To better understand the grouting process and the effect of grouting on the performance of a nuclear waste repository, the Japanese Atomic Energy Agency (JAEA) has initiated a grouting test carried out in the fractured granite of the Grimsel Test Site (GTS) located in the Swiss Alps. This paper describes the characterization of the rock mass, how the data obtained has been used to make a discrete fracture network (DFN) model and how an up-scaled equivalent continuous porous media (ECPM) model for the purpose of numerical simulation of the grout injection process is generated. Using the optical borehole television (BTV) and hydraulic test data from the boreholes drilled in this project, a number of DFN models have been constructed. The DFN models consist of a stochastic and a deterministic part. The known fractures (from BTV) are included deterministically in the model and their transmissivities have been optimized using the measured hydraulic test results. The distribution of fractures as well as their transmissivities for the stochastic part is based on the distributions extrac-ted from the measured values. The resulting DFN model is then up-scaled using 0.5m cubic blocks to obtain a detailed ECPM model. The generated DFN model and the up-scaled ECPM model was able to reproduce the measured fracture characteristics (e.g. orientation, density) as well as the hydraulic behavior observed in the field (e.g. trans-missivity distribution, anisotropy, heterogeneity) and has proven to be suitable for modeling tracer tests and grouting.
To better understand the grouting process and the effect of grouting on the perform-ance of a nuclear waste repository, the Japanese Atomic Energy Agency (JAEA) has initiated a grouting test carried out in the fractured granite of the Grimsel Test Site (GTS) located in the Swiss Alps.
