摘要
研究目的:娄底市共荣路上跨娄邵铁路采用(25+40+25)m预应力混凝土斜交连续箱梁,斜交角度为55°,支架现浇施工方法。由于该梁桥面较宽,斜交角度较大,为了对实际结构进行更准确的模拟,本文采用空间梁格及平面单梁两种有限元分析方法对预应力混凝土斜交连续梁进行对比分析研究。研究结论:(1)为方便预应力混凝土斜交连续梁设计,建议采用单梁法设计,空间梁格法进行验证;(2)大角度斜交连续梁跨中最大正弯矩和中支点负弯矩在恒载作用下均小于正桥,但剪滞效应比正交箱梁更为显著,设计时必须充分考虑其剪滞效应;(3)斜交连续梁钝角边侧支点反力比锐角边侧支点反力要大15%左右,设计时特别注意支座的选择及下部结构设计;(4)为增加各箱室之间横向刚度,建议在边跨及中跨设置几道横隔板;箱内可采用两次倒角使其不出现锐角,以消除应力集中现象;梁体建议采用全预应力结构设计,并将梁体普通钢筋适当加强;(5)本研究结论可为预应力混凝土大跨度斜交连续梁桥设计提供参考。
Research purposes ： Gongrong Road across Loudi - Shaoyang Railway in Loudi city uses （ 25 ＋ 40 ＋ 25 ） m prestressed concrete skew continuous box girder, oblique angle is 55 °, and uses support cast - in - place construction method. Because the bridge wide is larger and oblique angle is also larger, this article uses the space grillage and plane single beam two methods of finite element analysis to contrast and analyze the prestressed concrete skew continuous girders. Research conclusions： （1） For the convenience of prestressed concrete skew continuous girder design, it is recommended to adopt the single beam method for design, space grillage method for validation. （2） The most - positive bending moment and fulcrum negative bending moment of large angle of skew continuous beam are smaller than the moment of right bridge under the action of a constant load, but the shear lag effect is obvious better than orthogonal box girder, the design must fully consider the shear lag effect. （3） Skew continuous beam obtuse angle sides support reaction force is bigger than acute angle sides support reaction by about 15%, the design pay special attention to the choice of the bearing and the lower structure design. （4） To increase the lateral stiffness between the box offices, it is suggested that in side span and midspan set several horizontal clapboards. In order to eliminate the phenomenon of stress concentration, the two chamfering can be used to avoid acute angle appear. The whole girder body recommends prestressed structure design, and the ordinary reinforcement of girder body is strengthened properly. （5） In this paper,the conclusions can provide the reference for the design of large span prestressed concrete skew continuous girder bridge.
出处
《铁道工程学报》
EI
北大核心
2014年第12期52-56,共5页
Journal of Railway Engineering Society
关键词
斜交连续箱梁
连续梁
空间梁格法
平面单梁法
大角度
skew continuous box girder
spatial grillage method
plane single beam method
big angle
