The Yusuhara Bridge is a very unique structure from a modern perspective. Even though it was built in 2011, Kengo Kuma & Associates decided to use an older style of a structural system the looks just as well as it functions. The bridge is located in Taro-gawa Yusuhara-cho, Japan where it connects two public buildings and supports a facility on top of the bridge. Even though the bridge is small in length, around 27 meters, its short length allows for the structural system to be used with only one major column. The bridge uses a dougong system for supporting itself up along with the walkway and rooms on top of it. The dougong system looks like an inverted pyramid with a column connected to the tip of the pyramid. This column supports majority of the weight of the entire bridge because of the column’s central location1.
When looking at the beautiful structure, it is clear that the pieces of it are not that large compared to modern technology beams and supports. In fact all the pieces are is square timber that slowly gets longer near the top of the structure. It is the arrangement of the timber that gives it its strength. The strength comes from the interlocking of the pieces without any glue or fasteners. The most common shape of this pyramid of interlocking is in a rectangle or square. Each level of timber runs in the perpendicular direction tying in each one treating the whole system as one giant piece. This is very similar to Lincoln Logs even though it was used way before Lincoln Logs ever existed. The Chinese use this style thousands of years ago and it has proved to be very stable in all kinds of situations2.
Another one of Kuma’s museums is located in Aichi in central Japan and it is called the Prostho museum Research Center is a wooden building with a very small structural grid which allows for its structure to be the eye candy for the building. The structure is composed of over 6000 cypress rectangular sticks the form several hundred open cubes. This gives the building a shape and yet it is completely open from all angles. The museum inside has no need for much artificial lighting because of how transparent the walls are3. At certain points the 50cm grid in both the X, Y, and Z directions will have no sticks to allow for spaces and doorways to form inside of the system. Inside there is a museum for dental work and history while in the actual encased walls hidden inside of the grid, the dental research department is right above the museum. Kuma based this design off of an old Japanese toy game called Cidori. The game had several sticks that could fit together to make different joints and shapes. This building system is almost identical to the game but on a much larger scale. No glue, bolts or nails are keeping these pieces together. That is the genius part of the system3.
Kuma explained the interiors as being in a forest where you can see the light piercing through the branches and leaves3. This building represents how structures and walls can be built today without using machinery. Each piece of cypress was placed by hand and did not require and special tool to lock them in place. This has been one of many works of art that Kuma designs to show off the simplicity and elegance of using basic technologies from the older era of his time.
1. Yusuhara Wooden Bridge Museum / Kengo Kuma & Associates. 16 Feb 2012. ArchDaily. Accessed 30 Jan 2014. http://www.archdaily.com/?p=199906
2. Stan Wepundi. Chinese Dougong Structure. Accessed 30 Jan 2014. http://www.academia.edu/3637156/chinese_dougong_structure
3. Stratos Bacalis. (May 27, 2012). Prostho Museum Research Centre by Kengo Kuma. The Sandman Chronicles. Viewed Jan 30, 2014. http://sandman-chronicles.blogspot.com/2012/05/prostho-museum-research-centre-by-kengo.html