基于破坏概率的岩土试件剪切破坏角分析

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

岩土体剪切破坏时剪切破坏角是一个一直在探讨的问题,传统理论解为Mohr-Coulomb解和Roscoe解,基于试件的宏观破坏现象受微观破坏概率的分布制约这一前提,从岩土体试件内部破坏概率分布函数的角度重新研究了这一问题。通过对试件内部微观破坏概率由微观到宏观的统计分析与坐标变换,发现在形式上破坏概率主轴即相当于主应力,并基此给出了破坏概率破坏莫尔圆。还对Mohr-Coulomb破坏准则与微观破坏概率统计之间的关系开展了探索分析,结果表明Mohr-Coulomb准则是描述试件剪切破坏时大量微破坏行为共同作用的统计结果,Weibull分布仅是岩土试件内部破坏概率分布形式的一种描述,基于数学概率推导的岩土试件破坏模型能更好的与试件的破坏准则联系起来。

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.