Hoover Dam Bridge

Hoover Dam Bypass, officially called Mike O´Callaghan-Pat Tillman Memorial Bridge, its one of the most spectacular concrete arch bridge. The bridge links the states of Arizona and Nevada across the Colorado river.

The total length of the bridge is 579 meters (1900 feet) and the road it´s 256 meters (840 feet) above the river. When complete, the 323 meter arch will be the forth longest concrete arch in the world.

The master design is by HDR Engineering, T.Y. Lin International desings the bridge and Sverdrup Civil Inc is designing the approaches.

Construction started on 2006 and it will be finished on 2010.

Next video, composed of 5 videos, explains the construction of the Hoover Dam bridge.

Building Hoover Dam Bridge 1/5

Building Hoover Dam Bridge 2/5

Building Hoover Dam Bridge 3/5

Building Hoover Dam Bridge 4/5

Building Hoover Dam Bridge 5/5

From: wikipedia, youtube, and HDR Engineering website

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

Hoover Dam

The Hoover Dam is in the Black Canyon of the Colorado river, between the states of Arizona and Nevada.
Its construction began in 1931 and was completed in 1935.
This dam is named Hoover because Herbert Hoover played an instrumental role in its construction, first as the Secretary of Commerce and later as the President of the United States.


It´s a very intersenting video showing the hard construction of this beautiful dam. It´s composed of 5 videos.

Hoover Dam 1/5




Hoover Dam 2/5




Hoover Dam 3/5




Hoover Dam 4/5




Hoover Dam 5/5




From: youtube and wikipedia