Experimental investigation on mechanical properties and representative elementary volume for chemically grouted fractured rock masses

• 1、State Key Laboratory for Geomechanics and Deep Underground Engineering, School of Resources and Geosciences, China University of Mining and Technology, Xuzhou, Jiangsu 221008, China

Abstract：This paper presents an experimental investigation on the strength and deformation characteristics of chemically grouted fractured rock through uniaxial compression and shearing test in laboratory and a numerical simulation study of the representative elementary volume of fractured rock before and after grouting. In the experiments, the specimen with different dips of fracture has three failure forms, which are columnar cleavage failure, sliding-splitting failure and sliding failure. With the increase of dip angle from 0° to 90°, the specimen’s uniaxial compression strength decreases and then increases. The modulus of elasticity is affected by fracture width significantly. It is found through the shearing test that shearing strength of rock masses is related to the angle between shear surface and fracture surface and the density of the fracture network. After grouting reinforcement, the fractured rock’s representative elementary volume is decreased to some extent, and the equivalent compression strength and modulus of representative elementary volume are raised. The results indicate that the completeness and quality of fractured rock masses after grouting reinforcement have been improved to varying degrees.

Keywords： grouting fractured rock masses uniaxial compression test shearing test representative elementary volume