Abstract: In tests of rock specimens containing single flaw, researching the crack types and failure modes are conducive to predicting the initiation and propagation of cracks; yet in engineering design, the bearing capacity, namely damage strength, should receive more attention. In order to investigate into the relation between crack and rock strength, we built numerical models for corresponding test specimens in FLAC^3D, and furthermore researched theinfluence of single crack’s geometric parameters (inclusive of inclination angle, length, and thickness) on the damage strength of rock specimens by adjusting the parameters in numerical model. Results revealed that the peak strength of specimen declined continuously as crack length increased; while when inclination angle increased, peak strength displayed a trend of increasing in general, increasing slowly when inclination angle was smaller than 60°and rapidly when inclination angle was larger than 60°. Within the test range, peak strength remained unchanged as flaw thickness increased.

Key words: single flaw, FLAC^3D, uniaxial compression, geometric parameters, peak strength, failure mode