A STUDY ON THE LIQUEFACTION RESISTANCE OF TOKYO FORMATION SAND LAYER

Abstract

Liquefaction of a Pleistocene Tokyo formation sand layer in Edo era was confirmed by a series of investigations in the ruins of Yotsuya-Gomongai of Edo castle located at Shinjuku, Tokyo. In this paper the liquefaction resistance of the sand layer of the site was compared with the layer around the site. The study was carried out using the following procedures: 1) statistical analysis of SPT N-value around the site, 2) Swedish sounding in situ, 3) comparison between tested resistance by undisturbed sampling and estimated resistance of the layer. It was concluded that a low-liquefaction resistance part exists in relative abundance in the upper part of the Tokyo formation sand layer.