岩石蠕变破坏过程的自组织特征分析

用重正化群方法研究发现 :岩石内部微元累进破坏过程中存在一个可用微元临界破坏概率来表征的自组织临界状态 ;在该临界状态以前 ,微元的破裂是随机、独立和短程相关的 ,岩石蠕变为稳定蠕变 ;在该临界状态以后 ,微元的破裂便是相互协同和长程相关的 ,并且原来随机、无序分布的破裂微元会逐渐向某一吸引域集中而形成宏观贯通的破裂面 ,岩石蠕变为不稳定蠕变 ;与该临界破坏概率相对应的应力值是岩石的长期强度 ,它约为岩石峰值强度的 80 %。

Analysis on Self-organized Characteristics in Process of Creep Failure of Rock

The cause of rock creep failure is the softening effect and hardening effect resulted from the structural nonhomogeneity and micro-crack of the rock mass. The study using the renormalization group method shows that there is a self-organized criticality characterized by the critical cracking probability of the micro-cells in the process of the progressive cracking of the inner micro-cells of rock. As prior to the critical probability, the cracking of the micro-cells would be random, separate and in small-size relation, so that the rock creep is stable, and after the critical probability, the cracking would be synergetic and in big-size relation and gradually centralized in certain attractive zone to form the visible run-through failure plane so that rock creep is unstable, and the stress value corresponding to the critical cracking probability is the long-term strength of rock, which is 80% or so of the peak strength of rock material.