The image above shows damage in Taro, Japan, caused by the Tohoko earthquake and tsunami of 2011.
Dr Katsu Goda is a Senior Lecturer in Civil Engineering at the University of Bristol, whose research is focused on catastrophic earthquake-related risk management. He has been a member of EEFIT, the Earthquake Engineering Field Investigation Team, since 2010. Here he discusses why an EEFIT team is travelling to Japan, and what they hope to achieve.
EEFIT is a UK-based group of earthquake engineers, architects and scientists who collaborate with colleagues in earthquake prone countries to improve the seismic resistance of structures. We undertake field studies following major earthquakes, collecting data and making observations which could help create improvements in design methods and techniques, and identify where more study is needed. Over the years we have undertaken missions in Australia, Chile, Colombia, Ecuador, Greece, Iran, Italy, India, Japan, Mexico, Nepal, the Philippines, San Salvador, Sicily, Taiwan, Turkey, Romania and the United States of America.
EEFIT decided to send a team to Japan shortly after the mainshock struck the Kumamoto region on 16 April 2016. Also on the team are three academics, one PhD, and four industry professionals – representing a cross section of expertise including geophysics and geology, seismology, earthquake engineering, structural engineering, geotechnical engineering, and earthquake impact assessment – a great example of interdisciplinary co-operation. We will also work alongside two Japanese teams (from Kyoto University and Gifu University), building on the long-term collaborative relationships our members share with Japanese researchers. We’ll be in Japan for five days (22 May to 27 May) visiting two main areas: Kumamoto City and Minami Aso Village, in a nearby mountainous region.
There has been severe damage to houses, roads, and lifelines in Kumamoto City, because multiple moderate-to-large earthquakes struck the same region over a period of two days; numerous landslides were triggered and blocked major roads and, at several locations, major destruction to bridges was caused- which in turn has created significant disruption in evacuation, rescue, and recovery work.
We believe there is much to learn from Kumamoto, because there are several notable things about the earthquake - like the large scale landslides and local volcanic eruptions the area experienced. The local building stock also includes structures built before and after a major revision to Japan’s seismic design codes made in 1981, which should highlight what difference, if any, changes to the codes made. Japanese codes are of the highest standard, but there are still many buildings that were constructed based on outdated seismic requirements. Additionally we know that more action needs to be taken to upgrade older buildings by promoting retrofitting schemes.
We are also very interested in social factors: how the local population, industry and business has recovered since the event. A Mw7 earthquake like this can be devastating to local communities (such as in Kobe (1995) and Christchurch (2011)). This was a lower scale event than Japan’s Mw9 2011 Tohoku earthquake, but was closer to urban areas. Still, judging by the recovery effort so far, Japan seems to have learned a lot from that event, especially about the importance of efficiently maintaining the supply chain to affected areas.
Members can access EEFIT reports
from previous expeditions on the Institution website – an invaluable archive that allows you to investigate our previous findings and compare missions from different nations. I’d encourage anyone with an interest in earthquake engineering to explore the archive; it really is a fascinating insight into the many challenges faced by different nations in responding to earthquakes and promoting seismic resilience - and how engineers are helping to create solutions.