2020 Volume 69 Issue 1 Pages 97-104
In the Tsukiji district in Amagasaki city, Hyogo prefecture, Japan, where the extremely severe liquefaction-caused residential damage happened during the 1995 south Hyogo earthquake, the groundwater level has been controlled to keep GL-3.0m as the liquefaction measure by the groundwater lowering method. In this study, various ground investigations were performed at Tukiji area in June 2017 to investigate the effect of liquefaction measure by groundwater lowering as well as the present ground properties in the area where about 20 years have passed since the implementation of the measure to lower groundwater. Additionally, the liquefaction strength of the alluvial sand layer was investigated by laboratory tests using sampling specimens. In the paper, the present ground properties obtained by ground investigations were presented. Further, a result of the verifying the effect of liquefaction measure by the groundwater lowering method was reported. In the verification, liquefaction potential was evaluated for both the ground after and before the groundwater lowering was implemented on the basis of ground investigation results obtained in 2017 and 1995.
