ANALYSIS TO ANGLE BY SHEAR FAILURE OF ROCK AND SOIL SAMPLES BASED ON FAILURE PROBABILITY

The research of angle by shear failure is a hot topic and key point in engineering geology, and the conventional analytic solutions are MohrCoulomb solution and Roscoe solution. Consider the fact that the macrofailure is controlled by the distribution probability of those microfailures in samples, A failure probability model is introduced to analyze the rock and soil shearing failure angle, and then a Mohr circle of failure probability is given out on the base of a found that the principal axis of failure probability is the equal of the principal stress axis. Moreover, an analyses about the relation between microfailure probability and MohrCoulomb failure criterion is carried out, and Its found that MohrCoulomb criterion is a statistical result of large number microfailures in the failure progress and the Weibull model is only a special case of the distribution probability of failures, and so the failure model based on probability can accord with the failure criterions admirably．