摘要
岩石在长时间的蠕变发展中,会呈现出不同的阶段性特性,开始表现为衰减蠕变,蠕变速率逐渐减小,紧接着保持稳定的蠕变速率呈现稳定蠕变发展,最后外界应力超过屈服应力导致加速蠕变.常用的元件模型只能有效地模拟衰减和稳定蠕变阶段,加速蠕变特性则需要引进非线性特性的元件模型或是损伤理论,本文引进损伤理论和损伤元件,与常用元件组合模型串联组合,即可模拟出全过程的岩石蠕变特性,通过引进弹塑性损伤元件和Kelvin元件模型,建立了三维改进的Kelvin蠕变损伤模型,并推导了三轴压缩下岩石的轴向应变方程,用砂岩蠕变试验数据拟合出模型参数.建立的模型参数较少,易于确定,而且推导的三维模型更能真实的反应岩石在自然界中的应力状态.
Rock creep will present different phased characteristics in the long time creep developing;it begins to show the attenuation creep,creep rate decreasing,and then keeps steady creep development in a stable creep rate;finally it evolves to accelerated creep after the external stress exceeding yield stress.Common component model can only effectively simulate the attenuation and stable creep stage;accelerated creep properties require the component model or damage theory to simulate the nonlinear characteristics.This paper introduces the damage theory and damage elements,combined with commonly used components in series to simulate the whole process of rock creep property.Meanwhile by introducing elastopalstic damage components and Kelvin components model,a three-dimensional modified Kelvin creep damage model is established;and a rock equation of axial strain under triaxial compression is deduced;and fitting model parameters with creep experimental data of sandstone.The established model＇s parameters is less and easy to determine;and the derived three-dimensional model can better reflect the rock stress state in nature.
出处
《三峡大学学报（自然科学版）》
CAS
2016年第2期29-32,共4页
Journal of China Three Gorges University：Natural Sciences
基金
国家重点基础研究发展973项目(2011CB013504)
留学回国人员科研启动基金(51103312)
关键词
加速蠕变
损伤理论
弹塑性损伤
轴向应变
accelerated creep
damage theory
elastoplastic damage
axial strain
