Nonlinear Analysis for the Cooling Effect of Road Subgrade with Varying Spacings of Thermosyphons in Cold Region

Thermosyphons are usually used to maintain the stability of construction foundation in cold regions. This paper presents a three-dimensional, finite element, thermal analysis conducted to simulate 30 years' running to study the cooling effect of the road subgrade with thermosyphons. The spacings of the thermosyphons used in the computation are 3 m, 4 m, 5 m and 6 m, respectively, and the diameter of the thermosyphon is 89 mm. Preliminary results indicate that the thermosyphon can lower the soil temperature substantially, and the cooling effect becomes less effective as spacing increases. For the geological conditions in the Tibetan Plateau, the effective operating radius of the thermosyphon with the diameter of 89 mm is about 1.6 m and the reasonable spacing between thermosyphons is 4 m.