Transmission conditions for a poroelastic interface in a rectangular domain

We investigate a pair of rectangular poroelastic layers separated by a thin poroelastic interface. The domain has either permeable or impermeable boundaries. The interfaces material and hydrological properties may vary significantly from those of the main body, impacting the resulting displacement, stress and pore pressure fields. A total of eighteen transmission conditions are considered: eight independent conditions derived from asymptotic analysis and ten auxiliary conditions obtained through their combinations. Numerical simulations are performed for both mechanical loading and external pressure loading, providing a systematic comparison between the proposed transmission conditions and the classical ideal contact model. The results demonstrate pronounced qualitative and quantitative differences, with the contrast between the layers’ poroelastic constants significantly affecting the redistribution of stress, deformations and pore pressure, highlighting the limitations of idealized interface assumptions. The effect of boundary permeability on the poroelastic stress state reveal its significant role in the overall response of the system. The findings underscore the relevance of advanced transmission conditions for realistic modeling of layered poroelastic structures and provide guidance for selecting appropriate interface models in practical engineering applications.