Numerical Studies on Critical Height of Embankment for Gravel Road Surface in Permafrost Regions

摘要

In permafrost regions of Qinghai-Tibetan Plateau, the critical embankment height must be considered in the process of the construction of highway, especially for the global climatic warming. In this paper, the two-dimensional numerical analysis for the critical embankment height (for gravel road surface and coarse-grained soil) has been performed by using the finite element method. In the calculation, we think that the service life of the construction is at least 50 years. The mean annual air temperatures applied to the calculation model are -6. 5°C , -6. 0°C , -5. 5°C, -5. 0°C, -4. 5°C and -4. 0°C, respectively, and the value of temperature rise are taken as 1. 10°C in the coming 50 years. The minimum embankment heights derived from the analysis are 0. 85 m, 0. 92 m, 1. 01 m, 1. 18 m, 1. 60 m and 2. 66 m for the different mean annual air temperatures and the maximum embankment heights are 7. 68 m, 7. 55 m, 7. 34 m, 7. 00 m, 6. 45 m and 5. 85m, accordingly. On condition that the service life of embankment is 50 years, the critical value of the mean annual air temperature is -3.5°C. Namely, in the areas where the mean annual air temperature is higher than -3. 5°C, the critical embankment height does not exist.