1. Each tower was supported by a structural coreextending from its foundation in the bedrock tothe roof. This inner core housed all of theelevators and stairwells as well as having aflooring system structurally independent of theouter walls. This entire core structure was100% steel framed and was made to reduceweight and increase strength.The perimeter walls and the inner core were supported bycross-braces running horizontally all of the way up thebuildings.Because of the WTCs immense height, the steel framed coreincreased the structures strength, something which wouldprove to be important.

2. The WTCs were the first skyscrapers to be built without anymasonry, instead they were mainly steel. When constructionhad finished in 1971 200,000 tons of steel had been used ineach tower.Construction process which would usually have to be donein sequence could be done quickly and at the same time dueto the openness of the hollow structure.The inner core of steel wasconstructed bit by bit, and theperimeter walls and floors were builtaround it. By the time the building wasfinished the steel beams in the corewere the length of the building. 3. On September 11, 2001 two airliners, hijacked by AlQaeda members were intentionally flown into the WorldTrade Centres. Within 2 hours of being hit, both towershad collapsed. The manner in which they did however hasbeen hotly debated since.The towers pancaked which means the stories fallingabove caused the ones below to collapse, making thebuilding fall straight down.There remains some doubt regarding this story. Manypeople believe that the steel inside should have held it upand even if it did collapse that it shouldnt have pancakedor fallen at the speed it did. Post-9/11 reports have confirmed that the WTCs were certainly strong enough to withstand the plane crash and that a internal fires wouldnt have damaged or weakened the structure enough to destroy it. 4. The Colosseum was usedto host gladiatorial showsas well as a variety ofother entertainment. The Colosseum was the largest ever built. 5. The Colosseum is oval shaped with 2 axis, long.one is 188 m and the short one 156. The wholebuilding has four floors. There were eighty archeson every floor, divided by pillars with a halfcolumn. The floor was made out of wooden planks then completely covered in sand. 6. The Velarium was made outof sailcloth, attached tospokes of rope.The arches are 4.20 m wideand 7.05 m high, while onthe upper floors they areonly 6.45 m high. theoverall height of thebuilding is 48,5 m. 7. The Burj Khalifa is askyscraper in Dubai and is thetallest man made building inthe world standing at animpressive 828m. 8. The design team led by WillBaker and Adrian Smithcreated the superstructurewith the core in a y shapedformation creating a muchmore stable building. 9. The Spire Nick Flaherty 800m above groundThe crowning point on the BurjKhalifa is its spire, reaching over200m it secures the title of worldstallest building as well finishing thecreation off perfectly. 10. Marina Bay Sands 11. Marina Bay SandsThe Marina Bay Sands is aintegrated resort, onmarina bay in Singapore. Itis the worlds mostexpensive resort. 12. Marina Bay Sands - DesignArt and sciencemuseumCasino Convention centre and Shopping centreHotel and sandsskypark 13. Marina Bays Sands -SkyparkThe sands skypark is a park atthe very top of the resort. Itspans the roof tops of the hoteltowers and acts as a viewingdeck. 14. The Taipei 101 skyscraper is found in Taiwan. It has an impressive height of 508.2m (1670.6ft). It was constructed from 1999 2004 It has 101 stories above the ground and 5underground The Taipei 101 includes:office, communication, conferenceroom, library, observation, restaurant, retailand a fitness centre. 15. The Taipei 101 is designed to hold up againsttyphoon winds and earthquake tremors thatare common in this area of Asia. Taipei 101 is flexible in strong winds enough toprevent large sideways movement. Flexibilityprevents structural damage while resistanceensures comfort for the occupants andprotection of glass. 16. A Tuned Mass Damper is a device placed in buildingsto prevent: discomfort, damage and outrightstructural failure.The dampers are huge concrete blocks or steel bodiesplaced in skyscrapers, it moves in opposition to theresonance frequency oscillations of the structure bymovement of springs.http://www.youtube.com/watch?v=NYSgd1XSZXc 17. The Taipei 101 has the worlds largest passivetuned mass wind and earthquake damper, itweighs 660 metric tons with a diameter of 5.5meters, suspended from Level 92 to Level 88. It helps the building to ensure stability of thetower and comfort for the occupiers. 18. The design achieves both strength and flexibilityfor the tower through the use of high-performance steel construction. Thirty-sixcolumns supporting, including eight "mega-columns" packed with 10,000-psi concrete.Every eight floors, outrigger trusses connectthe columns in the buildings core to those onthe exterior. The Tower is built on 380 concrete piles, sunk80 meters into the ground. 19. Massive Steel Outrigger Trusses span between thecolumns on every eight floors. The structure is reinforced by a Moment Frame Systemlinking the columns on all floors. 36 columns provide vertical support, including eightmega columns around the perimeter. The worlds largest passive tuned mass winddamper, suspended from level 92 down to level88, helps to ensure stability and comfort. 20. Conclusion All of these buildings had their own structuraladvantages, whether it be support to withstand the forces of nature or using revolutionarymaterials such as bricks for the colosseum.Architects are imagining buildings with new andinnovative materials and technology. The wonders of the world that are pushing the boundaries now will soon be forgotten as newsuper structures are created. 21. http://www.burjkhalifa.ae/language/en-us/the-tower.aspxhttp://en.wikipedia.org/wiki/burj_khalifahttp://burj-khalifa.euhttp://sydney.edu.au/engineering/civil/wtc.shtmlhttp://911research.wtc7.net/wtc/arch/core.htmlhttp://www.skyscraper.org/TALLEST_TOWERS/t_wtc.htmhttp://911research.wtc7.net/wtc/evidence/blueprints.htmlhttp://www.themarinabaysands.com.sg/http://www.dailymail.co.uk/news/worldnews/article-1289194/Marina-Bay-Sands-resort-opens-Singapore.htmlhttp://www.marinabaysands.com/SandsSkypark/Sands_Sky_Park.aspxhttp://www.marinabaysands.com/?utm_source=google&utm_medium=cpc&utm_campaign=c2chttp://www.taipei-101.com.tw/en/Tower/buildind_05-1.htmlhttp://skyscraperpage.com/cities/?buildingID=18http://altlasobscura.com/place/tuned-mass-damper-of-taipei-101http://www.unrv.com/culture/colosseum.phphttp://www.oldandsold.com/articles10/famous-buildings-11.htmlhttp://www.mariamilani.com/colosseum/colosseum_structure.htm