ABSTRACT
The theoretical approach of grouting enables the estimation of grout spread distance by simplifying the fractured rock in the grouting section to a single fracture. In this approach, a constant pressure limited to a dilation triggering force is applied to a single stable mix, and the grout spread distance in that representative fracture is estimated. The procedure has been tried in several projects and proven applicable in crystalline and sedimentary rock, especially where extensive investigation and characterizations have been performed. This approach is relevant as long as the aperture size of the representative fracture is constant.
In recent developments, the spread of grout in a perpetually dilating fracture under relatively high pressures has been studied. The higher injection pressure enhances the penetrability of the grout mix and speeds up the grouting process. This approach controls fracture dilation by limiting the injection pressure to a Deformation Limiting Curve (DLC) corresponding to that dilation. Unlike the GIN method, this approach considers site-specific conditions and estimates fracture dilation and grout spread distance in real-time. This paper showcases the latest developments, studies cases and discusses the benefits and disadvantages of using higher pressure while controlling dilations, to open discussion and bring this method closer to practice.
