Based on the wave theory of unsaturated porous elastic media

a wave equation for unsaturated porous thermo-viscoelastic media is established by considering the viscosity of the soil skeleton and thermal effects

and utilizing the Kelvin-Voigt viscoelastic model

the equations of motion for unsaturated porous viscoelastic media

and the generalized thermoelasticity theory. By introducing displacement potential functions for each constituent phase

the dispersion characteristic equations for body waves in unsaturated porous thermo-viscoelastic media are derived. Numerical calculations are performed to analyze the influence of thermophysical parameters

such as relaxation time

thermal conductivity

medium temperature

specific heat capacity of the solid phase

and saturation

on the wave velocity and attenuation coefficient of thermo-viscoelastic waves. The results show that for every 0.5×10⁻³ s increase in relaxation time

the velocities and attenuation coefficients of the P wave increase by up to 2.93% and 44.51%

respectively; those of the S wave increase by up to 17.49% and 51.32%

respectively; while the velocity and attenuation coefficient of the T wave decrease by up to 25.4% and 20.3%

respectively. The thermal conductivity coefficient only affects the T-wave velocity and attenuation coefficient. For every 1 J/(m·s·K) increase in thermal conductivity

the T-wave velocity increases by 21.62% and its attenuation coefficient decreases by 6.83%. For every 20 K increase in medium temperature

the P1-wave velocity increases by approximately 0.3% and its attenuation coefficient decreases by approximately 0.2%. An increase in the specific heat of the solid phase causes the wave velocities of both the P1-wave and the T-wave to gradually increase. Saturation has a significant effect on the wave velocities of P

P3

and S waves. When the saturation decreases from 0.99 to 0.4

the wave velocities of the P and S waves increase by up to 15.6% and 6.5%

respectively

and the wave velocity of the P wave increases by up to 4.4 times.