液状化現象からみた砂質堆積物の物理的・堆積学的特徴  [in Japanese] Physical and sedimentological properties of liquefiable sandy deposits produced by the strong earthquake in Japan  [in Japanese]

The author has found many locations of liquefation to investigate the damaged area produced by strong earthquakes since the 1964 Niigata earthquake. Liquefation phenomena were found mainly in the reclaimed fills, on the floodplains of rivers, and on the margins of sand dunes. Geological and geomorphological features of liquefaction sites and the characteristics of liquefied sand in Tohoku District, Japan prouduced by the 1978 Miyagiken-Oki (Off-Miyagi Prefecture) earthquake and the 1983 Nihonkai-Chubu (Japan Sea) earth-quake are discussed in this paper. The relation between soil mechanical properties and geological age of sandy deposits are described. Depositional environments of boiled sand are inferred by grain size distributions and relative densities.