冻融荷载耦合作用下岩石损伤力学特性

DAMAGE MECHANICAL CHARACTERISTICS OF ROCK UNDER FREEZE-THAW AND LOAD COUPLING

  • 摘要: 以寒区岩体工程为背景,针对冻融受荷岩石,从细观力学机理出发,运用宏观唯象损伤力学和非平衡统计的概念和方法,得到了以冻融循环次数和应变为损伤演化控制变量的损伤演化方程;应用推广后的应变等价原理,建立了较为真实的岩石冻融受荷损伤扩展本构关系;探讨了岩石材料细观结构损伤及其诱发的材料力学性能演化途径。研究表明:岩石的冻融损伤是一个疲劳损伤破坏过程;冻融与荷载的双重作用对岩石损伤的影响表现出明显的非线性特征,其耦合效应使总损伤有所弱化;岩石的岩性、初始损伤状态确定冻融循环和应变对损伤扩展的影响特性。

     

    Abstract: The paper derives the damage evolution equation in terms of freeze-thaw cycle and strain for the freeze-thaw and loaded rock based on micro mechanical mechanism and using the methods of macro phenomenological damage mechanics and non-equilibrium statistics. The real damage propagation constitutive relation of the freeze-thaw and loaded rock is established by using the generalized theory of strain equality. And the evolutionary route of micro-structural damage and materials mechanical properties for the rock are discussed. It is shown that the damage of freeze-thaw rock is mainly caused by fatigue. The dual effect of the freeze-thaw and the load on the rock damage presents obvious nonlinear property, and the coupling effect weakens the whole damage. Moreover, the influence of freeze-thaw cycle and strain on the damage propagation is determined by the lithology and the initial damage state of the rock..

     

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