MECHANISM OF DEVELOPMENT OF GROUND DAMAGE AFFECTING SAND BOILS BEHAVIORS IN THE INSIDE AREA OF RIVER LEVEE

Abstract

 In this paper, we conducted model tests to observe the process of ground deformation referred to an open-cut investigation of the Kita River levee in Miyazaki Prefecture, where sand boil and collapse repeatedly occurred in 2016-2018 and 2022, and attempted to elucidate the mechanism of progression of ground damage that affects sand boil behaviors. As a result, it was revealed that sand chambers and sand channels generated below the collapse of the subsidence of impermeable surface layers. It was also suggested that a single sand boil in the inside area may not cause damage to the entire foundation if the ground is sufficiently compacted. The evaluation method of sand boils-deformation behaviors was discussed.