<p>Under short-duration and high-rate thermal loading, such as underground explosions and laser-assisted rock breaking, saturated porous rocks exhibit coupled thermal, hydraulic and mechanical responses<b>.</b> These responses involve finite-speed heat propagation, delayed thermal relaxation and strong history dependence. Existing time-fractional formulations have been used to describe the memory-dependent effects associated with heat-flux relaxation and temperature-gradient relaxation in the dual-phase-lag heat conduction law, as well as in hydro-thermo-mechanical response analysis. However, these formulations are generally based on full-history convolution operators, whose definitions are not unique and whose memory kernels are not always easy to interpret physically or prescribe flexibly. To address these limitations, this paper develops a fully coupled hydro-thermo-poro-viscoelastic model for saturated porous media based on the dual-phase-lag heat conduction law with memory-dependent derivatives. By introducing adjustable kernel characteristics, the proposed framework describes thermal memory effects, lagging behavior and transient structural responses in a more flexible manner. The proposed model is then applied to an unlined circular tunnel subjected to thermal-shock loading. Semi-analytical solutions are obtained through the Laplace transform combined with an FFT-based numerical inversion. Dimensionless parametric analyses show that the kernel functions and time-delay parameters in the memory-dependent derivatives can effectively characterize temporal memory effects and finite-speed heat transport, thereby systematically regulating temperature attenuation, pore-pressure evolution and stress responses. These results provide a theoretical basis for hydro-thermo-mechanical regulation and safety assessment of saturated tunnels under ultrafast heating conditions.</p>