带外伸横梁的匝道桥上部结构设计研究

发布时间：2019-06-19 07:22

【摘要】：随着我国城市的交通建设进一步的发展，互通立交桥梁、高架桥得到了广泛的应用。为实现交通转向功能的匝道，由于其连接的主干线与交叉线间较大的高程差，往往需要设计为匝道桥梁。同时在城市中受到地形、地物、地下管线等多方面因素的影响，为了使匝道桥设计满足路线平面及道路建筑界限净空的要求，在关键节点处需要设置门架式横梁跨越桥下的道路。本文对带外伸横梁的匝道桥的设计计算理论与方法作了初步的介绍，分析了影响此类桥梁上部结构受力的主要因素，并结合惠州金恺大道A匝道4x30m预应力混凝土连续箱梁桥为实例进行设计研究，主要研究内容有：（1）由于门式横梁的存在，主梁的弯扭耦合效应更为复杂，分析研究主梁在自重及整体温度等荷载工况及荷载组合下的内力分布情况。（2）因约束支座布置情况的不同，在荷载工况作用下对纵向主梁的内力分布情况及PSC截面设计方面的影响，以及支承反力的变化。（3）根据现行桥梁抗震设计规范，对比纵向固定支座设置的不同，在地震工况作用下的支反力变化。通过Midas Civil有限元软件计算分析，总结了此类桥梁因外伸横梁的存在，对纵向主梁内力分布、截面设计、支承反力影响：（1）由于大外伸横梁的存在，使得大横梁处的主梁负弯矩减少约10%、扭矩值增加约一倍、剪力值无大变化。（2）由于纵向主梁与大横梁的相互制约，在整体温度工况下将产生较大的水平支反力，，对于下部桥墩以及基础起不利作用。（3）纵向固定支座建议设置在外伸大横梁处，同时需重视对下部结构的抗震设计。通过以上的结论可以为今后在类似匝道桥设计和施工中提供一些参考。
[Abstract]:With the further development of urban traffic construction in China, interchange bridges and viaducts have been widely used. In order to realize the ramp of traffic steering function, because of the large elevation difference between the main line and the crossing line, it is often necessary to design the ramp bridge. At the same time, affected by terrain, ground objects, underground pipelines and other factors in the city, in order to make the ramp bridge design meet the requirements of route plane and road building boundary clearance, it is necessary to set up a portal beam across the road under the bridge at the key node. In this paper, the design and calculation theory and method of ramp bridge with extended beam are introduced, and the main factors affecting the force of superstructure of this kind of bridge are analyzed, and the design and research of 4x30m prestressed concrete continuous box girder bridge on ramp A of Jinkai Avenue in Huizhou are carried out as an example. The main research contents are as follows: (1) due to the existence of portal beam, the coupling effect of bending and torsional of main beam is more complex. The internal force distribution of the main beam under load conditions such as self-weight and overall temperature and load combination is analyzed and studied. (2) due to the different arrangement of constraint supports, the influence on the internal force distribution of longitudinal main beam and the design of PSC section under the action of load condition, as well as the change of support reaction force. (3) according to the current seismic design code of bridge, the change of support force under seismic working condition is compared with the different setting of longitudinal fixed support. Through the calculation and analysis of Midas Civil finite element software, this paper summarizes the influence of the existence of this kind of bridge on the internal force distribution, section design and supporting reaction force of the longitudinal main beam: (1) because of the existence of the large extended beam, the negative bending moment of the main beam at the large beam is reduced by about 10%, the torque value is about doubled, and the shear value has no great change. (2) due to the mutual restriction between the longitudinal main beam and the large beam, there will be a large horizontal support reaction force under the overall temperature condition, which will play an adverse role in the lower pier and foundation. (3) it is suggested that the longitudinal fixed support should be installed at the extended beam, and the seismic design of the lower structure should be paid attention to at the same time. The above conclusions can provide some references for the design and construction of similar ramp bridges in the future.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U442.5

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