On the treatment of convective terms in coupled hydro-mechanics for porous media subject to dynamic loading

Abstract

The physical problem of interest is that of a road structure that is subjected to dynamic loading from repeated over-rolling of car wheels. Primarily, we are interested in the mechanical response of bitumenbased porous granular media (such as the asphalt layer). The porous medium is modelled as a mixture of a solid phase, in the sense of a porous solid skeleton, and a fluid phase that represents both liquid and air in the pores. The solid particles are assumed to be intrinsically incompressible, i.e. the compressibility of the solid bulk is brought about by a rearrangement of the particles. In the presence of air, the fluid is assigned a finite intrinsic compressibility; hence, it suffices to consider a binary mixture. An important practical problem is internal erosion of the solid material by the fluid transport, which means that mass of the individual phases is not conserved; however, this effect is ignored here.