Recon Mission Studies Japan Earthquake
6/6/2011 7:05:00 AM
Professor Youssef Hashash poses by tsunami-damaged cars in Sendai Harbor.
As part of an engineering reconnaissance mission to Japan, Professor Youssef Hashash got a first-hand view of the aftermath of the massive earthquake and subsequent tsunami that devastated the country in March.
The purpose of the trip was to gather data about the response of the country’s infrastructure to the disaster, said Hashash, the John Burkitt Webb Endowed Faculty Scholar. Experts in structural engineering, geotechnical engineering, and tsunamis made up the team, which traveled to Japan April 9-15. The group was briefed by faculty at Tokyo Institute of Technology before traveling north to Sendai, where some of the worst damage occurred. A preliminary report on the mission is available online.
The Magnitude-9.0 undersea earthquake, one of the five strongest recorded, struck off the shore of Japan on March 11 and triggered a tsunami. The team experienced several aftershocks during their trip, including one that struck during a briefing by the Japanese Society of Civil Engineers, Hashash said.
Hashash’s specific focus was examining the performance of the country’s geotechnical structures. Overall, structures that were not subjected to the tsunami fared relatively well with limited damage, he said, while those in the path of the surge suffered extreme damage or complete loss. Widespread liquefaction was observed in areas of reclaimed land in Tokyo.
“The magnitude of the tsunami was like nothing I’ve ever seen before,” Hashash said. “In some places it was up to 30-40 meters high. Numerous traditional wood structures in coastal areas were completely wiped out. In one area, even concrete buildings were lifted up off their pile foundations. That’s a testament to the ferocity of the waves.”
The trip was sponsored jointly by the Earthquake Engineering Research Institute, Geo-engineering in Extreme Events Reconnaissance, and the Pacific Earthquake Engineering Research Center.
Geotechnical team members (left to right) professors Kyle Rollings of Brigham Young University, Youssef Hashash of Illinois, and Steven Kramer of Washington University pose before a boat displaced by the tsunami in Kesennuma.
Hashash examines liquefaction-induced lateral spreading in Shin-Urayasu, Tokyo.
A tsunami-damaged city block in Kesennuma.