Abstract
In order to reinforce the technology for grouting a fracture in a rock mass, the process of grouting in a borehole to grout a fracture was visualized in a model test. The test revealed the following points. (1) Grouting of a fracture in a rock mass is greatly by clogging in the intersection part of an injection hole and a fracture. Clogging at the intersection between the borehole and the fracture in particular causes grout flow rate to be reduced with time even the condition of fixed pressure. (2) The phenomenon is largely ascribable to the effects of coarse particles and aggregated materials with a larger diameter than the fracture width that are contained in cement grout in minute quantity. (3) Grout flow rate is related to the width of the fracture, injection pressure, and grout mixes. (4) Screening the grout is effective for preventing clogging.
