Aperture controlled grouting - benefits of the discrete fracture network approach

Fractured rocks, specifically sedimentary sequences, present a particular challenge for grouting, as major connected fractures that must be sealed will rarely be intersected by vertical groutholes. The aperture controlled grouting (ACG) method can be readily applied using discrete fracture network (DFN) analysis approaches to understand the pattern of fractures that need to be grouted. Aperture controlled grouting then utilises a combination of the principles of fracture grouting and grouting intensity number (GIN) grouting for practical and cost-effective grouting of tunnel, dam, shaft, or environmental restoration projects. This paper illustrates the application of DFN techniques for fracture assessment for grouting design and then compares the ACG approach to more conventional grouting approaches based on recent grouting experience.