Qualitative Improvement of Low Quality Impervious Core Material for Rock-fill Dam

Abstract

Core materials of the Minamiaiki dam are low quality such as coarse grain size distribution, high natural water content, and great variation in the water content. Therefore, such materials were not used as impervious core materials in Japan. To improve this low quality material, it was necessary to solve characteristic problems by increasing the fine fraction content and lowering the mean value and the variation of water content simultaneously. This paper describes a development of advanced quality control method of piling up and slicing off, which mixes the core material with crushed rock together. The quality of the material is evaluated using the two-stage sampling method.