2017年1月下第46卷
第2期
D0I;10.7672/sgjs2017020063
施工技术
CONSTRUCTION TECHNOLOGY
体内体外混合预应力配束连续刚构桥
力学性能对比分析
陶庆东1,2,刘跃国"
（1.绵阳职业技术学院建筑工程系，四川绵阳621000；2.重庆交通大学土木建筑学院，重庆400074）【摘要】以重庆新弹大桥体内体外混合配束连续刚构桥为工程实例，运用有限元软件分析其左辐全体内预应力与右幅体内体外混合配束的受力特点，并对比左右幅桥梁相同位置处的剪应力、经济性及工程实用性，得到连续刚构桥的体内体外混合配束的特点及优势，进面探讨采用优化配置的织向体内体外预应力锅束取代竖间预应力筋来承担混凝土的主拉应力的可行性，避免由于竖向预应力的施工质量难以保证，使成桥后主梁易出现混凝土开裂等病害。
【关键调】桥巢工程；预应力；连续刚构桥；有限元分析
【中图分类号】U445
【文献标识码】A
【文章编号】1002-8498(2017)02-0063-06
Comparative Analysis of the Mechanical Properties of the In-vivo and
In-vitroMixedPrestressedContinuousRigidFrameBridge
63
Tao Qingdong"2,Liu Yueguo
(1.Mianyang Vocational and Technical College,Department of Archilectural Enginring,Mianyang,Sichuan621000,China;
2. School of Civil Engineering and Architecture,Chongqing Jiaotong Unisersity, Chongqiag400074,China)
Abstract: Taking Chongqing Xintan continuous rigid frame bridge with mixed beam in-vivo and in-vitro as an engineering example, the stress characteristics that the left in-vivo bridge and the right mixed beam in-vivo and in-vitro bridge were analyzed with the finite element software, and the left and right bridge' s shear stress, economical efficiency and engineering practicability at the same position were compared, by which the characteristics and advantages of mixed beam in-vivo and in-vitro of continuous rigid frame bridge were obtained. Then the feasibility of using the optimized configuration of the longitudinal in-vivo and in-vitro prestressed steel beam to replace the vertical prestressed reinforcement to bear the main tensile stress of concrete was discussed, which avoided the diseases of the main beam concrete cracking because of the difficulty of the vertical prestress construction quality.
Key words:bridges; prestressing; continuous rigid frame bridge; finite element analysis
0
在役的大跨度预应力混凝土PC连续刚构桥多为体内预应力体系，成桥后运营过程中普遍存在跨中挠度、裂缝随时间加大等病害，主要原因在于体内竖向预应力筋的应力损失过大，施工过程中的施工技术、工艺缺陷造成纵向预应力损失增大。体外预应力体系中的体外索可补张拉及替换，解决体内预应力混凝土梁预应力损失无法弥补的缺点，进
●四川省教育厅项目（15ZB0409；16ZB0462）
【作者简介】陶庆东，博士研究生，助教，E-mail;290242665@qq.com【通讯作者】刘跃国，副教授，E-mail：1569103452@qq.com
【收稿日期】2016-05-09；[修订日期】2016-06-27 万方数据
而解决成桥后运营过程中预应力混凝土桥梁普遍存在跨中挠度大、裂缝等间题。同时，考虑桥梁加固中体外预应力技术的优点及丰富的工程加固经验，将其运用到大跨度预应力混凝土PC连续刚构桥中，采用将体内、体外预应力技术相结合的方式保证桥梁预应力的意义显而易见。
体外预应力钢束相比体内预应力钢束，束体与箱梁底板上缘有一定的间隙，偏心距较体内预应力钢束小，进而降低体外预应力钢束的使用效率，对于跨中弯矩大的简支梁，体外预应力筋的需要量非常大。但在多跨连续梁结构中，体外预应力钢束常作为成桥钢束，束型较复杂，施工需多次转向，但其