Abstract: In the construction of tunnels with high geotemperature in tropical areas, ice cubes are often used as an auxiliary means of cooling due to its economic and easy access. In order to solve the problem of selecting the quantity and layout parameters of ice cooling in use,based on the Hainan Wuzhishan extra-long highway tunnel project, this article uses Fluent to simulate the changes in the temperature field of the tunnel under ventilation and ice cooling, and analyzes the influence of two factors, namely the amount of ice and the placement position, on the longitudinal and tunnel temperature fields. The conclusions are as follows: (1) The temperature drop is more obvious within 5m before and after the ice block placement position, and the temperature drop range gradually expands over time. When 1.5m³ ice cubes are arranged on both sides, the lowest temperature within 5m of the tunnel surface is about 18℃, which is about 10℃ lower than when no ice cubes are arranged,；and the temperature at a further distance is about 23℃, which is about 5~8℃ lower than when no ice cubes are arranged. (2) Compared with the working conditions with only ventilation, 1m³ of ice cubes (0.5m³ on both sides) can reduce the temperature of the face of the tunnel by about 6℃. On this basis, every additional 1m³ of ice cubes can lower the temperature of the tunnel surface by about 3℃. (3) For the same amount of ice, arranging the ice on the axis of the air outlet of the air duct can lower the temperature of the tunnel surface by 3~5℃,which is more than that on both sides, and the effect of continuous cooling is stronger.

Key words: highway tunnel, ice cooling, numerical simulation, tropical area