Analysis of Long-term Temperatures inside Tunnels during Winter in Gangwon, South Korea

Abstract

Tunnels are among the main components of transport infrastructure systems and as such must be protected against damage. As damage is particularly prevalent in cold climates, this research investigates tunnels in Gangwon Province (the coldest region of South Korea). Herein, the temperatures inside three tunnels, specifically, one short tunnel and two medium-length tunnels, were measured during the winter season using i-button sensors installed on the surface of the tunnel lining at a height of 2 m from the ground. The long-term temperature data as measured in this way were analyzed, indicating that January showed the lowest temperature compared to those in November, December, February, and March. Moreover, the minimum and maximum daily temperatures of air mostly frequently appeared during 3 to 6 AM and 2 to 4 PM, respectively. Also, the highest temperature gradient occurred at a position of 30 m from the entrance or exits. The temperatures inside the tunnels were significantly affected by the external wind, which was induced by the vehicle traffic volume compared to the natural wind direction, the wind velocity, or the presence of rainfall. Hence, tunnel damage caused by frost heaves and freeze-thaw action can be reduced by frequent inspection and evaluations.