统一流变力学模型同时包含黏弹性、黏塑性、黏性、黏弹塑性4种基本流变力学性态,根据岩石在不同应力水平下的加卸载蠕变试验曲线特性,可以全面地对统一流变力学模型及其14个特殊情况下的模型进行辨识。以采用统一流变力学模型对流变模型进行辨识的方法为基础,对流变力学模型参数的确定方法进行研究。先介绍黏弹性、黏塑性、黏性、黏弹塑性这4个基本流变力学模型模型参数的确定方法。然后,将蠕变试验数据中的蠕变应变量分离成衰减蠕变应变分量(其蠕变曲线函数可表示为指数函数)和定常蠕变应变分量(其蠕变曲线形函数可表示为与时间成比例的线性函数)2部分。并分别介绍衰减蠕变应变分量中同时含有黏弹性和黏弹塑性2种应变,以及定常蠕变应变分量中同时含有黏性和黏塑性2种应变这2种情况的流变力学模型参数确定方法。最后,通过锡矿山页岩和东乡铜矿红砂岩2种岩石在不同应力水平下加卸载蠕变试验结果,给出2个流变模型参数确定的实例。
The unified rheological mechanical model includes four fundamental rheological behaviors: viscosity, visco-elasticity, visco-plasticity, and viscoplasto-elasticity. And the others fourteen rheological models can be derived from the unified rheological mechanical model. The unified rheological mechanical model and the 14 models can be identified according to load-unload creep tests of rock under different stress levels. The methods to determine parameters of the rheological models are studied based on identifying rheological models by the unified rheological mechanical model. First, the methods to determine parameters of the four fundamental models of viscosity, viscoelasticity, viscoplasticity and viscoelasto-eptasticity are introduced. Then, the creep strain components are separated into transient strain components(be expressed by the exponential function) and steady- state strain components(be expressed by a linear function). Further, the methods to determine parameters of rheological models are presented under two states: one is that both the viscoelastic strain and the viscoelastoplastic strain exist in transient strain components, another one is that both the viscosity strain and the viscoplastic strain exist in the steady-state strain components. Finally, two examples are given to determine the parameters of theological models of shale in Xikuangshan Mine and red sandstone in Dongxiang Copper Mine by load-unload creep test results under different stress levels.