Posts in Category International Matters

Japanese earthquake + Tsunami. NEW challenge for the anti-seismic architecture and engineering.

12 September, 2012 No Comments

Due to our profession, we deal on a daily basis with homes, buildings, plots etc, and it was easy to be touched by the enormous destruction that Japan suffered on March of 2011.

After the 8.9 magnitude earthquake that Japan suffered last year, the response of Japanese architecture has been astonishing. Today Japan has the best buildings in the world to withstand possible future earthquakes. These buildings have been designed in such manner that allows them to absorb the vibrations, replacing a sudden movement with a more balanced swing. Many years ago, Japanese homes were built from bamboo and rice paper which, during earthquakes, allowed them to swing instead of cracking. And even if the homes cracked, they were easier to repair and at a lower cost.

This is a brief summary of the earthquake-resistant architectural features used in Japan:

Shigeru Ban (Tokyo 1957) is an architect and consultant to the United Nations who builds shelter for the UN in disaster zones. He emphasized in an interview (in Spanish Newspaper “EL PAIS” 03/20/11) that no building built after 1981, when construction laws were amended, had collapsed during or after the earthquake. Ban states that earthquakes are not what causes so many people to die, it’s the consequences of it, in other words the building’s debris when they collapse. He also added that, after the tsunami, it would be wise to modify the cities’ urban plans and build brick buildings of at least four stories high by the coasts, in order to function as a protective wall in case of future tsunamis.

For the half a million people who were temporarily sheltered in athletic stadiums for months until temporary homes were ready, the government installed a system based on hard cardboard tubes and paper to create individual spaces. With this structure, families intend to dissipate a reality, that is, psychologically very hard to accept; the lack of privacy.
What is the Japanese anti-seismic architecture about?

Basically, the buildings’ structures are highly reinforced performing a vertical weight distribution, in other words, the lower floors support more weight. The broader the base of the building, the stronger it will be during an earthquake.

The buildings are symmetric and elastic to better absorb the ground’s vibration. The law requires a separation of several inches between the medians of the blocks to allow buildings to move but without  hitting each other, thus avoiding the domino effect between buildings. Mr. J.Garcia Rodriguez, PhD in Architecture from the University of Navarra, compares the behavior of a building under a seismic action to that of a whip when swung. In this comparison, the earthquake would be the hand that moves the whip, and the building is the whip spreading the earthquake’s energy. To deal with this uncontrolled movement, Japanese architecture proposes two solutions:

1-An architecture based on a small number of floors. These buildings are built with rigid structures that resist the impact with little deformation, thus the earthquake’s impact is smaller.

2 – However, in taller buildings, they choose to build more flexible structures. They are designed to oscillate laterally (as the whip would) in a safely manner without major damages. Steel is used in these structures, as it is highly resistant and ductile.

Down below I’ ll give you some highlights on the Japanese housing market as of 2011:

* From 2007 and on, housing prices began to rise out of control due to the increment in prices of building materials as those materials ought to be able to withstand frequent earthquakes. Buildings should be no more than 30 years old, so as a consequence rental prices also soared in recent years. The value of Japanese homes ​​varies depending on the land it is built.

* In Japan the magnitude of a house is measured in tatami, equivalent to 1.6 square meters (from now on m2) approximately. The average dwelling size is usually 90 m2 (3-4 bedrooms) and home of more than 100 m2 is considered a luxury. In general, Japanese people prefer buying a home than renting it, but due to the high prices not everyone can afford it, the main reason for their high index of young and elderly adults living with relatives. However, there is still the opportunity for one to live independently. There has been a curious form of housing: people who cannot afford to either purchase a home or to rent it, can sleep in Cyber Cafes, in which for only 10€ are entitled to a small room with a sofa, TV, and a computer with internet connection.

* It is a real estate market, in which there are almost no legal restrictions for foreign investors to buy property in Japan.

***** Two weeks onset of the earthquake and the subsequent tsunami that devastated part of the country, with 27,000 casualties between deaths and missing people, plus the nuclear crisis (more updated info in International Atomic Energy Agency, www.iaea. org, Spanish Embassy in Tokyo) had the international community very aware of Japan. We felt for the Japanese, …. and we shall remark what an example of organization and integrity in such a moment in their lives they were for the rest of us. Following in this tonic, I wanted to make a post, (avoiding catastrophic images) with the intention of highlighting the human effort made in the form of anti-seismic architecture to counteract the continuous devastating effects of the earthquakes affecting the country, thereby preventing an even higher number of victims.

From here, I wanted to convey solidarity and support to the Japanese people and their victims.

I include links to press reports during the later days of the catastrophic events: