Study on filtration property of grouting materials; High-pressure filtration test

Nobuto, Jun*; Mikake, Shinichiro ; Sato, Toshinori  ; Nishigaki, Makoto*; Larry Pax, C.*

Authors are conducting research on method to achieve high-level water tightness in crystalline rock with suspension grout like cement slurry is studied. Grout should be infiltrated into very fine fractures to enhance the water tightness. For such fine fractures, the clogging phenomenon of grout material at the entrance of rock fractures tends to occur, and it results in insufficient infiltration of grout. Herein, laboratory experiment is conducted to investigate the clogging phenomenon using steel apparatus with fine slits simulating rock fracture. The results indicate clogging can be prevented to a significant level by increasing the injection pressure, although grout material accumulates over the slit.