饱和粉土相变能源桩热响应模型试验及验证

Model tests on thermal response of phase-change pile in saturated silt foundation

利用复合相变材料制备了相变混凝土能源桩,并在粉土中开展了相变桩热力响应模型试验,在此基础上建立了能源桩有限元模型,对比分析了相变桩和普通桩的热响应特性。结果表明:在夏季(10℃→40℃→10℃、10℃→25℃→10℃)和冬季(16℃→5℃→16℃)工况下的热响应过程中,相变桩的桩身温度变化幅度均小于普通桩,有利于缓解桩周土体热堆积效应的作用。相变陶粒的掺入减少了能源桩在热交换过程中由桩土热膨胀引起的位移。

The phase-change concrete energy pile is prepared by using the composite phase-change materials,and the thermal response model tests on the phase-change pile is carried out in silt.On this basis,the finite element model for energy pile is established,and the thermal response characteristics of the phase-change pile and ordinary pile are compared and analyzed.the results show that during the thermal response process in summer(10℃→40℃→10℃,10℃→25℃→10℃)and winter(16℃→5℃→16℃).The variation range of temperature of the phase-change pile is smaller than that of the ordinary pile,which is helpful to alleviate the thermal accumulation effects of the soil around the pile.The addition of phase-change ceramsite reduces the displacement of the energy pile caused by the pile-soil thermal expansion during the process of heat exchange.