特大方量异形结构大体积混凝土冷却水管布置与参数研究

发布时间：2018-05-20 15:31

本文选题：斜拉桥 + 桥塔　；参考：《世界桥梁》2017年05期

【摘要】：为避免特大方量异形结构大体积混凝土施工过程中产生温度裂缝,以沪通长江大桥桥塔下横梁为工程背景,采用MIDAS软件建立大型有限元温度场模型。针对下横梁大体积(11 600m~3)、高强度(C60)、结构不规则的特点,以内部最高温度及最大主拉应力为主控参数,优化冷却水管布置及相关参数选取。结果表明:冷却水管布置的间距越小、根数越多,下横梁混凝土降温越快,这会造成混凝土内部收缩过快,使得最大主拉应力变大;冷却水管通水温度越低、通水时间越长、通水流速越大,会导致与混凝土内部温差过大,增加收缩应力。实践证明,采用优化的方案后,各项温度参数均满足规范要求,有效地避免了结构产生有害的温度裂缝。
[Abstract]:In order to avoid the temperature crack in the construction of large volume concrete with large square shaped structure, the temperature field model of large finite element is established by using MIDAS software, taking the cross beam under the tower of Hutong Yangtze River Bridge as the engineering background. In view of the large volume of 11600mm3, high strength and irregular structure of the lower crossbeam, the maximum internal temperature and the maximum main tensile stress are taken as the main control parameters to optimize the arrangement of the cooling water pipe and the selection of the relevant parameters. The results show that the smaller the spacing of the cooling water pipes, the more the root number, the faster the cooling of the lower beam concrete, the faster the shrinkage of the concrete, the greater the maximum main tensile stress, and the lower the cooling water temperature, the longer the water flowing time. The higher the flow velocity, the greater the temperature difference between the concrete and the concrete, which increases the shrinkage stress. It is proved by practice that all the temperature parameters meet the requirements of the code and the harmful temperature cracks are avoided effectively after the optimized scheme is adopted.
【作者单位】：中铁大桥科学研究院有限公司;桥梁结构健康与安全国家重点实验室;甘肃省交通建设集团有限公司;
【分类号】：U445.57

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