闽江桥道碴桥面槽形梁结构受力分析

【作者】 胡俊；

【导师】 郭向荣；

【作者基本信息】 中南大学 ， 桥梁与隧道工程， 2007， 硕士

【摘要】 高速铁路大跨钢桁梁桥结构设计中，其桥面结构的设计，是一项重要内容。新建铁路福州至厦门线的闽江特大桥是一座(99+198+99)m的连续钢桁梁柔性拱桥。闽江桥通过支承在钢横梁上的槽形梁实现道碴桥面，槽形梁纵向设计成两跨一联，横向为两侧带翼板的“ш”形截面。全桥共18联槽形梁。槽形梁作为道碴桥面具有建筑高度低，降噪效果好，断面空间利用率高，外形美观，综合造价低等特点。本文以闽江桥为背景，进行了其桥面槽形梁的结构受力分析。主要做了以下几个方面的工作：①利用专用软件MIDAS建立了单片槽形梁的实体模型，详细探讨了单片槽形梁弹性支撑于地面时，其在自重，预应力，二期恒载以及活载作用下的变形，纵向正应力，剪力滞后效应，横向正应力，竖向正应力，以及水平剪应力的空间分布规律。②建立了槽形梁的空间梁格模型，并与实体模型进行了对比分析，验证了梁格模型具有较高的精度。进而将槽形梁的梁格模型应用于全桥结构分析，利用全桥整体模型，分析了槽形梁在自重、预应力、二期恒载以及活载作用下的变形及受力情况。③在全桥整体分析的结果中，发现槽形梁的拉应力超过了混凝土的容许应力，因此必须对槽形梁的受力进行优化。文中采用结构物调值的影响矩阵法，通过调整支座高度来改变槽形梁的支座反力，达到了优化槽形梁受力的目的，将槽形梁的拉应力值控制在了容许范围。更多还原

【Abstract】 The design of the bridge floor of the long span high way steel truss bridge is very important. The Minjiang River Bridge of the new railway line from Fuzhou to Xiamen is a (99+198+99) m continuous steel truss Bridge with flexible arch. The ballast deck of Minjiang River Bridge is achieved by the use of the trough girder supporting on the steel cross beam. And the section of trough girder is designed as "?"type.There are 18 trough girders on the bridge. And the trough girder has the advantages of small building height, a low noise effects, good space utilization of cross-section, and graceful appearance, low cost in total, and so on. Based on the Minjiang River bridge as a backdrop, the analysis of the Minjiang River Bridge deck trough girder is made in this paper. The main parts are as follows:①. Using the special software MIDAS, an entity model of the single trough girder is established, and made numerical analysis for it by entity element method. It Detailed studies a singer trough girder’s spatial distribution of longitudinal normal stress, shear lag effect, transverse normal stress, vertical normal stress, and the horizontal shear stress under the action of dead load, prestressing force ,superimposed dead load and live load while supporting on the ground.②.It establishes a space gridiron model of trough girder, and adds it to the model of the whole bridge in this paper. And the analyses under the action the entire bridge self-weight, prestressing force superimposed dead load and live load are made respectively.③.The results of the whole bridge shows that the trough girder in the bridge are overstressed.So the stress of trough girder must be optimized . In this paper we apply the method of impact matrix ,and change the reactions of the trough girder by alter the height of the bearing in order to optimize the stress state of the trough girder.更多还原