多次温度循环对能量桩桩顶位移影响分析

发布时间：2018-09-06 19:45

【摘要】：能量桩是一种在承载上部建筑荷载的同时获取地热能源的新技术。但目前对于能量桩在冷、热循环过程中尤其多次冷、热循环情况下的热力学效应研究较少。基于模型试验方法,针对预埋钢管单U型新型能量桩,开展工作荷载作用下多次冷、热循环时的传热特性和承载特性,尤其是桩顶位移变化规律的研究;并开展无荷载作用下单次冷、热循环试验进行分析。试验结果表明,冷、热循环引起的桩体热应变,在加热时桩体内部产生压应力,而在制冷时桩体内部产生拉应力,同时温度引起桩侧不同部位分别产生正摩阻力和负摩阻力。相较于工作荷载,无荷载作用下加热会使桩体位移上升约41%,而一次加热与制冷循环作用后,无荷载作用下桩顶残余位移约为工作荷载作用下的10%。多次冷、热温度循环会导致桩体沉降不断积累。
[Abstract]:Energy pile is a new technology to acquire geothermal energy while bearing the load of upper building. However, there are few studies on the thermodynamic effect of the energy pile in the case of cold and thermal cycling, especially in the process of cooling and thermal cycling. Based on the model test method, the heat transfer characteristics and load bearing characteristics of single U type preburied steel pipe under working load under multiple cooling and thermal cycles are studied, especially the displacement of pile top. The secondary cooling and heat cycling tests without load are carried out. The test results show that the thermal strain of the pile caused by the cold and thermal cycles produces the compressive stress in the pile body while the tensile stress in the pile body is produced in the refrigeration process, and the positive friction and negative friction are produced at the different parts of the pile side caused by the temperature, respectively. Compared with the working load, heating under no load will increase the displacement of the pile by about 41%, and after the first heating and refrigeration cycle, the residual displacement of the pile top under no load is about 10% of that under the working load. Repeated cooling and thermal temperature cycling will lead to the accumulation of pile settlement.
【作者单位】：河海大学土木与交通学院;重庆大学土木工程学院;重庆大学山地城镇建设与新技术教育部重点试验室;江苏省有色金属华东地质勘查局;
【基金】：国家自然科学基金项目(No.51378178) 教育部博士点联合基金项目(No.20130094140001) 山地城镇建设与新技术教育部重点实验室开放基金项目(No.0902071812401) 江苏省自然科学基金(No.BK2012478)~~
【分类号】：TU473.1

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