Ground failures and their effects on structures in Midorigaoka district, Japan during recent successive earthquakes

ABSTRACT: Midorigaoka, Kushiro City, northeast Japan, suffered liquefaction-induced ground failures during four successive earthquakes in the past thirty years. This paper presents the ground failures and their effects to structures observed in Midorigaoka during the earthquakes, and examines the relationships between recurrent liquefaction-induced damage and subsurface conditions. As a result, thick liquefiable fill, slope of the ground surface, and subsurface water conditions, which resulted primarily from filling a marshy valley, are found to be responsible on the damage.

1 INTRODUCTION