Strength and mechanics of fractured rocks under triaxial loadings

P. G. Ranjith, F. P. Siew, A. M. Hefny, J. Zhao

Research output: Contribution to conferencePaper

2 Citations (Scopus)


Fracture initiation and propagation, being one of the most intensive subjects in rock mechanics; contribute significantly to the deformation of jointed rock masses. An experimental study on fractured granitic rock was carried out to determine the peak strength of specimen under triaxial loading conditions. The commonly observed failure mode for rock specimens in this study was found to be the shearing of the plane of weakness. The minimum peak strength of fractured rock is observed when the joint orientation is approximately 70o to the horizontal axis. Based on experimental test data, an empirical expression was developed to accommodate the effect of joint orientation and joint trace length in estimating the peak strength of fractured rocks. The predicted values of peak strength using the proposed equation well agree with the experimental results carried out on singly fractured specimens under triaxial loading conditions. The threshold stress values of crack initiation and propagation depend on joint geometrical parameters, their degree of interconnectivity, as well as surrounding stresses on the fracture plane.

Original languageEnglish
Number of pages7
Publication statusPublished - 1 Jan 2003
Externally publishedYes
Event10th International Society for Rock Mechanics Congress, ISRM 2003 - Sandton, South Africa
Duration: 8 Sep 200312 Sep 2003


Conference10th International Society for Rock Mechanics Congress, ISRM 2003
CountrySouth Africa

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