基于能量守恒原理的巷道混凝土损伤蠕变模型

Damage Creep Model of Roadway Concrete Based on Energy Conservation Principle

为了更好地获取深部地下混凝土结构的长期变形特性,采用TAW-2000试验系统开展了混凝土的单轴力学特性和蠕变特性试验,分析了不同应力作用下混凝土的蠕变变形规律以及获得了混凝土的长期强度。在不考虑岩石内部热交换的情况下,由能量守恒定律重点研究岩石加速蠕变,建立了一维状态下基于能量守恒原理的混凝土损伤蠕变模型。在此基础上,假设深部地下工程中混凝土结构的力学参数和流变参数都是关于时间的函数,构建了基于能量守恒原理的非定常蠕变模型。结果表明:基于能量守恒原理的混凝土损伤蠕变模型可以较好地描述混凝土的蠕变全过程曲线,且模型曲线和试验曲线的相关性系数均在0.95以上,这说明了本文所建立蠕变损伤模型的正确性。该模型不仅准确地反映衰减和稳定蠕变阶段的蠕变特性,也较好地描述了加速蠕变的缺点。

In order to better obtain the long-term deformation characteristics of deep underground concrete structures,the uniaxial mechanical properties and creep properties of concrete are tested by TAW-2000 test system.The creep deformation law of concrete under different stress and the long-term strength of concrete are analyzed.Without considering the internal heat ex-change of rock,the accelerated creep of rock is studied by the law of conservation of energy,and the damage creep model of concrete based on the principle of conservation of energy in one-dimensional state is established.On this basis,it is assumed that the mechanical parameters and rheological parameters of concrete structures in deep underground engineering are functions of time.An unsteady creep model based on the principle of energy conservation is constructed.The results show that the dam-age creep model of concrete based on the principle of energy conservation can better describe the whole creep process curve of concrete.The correlation coefficient between the model curve and the test curve is above 0.95.This shows the correctness of the creep damage model established in this paper.The model not only accurately reflects the creep characteristics of the attenu-ation and stable creep stages.The shortcomings of accelerated creep are also well described.