基于室内缩尺试验研究了含能量桩群桩在4次冷热循环过程中的桩身热力学特性及桩基承载变形特性变化规律,分析冷热循环对桩土温度、承台沉降、桩顶荷载及桩身摩阻力的影响。试验结果表明：冷热循环过程中能量桩较浅位置处桩身及桩侧土温度始终高于较深处,热循环过程中能量桩的传热效率高于冷循环过程。冷热循环会使承台顶面的工作荷载及群桩中各基桩的桩顶荷载发生往复变化,相应地引起承台发生往复倾斜,热循环引起的承台倾斜稍大于冷循环。热循环引起的能量桩桩身上部摩阻力为负,下部为正,冷循环时则相反。
Abstract
Based on indoor scaled tests, the thermodynamic characteristics of the pile body and the variation law of the bearing deformation characteristics of the pile foundation under four cycles of cold and hot cycles of energy containing pile groups were studied. The thermal-induced pile-soil temperature, the pile-cap settlement, pile top load, as well as pile skin friction were mainly analyzed. The results show that the temperature in a pile and surrounding soils caused by the cooling-heating cycles at a shallower position below the soil surface is always greater than that at a deeper position. The heat transfer efficiency of the energy pile during heat cycles is higher than in cold cycles. Both the working load applied on the pile cap, and the load on the pile top will also be altered due to the thermal process, which consequently causes the pile cap to be tilted from one direction to another direction. It was also found that the tilting of the cap during the heat cycle is a little more significant than in the cold cycle. The heat cycle-induced skin friction on the upper pile shaft is negative and positive on the lower shaft, and vice versa during the cold cycle.
关键词
能量桩 /
黄土 /
模型试验 /
承载变形性状 /
冷热循环 /
传热效率 /
承台
Key words
energy pile /
loess soil /
model test /
bearing deformation behavior /
cooling-heating cycles /
heat transfer efficiency /
pile cap
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基金
陕西省自然科学基础研究计划一般面上项目（2024JC-YBMS-299）
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