CHARACTERISTICS OF LIQUEFIED SANDS DURING MINO-OWARI, TOHNANKAI AND FUKUI EARTHQUAKES

[摘要] References(19)Cited-By(6)This paper presents the results of field investigations at the places where sand volcanoes were formed and eruption of water and soil was observed during Mino-Owari, Tohnankai and Fukui earthquakes. The soil strata which were presumed to have liquefied were identified on the basis of previous studies and compared with the observed phenomena during the earthquakes. The results indicate that the eruption of water and soil during the earthquakes was not necessarily associated with a complete liquefaction of sand of the type observed during the Niigata earthquake of 1964. The Seismic intensities during the earthquakes were from V to VI according to the Japanese Meterological Agency Intensity Scale, and most of the liquefaction of the saturated sand occurred under the following conditions : The soil was coarse grained in accordance with the unified classification system, having the 50% size of less than 2.0 mm and the uniformity coefficient of less than 10. The effective overburden pressure was less than 2.0 kg./cm2, the relative density was less than 75% and no fine grained soil strata lay above the saturated sand. Also presented are microscopic photographs of sands which are presumed to have liquefied.

[学科分类] 建筑学