Centrifuge Model Tests and Image Analyses of a Levee with Partial Floating Sheet-pile Method

抄録

A steel sheet pile is used as a settlement countermeasure method for levees on soft ground. It is expected that settlement of landside ground can be suppressed by penetrating steel sheet piles nearby toe of slope of the levee. In order to improve the performance of existing two methods, full bottom landing and floating method, the Partial Floating Sheet-pile method (PFS method) was proposed. However, the PFS method has a limited number of experimental studies and construction examples. Thus, the effect of the PFS method is not well-understood. In this study, a 1/50 scale ground models with levees and two types of sheet pile walls were built and self-weight consolidation experiments were conducted with and without the countermeasure using centrifuge apparatus. The objective was to confirm the effect of the PFS method on the settlement of landside ground and failure mode of the levees. The experimental results showed that the countermeasure cases suppressed the settlement of landside ground more than the non-countermeasure case. It was observed from image analyses that in the countermeasure cases, relative displacement of clay layer occurred near sheet piles. Continuous shear strain induced by relative displacement is considered to cause cracks on the slopes of the levees.