桩埋管式地源热泵(也称能量桩)是一种可以节省地下空间和施工埋管费用的新技术,目前在国内外得到了一定的应用。然而,针对其在干砂中的传热特性和力学特性的研究却相对较少。基于模型试验方法,对不同埋管形式下,干砂中钢筋混凝土桩的传热特性及其力学特性进行了对比模型试验研究。试验测得桩体、桩周土体的温度变化规律,桩体应变和桩体热应力的变化规律,并对比分析了温度影响下基桩的极限承载力。试验研究结果表明,同样输入功率条件下,不同埋管形式相比,W型和螺旋型桩的应力变化和桩顶沉降量均较单U型桩要大。 Pile-buried ground source heat pump (also called energy pile) is a new technology that can save the cost of underground space and construction buried pipe, and it has been applied at home and abroad. However, there are relatively few studies on its heat transfer and mechanical properties in dry sand. Based on the model test method, the heat transfer characteristics and mechanical properties of reinforced concrete piles in dry sand under different tube forms were compared and studied. The variation of the temperature of the pile body, the soil around the pile body, the strain of the pile body and the thermal stress of the pile body were measured. The ultimate bearing capacity of the pile under the influence of temperature was also analyzed. The experimental results show that the stress change and pile top settlement of W-type and spiral-shaped piles are all larger than that of single U-shaped piles under the same input power.