关键词: 城市隧道, 能源桩, 路面下埋管, 地热防结冰

Abstract: The traditional deicing methods have many disadvantages such as low efficiency, need for postprocessing, incomplete melting, and pollution risk. Accordingly, the application of shallow geothermal energy in underground engineering construction is analyzed, and the system principle and the operation theory of the pavement deicing technology by extracting shallow geothermal energy through energy piles is introduced. Then, a specific design of the Qingliangmen tunnel deicing project is proposed. The system heat transfer performance, mechanical characteristics of the buried pipe under the pavement, and the system operation effect are analyzed by a numerical modeling method. The results show the following: (1) The antifreeze requirement of the pavement in the open section of the tunnel is satisfied by using energy piles in winters. (2) By adopting insulation measures in the lower part of the heat transfer tube, the tensile stress of the concrete structure under the pavement and the heat loss when transferring to the road foundation are reduced, thereby improving energy efficiency. (3) Compared with the deicing technology based on the carbonfibercable heating method, the electricity consumption per year of the deicing technology based on geothermal energy piles is less by 60%, which indicates a good energysaving effect.

Key words: urban tunnel, energy piles, pipes buried under pavements, deicing using geothermal energy