Liquefaction Induced Permanent Ground Displacement in Niigata City

Permanent ground displacement resulting from the 1964 Niigata Earthquake were studied based on pre- and post-earthquake aerial surveys. In the area along the Shinano River and the Tsusen River, extensive large ground displacements up to about 10 m occurred towards the river, though the ground was almost flat. To ascertain the mechanism of such large ground displacement, several detailed soil investigations were conducted. And it was clarified that the gradient of the ground surface, the gradient of the bottom of the liquefied layer and the thickness of the liquefied layer were main factors affecting to the such large ground displacement