湖北燕矶长江大桥动力特性研究  

Research on Dynamic Property of Yanji Changjiang River Bridge in Hubei Province

作　　者：丁少凌 李志刚[2] 蔡春声[1] DING Shaoling;LI Zhigang;CAI Chunsheng(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China;CCCC Second Highway Consultants Co.,Ltd.,Wuhan 430056,China)

机构地区：[1]长沙理工大学土木工程学院,湖南长沙410114 [2]中交第二公路勘察设计研究院有限公司,湖北武汉430056

出　　处：《桥梁建设》2023年第5期9-16,共8页Bridge Construction

基　　金：国家自然科学基金项目(52178452,52178450)。

摘　　要：湖北燕矶长江大桥为主跨1860 m的双层桥面钢桁梁悬索桥,采用内外缆不同垂跨比四主缆布置方式,内主缆跨度布置为(550+1860+450)m,跨中垂度142.445 m,垂跨比1/13.058;外主缆跨度布置为(510+1860+410)m,跨中垂度153.345 m,垂跨比1/12.130。为研究这种新型大跨悬索桥的动力特性,采用ANSYS软件建立大桥成桥状态有限元模型,在内缆垂跨比不变的前提下,仅改变外缆垂跨比,分别取1/13.058、1/12.700、1/12.400、1/12.130(最终方案)、1/11.800、1/11.500、1/11.200,探讨桥梁动力特性随外缆垂跨比的变化规律,并分析主缆锚固方式对桥梁动力特性的影响,最后对四主缆最终方案与不同垂跨比[1/13.058,1/12.130]双主缆方案的动力特性进行对比分析。结果表明:外缆垂跨比从1/12.700增大至1/11.500,可使桥梁侧向刚度和扭转刚度有所提升;桥梁一阶反对称和正对称竖弯自振频率随外缆垂跨比的增大而表现出先增大后减小的规律,其中一阶正对称竖弯自振频率以四主缆最终方案为最大;主缆锚固方式对桥梁动力特性影响很小;四主缆最终方案较垂跨比在[1/13.058,1/12.130]范围内的双主缆方案具有更高的竖向刚度。综合分析表明,在塔高受限条件下采用内缆垂跨比1/13.058、外缆垂跨比1/12.130的四主缆方案具有更优的动力特性。The Yanji Changjiang River Bridge in Hubei Province is a suspension bridge with a main span of 1860 m.Consisting of steel trusses,the stiffening girder of the bridge accommodates two levels of decks.The bridge features its four main cables,where the outer pair and inner pair of main cables exhibit different sag-to-span ratios.In particular,the inner main cables are arranged in three spans of 550,1860 and 450 m,with a sag of 142.445 m measured at the midspan of the central span,resulting in a sag-to-span ratio of 1/13.058.While the outer main cables are laid out in three spans of 510,1860 and 410 m,with a sag of 153.345 m measured at the midspan of the central span,creating a sag-to-span ratio of 1/12.130.The dynamic property of the bridge was numerically simulated in ANSYS.Assuming that the sag-to-span ratio of the inner main cables was certain,the influence of the sag-to-span ratio of outer main cables on the dynamic property of the bridge was calculated,in which seven values of sag-to-span ratios,including 1/13.058,1/12.700,1/12.400,1/12.130,1/11.800,1/11.500 and 1/11.200,were considered.The influence of main cable anchorage was also investigated.The dynamic property of the suspension bridge with four main cables were compared with that of the suspension bridge with two main cables of a sag-to-span ratio of 1/13.058 as well as the suspension bridge with two main cables of a sag-to-span ratio of 1/12.130,respectively.As per the analysis,when the sag-to-span ratio rises from 1/12.700 to 1/11.500,increased lateral and torsional stiffness of the bridge are observed.As the sag-to-span ratio of the outer main cables increases,the natural frequencies of first vertical symmetrical and asymmetrical modes show sign of decreasing after an increase,when the sag-to-span ratio is at 1/12.130,the natural frequency of the first vertical symmetrical mode of the four-main-cable solution is the biggest.The main cable anchorage exerts minor influence on the dynamic property of the bridge.When the sag-to-span ratios of the pair of

关 键 词：悬索桥 四主缆 不同垂度主缆 垂跨比 主缆锚固方式 动力特性 有限元法 

分 类 号：U448.25[建筑科学—桥梁与隧道工程] U443.38[交通运输工程—道路与铁道工程]