Energy pile is a new building energy-saving technology

which has both functions of the bearing performance and the ground source heat pump heat exchanger. Based on the pile foundation engineering project of Zhoukou Normal University gymnasium in Henan province

field tests on the thermo-mechanical response and bearing capacity of PHC energy pile under cooling-heating cyclic temperature are carried out. The temperature and the strain of PHC energy pile are measured. The temperature-induced stress

side resistance

and heat exchange performance are analyzed and discussed. Test results show that: the distribution of the temperature-induced stress along pile depth varies greatly under cooling-heating cyclic temperature in this study. There is some negative shaft friction resistance developed in the upper part of the pile. The multiple relationship between the maximum thermal stress and temperature difference is 212 or 115 under summer or winter mode. Finally

a calculation formula of pile-soil friction coefficient considering temperature effect is proposed. Using this formula

the calculation method of bearing capacity of PHC energy pile is modified. The calculation results are in good agreement with field test results.