This paper explores the potential use of a pipe pile as a heat exchanger. The comparison between the thermomechanical characteristics of the solid energy pile and pipe energy pile was analyzed by using the model test method. The potential effects of thermal cycles on the horizontal earth pressure and the pile resistance redistribution were analyzed and discussed. Moreover, this paper also presents a preliminary investigation on the thermally induced contraction of the surrounding sandy soil. The results showed that the repeated expansion and contraction of energy piles would induce decreases in the horizontal earth pressure and impose an increased tip resistance to balance the shaft resistance reduction during the thermal cycles. Settlement would gradually accumulate at a reducing rate for the energy piles, and the accumulation of the pile settlement could be accompanied by the thermal contraction of the sandy soil. After three thermal cycles, the solid pile accumulated a 20% greater percentage of pile settlement than the pipe pile. However, the reduction in the shaft resistance of the pipe pile was larger than that of the solid pile. Hence, for the practical design of pipe energy piles, attention must be paid to the potential impact of thermal cycles on the pile structure.

本文探讨了管桩作为热交换器的潜在用途。利用模型试验方法分析了固体能桩和管道能桩的热机械特性的比较。分析和讨论了热循环对水平土压力和桩阻力重新分布的潜在影响。此外，本文还对周围沙土的热诱导收缩进行了初步研究。结果表明，能量桩的反复膨胀和收缩会引起水平土压力的降低，并施加增大的端部阻力，以平衡热循环过程中轴阻力的减小。对于能量堆，沉降将逐渐以减少的速率积累，桩沉降的累积可能伴随着沙土的热收缩。经过三个热循环后，实心桩的堆积沉降百分比比管桩大20％。但是，管桩的竖井阻力减小量大于实心桩。因此，对于管能桩的实际设计，必须注意热循环对桩结构的潜在影响。