Thermo-hydro-mechanical dynamic response of a cylindrical lined tunnel in a poroelastic medium with fractional thermoelastic theory

This study deals with the coupled thermo-hydro-mechanical dynamic response of a cylindrical lined tunnel in a poroelastic medium when subjected to the joint action of a thermal and mechanical source. With the fractional-order thermoelasticity theory, the fully coupled thereto-hydro-mechanical dynamic model is presented based on the equations of motion, fluid flux, and fractional heat conductivity. The soil is regarded as a saturated porothermoelastic medium and solved by the generalized energy equation of porothermoelasticity with fractional derivative. Furthermore, the lining structure is equivalent to the elastic material by the theory of thermoelastic shell. The study derives the temperature increment, displacement, stresses, and pore water pressure by using the differential operator decomposition method and the Laplace transform method. The influences of the fractional derivative parameter on the responses are discussed and the numerical results compared with the results of the theory of saturated porous medium and the cavity without lining.