Abstract
A new fluorescent approach was developed to visualize the cracks filled with grout on the bore-hole wall and was applied to the water interception grout test in the dam site. As the result, it was proven that the infiltration behavior of the grout was surely grasped. By applying the fluorescent of the color which differs for the every grouting stage, the relationship between the various conditions of grouting (concentration of grout, sequence of grout and so on) and the infiltration direction of grout, the infiltration range of grout were also clarified. It was considered that the useful information for design and construction of the grouting has been brought from this method.