This paper describes a new incremental approach to simulate the axial load–displacement response of energy piles. A load transfer approach is used to model the interaction of pile with surrounding soil, the underlying layers, and the superstructure. Interface springs are nonlinear–hyperbolic and Masing’s rule applies to model their hysteresis behaviour. Mechanical and thermal loads are incrementally applied to the pile using an iterative finite difference method. This strategy makes it possible for both mechanical and thermal loads to have arbitrary time histories during analysis. The self-weight of the energy pile can also be considered. The simulation results are found to compare favourably with published experimental results from field and laboratory testing of three energy piles. The effects of amplitudes of mechanical load and temperature change as well as those of the stiffness of the pile extremities on the thermomechanical response of the pile and the position of the null point are evaluated and discussed. The simulations show that the thermal-induced axial force due to a unique temperature change was greater for an energy pile under lower amounts of mechanical load. It is found that the effect of the end restraining condition on the response of the energy piles is more considerable during the heating processes than during the cooling processes. More restrained pile–superstructure connection also results in more thermal-induced axial force in the energy pile. The null point is always located closer to the stiffer extremity of the energy pile.

本文描述了一种新的增量方法来模拟能量桩的轴向载荷-位移响应。荷载传递方法用于模拟桩与周围土壤、下伏层和上部结构的相互作用。界面弹簧是非线性双曲线的，Masing 规则适用于对它们的滞后行为进行建模。机械载荷和热载荷使用迭代有限差分法递增地施加到桩上。这种策略使机械和热负荷在分析过程中具有任意时间历史成为可能。也可以考虑能量桩的自重。发现模拟结果与来自三个能量桩的现场和实验室测试的已发表实验结果相比具有优势。评估和讨论了机械载荷和温度变化的幅度以及桩端刚度对桩的热机械响应和零点位置的影响。模拟表明，在较低机械载荷下，能量桩由于独特的温度变化而产生的热致轴向力更大。发现端部约束条件对能量桩响应的影响在加热过程中比在冷却过程中更为显着。更受约束的桩-上部结构连接也会导致能量桩中更多的热致轴向力。零点总是位于更靠近能量堆较硬的末端。