Abstract
The snow-melting system using underground thermal energy collected by foundation piles for a building has been commonly used in parking lots and sidewalks in Fukui City because this system is cost-effective and energy-consuming. This system has been applied to bridge in order to prevent the road surface from freezing and being covered with snow. Large inner diameter steel piles placed a few meters apart in rows and columns typically for a bridge foundation are at a heavy disadvantage in collecting underground thermal energy. Though the numerical simulation shows that the group of piles is effective in storing solar energy collected by running the pump in summer until winter.