Liquefaction Analysis of Reclamation Dike during Earthquake

点击翻译按钮获取中文摘要

There are eighty-eight reclamation dikes in the Chugoku,Shikoku and Kyushu region which have been completed after the Second World War. Twenty-eight of these dikes and forty-one of these foundation grounds consist of sandy soil. Seismic risk analysis were carried out for all construction sites by making use of the attenuation equations which were established by Research Institute,Ministry of Construction. From this analysis, the 100-year earthquake motion was calculated and three district(Miyazaki,Miike,Tokushima) had the value more than 100 gal, five districts (Takehara,Kojima,Yonago,Kokubu,Nishikunisaki) had the value no more than 100 gal but no less than 80 gal and the others had the value no more than 80 gal.Liquefaction analysis by Research Institute,Ministry of Construction's method were carried out by using the 100-year earthquake motion,stamdard penetration value(N-value), blueprins, soil explorations and groundwater level. First, this cnalysis was applied to ground models which have different N-vaiues, groundwater levels, grain sizes and specific gravities, then, to each dikes which consist of sandy soil and safty factors were calucated. When the condition of soil and ground become worse,few of them were less than 1.0. But, these happening depths from dike crests were deeper than 6.0m and,moreover,these dikes and foundation ground must consit of more fine soil in practical ploblems,accordingly from these results of liquefaction analysis for the 100-year earthquake motion, it was concluded that these dikes will be in safety. Finally,there was no dikes which was damaged by earthquake during these forty years.