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

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 Chuetsu-offshore 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 steel-pipe 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.