【作者】 李天飞；

【导师】 张哲；

【作者基本信息】 大连理工大学 ， 桥梁与隧道工程， 2009， 博士

【摘要】 自锚式悬索桥以其美观的外形、良好的适应性和适中的经济指标等优点,在国内得到迅速发展并被大量设计采用。本文结合交通部西部课题（No.200631882350）及教育部博士点新教师基金（No.20070141073）中的关键问题,以金州海湾大桥为工程背景,对其自振特性、地震响应、静风响应和颤振稳定性展开研究,主要工作及结论如下:（1）对金州海湾大桥和与之具有相同结构参数的地锚式悬索桥模型进行了自振特性分析,并研究了结构参数变化对两类悬索桥自振特性的影响。结果表明:自锚式悬索桥的主梁竖向频率要低于地锚式悬索桥,而纵飘频率比地锚式悬索桥大38%,两类悬索桥主梁侧向、主塔横向、索振、主梁扭转频率比较接近;恒载、加劲梁刚度、主缆抗拉刚度的变化对结构的频率影响较大,而桥塔刚度和吊杆抗拉刚度变化的影响很微小。（2）应用时程分析方法,对金州海湾大桥进行了抗震分析,讨论了行波输入、桩-土-结构相互作用和竖向地震动分量对地震反应的影响。通过研究发现对自锚式悬索桥进行抗震分析时,以上各种因素比较重要,不可忽略。（3）采用每级风速下迭代一定次数考虑静风荷载非线性的方法,计算分析了金州海湾大桥在静风作用下,桩基础、缆索系统风荷载等因素对主梁、桥塔静风位移、静风失稳风速和振动频率随风速演变特点。结果表明:桩基础对主梁和桥塔侧向位移响应影响较大;缆索系统所受的横向风荷载在全部横向风荷载中所占超过20%,所占比例较大;不考虑主梁附加攻角,会对位移响应和静风失稳风速带来不可忽略的误差。（4）考虑结构参数的不确定性,应用响应面法系统研究了金州海湾大桥在静风作用下,材料、几何尺寸的随机性对主梁主跨中点位移的影响,并讨论了参数拟合精度的影响。结果表明:取均值加减方差的倍数不大于1.96作为样本点时参数拟合误差很小;几何尺寸、材料特性等的变异对自锚式悬索桥在静风作用下的位移响应影响较大。（5）基于桥梁三维颤振分析理论,利用ANSYS软件实现了能同时考虑静风作用、缆索上的气动力和缆索振型等多种因素影响的全桥三维颤振分析。重点研究了初始攻角、静风荷载作用等因素对自锚式悬索桥颤振稳定性的影响。结果表明:不同初始攻角下,颤振临界风速相差较大,+3°攻角为颤振最不利状态;考虑静风荷载作用后,结构自振特性变化对颤振稳定性影响很小,主梁的附加攻角则影响显著;缆索上气动力和缆索振型使颤振稳定性提高;在各气动导数中,以耦合气动导数A₁^*、H₃^*和非耦合气动导数A₂^*、A₃^*对颤振的影响最为显著,其他几个气动导数对颤振影响相对较小。更多还原

【Abstract】 Many self-anchored suspension bridges have been designed and constructed for their esthetic appearance, favorable adaptablily, economical performance and other notable advantages. Combined with key problems of Western Issues of Ministry of Communications （No: 200631882350） and Doctoral Discipline for New Teachers Fund of Ministry of Education （No: 20070141073）, a self-anchored suspension bridge—Jinzhou Strait Bridge is taken as an example, the natural vibration characteristics, seismic response, aerostatic response and flutter stability of the bridge were researched. The main work and conclusions are as follows:（1） Natural vibration characteristics of Jinzhou Strait Bridge and the ground-anchored suspension bridge model, which has the same structural parameters as Jinzhou Strait Bridge, is calculated. Furthermore, the influence of natural vibration changed by varied structure parameters is also studied. The results show that the main girder vertical frequencies of self-anchored suspension bridge is lower than the ground-anchored suspension bridge, while the longitudinal drift frequency of the former exceedes the latter 38%. Their lateral and torsion frequency of main girder , horizontal frequency of main tower, cable vibration frequency is closer. The changes of dead loads,stiffening stiffness and tensile stiffness of the main cable on structural changes in the frequency is greater ,while the changes of stiffness of main tower and tensile stiffness on structural changes in the frequency is very small.（2） Seismic response analysis for Jinzhou Strait Bridge is completed with time history method. Traveling seismic excitations, pile-soil-structure interaction and vertical excitations are discussed. The results show the above-mentioned factors are more important, which can not be ignored.（3） A certain number of iterations under each wind speed are adopted to consider static wind load non-linear. The influence of some factorson deck displacements, pylon displacements, aerostatic divergence wind velocities and mode frequencies are comprehensively investigated, such as the pile foundation rigidity, cable segmentations. The foundation rigidity has a greater impact on the lateral displacement of the beam and tower. Among the total wind loads on structure, the contribution of cables exceeds 20%.The aerostatic divergence wind velocity and dis placements will be overestimated if the added attack angle of the deck is omitted. （4） In order to consider the uncertainty of structural parameters,taken Dalian Jinzhou Strait Bridge as an example,the static wind displacement effect at the mid-point of main span caused by randomness of material character and geometry dimension is studied in detail with Response Surface Method. The accuracy of parameter fitting is also discussed. The results show that the variation of material and geometric dimension have a greater impact on displacement of self-anchored suspension bridge under static wind.（5） Based on three-dimensional flutter analysis theory of bridge, three-dimensional flutter analysis is conducted by using ANSYS software. Many factors simultaneously such as the influences of static wind action, self-excitation force of cables and modes of cables can be considered simultaneously in flutter analysis. Effects of some factors such as the initial attack angle and the static wind action on flutter stability of self-anchored suspension bridge are specially studied. The results show that the flutter critical wind speed is different under various initial angle of attack and the lowest wind speed under angle of attack is 3 deg; the changes in vibration characteristics have little effect on the flutter stability by Considering static wind, while angle of attack of main beam has significant effects; self-excitation force of cables and modes of cables can improve flutter stability;Coupled aerodynamic derivatives A₁^* , H₃^* and non-coupled aerodynamic derivatives A₂^*, A₃^* have significant effect on flutter stability and other derivatives have small effect relatively.更多还原