Evaluation Method of Ground Condition Based upon Liquefaction in Reclaimed Lands due to Hyogo-Nanbu Earthquake

Abstract

In this paper, two aspects of the investigation into the liquefaction behaviour that occurred in the reclaimed lands by the Hyogo-Nanbu earthquake are discussed. Firstly, the conventional simplified method of predicting liquefaction based upon a grain size distribution curve has been proven to lead to a discrepancy between theory and practise. Therefore, by considering the representative diameter of grain size from the distribution curve as the basis, a predicting method in proposed to get the result harmonizing with other engineering properties. Regarding the second aspect, in some zones where liquefaction occurred, it was found that such measures as sand compaction, sand drain, packed drain, and rod compaction were also to be considered for improvement. Therefore, using the effective stress dynamic analysis, it is proposed that a critical strength level exists for protecting or reducing the degree of damage cauesd by liquefaction due to strong earthquakes.