This paper presents two in situ experimental investigations of the influence of intermittent and continuous cooling operation on thermal and mechanical responses of a foundation. The experiment was conducted with 16 h of cooling operation and 8 h of rest (C-16 mode) for 46 days and with 24 h of cooling operation (C-24 mode) for 32 days. A lower number of daily operating hours promoted natural ground thermal recovery and led to higher heat exchange rates with lower thermal loads on the foundation. The constant heat exchange rate in C-16 was approximately 115 W/m, which was 53.3% higher than the constant heat exchange rate at the same time in C-24. The pile temperatures at all depths in C-16 were decreased by 29.0–36.8% compared to those in C-24. Thermally induced stresses of the pile and raft in C-16 were 25.8–35.7% and 85.9% lower than the thermally induced stresses of the pile and raft in C-24. The mechanical responses of the energy pile in C-16 were reversible. During the cyclic cooling and recovery of C-16, stable changes in axial strain and stress with pile temperature were observed over further cycles, without significant variations in pile end displacement and the vertical stress at the pile toe.

本文介绍了间歇和连续冷却操作对基础热和机械响应的影响的两个原位实验研究。实验进行了 16 小时的冷却操作和 8 小时的休息（C-16 模式），持续 46 天，并进行了 24 小时的冷却操作（C-24 模式），持续 32 天。较低的每日运行小时数促进了自然地热回收，并导致更高的热交换率和较低的地基热负荷。C-16 的恒热交换率约为 115 W/m，比 C-24 同时的恒热交换率高 53.3%。与 C-24 相比，C-16 中所有深度的桩温降低了 29.0-36.8%。C-16 中桩和筏的热致应力为 25.8-35.7% 和 85。比 C-24 中桩和筏的热致应力低 9%。C-16 中能量堆的机械响应是可逆的。在 C-16 的循环冷却和恢复过程中，在进一步的循环中观察到轴向应变和应力随桩温的稳定变化，而桩端位移和桩尖处的垂直应力没有显着变化。