摘要
结构面对岩体力学性质、渗透特性及水力(HM)耦合过程起控制作用,其变形、渗流及HM耦合机制是岩体多场耦合研究的关键科学问题。从岩体HM耦合分析的角度,将结构面概化为界面层,采用张开度、刚度或Lame常数等参数表征界面层的几何特征及物理力学特性,研究界面层在法向应力作用下的闭合变形特性、压剪作用下的剪胀与剪缩演化规律以及变形与渗流耦合特性,建立考虑弹性、弹塑性及峰后力学特性的界面层变形模型,推导能考虑HM耦合效应的渗流广义立方定理及非饱和渗流模型。研究表明,基于界面层的结构面变形、渗流及HM耦合模型可以得到试验验证,模型参数可以通过简单的试验获得。采用界面层模型进行HM耦合研究使得变形与渗流分析建立在相同的物理模型基础上,有利于更好地揭示岩体HM耦合机制,提高多场耦合分析的可靠性。界面层模型不仅可应用于不连续介质的HM耦合分析,也可用于等效连续介质的HM耦合分析。
The mechanical and hydraulic properties as well as the coupled hydromechanical（HM） behaviours of fractured rock mass are mainly controlled by its geological discontinuities. The deformation, fluid flow and coupled HM mechanisms of discontinuities are key scientific issues for multi-field coupling analysis. From the viewpoint of coupled HM analysis, the discontinuities are characterized as an interfacial layer. The geometrical and mechanical properties of the interfacial layer are described by apertures, stiffness coefficients or Lame constants. The closure behaviour, shear dilation and contraction, and coupled HM process of the interfacial layer under normal load or combined normal and shear loads are investigated. Deformation models are established to characterize the elastic, elastoplastic and post-peak responses of the interfacial layer. Based on these, a generalized cubic law and an analytical unsaturated flow model are proposed by considering the coupled HM effects. The proposed deformation models, flow models and coupled HM models based on the concept of the interfacial layer are validated by experimental tests~ and the model parameters can be determined by simple experimental tests. With the interfacial layer model, the deformation analysis and the flow analysis of discontinuities and rock masses can be performed on the basis of the same physical model. As a result, the coupled HM mechanism of rock masses can be better understood; and the reliability of multi-field coupling analysis can be improved. Moreover, the interfacial layer model can be applied to the coupled HM analysis not only for the discrete media but also for the equivalent continua.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2008年第6期1081-1093,共13页
Chinese Journal of Rock Mechanics and Engineering
基金
国家杰出青年基金项目(50725931)
国家自然科学基金资助项目(50709026)
高等学校博士点基金项目(20060486016)
关键词
岩石力学
结构面
水力耦合
界面层
剪胀
广义立方定理
rock mechanics
discontinuity
hydromechanical（HM）coupling
interfacial layer
shear dilation
generalized cubic law
