AN IMPROVED SHEAR-FLOW TEST APPARATUS AND ITS APPLICATION TO DEEP UNDERGROUND CONSTRUCTION

摘要

Evaluations of shear strength and flow behaviour of rock joints play an important role in designing of deep underground openings and in performing underground waster disposal risk assessments. Although shear strength and flow behavior can be investigated in a laboratory using a direct shear apparatus, the experimental results are influenced by boundary conditions and the simulation conditions may not be representative of the field conditions. This paper introduces a newly developed automated servo-control hydro-mechanical direct shear apparatus that is capable of automatically adjusting the normal stiffness according to the deformational capacity of the surrounding rock masses, thereby accurately simulating the high pressure head in deep underground locations. The proposed apparatus was used to perform shear tests on artificial joint specimens. Experimental measurements of the coupled mechanical and hydraulic behavior of rock joints under CNL and CNS conditions were analyzed. The shear strength and permeability results exhibited a regular variation due to the interaction of the joint roughness and gouge production. The rock joint permeability results can be applied to deep underground construction.