安庆铁路长江大桥受力性能研究

【作者】 江名宝；

【导师】 叶梅新；

【作者基本信息】 中南大学 ， 土木工程， 2011， 硕士

【摘要】 在建中的安庆铁路长江大桥主桥为(101.5+118.5+580+217.5+159.5+116)m六跨双塔四线铁路连续钢桁梁斜拉桥,是目前我国最大跨度的铁路专用斜拉桥。该桥采用正交异性整体钢桥面结构,受力情况复杂。本文采用有限单元法对该桥的受力特性作了系统的研究,主要工作和研究成果如下：1、对特大钢桁梁正交异性板整体桥面斜拉桥的有限元模拟方法进行了研究,建立了两个不同的全桥空间板梁有限元模型,分别用于恒载、最不利活载和附加力作用下的计算。2、研究了恒载、最不利活载和各种主力组合下的受力性能,结果表明：最不利活载作用下桥梁挠跨比为1/732,刚度满足要求；各主力组合作用下,主桁、钢桥面、主塔和斜拉索等的应力都满足设计规范。3、研究了附加力作用下全桥的受力特性,包括两种温度荷载、风荷载和列车制动力,结果表明：温度荷载、风荷载对下弦杆和纵横梁应力影响较大,对桥梁其他构件的应力影响较小,列车制动力对桥梁的应力和位移等影响较小,主力和附加力共同作用下桥梁所有构件均在设计规范允许范围内。4、研究了斜拉索索重和拉索的垂度效应,结果表明：对于像安庆桥这样特大跨度的斜拉桥,斜拉索的索重很大,达4300多吨,对结构挠度影响较大,必须考虑；垂度效应对结构应力和挠度影响较小。本文的研究成果为安庆长江大桥的设计提供了依据,对其他类似大型复杂的钢—混凝土组合结构斜拉桥也有参考价值。更多还原

【Abstract】 Anqing Changjiang River Bridge is a six-span continous steel truss girder cable-stayed bridge with span arrangement (101.5+118.5+580+ 217.5+159.5+116)m. It is a railway-exclusive cable stayed bridge with the longest span in China up to now.Orthotropic integral steel bridge panel structure is adopted for the bridge floor system, the stress situation is complicated. The mechanical characteristics of the bridge are studied in this paper, the main research tasks are as follows:1、The FEA simulative method for the extra large steel truss cable-stayed bridge with orthotropic integral panel is studied. Two different FEA models for the whole bridge are established to calculate the dead load case and the worst-case of living load together with additional forces case respectively.2、The mechanical properties of the whole bridge under dead load、worst-case of living load、combination load of all kinds of main forces are studied. The results show that:the deflection-span ratio of the bridge under worst-case of living load is 1/732; the rigidity of the bridge satisfies the requirements; the main trusses、steel panels、pylons and cables satisfy the design specifications when the combination load of all kinds of main forces acts on the bridge.3、The mechanical properties of the whole bridge under additional forces (including temperature load、wind load、train braking load) are studied, the results show:temperature load and wind load affect the lower chords、girders and the cross beams a lot, but other members of the bridge slightly. Train braking load affects the internal forces and displacements of the bridge slightly. All members of the bridge are within the design bounds when the main forces and additional forces act on the bridge together.4、The cable weight and the cable sag effect are studied in this paper, the results show:for a cable-stayed bridge with such an extra span as Anqing Changjiang River Bridge,cables are very heavy, weighing as much as 4300 tons, thus they affect the deflection of the bridge significantly, which shoud be counted into consideration; the cable sag effect influences the structure stress and deflection slightly.The research results of this paper provide basis for the design of Anqing Changjiang River Bridge, and it is also of reference value for other similar huge and complicated cable-stayed brige of steel-concrete composite structure.更多还原