承台现浇大体积混凝土温度效应及影响参数分析  

Analysis of temperature effect and influencing parameters of cast-in-place mass concrete for pile caps

作　　者：杨新浩 张凌云 董军[1] 张尧 刘旭 YANG Xinhao;ZHANG Lingyun;DONG Jun;ZHANG Yao;LIU Xu(Beijing Higher Institution Engineering Research Center of Structural Engineering and New Materials,Beijing University of Civil Engineering and Architecture,Beijing 100044,China;China Communications First Highway Engineering Co.,Ltd.,Beijing 100024,China;Research Institute of Highway Ministry of Transport,Beijing 100088,China;Liaoning Branch of China Road High-Tech Transportation Testing Certification Co.,Ltd.,Shenyang 110020,China;China Communications First Highway Engineering Xiamen Co.,Ltd.,Xiamen 361000,China)

机构地区：[1]北京建筑大学工程结构与新材料北京市高等学校工程研究中心,北京100044 [2]中交一公局集团有限公司,北京100024 [3]交通运输部公路科学研究院,北京100088 [4]中路高科交通检测检验认证有限公司辽宁分公司,辽宁沈阳110020 [5]中交一公局厦门工程有限公司,福建厦门361000

出　　处：《混凝土》2025年第3期12-19,23,共9页Concrete

基　　金：北京市自然科学基金(8202012);河南省交通运输厅科技计划项目(201602)。

摘　　要：大体积混凝土水化热作用会使结构产生裂缝,并降低结构的耐久性和稳定性.因此,提前进行水化热分析并制定有效的温控方案对于保障结构施工质量尤为重要.以重庆市嘉陵江某特大斜拉桥11#索塔承台为研究案例,利用MIDAS/FEA有限元软件并结合承台温控方案以及现场实测方式对分两次浇筑成型的承台水化热效应以及影响参数进行探索和分析.研究表明:承台温控方案对应承台模型水化热结果均满足大体积混凝土施工规范的温控指标要求,模型部分参数依据现场实际变化调整后,与实测数据吻合度较好;浇筑层顶层冷水管距顶面的距离会对顶面的降温效果产生影响.上层混凝土浇筑会对下层已浇混凝土有二次升温的作用,其影响程度与距浇筑层分界限线的距离相关;浇筑方式可通过控制浇筑层厚度从而对水化热的温度峰值以及降温速率产生影响.对于水化热温度峰值较高的大体积混凝土结构,采用前期恒温水与后期动态调控相结合的方式要比恒温水方式在降温速率的控制方面效果更佳.承台中心二次升温的温度峰值与两浇筑层之间的间隔时间有关。The heat of hydration in mass concrete can lead to structural cracking,reducing durability and stability.Therefore,conducting hydration heat analysis in advance and formulating effective temperature control strategies are crucial for ensuring construction quality.It investigates the hydration heat effects and influencing parameters of a pile cap cast in two stages,using the No.11 tower pile cap of a large cable-stayed bridge over the Jialing River in Chongqing,China,as a case study.MIDAS/FEA finite element software,combined with a temperature control plan and on-site measurements,was utilized for the analysis.The results show that the hydration heat outcomes of the pile cap model under the proposed temperature control scheme meet the temperature control standards specified for mass concrete construction.The model's parameters,adjusted based on on-site conditions,exhibit good agreement with the measured data.The distance between the cooling water pipes and the top surface significantly affects the cooling efficiency of the surface.The second-stage concrete placement induces secondary temperature rises in the first-stage concrete,with the degree of influence related to the distance from the interface between layers.The placement method can control the peak hydration temperature and cooling rate by adjusting the thickness of each concrete layer.For mass concrete structures with high hydration temperature peaks,combining early-stage constant-temperature cooling with later-stage dynamic temperature control is more effective in managing cooling rates than constant-temperature cooling alone.Additionally,the peak temperature of the secondary rise at the center of the pile cap is related to the interval time between the two concrete placement layers.

关 键 词：大体积混凝土 索塔承台 水化热效应 影响参数 有限元分析 

分 类 号：TU528.31[建筑科学—建筑技术科学]