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.