在法向荷载和切向荷载的作用下岩体节理的剪切应力由抗剪断效应、剪胀效应和摩擦效应所引起的三部分应力构成,但三个组成部分在节理的剪切过程中并不是同时发挥其最大作用。在详细分析边坡岩体节理工程地质特性的基础上,提出一种节理分量式剪切本构模型,主要特征为(1)体现了剪胀与剪切之间的耦合效应;(2)采用分量式表达,物理意义更明确;(3)每一分量采用简单函数,避免了总量式分段构造函数的不足。在节理分量式本构模型基础上,提出应用于岩质节理边坡的双安全系数的概念和求解原则,双安全系数能够较好地反映岩体节理剪切破坏直至残余强度的物理过程。最后,通过双安全系数算例明确了各个分量对于边坡稳定性的贡献。
The shear stress of a rock joint is composed of three components triggered by anti-shear effect, dilatancy effect, and frictional effect under normal load and shear load; but the three components will not exert their maximum at the same point in the shear process of a rock joint. Firstly, the five main engineering geological properties of rock slope joints are analyzed in detail, which will provide engineering conditions for the component constitutive model. A component constitutive model of rock joints is presented and its characteristics are as follows: (1) The coupling effect between dilation and shearing is considered. (2) The component constitutive model has obvious physical meanings. (3) Each component is composed with a simple function, so segmental fitting functions are not needed. Furthermore, based on the component constitutive model of rock joints, the concept and solving principle of dual safety factors for jointed rock slope are put forward, which will directly show the physical process from shear failure to residual strength. The three components' contribution to the slope stability is clarified by a calculation example.