地震和台风作用下多塔斜拉桥横向结构体系综合控制方法

发布时间：2019-05-14 00:51

【摘要】：多塔斜拉桥横向结构地震、台风响应比较复杂。在斜拉桥的横桥向,一般采用抗风支座来制约主梁与索塔的相对运动。这种“刚性”的约束体系通常使得斜拉桥的横桥向地震、台风响应较大。本文以嘉绍大桥为工程背景,分析研究了不同横向结构体系地震、台风响应特点,并针对横向全自由体系下提出了多组被动减震(振)控制方法并进行比较分析,最后利用响应面法和非线性约束优化算法给出了优化减震(振)方案。本文的主要工作和成果如下：1.基于Ansys软件平台建立了嘉绍大桥有限元模型,分析了地震、台风作用下不同横向结构体系有限元模型的响应特征。研究结果表明：(1)地震作用下横向全自由体系的主梁横向位移反应较大,而塔底横向内力反应和塔顶横向位移反应均较小；横向全固结体系的塔底横向内力反应和塔顶横向位移反应较大,而主梁横向位移反应则较小。(2)台风作用下横向全自由体系的墩底横向内力较大,主梁横向位移亦较大,而塔底横向剪力则较小；横向全固结体系的塔底横向剪力较大,而墩底横向内力以及主梁横向位移则较小。此外,塔梁横向连接方式对塔底横向弯矩、塔顶横向位移等风振反应影响较小。2.针对横向全自由体系提出了与之相适应的减震(振)方案,分析比较了不同减震(振)方案的减震(振)效果。结果表明：(1)地震作用下塔梁间设置弹性拉索或粘滞流体阻尼器可以显著减小主梁横向位移响应,但对塔底横向内力及塔顶横向位移有一定的放大作用,粘滞阻尼器减震效果优于弹性拉索;(2)台风作用下粘滞阻尼器和弹性拉索都可以显著减小辅助墩的横向内力反应以及主梁横向位移反应,此外采用粘滞阻尼器可以有效降低塔底横向内力反应以及塔顶横向位移反应。减震(振)方案设置合理的装置参数可以取得较好的控制效果。为了进一步地控制台风作用下主梁横向位移,采用弹性拉索+粘滞流体阻尼器联合控制方案,两种装置可以协同工作,取得更好的控制效果。3.利用响应面法及非线性约束优化算法对地震台风作用下横向结构体系减震(振)方案进行了优化分析。分析结果表明：响应面法拟合所得减震(振)响应面效果较为理想,可用于地震、台风响应控制的优化设计中；利用非线性约束优化算法进行减震(振)方案优化分析,并得到了优化结果。针对多塔斜拉桥地震、台风各自响应特点及控制目标,对控制方案进行调整改进,能够同时有效控制多塔斜拉桥横向结构体系地震和台风响应,得到地震和台风作用下多塔斜拉桥横向结构体系综合控制方法。
[Abstract]:The response of typhoon to transverse structure earthquake of multi-tower cable-stayed bridge is more complex. In the transverse direction of cable-stayed bridge, wind support is generally used to restrict the relative motion of the main beam and the cable tower. This kind of "rigid" constraint system usually makes the transverse bridge of cable-stayed bridge seismic and typhoon response is large. In this paper, based on the engineering background of Jiashao Bridge, the characteristics of earthquake and typhoon response of different transverse structure systems are analyzed and studied, and several groups of passive shock absorption (vibration) control methods are proposed and compared under the transverse fully free system. Finally, the optimal damping (vibration) scheme is given by using the response surface method and nonlinear constrained optimization algorithm. The main work and achievements of this paper are as follows: 1. Based on Ansys software platform, the finite element model of Jiaxao Bridge is established, and the response characteristics of finite element models of different transverse structure systems under earthquake and typhoon are analyzed. The results show that: (1) the transverse displacement response of the main beam of the transverse free system under earthquake is larger, while the transverse internal force response of the bottom of the tower and the transverse displacement response of the top of the tower are small; The transverse internal force response and the transverse displacement response of the tower top of the transverse fully consolidated system are larger, while the transverse displacement response of the main beam is smaller. (2) the transverse internal force of the bottom of the transverse fully free system is larger and the transverse displacement of the main beam is also larger under the action of typhoon. However, the transverse shear force at the bottom of the tower is smaller. The transverse shear force at the bottom of the tower is larger, while the transverse internal force at the bottom of the pier and the transverse displacement of the main beam are smaller. In addition, the transverse connection mode of tower beam has little effect on wind-induced vibration response such as transverse bending moment of tower bottom and transverse displacement of tower top. A corresponding damping (vibration) scheme is proposed for the transverse fully free system, and the damping (vibration) effects of different damping schemes are analyzed and compared. The results show that: (1) the transverse displacement response of the main beam can be significantly reduced by setting elastic cables or viscous fluid dampers between the tower beams under earthquake, but the transverse internal force at the bottom of the tower and the transverse displacement at the top of the tower can be magnified to a certain extent. The damping effect of viscous dampers is better than that of elastic cables. (2) both viscous dampers and elastic cables under typhoon can significantly reduce the transverse internal force response of auxiliary piers and the transverse displacement response of main beams. In addition, viscous dampers can effectively reduce the transverse internal force response at the bottom of the tower and the transverse displacement response at the top of the tower. Good control effect can be obtained by setting reasonable device parameters in shock absorption (vibration) scheme. In order to further control the transverse displacement of the main beam under the action of typhoon, the two devices can work together and achieve better control effect by using the joint control scheme of elastic cable viscous fluid dampers. The response surface method and nonlinear constrained optimization algorithm are used to optimize the shock absorption (vibration) scheme of transverse structure system under the action of earthquake and typhoon. The analysis results show that the effect of shock absorption (vibration) response surface fitted by response surface method is ideal and can be used in the optimal design of earthquake and typhoon response control. The nonlinear constrained optimization algorithm is used to optimize the damping (vibration) scheme, and the optimization results are obtained. According to the earthquake and typhoon response characteristics and control objectives of multi-tower cable-stayed bridge, the control scheme is adjusted and improved, which can effectively control the seismic and typhoon response of the transverse structure system of multi-tower cable-stayed bridge at the same time. The comprehensive control method of transverse structure system of multi-tower cable-stayed bridge under earthquake and typhoon is obtained.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.27

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