Abstract:

The present research is to explore the influence of end friction on the strength of rock. On the basis of continuum mechanics, a mesoscale model of rock with nonlinear damaged stress-strain constitutive relations is presented to describe the mechanical behaviors of rock. Furthermore, the Weibull random probabilistic distribution for the heterogeneities of mechanical properties of rock and the damage localization is introduced. Numerical simulation of rock’s uniaxial compression tests with different friction coefficients is carried out. The results indicate that the effect of end constraint occurs during rock’s uniaxial compression test. The uniaxial compressive strength, stress-strain curve and fracture pattern of rock specimen(in particular, short specimen)are significantly affected by the end effect. It is necessary to control the experimental condition to reduce the influences of end effect on measurement results.

Key words: end effect, uniaxial compressive strength, meso-mechanics, heterogeneity, numerical simulation