三塔两跨悬索桥施工过程动力特性研究
发布时间：2018-11-27 15:54
【摘要】：2012年底,第一座千米级的三塔两跨悬索桥——泰州长江公路大桥建成通车后,在国内外掀起了对多塔多跨悬索桥的研究热潮。随后,马鞍山长江公路大桥和武汉鹦鹉洲长江大桥也分别在2013年和2014年底建成通车。然而由于对多塔多跨悬索桥的研究还未成熟,特别在施工状态下其结构尚未成型时,受到强风作用时的危险程度可能比成桥下更大。为研究新型三塔两跨悬索桥结构施工阶段的振动特性,分析出其振动过程中不同于传统悬索桥的性质,以便了解其施工过程中的动力稳定性问题,并进一步提出解决措施。对三塔两跨悬索桥施工阶段建立了有限元模型。通过Irvine自由振动线性理论验证了模型的正确性。在定义局部和全局振型的基础上,分析了三塔两跨塔索系统和塔索梁系统的模态特征。研究表明三塔两跨塔索系统仍保持着各结构部分独立的模态特性,但又具有其独特的模态属性。在低阶频率下,系统振动可理想的分为非耦合的面内和面外振动,并产生了一些新的特征频率和振型。低阶边跨索的振型耦合了高阶主跨索的振型,在一些特定的模态属性和组合下,将分别产生相应局部和全局面内面外振动。各个吊装阶段梁段受主缆的影响较大,索的面外、面内振动分别引发了梁段的摆动、提升和扭转模态。随着梁段数量的增加,各种模态频率产生不同程度的变化导致模态超越现象,反映了主梁成型过程中结构动力特性的不稳定性。为改善吊装过程中结构的抗风稳定性,本文采用设置抗风缆的方法,有效的提高了加劲梁的颤振临界风速。
[Abstract]:At the end of 2012, the first three-tower and two-span suspension bridge, Taizhou Yangtze River Highway Bridge, was completed and opened to traffic. Subsequently, the Maanshan Yangtze River Highway Bridge and Wuhan Paraozhou Yangtze River Bridge were completed and opened to traffic in late 2013 and 2014 respectively. However, because the research of multi-tower and multi-span suspension bridge is not mature, especially when the structure is not formed under the construction state, the dangerous degree of the bridge under the action of strong wind may be greater than that under the bridge. In order to study the vibration characteristics of a new type of three-tower two-span suspension bridge during construction, the characteristics different from the traditional suspension bridge in the vibration process are analyzed, in order to understand the dynamic stability problem in the construction process and further put forward the solving measures. The finite element model of three-tower two-span suspension bridge is established. The correctness of the model is verified by Irvine free vibration linear theory. Based on the definition of local and global vibration modes, the modal characteristics of three-tower two-span tower cable system and tower girder system are analyzed. The study shows that the three-tower and two-span tower cable system still maintains the independent modal characteristics of each part of the structure, but it has its unique modal properties. At low frequency, the vibration of the system can be divided into uncoupled in-plane and off-plane vibration, and some new characteristic frequencies and modes are generated. The vibration modes of the low-order side span cables are coupled with those of the higher-order main-span cables. Under some specific modal properties and combinations the corresponding local vibration and the in-plane vibration will be generated respectively. The influence of the main cable on the beam segment in each stage of hoisting is great. The out-of-plane and in-plane vibration of the cable causes the swinging, lifting and torsional modes of the beam section respectively. With the increase of the number of beam segments, various modal frequencies produce varying degrees of modal transcendence, which reflects the instability of the dynamic characteristics of the structure during the forming process of the main beam. In order to improve the wind-resistant stability of the structure during hoisting, the method of setting wind-resistant cable is used in this paper, which effectively improves the critical flutter velocity of stiffened beam.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.4;U448.25
本文编号：2361358
[Abstract]:At the end of 2012, the first three-tower and two-span suspension bridge, Taizhou Yangtze River Highway Bridge, was completed and opened to traffic. Subsequently, the Maanshan Yangtze River Highway Bridge and Wuhan Paraozhou Yangtze River Bridge were completed and opened to traffic in late 2013 and 2014 respectively. However, because the research of multi-tower and multi-span suspension bridge is not mature, especially when the structure is not formed under the construction state, the dangerous degree of the bridge under the action of strong wind may be greater than that under the bridge. In order to study the vibration characteristics of a new type of three-tower two-span suspension bridge during construction, the characteristics different from the traditional suspension bridge in the vibration process are analyzed, in order to understand the dynamic stability problem in the construction process and further put forward the solving measures. The finite element model of three-tower two-span suspension bridge is established. The correctness of the model is verified by Irvine free vibration linear theory. Based on the definition of local and global vibration modes, the modal characteristics of three-tower two-span tower cable system and tower girder system are analyzed. The study shows that the three-tower and two-span tower cable system still maintains the independent modal characteristics of each part of the structure, but it has its unique modal properties. At low frequency, the vibration of the system can be divided into uncoupled in-plane and off-plane vibration, and some new characteristic frequencies and modes are generated. The vibration modes of the low-order side span cables are coupled with those of the higher-order main-span cables. Under some specific modal properties and combinations the corresponding local vibration and the in-plane vibration will be generated respectively. The influence of the main cable on the beam segment in each stage of hoisting is great. The out-of-plane and in-plane vibration of the cable causes the swinging, lifting and torsional modes of the beam section respectively. With the increase of the number of beam segments, various modal frequencies produce varying degrees of modal transcendence, which reflects the instability of the dynamic characteristics of the structure during the forming process of the main beam. In order to improve the wind-resistant stability of the structure during hoisting, the method of setting wind-resistant cable is used in this paper, which effectively improves the critical flutter velocity of stiffened beam.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.4;U448.25
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相关期刊论文 前3条
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，本文编号：2361358
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