<p>The strength-displacement behaviour of soil-structure interface should be carefully considered during slope stabilisation using soil nail. Experimental evidences have demonstrated that tangential displacement between the soil and structure could deteriorate the microstructure within the interface, resulting in a strength degradation of the soil-structure system. To capture such responses, an elastoplastic model is developed by adopting particle probabilistic entropy to characterise the evolution of particle rearrangement within the interface, where a microstructure-dependent plastic flow rule and a kinematic hardening law are proposed. The capability of the model is verified by simulating a series of interface direct shear tests, where the normal-dilatancy response and strain softening of the interface under low normal stress as well as the distinct normal-contraction under cyclic loads are well simulated. Then, the model is further implemented through FRIC subroutines for finite element (FE) simulation of the pull-out tests on a soil–nail under different overburden pressures. It is found that the FE model can reasonably simulate the pull-out behaviour of a soil nail. The stress and strain fields around the soil nail as well as the pull-out force and displacement response can be reproduced.</p> Graphical Abstract <p></p>