软土场地热固结对能源桩受力特性的影响研究  

Effect of thermal consolidation on mechanical properties of energy pile in soft soil site

作　　者：俞磊 邓岳保[1] 张付林 YU Lei;DENG Yuebao;ZHANG Fulin(School of Civil Engineering and Environmental Engineering,Ningbo University,Ningbo 315211,China;Ningbo Rail Transit Group Co.,Ltd.,Ningbo 315012,China)

机构地区：[1]宁波大学土木与环境工程学院,浙江宁波315211 [2]宁波市轨道交通集团有限公司,浙江宁波315012

出　　处：《宁波大学学报（理工版）》2021年第6期85-90,共6页Journal of Ningbo University：Natural Science and Engineering Edition

基　　金：浙江省基础公益研究计划(LGG21E080005);宁波市自然科学基金(2019A610398).

摘　　要：能源桩具有较好的节能减排功效,但软土场地能源桩的热交换会使桩周土产生明显的热固结沉降,从而影响桩-土荷载传递规律及其承载特性.本文根据温度效应的一维固结理论,计算任意时刻桩周土体的热固结沉降,结合佐腾悟双折线负摩阻力公式,建立考虑桩周土温度效应的能源桩荷载传递模型.算例分析表明:桩周土体的升温导致桩侧负摩阻力和桩身轴力增加,中性点位置下移;温度变化所产生的热固结沉降是影响桩身侧摩阻力的主要原因;由升温导致的土体黏聚力和内摩擦角的下降对桩身侧摩阻力变化影响较小.Energy piles have attracted wide attention in the construction field with good energy saving and emission reduction effect.However,the heat exchange of energy pile in soft soil site will cause obvious thermal consolidation settlement of soil around the pile,thus affecting the load transfer law and the bearing characteristics of pile-soil.The one-dimensional consolidation theory considering temperature effect is used to calculate the thermal consolidation settlement of the soil around the pile at arbitrary times,and the load transfer model of the energy pile considering temperature effect of the soil around the pile is established by exploiting Zottenwu’s negative friction formula.The case study shows that the temperature rise of soil around the pile leads to the increase of negative friction resistance and axial force of the pile body,and the position of the neutral point moves downward.The change of soil compression properties caused by temperature rise is the main reason affecting the lateral friction resistance of the pile,while the decrease of soil cohesion and internal friction angle caused by temperature rise has little effect on the lateral friction resistance of the pile.

关 键 词：能源桩 热固结 先期固结压力 荷载传递模型 黏聚力 内摩擦角 

分 类 号：TU411.5[建筑科学—岩土工程]