Constitutive Model of Soil-Structure Interface under Constant Stress Increment Ratio Stress Paths

The soil-structure interaction attaches great importance to the stability of embankment and retaining wall in expressway engineering. Based on the simple shear test results of sand-concrete interface under the constant stress increment ratio stress paths (CSIRSP), a nonlinear elastic coupling constitutive model is proposed on purpose for describing the interface deformation behavior, including strain softening and normal dilatancy, as well as the effect of stress paths. In the model, the relation curves of shear stress and tangential strain are fitted by a piecewise function composed by hyperbolic function and hyperbolic secant function, while the relation curves of normal strain and tangential strain are fitted by another piecewise function composed by quadratic function and hyperbolic secant function. Finally, the predictions of the model have been compared with experimental results, and results show the model is reasonable and practical.