<p>This study proposes a physics-based model for characterizing the contact behavior and state of joint surfaces. Based on the microcontact mechanics model, surface topography, material properties, loads, and asperity interactions were combined to construct a normal contact model. Subsequently, the sticking and sliding behaviors of a single asperity were characterized with the Jenkins element from the Iwan model. Conversely, a parallel arrangement of multiple Jenkins elements represented the overall stick–slip behavior. A distribution function incorporating non-Gaussian distribution and asperity interactions was derived to describe the tangential yield force distribution, thereby constructing a physically explicit tangential contact model. Finally, the results of the predictive model were validated against the experimental data. A slip ratio was introduced to quantifiably evaluate the surface contact states—full stick, stick–slip, and gross slip micromotion, and the factors influencing the contact characteristics of the joint surface were investigated.</p>