Numerical analyses on the spatial-temporal thermal influence range of embankment in the Qinghai-Tibet Engineering Corridor

The density of linear engineering projects within the Qinghai-Tibet Engineering Corridor has increased, and the study of the thermal influence range of a single linear engineering project has become more important. This paper employs the finite difference method to investigate the influence of embankment size, mean annual ground temperature (MAGT), and construction time on the spatial-temporal evolution of the embankment's lateral and vertical thermal influence range. Additionally, a parameter sensitivity analysis of the lateral and vertical thermal influence ranges throughout the entire service life of the embankment is conducted. The results indicate that under the same service time, the lateral-vertical ratio (Lc/D), as well as the lateral thermal influence range (Lc) and the vertical thermal influence range (D), increase linearly with increasing embankment height and pavement width. The Lc/D increases with increasing MAGT, but the Lc and D decrease with increasing MAGT. The Lc/D, the Lc, and the D are not significantly affected by construction time. During the 50-year service life of the embankment, the most significant factor impacting the Lc is the pavement width, and the MAGT is the most significant factor impacting the D. The results are expected to serve as a guide for the design and construction of roads in the permafrost regions of the Qinghai-Tibet Plateau.