考虑温度效应的花岗岩分数阶蠕变模型研究

Fractional integral creep model of granite considering temperature effect

温度是影响岩石蠕变特性的一个重要因素,不同温度影响下岩石蠕变行为对深部地下工程、高放射性核废料处理工程等有着显著影响,研究温度-应力耦合作用下的岩石蠕变力学行为具有重大意义。在分析20℃~300℃花岗岩蠕变试验数据的基础上,引入能反映岩石黏弹性的分数阶蠕变元件,并通过元件组合建立了考虑温度效应的花岗岩黏弹塑性蠕变本构模型,进而获得了岩石非稳定蠕变阶段前参数随温度变化的函数。同时开展了蠕变参数的敏感性分析,得到了各参数对蠕变模型的影响规律。研究表明:随着温度增加,蠕变参数的变化均会影响花岗岩进入稳态蠕变的时间,其中黏性系数影响较大。

Temperature is an important factor affecting the creep properties of rock. The creep behavior of rock under different temperatures has a significant impact on deep underground engineering and highly radioactive nuclear waste treatment engineering. Based on the analysis on granite creep test data at 20℃~300℃, a fractional creep component reflecting rock viscoelasticity was introduced, and a viscoelastic-plastic creep constitutive model of granite considering temperature effect was established by component combination. The function of rock parameters to temperature before the unsteady creep phase was obtained. At the same time, the sensitivity analysis of creep parameters was carried out, and the influence of various parameters on the creep model was obtained. Studies show that as the temperature increases, the change of creep parameters will affect the time when the granite enters the steady state creep, among which, the viscosity coefficient has a greater influence.