Truss Bridge à Sky Gate Bridge R

http://www.japanese-greatest.com/civil-engineering-construction/truss-bridge.html

http://www.infoplease.com/encyclopedia/world/truss.html

A truss structure is a structure composed of triangular units and beams that act as the support. It ensures great rigidity, as the triangle is one of the most stable structures found in architecture. A truss works typically through its rigidity and its complements of forces, including tensile or compression forces.

The structure we are examining is the Sky Gate Bridge R, a truss bridge located in Japan. Completed in 1994, it acts as the main access bridge to the Kansai International Airport. The airport was designed by the Italian architect Renzo Piano, although the architect of the bridge is uncertain. It is 3,750 m long and acts as both a highway system and a railroad system. The highway system runs above the railroad system, acting as dual transportation. One common thought about a bridge this long is that it would be considered a suspension bridge, but it surprisingly is not. It is a truss bridge whose main support is a girder system connected in the form of a triangle. A girder is merely a support beam.

This example is very fitting for that of a truss bridge and seems to stand out greatly from others. It is a dual transportation system that extends for a very long distance, and it is so interesting to learn that given a structure as long as this, it was supposed to be a suspension structure, as this is the typical design for something this long. But, with a change in the support system, the architects/engineers found a different way to produce this monstrosity. This to me is pretty outstanding, as it shows how aspects of architecture are so interchangeable and flexible in their use. There is more than one correct way to build something structurally, and that aspect of architecture is crucial for both application and knowledge purposes. 

*Note: Photos of this bridge were very difficult to find for some reason, but the picture on the left is a good depiction of the truss system and how it acts throughout the entire bridge. 

Dome à Beijing National Stadium, AKA Birds Nest 

Domes are geometrically ordered structures made predominantly of hemispheres that form a roof or a ceiling. One extremely special and unique dome is the Beijing National Stadium Dome, also known as the birds nest. This was used in the 2008 Beijing Olympics and is a structure that is composed of exposed steel bands. It is located in the Olympic Green Village, Chaoyang District and was designed by Swiss architects Jacques Herzog and Pierre de Meuron and Chinese architect Li Xinggang and the others. One very interesting aspect of this dome is that it was built in an earthquake zone, so it had to be made to withstand such forces. In order to do so, the stadium was built in two separate parts; one part is a steel lattice structure and the other is a concrete bowl. This was done in order to maintain flexibility of the structure so it could withstand seismic activity. These pieces of the building are not actually connected. This allows each portion of the structure to move independently from one another. This structure is extremely massive and was made to resist over 50,000 tons of vertical load.

In order to do so, a special plinth, or platform, was chosen during construction. Both the horizontal and vertical load are used to support the structure evenly. To me, this was an extremely outstanding structure, as its entire skeleton is exposed and this allows for the natural aspects of the building to be shown. What can be seen merely from the outside of the structure is how massive it actually is; one can physically feel the weight of the structure just when looking at the image alone, and I think that is an extremely interesting aspect of a building that can be deciphered merely through an image. Its intricate exterior shows how complex the building truly is, and this holds true considering it was built in order to withstand potential earthquakes. An additional extremely interesting aspect of this dome is that its roof is open. The philosophy behind building two separate structures is extremely interesting, as it allows for individual flexibility of both and the potential to withstand earthquakes. This dome is unlike one I have seen before and its features are no doubt unique and outstanding.