フィルダムの水理的破壊現象に関する遠心模型実験

Abstract

Centrifuge loading tests were performed in this study in order to discuss the mechanism of hydraulic fracturing and the evaluation of safety against associated seepage failures such as erosion and piping occurring in fill-type dams. Three types of model tests were carried out to investigate the relationship between the deformation of embankment and the abutment configuration, and the deformation pattern of centrally located core placed in trenches with different sizes, and to realize seepage failures in model rockfill dams by filling water in the upstream side to know the actual process of hydraulic fracturing. It was recognized in the former two types of tests that shear deformation and stress transmission in model fills are fairly influenced by the boundary conditions including shapes of the abutment and the core trench; these results are supported qualitatively by the conventional FE turn-on stress analysis. It was noticed in the third test that the decrease in the confining pressure caused by the differential settlement and the stress redistribution in the core is to be the most influential factor in the seepage failure in fill-type dams.