A study of the grouting at the bottom of the Yashio dam reservoir and the evaluation of the leakage by grouting

In the Yashio dam reservoir, there is a network of fissures which assumed open fissures of the high dip angle that has the hydrothermal alternation and a large-scale bedrock creep regarded as the main generation factor of the subject in deeper areas. As a result of the test grouting which we performed before the construction for leakage stoppage, we utilized an injection pressure and a limit sedimentation velocity of cement particles and performed effective grouting for fissures of the big width at the bedrock of the bottom of the reservoir filled with water. Further, we confirmed that the leak had been reduced. In this article, we have conducted a qualitative consideration of the grouting mechanism.