【作者】 罗浩；

【导师】 郭向荣；

【作者基本信息】 中南大学 ， 桥梁与隧道工程， 2011， 博士

【摘要】 目前,日本、法国、德国等国的高速铁路桥梁通常以中小跨度为主,主要结构形式包括简支梁和连续梁,与简支梁相比,连续梁具有整体性强,梁缝少,梁端变形折角小,轨面平顺度高等优点,因此连续梁应用于高速铁路大跨度桥梁具有较强的竞争力。高速铁路采用全封闭式行车,要求轨道具有高平顺性,并且对线路平纵面参数限制严格,预应力混凝土桥梁由于徐变因素会影响桥面的轨道不平顺,若要保证桥面轨道的平顺性,就必须了解轨道铺设后桥梁的徐变变形对高速列车走形性的影响。本文以武广客运专线四座典型高速铁路大跨度预应力混凝土连续梁桥为研究对象,就大跨度预应力混凝土连续梁的徐变变形对高速列车的走形性影响进行研究。本文取得以下主要研究成果：(1)采用大型通用软件计算了四座典型高速铁路大跨度预应力混凝土连续梁桥的徐变变形,并将计算值与实测值进行了对比分析。(2)采用较高精度的箱梁梁段有限元法建立了高速列车一桥梁系统动力学模型,对四座典型高速铁路大跨度预应力混凝土连续梁桥进行了详细的动力学仿真分析,计算结果表明：在所有计算工况下,四座桥梁的动力响应均满足要求；各车的车体竖、横向振动加速度均满足限值要求,列车行车安全性和舒适性均满足要求。(3)计算了桥梁徐变变形对列车走形性的影响,计算结果表明：当高速列车通过时,以上四座典型高速铁路大跨度预应力混凝土连续梁桥的后期徐变变形对桥梁的动力响应影响极小,对高速列车的走行性从定性上也没有造成明显的影响,但从数值上对高速列车的轮重减载率、车体竖向振动加速度及竖向舒适度指标有一定程度的增大。(4)分析了大跨度预应力混凝土连续梁桥后期徐变变形的容许值,分析结果表明：相关规范所规定的无砟轨道桥梁的徐变限值10mm对大跨度预应力混凝土连续梁桥是可以放松的。(5)综合国内外关于铁路桥梁刚度的评价标准,根据我国国情,提出适合我国高速铁路大跨度桥梁刚度的计算方法,并对高速铁路大跨度预应力混凝土连续梁的刚度合理值提出具体的建议,为同类结构的设计、施工提供参考。更多还原

【Abstract】 At present, medium and short span bridges are primarily adopted on high-speed railway in Japan, France, Germany and other countries. The main structure forms include simply-supported beam bridges and continuous beam bridges. Compared with simply-supported beam bridges, continuous beam bridges have many advantages such as strong integrity, less beam joints, small fold angles, and high performance of flatness and smoothness of track. As a result, continuous beam bridges are greatly applied in high-speed railway. Due to the fully closed travelling of high-speed railway, the longitudinal and plane parameters of line are strictly restricted. And the high performance of flatness and smoothness of track is also requested. The smoothness of rail is influenced by the creep of prestressed concrete bridges. In order to ensure the smoothness of track, it is necessary to understand and control the creep deformation of bridges after laying ballastless track. Based on the four typical long-span prestressed concrete continuous beam bridges used on Wuhan-Guangzhou passenger special line, the paper gives an analysis on the impacts of post creep deformation of long-span prestressed concrete continuous beam bridges on high-speed train running performance. The main contents in the paper are as follows:(1) The creep deformation of four typical long-span prestressed concrete continuous beam bridges are calculated by finite element analysis. And the numerical results are compared with the measured data.(2) The dynamic models of the above four train-bridge systems are established by adopting a finite element method of box beam segments. The detailed calculation data are analyzed with dynamic simulation. The result indicates:the vibration responses of the above four train-bridge systems are within their permission values; the lateral and vertical maximum acceleration of car bodies are all in the range of allowable values; the safety, comfort and stability can be satisfied in the range of the design speeds.(3) The impacts of post creep deformation of the four long-span prestressed concrete continuous beam bridges on high-speed train running performance are analyzed. The result shows:when the high-speed train passes through the bridge, the creep deformations of the above four bridges have little effect on the dynamic response of bridges, and cause no apparent effect on the running performance of high-speed trains qualitatively. But numerical results show that the wheel load variance, the vertical vibration acceleration and vertical comfort index of high-speed trains will increase to a certain extent.(4) The reasonable values of post creep deformation of long-span prestressed concrete continuous beam bridges are analyzed. The results show that the 10mm creep deformation limit of ballasted track bridges could be relaxed in the provisions for design.(5) In summarization of the literatures and references about evaluation criteria on stiffness limit of railway bridges in domestic and abroad, suggestions are made for stiffness limit of long-span prestressed concrete continuous beam bridges on high-speed railway. The results provide a reference for design and construction of such kind of bridges.更多还原