ON WAVES PROPAGATING THROUGH AN EMERGENT POROELASTIC MEDIUM

Abstract

This paper describes a theoretical study of the problem of linear waves propagating over an emergent poroelastic medium. Lan-Lee's poro-elastomer theory is extended to derive a new analytical solution for describing this problem, with the free surface boundary condition discussed in the context of a poroelastic medium, a topic that has rarely been covered by previous studies. In the present approach, the problem domain is divided into three subregions and a negligible water-exposed region. Using general solutions for each region and the matching dynamic and kinematic conditions for neighboring regions, a set of simultaneous equations is developed and numerically solved. The present analytic solution compares reasonably well with simplified cases of impermeable, rigid structures and porous structures. Using this analytic solution, the wave reflection and transmission induced by different key parameters of the poroelastic medium are studied. The results show that softer poroelastic media can transform the incident waves. For almost impermeable conditions, a softer emergent medium induces resonance, whereas higher permeability depresses the resonant effects and induces significant wave damping.