Abstract: In the present research, the characteristics and influence factors of temperature field distribution in energy piles with buried spiral pipe were investigated by numerical means based on field prototype tests on temperature field distribution in energy piles as well as measured values of temperatures at pile wall and pile core during heat exchange. Results reveal that the regularity of temperature rise in energy pile is consistent with temperature variation at the inlet and outlet of buried pipe, which suggest that temperature field in energy pile is mainly dominated by temperature at the inlet and outlet of buried pipe. When energy pile is heated or refrigerated, temperature in pile declines or rises in a parabola along the way of the buried pipe. Moreover, the conductivity coefficient of backfill material and the pile diameter are two main factors affecting the temperature field distribution in energy pile. As conductivity coefficient increases, the temperature in pile rises at given heat durations; and in particular, temperature at the core of pile rises linearly. As pile diameter increases, the temperature in pile declines in equal proportion at given heat durations. The research results could be taken as reference for the promotion of energy piles.

Key words: energy pile with buried spiral pipe, temperature field distribution, influence factors, prototype test, numerical simulation