Analytical solution for concrete/rock interface shearing under CNS considering interlocking effect and wear behavior and its application

Using a two-order profile to characterize the concrete/rock interface, this paper proposes an analytical solution for the shear behavior of the concrete/rock interface under constant normal stiffness (CNS), taking into account the interlocking effect and wear behavior. The interlocking effect of second-order asperities is reflected by considering the work and energy, and the analytical expression of wear behavior is obtained by geometrically decomposing the worn rock asperity into finite tiny triangles. Subsequently, the proposed analytical model, consisting of the elastic stage, the sliding stage, and the progressive damage stage, is substituted into the load-transfer governing equation, and the bearing characteristics of rock-socketed piles are figured out by taking advantage of the finite-difference method. Finally, a parametric analysis is conducted to investigate the effects of second-order asperity distribution parameter \(\eta\) $\eta$ , wear coefficient \(\xi\) $\xi$ , and first-order asperity angle \({\alpha }_{0}\) ${\alpha }_0$ . Both laboratory CNS direct shear tests and field vertical load pile tests are selected to verify the reliability of the proposed analytical model. The results indicate that the proposed analytical model can effectively reflect the variation characteristics of the shear stress-displacement curve and the normal stress-displacement curve under CNS conditions, and its application in the load-transfer behavior of rock-socketed piles can well predict the bearing characteristics.