Numerical Analysis of Two Wooden House Damages Induced by Dune Liquefaction during the 2007 Niigata Chuetsu-Offshore Earthquake

摘要

Many wooden houses near a dune at Kariwa Village, Kashiwazaki City, Niigata Prefecture were damaged because of the liquefaction of the dune during the 2007 Niigata Chuetsuoffshore Earthquake,Mw = 6.8. This paper performs fully coupled dynamic finite element analysis to reproduce the ground liquefaction of two wooden houses. Here, wooden house A of which the ground was improved only using horizontal drainage pipes was fully damaged; however, wooden house B of which the ground was improved by horizontal drainage system to lower the ground water level, surface ground improvement, and steelpipe piles was slightly deformed. For wooden house B, it was found, based on the numerical results, that steel-pipe piles were more effective liquefaction mitigation measure.