E-Defense is a 3D full-scale earthquake testing facility that simulates seismic activity on actual-size buildings. This facility is built by the National research Institute for Earth science and Disaster prevent (NIED) and has the world’s largest shaking table. It can hold a real concrete building and has 24 large cylinders with a diameter of more than 2 meters, which can simulate almost all kinds of earthquakes of any magnitude. Researchers can put actual-sized wooden buildings or oil tanks onto the table and observe to what extent does the structure stand against the quakes.
Over the years, researchers can only observe what a building looks like before and after the quakes to determine and strength of the building. In other words, there is no way that one can observe the destruction of a building directly. Therefore, NIED built the E-Defense. This facility is capable of letting a life-size four storey concrete building (about 1200 tons) to experience seismic activity directly.
The core of E-Defense is a huge and powerful shaking table. With a loading capacity of 1200 tons, it is considered to be the largest of the same facility type in the world. The E-Defense can move up to 50 cm vertically and 100 cm horizontally. It can also create a vertical acceleration of 1.5 G and a horizontal acceleration of 0.9 G. This shakes the 1200 ton building in three directions and is the first facility in the world to have such capability.
Although the collapsing of buildings can be easily simulated by using a few computers, Japanese scientists think that actually observing the process of destruction is much more reliable. There are also many similar facilities around the world, but they use scale models to do the simulation. The materials used for the models do not completely resemble that of a real building, so the accuracy of the results is uncertain. Also, E-Defense is the only one that can shake up and down, back and forth, and left and right. Thus, NIED figure that it is necessary to build the new facility.
Located on the Pacific Rim of Fire, Japan has a strict construction code for earthquake endurance. The E-Defense contributes greatly in understanding the quality and strength of concrete pillars and walls. Thus, shock resistance of buildings rises greatly and more lives can be saved.