1-80m混凝土系杆拱有限元分析研究

研究目的:贵广铁路黄沙河桥采用1-80 m预应力混凝土系杆拱桥,系国内最大跨度的预应力混凝土系杆拱桥(混凝土拱肋),其箱宽较宽,采用单向多室结构。有效宽度、边中腹板厚度比例等均没有规范依据可查,横向环框简化计算模型没有相关的依据。本文利用midas FEA软件对80m系杆拱桥进行实体计算分析,确保结构安全,并对结构尺寸、钢束布置等进行一些探讨。研究结论:梁部的混凝土应力处于合理的水平,结构安全可靠;拱脚位置梁体正应力横向分布不均匀,远离拱脚的梁体截面正应力分布较为均匀;多腹板以及密横隔板形成的纵横向隔板体系增强了梁部结构整体性,箱梁横向位移差最大值仅仅为0.51 mm;设置拱脚竖向预应力能够有效减少拱脚与梁体交界面混凝土的主拉应力,增强交接面的抗剪能力,是必须的。

Finite Element Analysis and Research of 1 - 80 m Prestressed Concrete Tied Arch Bridge

Research purposes: 1-80 m prestressed concrete tied arch was used in yellow sand river bridge of guiyang-guangzhou railway,which is the largest prestressed concrete tied arch span(concrete arch)in china,with wide single box and three grid.There is no Clearly defined of The Effective width and thickness ratio of side and middle web,the same as Simplified model for horizontal ring box.According to 80m tied arch bridge’s 3D finite element analysis by the midas FEA software was done for structural safty,and also for the disscusion of the structure’s size and prestressing layout. Research conclusions:The concrete stress of the bridge is at a reasonable level,the structure is safe and reliable;The distribution of the beam normal stress is non-uniform,beam stress distribution in section away from the arch foot is more uniform;The vertical and horizontal diaphragm separator system,which was made by the multiple webs and multi-diaphragm plates,can make a strong overall performance of the bridge structure of the Department,the maximum Transverse displacement difference is only 0.51mm;It is necessary to set vertical prestressed tendons for the foot of the arch which can reduce the interface with the concrete beam principal tensile stress effectively,and enhance the interface shear strength.