Citigroup Center in New York

The Citigroup Center (First called Citicorp Center) is in New York City. There´s also another Citigroup Center in Chicago, but I´m going to speak about the skyscraper of New York. It is 278.9m (915 foot) tall, with 59 floors. It is easily distinguised in the skyline of NY because of his 45º angled top base, which was thought to have luxury apartments on it and then, solar panels, but finally they didn´t do anything.

The skyscraper, completed in 1977, was designed by the american architect Hugh Stubbins Jr. for Citibank. The engineers were William LeMessurier and Associates.

This building was pioneer in using a shock absorber, technically called tuned mass damper (TMD). They were used in bridges but not in buildings. Nowadays the tuned mass dampers are used in skyscraper architecture to reduce movements of the building in windy days or when earthquakes happen. The Citigroup Centers TMD is a 400 tonne concrete block moved by a hydraulic system.

In these 2 videos we can learn how engineers resolved structural problems before the design and once the skyscraper was built.

Citigroup Center´s secrets 1/2



Citigroup Center´s secrets 2/2



From: wikipedia, PBS, tuned mass damper, youtube

Massachusetts Institute of Technology - Students build a steel bridge

The Massachusetts Institute of Technology or MIT is located in Cambridge, Massachusetts. It's one of the most important Institutes of the USA and among its Professors and former students there have been a lot of Nobel prizes.

The MIT website contains many free videos allowing as to follow courses and lectures of their different departments: Architecture, Civil and enviromental engineering, Physics, Biology, Chemistry, History ...

In this video we can see building a steel bridge by the MIT Civil and Environmental Engineering team.



From: MIT

Rio Antirrio Bridge

It's called the Rio Antirrio Bridge (Γέφυρα Ρίου-Αντιρρίου in Greek) because it links the town of Rio in Peloponnese to Antirrio on mainland Greece, crossing the Gulf of Corinth. But its official name is Charilaos Trikoupis bridge, because Trikoupis was the first one who envisioned the brigde during his period as Prime Minister of Greece from 1875 to 1895. This bridge was finally constructed nearly a century later. Its building started on 1998 and it was inagurated on the 7th of August of 2004.

The cable stayed bridge was designed by the French group Vinci.


5 videos showing us how it was constructed. It´s really interesting.

Rio Antirrio Bridge construction 1/5




Rio Antirrio Bridge construction 2/5




Rio Antirrio Bridge construction 3/5




Rio Antirrio Bridge construction 4/5




Megastructures: Rio Antirrio Bridge construction 5/5



From: youtube