Dynamic Properties of Grouted Granitic Rocks

Abstract

Grouting is an empirical constructional technique aimed at improving poor ground conditions prior to construction of underground structures through the injection of cementitious, resinous or chemical grouts. For rock grouting, microcements are often used as a grout material due to their higher strength gain and lower bleeding potential compared to Type I ordinary Portland cement. The injected microcement grout flows through the innate discontinuities present in rock masses and contribute significantly to their mechanical behavior. The deformational characteristics of geological media are affected by the subjected strain levels and state of stress and for jointed rocks, the state of joints (roughness, filling material etc.) also have a significant effect. In this study, the dynamic properties of microcement grouted granitic rocks were analyzed using the rock mass dynamic test (RMDT) apparatus. Resonant column tests were conducted on a regularly spaced, planar jointed granitic rock specimen before and after grouting to analyze the effects of grouting on the strain-dependent shear modulus and damping ratio.