Abstract
Immediately after the Miyagiken-Oki earthquake of June 12, 1978, the authors found 38 liquefaction sites. At most of these sites, settlement of river dikes, uplift of sewage tanks, tilting of quay walls and other damage were caused by liquefaction. At some liquefaction sites, no structural damages were observed. The degree of liquefaction at each liquefaction site, the ground conditions, the relation between liquefaction and resultant damage, and the characteristics of liquefied sand are discussed in this paper. Sedimentary environments of boiled sands are inferred by grain size distributions at nine liquefaction sites. Moreover depths of liquefied layers at two sites are estimated based on the correlation between the grain size distribution of boiled sand and that of soil samples.
