摘要
热应力引起的岩石破裂称为岩石的热破裂,它是热和力之间相互耦合作用的结果。岩石热破裂研究的工程意义重大。根据岩体介质变形及其热力学的理论基础,充分考虑岩石的非均匀性和热固耦合作用,在原有的岩石破裂过程分析系统的基础上,建立了具有热固耦合作用的岩石热破裂分析模型。数值模型再现岩石的热破裂过程,并反映岩石热破裂的规律。运用数值模型,对含有单个内嵌颗粒的岩石试件在温度变化过程中的热开裂进行了数值模拟。研究结果表明:在温度升高过程中,如果内嵌颗粒的热膨胀系数大于基质的热膨胀系数,在基质内产生径向裂纹;如果内嵌颗粒的热膨胀系数小于基质热膨胀系数,便在基质内产生环向裂纹。数值模拟结果与试验结果有较好的一致性。RFPA2D-thermal模型为从细观力学角度上分析岩石的热破裂过程和机制提供了一种新的方法。
Rock failure induced by thermal stress is called thermal cracking. It is the result of thermal and mechanical coupling. Based on the basic theory of rock deformation and thermodynamics, considering the heterogeneity and the coupling of thermal and mechanics, a numerical model, RFPA^2D-thermal code, is proposed. With this model, the temperature and stress fields can be determined. The most important is that the failure process of rock induced by thermal or external stress can be simulated. Using this numerical model, the failure progresses of a rock sample with an inlaid grain was modelled during the change of temperature. It turns out that during temperature increment, if the thermal expansion coefficient of the inlaid grain is larger than that of the surrounding media, radial-cracks will be generated in the surrounding media, and them-cracks emerge if the thermal expansion coefficient of inlaid grain is smaller than that of the surrounding media. The results agree well with the experimental results. The RFPA^2D-thermal model provides a new method for analyzing the thermal cracking of rock samples in microscopic view.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2006年第10期2071-2078,共8页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(50504003)
关键词
岩石力学
热应力
非均匀性
数值模拟
热开裂
rock mechanics
thermal stress
heterogeneity
numerical simulation
thermal cracking
