2015 Volume 71 Issue 1 Pages 42-51
In the Great East Japan Earthquake, many coastal levees collapsed due to tsunami overflows. In there, concrete-covered levees showed a specific failure mode where back slope blocks and ground were washed out. Although several hydraulic experiments were conducted in order to understand the failure mechanism of concrete-covered levees, it has not yet been clarified especially from the geotechnical viewpoint. The present study examined the failure behaviour of levees due to overflow considering the ground behaviour by the ground model tests. Usage of the centrifuge technique was the key point of this study to reproduce the prototype ground stress and water pressure. The test results showed that the levees collapsed owing to water-flow over the back slope block combined with groundwater seepage.