Failure pattern and earth pressure of locally cement improved ground under earthquake motion

摘要

In Japan, cement treated soil is usually used as a backfill material behind a sea revetment or a quay wall in which soft dredged soil is mixed with relatively small amount of cement. The treated soil is expected to reduce the earth pressure and, as a result, to reduce the size of revetment or quay wall. As an interaction of the improved ground is so complicated that its failure pattern and earth pressure is not still clarified thoroughly. In this study, centrifuge model tests were conducted to investigate them under earthquake motion. The model improved ground consisted of a caisson type quay wall, backfill sand and a treated soil is subjected to several earthquake motions under 50 g centrifugal acceleration. This paper describes the model ground preparation and the test results to demonstrate the efficiency of the cement treated soil as a backfill material.