초록
느슨한 준설 매립층은 아주 작은 지진동으로 인해 액상화가 발생하는 경우가 있다. 새만금 준설토의 액상화 거동특성을 반복삼축압축시험에 의해 조사하였고, 타 문헌에서의 다른 모래의 액상화 특성과 비교하였다. 조사를 위해 상대밀도의 변화에 따른 일련의 비배수 반복삼축압축시험이 압밀구속압을 달리하여 수행되었다. 연구결과 반복응력은 압밀구속압에 따라 선형적으로 증가하나, 반복응력을 압밀구속압으로 무차원화한 반복응력비는 일정한 값을 보인다. 또한, 상대밀도의 증가에 따라 반복응력비는 선형적으로 증가하나, 문헌조사에 의한 다른 모래에 비해 액상화에 취약한 특성을 보인다.
In reclaimed loose sandy layer with dredged soil, liquefaction by the small scale earthquake coud be occurred easily. A study has been carried out to investigate the Liquefaction characteristic on Saemangeum dredged sandy soil, and compared with other results from the literature investigation. A series of undrained cyclic triaxial compression tests were performed on dredged sandy soil of Seamangeum area. The tests were performed at the three different initial relative densities(namely 30%, 50%, 70%), different cyclic stress ratio and different consolidation stress condition. The results of this study showed that cyclic stresses (${\sigma}_d$) increased linearly with increase of consolidation ratio, but the stress ratios (${\sigma}_d/2{\sigma}^{\prime}{_c}$) were almost same. The stress ratios were increased almost linearly with increase of relative density. Compared with other sandy soil, Saemangeum dredged sandy soil showed relatively weak liquifaction characteristics.