MEP Engineer. The design is created by WSP Flack + Kurtz; Daeil E & C; Yungdo Engineers. Main Contractor is TEKFEN Construction, and Installation Co., Inc. Material was supplied by Tuned Mass Damper MAURER AG. The design of the tower began in 2007. With 40 stories it is the tallest building in Azerbaijan and all of the Caucasus.
Raising up the foundation offered the first challenge. Other than that there were seismic factors that had to be kept in mind.“The Land of Fire”, Baku is a heavy seismic zone and has particularly strong winds. The complex geometric shape required sloping columns, mainly at the tower’s top, which when combined with the high seismic and wind loads provided numerous design challenges. Further, a tuned mass damper at the top of the roof ensures a controlled movement of the tower under wind loads to meet criteria for human comfort.
– The tower foundation is raft pile system
– The 59,000-square-meter (635,070-square-foot) office tower has an aluminium and glass podium and two levels below grade.
– The tower structure is hybrid by nature which consists of reinforced concrete core walls
– Its curving façade resembles a flame that comes to a point at the top
– The Height Architectural of the tower is 195.9 m / 643 ft
– Height: Occupied 171 m / 561 ft
– Height: To Tip 198.6 m / 652 ft
– Floors Above Ground 40
– Floors Below Ground 2
– Tower GFA 100,047 m² / 1,076,897 ft²
– The tower has a dual lateral structural system consisting of special reinforced concrete shear walls and a special steel moment frame.
The actual definition was difficult to define. As per writepass.com/journal report, in the Oxford Dictionary it is merely defined as ‘a tall building with many storeys’ but in Architectural terms, It is a building perhaps inspired by the height it reaches, and a building that pulls together all ofmankind’s technological breakthroughs to reach these new unknown heights in the construction industry.
– Taipei 101 was the world’s tallest skyscraper until 2007
– It is 508.0 meters (1,667 ft)
– It is crafted to withstand the typhoon winds and earthquake tremors which are common in Taipei and Taiwan.
– It consists of 101 floors
– The tower features a series of eight segments of eight floors each
Shanghai world financial centre:
– The Shanghai World Financial Center is a mixed-use skyscraper model
– The centre consists of offices, hotels, conference rooms, etc.
– It contains 174 rooms and suites.
– It is 492 meters (1,614.2 ft)
– The unique feature in the design of the building is the hole at the top of the structure.
– An alternative design replaced the circle with a trapezoidal hole
– The building looks like a giant bottle opener
These are only a few examples of variant artistic skyscrapers around the world.
Today high-rises provide low energy consumption and a greater potential forharnessing wind energy and a great potential for natural ventilation. Additionally, it also promotes sustainability. With the growth of innovation and technological enhancements, the concepts of the high-rise building are reaching new heights.