褥垫层作用下预应力高强混凝土能量桩热力响应特性现场试验  

Field tests on thermo-mechanical response characteristics of prestressed high-strength concrete energy pile under the action of cushion layer

作　　者：常洪林 孔纲强[1] 王福慧 王成龙[2] 周杨[1] CHANG Hong-lin;KONG Gang-qiang;WANG Fu-hui;WANG Cheng-long;ZHOU Yang(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing,Jiangsu 210024,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area of the Ministry of Education,Chongqing University,Chongqing,400045,China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210024 [2]重庆大学山地城镇建设与新技术教育部重点实验,重庆400045

出　　处：《岩土力学》2025年第4期1240-1251,共12页Rock and Soil Mechanics

基　　金：中央高校基本科研业务费专项资金(No.B240205006);国家自然科学基金(No.52108313)。

摘　　要：能量桩是一种兼具承载与换热功能于一体的建筑节能新技术,然而,既有研究主要围绕能量桩桩顶处于自由无约束状态或者桩基-承台/筏板等刚性约束状态,对于柔性约束状态下能量桩的热力响应机制尚不清楚,尤其是能量桩桩基复合地基的作用机制知之甚少。依托河南平舆坝道工程医院超低能耗绿色建筑项目,开展褥垫层对预应力高强混凝土(prestressed high-strength concrete,PHC)能量桩热力响应特性影响的现场试验;实测温度和荷载联合作用下桩身温度及应变的发展规律,初步探讨了约束应力、热致侧摩阻力、轴向位移、桩-土应力比、邻桩响应特性等演化规律。研究结果表明:试验条件下,褥垫层影响下桩顶处(0.133L)的约束度约为65%;加热96h后,距桩顶0.133L~0.333L处表现较小的负摩阻力,桩顶处(0.133L)产生的最大向上轴向位移约为桩径的0.14%;加热120 h后,距桩顶0.333L处的桩-土应力比增长了近3倍。Energy piles are a new energy-saving technology for buildings that combines load-bearing performance and heat exchange performance.Most studies on energy piles are carried out under free and unconstrained conditions or rigid constraints,such as pile-cap/raft systems.However,the thermo-mechanical response characteristics of energy piles under the relatively flexible constraint state of a composite foundation remain unclear.Field tests were conducted at the BeSTDR Infrastructue Hospital in Pingyu County,Henan Province,as an ultra-low energy consumption green building project to assess how cushion layers affect the thermo-mechanical response characteristics of prestressed high-strength concrete(PHC)energy piles.The development patterns of temperature and strain along pile body were measured,and the changes in constraint stress,thermal-induced side friction resistance,axial displacement,pile-soil stress ratio,and the response characteristics of the adjacent pile were preliminarily explored.The results show that under the experimental conditions,the constraint capacity at the pile top(0.133L)is approximately 65%due to the influence of the cushion layer.After 96 hours of heating,the region between 0.133L and 0.333L from the pile top exhibited minimal negative skin friction,with the maximum upward axial displacement at the pile top(0.133L)reaching about 0.14%of the pile diameter.After 120 hours of heating,the pile-soil stress ratio at 0.133L from the pile top nearly tripled.

关 键 词：PHC管桩 能量桩 褥垫层 柔性约束 热力响应特性 

分 类 号：TU473[建筑科学—结构工程]