Fundamental study on cement grout injection into soil - effect of soil voids on cement suspension

Grouting is normally based on empirical relationships and on the experience of the grouting personnel. To assist grouting projects, a large number of researches using mathematical modeling have been carried out into the clarification of the flow processes during grouting. From this point of view, we constructed a mathematical model to explain the injection process to the rock voids by grouting materials. There are many models of the description of flow paths, clogging of cement suspension in rock voids, flow properties of the grouting materials, and so on. In this analysis, we supposed that the clogging process of the rock voids is occurred by the injection of cement grout. As to the analysis of the voids clogging process, the mass conservation law, in which filtration theory was used, was applied and the analysis was done in one dimension. In this analysis, the concentration and the filter coefficient were considered as parameters to make the injection phenomenon clear. As a result, the voids clogging process by the difference in the cement grout concentration could be explained very well. And the voids clogging process by the difference in the filter coefficient which is in the inside of the mass conservation law, was also explained.