SEISMIC RESPONSE OF PEATY GROUND AND PIPELINE DAMAGE IN URAKAWA, HOKKAIDO

Abstract

 Peaty ground deposited in the northern part ofJapan, especially Hokkaido is so soft that it causes the ground deformation and uneven settlement to the housing lot and the damage to pipeline at an earthquake. This study focuses on Urakawa, Hokkaido, which experienced water supply outage due to the pipeline damage both in the 1982 Urakawa-off earthquake and in the 2003 Tokachi-off earthquake. Seismic response of peaty ground was analyzed based on the result of surface wave test investigated. Not only irregular subsurface ground including peaty ground and underlying soft ground but also softness of the peaty ground is considered to affect damage to the water pipeline.