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The effect of normal stiffness on the shear resistance of rock.
Obert-L; Brady-BT; Schmechel-FW
Rock Mech Rock Eng 1967 Jul; 8(2):57-72
This paper presents the theory and design of a shear machine whose normal stiffness could be varied by four orders of magnitude. Experimental techniques, testing procedures, and special equipment designed by the Bureau of Mines for determining the effect of normal stiffness on the shear stress-normal displacement behavior of intact and prepared joint surfaces of both hard (granite) and soft (sandstone) rock under constant shear displacement rate are described. Experimental results are presented which show that the effect of increasing the normal stiffness on either intact rock or fracture surfaces is to provide increased normal confinement. Increased normal confinement results in an increased shear strength rock. Engineering significance of this result is discussed.
OP; Journal Article
Issue of Publication
Rock Mechanics and Rock Engineering
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division