Geotechnical Effects of the Mw 9.0 Tohoku, Japan, Earthquake of March 11, 2011

September 2011. Earthquake Engineering Research Institute, and Geotechnical Extreme Events Reconnaissance.

The geotechnical effects of this earthquake provide important opportunities for learning about the seismic performance of a wide range of geotechnical systems and constructed facilities. Facilitated by the extensive network of strong ground motion recording stations in the area, the unique characteristics of this large earthquake, the wide geographical area affected, and the modern infrastructure throughout the affected areas, scientists will be able to gain insights into the correlation between ground motion characteristics and the type and extent of damage—in ways not previously possible. This report provides a brief summary of preliminary geotechnical observations from NSF-sponsored GEER reconnaissance teams working with other organizations and individuals, including the Pacific Earthquake Engineering Research Center, the American Society of Civil Engineers and the Federal Highway Administration. Additional details regarding some of these observations are included in a series of GEER Quick Reports available at www.geerassociation.org. The field teams could not cover all the affected areas, and avoided some locales due to ongoing humanitarian aid efforts and radiation concerns. Fuller coverage and greater detail on the geotechnical effects will emerge from the studies currently underway in Japan.