斜拉桥索塔锚固区直向短束预应力损失研究

发布时间：2018-01-04 23:32

本文关键词：斜拉桥索塔锚固区直向短束预应力损失研究　出处：《华南理工大学学报(自然科学版)》2015年12期 　论文类型：期刊论文

【摘要】：为克服斜拉桥混凝土索塔锚固区布置环形预应力筋在受力和施工方面的不足,提出一种新型单向预应力布置型式.该布置型式下预应力筋长度较短,其损失规律和施工工艺与普通长束预应力筋有所不同.为研究这种直向短束预应力筋的损失特点,进行了足尺模型试验,重点对摩阻(包括孔道摩阻和锚具摩阻)损失,锚固回缩损失以及伸长量控制方法进行了研究,并对锚下预应力筋进行了短期观测.结果表明:预应力总损失约为26%,锚固回缩损失占总损失的50%以上;孔道摩阻损失占总损失的12%左右,锚圈口摩阻损失占20%,此二项不同于大多文献和规范建议的作忽略考虑;"伸长量控制"在短束预应力施工控制中同样适用,但其对施工误差极为敏感,必须保证张拉质量,控制误差应放宽至±9%.
[Abstract]:In order to overcome the shortage of laying ring prestressed tendons in the anchoring zone of concrete cable towers of cable-stayed bridges, a new type of one-way prestressed tendons is proposed. The length of prestressed tendons is relatively short in this type of arrangement. The loss law and construction technology are different from that of normal long prestressed tendons. In order to study the loss characteristics of this kind of straight short prestressing tendons, full-scale model tests have been carried out. The loss of friction (including channel friction and Anchorage friction), the loss of Anchorage retraction and the control method of elongation are mainly studied in this paper. The results show that the total loss of prestressing force is about 26 and the loss of anchoring back is more than 50% of the total loss. The loss of pore and channel friction is about 12% of the total loss, and the loss of Anchorage ring is about 20. These two items are different from the neglect consideration of most literature and standard suggestions. The "elongation control" is also applicable in the construction control of short prestressing force, but it is very sensitive to the construction error, so the tension quality must be guaranteed, and the control error should be extended to 卤9.
【作者单位】：华南理工大学土木与交通学院;
【基金】：国家自然科学基金资助项目(51478193,51208208) 中国博士后科学基金资助项目(2013M542174) 华南理工大学中央高校基本科研业务费专项资金资助项目(2014ZZ0019)~~
【分类号】：U445.57;U446
【正文快照】： Foundation items:Suppouted by the Nation Natural Science Foundation of China(51478193,51208208)and the China PostdoctoralScience Foundation(2013M542174)目前,斜拉桥PC箱形索塔大多采用大吨位、小半径环形预应力,但其普遍存在施工定位和控制困难的问题,尤其是实际

【相似文献】