热-水-力耦合作用下岩石损伤力学模型与验证

摘要

为了探讨高温、高孔隙水压、高围压对岩石损伤破坏的影响,基于损伤力学基本理论,并结合应变等价性原理,建立热-水-力耦合作用下的损伤力学模型,构建表征岩石损伤演化的表达式,通过水-力耦合作用下热损伤花岗岩室内试验验证了该模型的合理性,并根据室内试验确定了模型参数.试验结果表明:提出的模型能较好地反映热-水-力耦合作用下岩石应力-应变过程,且能表征上述作用下岩石损伤演化规律;高温损伤会导致岩石由脆性逐渐向延性转变,而孔隙水压会进一步加剧岩石损伤演化.%In order to study the influence of high temperature,high pore water pressure and high confining pressure on the rock damage and failure,a damage mechanics model under the coupled thermo-hydro-mechanical effect was established based on the basic theory of damage mechanics and combined with the strain equivalence principle,then an expression representing the rock damage evolution was constructed.The correctness of the mode was verified through the laboratory tests on thermal damage of granite under coupled hydro-mechanical effect,and the parameters of the model were determined according to the laboratory tests.The results showed that the proposed model can reflect the stress-strain process of rock under the coupled thermo-hydro-mechanical effect better,and it can characterize the rock damage evolution also.The rock will transform from brittleness to ductility caused by the high temperature damage,and the pore water pressure will further exacerbate the damage evolution of rock.