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 thermo-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. • The generalized heat conduction equation with fractional derivatives is established. • The lining structure is equivalent to elastic material by utilizing the theory of thermoelastic shell. • The influences of the fractional derivative parameter on the responses are also discussed. • Numerical results are compared with the results of saturated porous medium and the cavity without lining. [ABSTRACT FROM AUTHOR]