a. Graduate Student, Kyushu University
b. Graduate schools of Engineering, Kyushu University, Higashi-ku, Fukuoka 812-8581, Japan

One-dimensional injection analysis was performed to understand the infiltration process and the filling process of grout materials into the voids of homogeneous ground. Regarding the analysis of the filling process, the material transport equation considering the filtration theory was introduced and used. Generally, a cement-based grout can be treated as a Bingham fluid characterized by plastic viscosity and yield stress. Regarding the analysis of the infiltration process, the equation of the plug flow related to the Bingham fluid inside the circular pipe was expanded and used. The results of this analysis are as follows:
1) After the injection, the change of discharge by grout injection shows a rapid decline, and it becomes gradual afterward.
2) As the concentration of grout thickens, the accumulated discharge of the grout material decreases and theaccumulated cement amount increases conversely.
3) The decline of the discharge depends remarkably on the characteristic of grout, the clogging of voids and the infiltration area of grout.
4) During the injection into ground, many cement particles in the grout were taken into custody in the voids near the inlet.
5) The concentrated grout is useful for filling the voids of the limited area.