Influence of the viscoelastic relaxation time on a foundation under generalized poro-thermoelasticity

Abstract

The present paper is aimed at studying the effects of coupled thermo-hydro-mechanical dynamics on an isotropic, uniform, fully saturated, and poroviscoelastic soil whose surface is subjected to either a mechanical force or a thermal load. A formulation is first deduced in the context of the Lord-Shulman theory. The general relationships among the non-dimensional vertical displacement, excess pore water pressure, vertical stress, and temperature distribution are then deduced via normal mode analysis and depicted graphically. This study continues the authors' work of applying normal mode analysis to the derivation of theoretical results in the multi-field coupling of viscoelastic soil. Via this method, the equation can be divided into two parts without integral transformation and inverse transformation, thereby increasing the speed of decoupling and eliminating the limitation of numerical inverse transformation. Furthermore, the differences between the coupled thermo-hydro-mechanical dynamic (THMD) model and the coupled thermo-hydro-mechanical viscoelastic dynamic (THMVD) model are presented. Comparisons are made within the theory in both the presence and absence of the viscoelastic relaxation time, and the influence of the viscoelastic relaxation time on each physical variable is also discussed. This proposed derivation method can be widely applied in the geotechnical engineering field.