Liquefaction Consequences and Learned Lessons During the 2011 Mw = 9 Gigantic Earthquake

Abstract

One of the major impacts caused by the Mw = 9 gigantic earthquake in Japan was subsoil liquefaction in young reclaimed lands. The intensive reconnaissance studies on damage distribution revealed that there was a clear contrast in liquefaction resistance between natural alluvial deposits and younger artificial subsoil. Moreover, liquefaction in originally compacted river levees was recognized. The elongated duration time of ground shaking that was induced by the main shock and strong after shocks probably increased the distortion of geotechnical structures. Liquefaction damage in private properties has led to liability problems. Thus more reliable liquefaction hazard maps are needed. In contrast, a good performance of existing mitigation technologies is noteworthy.