Investigation of Rock Failure in a Direct Shear Machine


Numerous methods of testing the shear strength of rock have been developed and several models have been proposed to increase understanding of the shear behaviour of a rock mass. The tests do not, however, produce satisfactory results in all possible conditions. For typical geological materials and mining environments the triaxial test is considered to yield the most representative shear-strength characteristics of intact rock. The direct shear test, on the other hand, is considered to provide valuable information on the strength parameters of rock joints but to be inferior when applied to intact rock specimens because of the non-uniform distribution of normal stress on the failure plane. Several specimens of intact rock, rock-concrete contacts and strongly bonded, jointed rock were tested in a shear box under a variety of normal loads and the results were analysed with the aid of the simulation software FLAG. Areas of critical stress concentration were identified during the investigations and good agreement was observed between the test results and the computer simulation. The work provided greater insight into the mechanism of failure and indicated ways of improving the test procedure. © The Institution of Mining and Metallurgy 2001.


Mining Engineering

Document Type

Article - Journal

Document Version


File Type





© 2001 Maney Publishing, All rights reserved.

Publication Date

01 Jan 2001