Active Use of the Advanced Earthquake Engineering Laboratory
Shimizu has begun experiments to replicate and analyze the effects of earthquake motion based on observations from the Kumamoto Earthquakes. The results will be used to develop earthquake mitigation technology in the future.
During 2016 Kumamoto Earthquakes that occurred in April 2016, there were two earthquakes in the town of Mashiki, Kumamoto that registered a 7 on the Japanese seismic intensity scale of 0 to 7, and 18 earthquakes with a seismic intensity of around 5 or above, just in April. These earthquakes caused major damage, most of which was centered in Kumamoto Prefecture. Shimizu conducted site surveys from an academic perspective in addition to surveying the degree of damage and mounting a recovery response. We have begun to analyze the correlation between the fault that produced the earthquake and the area of damage, as well as the pattern of damage, which differed from the patterns seen thus far.
Our Advanced Earthquake Engineering Laboratory, which was built in the Institute of Technology in 2015, has two shaking tables. These enable integrated experimentation, measurement, and analysis in research and development on earthquake mitigation. The E-Beetle is a large-scale shaking table that can replicate the shaking that occurred during various earthquakes around the world in the past. It enables us to conduct shaking experiments using life-sized mock-ups of structures and various types of equipment. We intend to use the experiments based on the earthquake motion observed during the Kumamoto earthquakes to replicate the damage and verify the effectiveness of aseismic technology.
Category 4* long-period earthquake motion, the highest category, was observed for the first time during the Kumamoto earthquakes. The E-Spider large-stroke shaking table can realistically replicate this sort of long-period motion in three dimensions. We want to determine the impact of long-period shaking, not only in terms of the damage to structures, but also in terms of the impact on equipment and fixtures, and on people as well.
Our goal is to step up earthquake response and BCP a level, and we have developed various kinds of technology from the three perspectives of the physical structures, operational aspects, and skills. We intend to use the experience gained from these earthquakes to strengthen the development and roll-out of technology that will realize communities that are stronger, safer, and more secure.
Categories of long-period earthquake motion: Because the magnitude of shaking in high-rise buildings and other structures caused by long-period ground motion during an earthquake is difficult to ascertain from seismic intensity, the Japan Meteorological Agency has set up and has been conducting trials since November 2013. During a Category 4 event, the highest category, people cannot stand up, and cannot move unless they crawl. Most furniture that is not anchored will move and some things will fall over.
|E-Beetle Large-scale Shaking Table||E-Spider Large-stroke Shaking Table|
|Table dimensions||7 m x 7 m||4 m x 4 m|
|Maximum load||70 tons||3 tons|
|Maximum acceleration||2.7 G (horizontal)
2.2 G (vertical)
* with a 35-ton load
|1.0 G (horizontal)
0.9 G (vertical)
* with a 3-ton load
|Maximum displacement||+/- 80 cm (horizontal)
+/- 40 cm (vertical)
|+/- 150 cm (horizontal)
+ 90 cm/- 70 cm (vertical)