ANALYSIS ON GROUTING TECHNOLOGY FOR CONTROLLING DEEP ROCK CRACKS AT JINPING Ⅰ HYDROPOWER

This paper analyzes the features of deep rock cracks and grouting technology. It then studies the grouting technology with cement-silicate for controlling the deep rock cracks. It particularly addresses the problems of grouting in deep cracks in Jinping Ⅰ Hydropower. First of all, the paper analyzes the mechanism of cement-silicate grouting. Then, it investigates the cement-silicate slurry mainly from the aspects of gel time and strength. It studies the influence law of gel time and strength from the dosage of silicate and retarder. It obtains a design formula for 5min.cement-silicate slurry. Finally, the paper proposes the grouting method using two pipe outlets for mixing the two grout fluids. One pipe outlet is for the cement grout and the other for silicate grout. The grouting method further includes the top-down approach, closed hole, and pure pressure grouting, according to the characteristics of the deep rock cracks. Thus, the paper has initially established the research programs of grouting treatment technology for deep rock cracks at Jinping Ⅰ Hydropower.