基于静动力特性的多塔长跨斜拉桥结构体系刚度研究

发布时间：2018-01-05 20:13

本文关键词：基于静动力特性的多塔长跨斜拉桥结构体系刚度研究　出处：《北京交通大学》2014年博士论文　论文类型：学位论文

【摘要】：摘要：多塔斜拉桥在二十世纪中期就已经出现,但是发展一直较缓慢,制约其发展的一个关键因素就是整体刚度偏弱,为此国内外学者开展了一定的研究。当多塔斜拉桥进入大跨径时,其刚度问题更加突出,本文在前人研究成果的基础上,结合交通运输部科技项目“多塔长大斜拉桥关键技术研究”(项目号：2013315494011),主要针对多塔长跨斜拉桥的刚度相关问题进行系统性的研究。本文的主要工作包括以下几个方面： (1)提出了多塔斜拉桥整体刚度指标,定义了多塔斜拉桥竖向刚度代表值,并对其限值进行了讨论,为本文的后续研究提供了判别标准。在广泛收集资料的基础上,对已建及拟建多塔斜拉桥的结构参数进行了统计并结合理论分析提出了多塔斜拉桥的合理塔跨比区间。 (2)提出了多塔斜拉桥结构变形计算的隔离结构法,基于Matlab语言编制了相应程序,提高了刚度参数优化时主梁活载变形计算的效率。基于多塔斜拉桥不同于常规斜拉桥(双塔或单塔斜拉桥)的受力特点,推导了考虑塔梁刚度的拉索支承刚度系数的计算公式并进行了验证。推导公式时,认为中间塔两侧主梁不能与有辅助墩的边跨主梁一样视为刚性梁,而是具有一定的柔度,只对桥塔提供一定程度的约束,同时考虑了桥塔自身抵抗变形的能力,最后讨论了桥塔刚度、主梁刚度、拉索刚度以及拉索倾角等因素对拉索支承刚度的影响,得出的结论可以用于指导概念设计。 (3)以琼州海峡大桥方案之一的主跨828m的五塔斜拉桥为工程算例,研究了多塔长跨斜拉桥刚度问题的解决方法。通过参数敏感性分析,对原方案的刚度参数进行了优化,给出了塔梁刚度取值的合理匹配区间,确定了拉索刚度以及塔跨比的合理取值范围。对采用各种加劲索的方案进行了比较分析,给出了基于静力特性优化后的琼州海峡大桥方案并进行了力学特性检算。 (4)提出了多塔斜拉桥塔梁刚度比的概念,基于拉索支承刚度系数计算式给出了相应的数学表达式。与索的刚度相比,塔的刚度与梁的刚度对多塔斜拉桥整体刚度的影响较大,设计自由度也较大,从刚度的角度出发,可通过塔梁刚度比将多塔斜拉桥划分为柔性塔体系与刚性塔体系。 (5)提出了一种新型的多塔斜拉桥结构体系一改进的莫兰迪结构体系(AMSS)。解决了柔性塔体系的多塔(四塔及以上)长跨斜拉桥的刚度问题。该体系是在斜拉桥索塔顺桥向两侧间隔一定距离设置塔梁竖向支座,从而同时实现塔梁之间的竖向约束和转动约束,在力学行为上接近塔梁固结,而构造上表现为塔梁分离。通过对其力学性能分析,发现其具有塔梁固结体系提高整体刚度的功能,同时避免塔梁固结处产生较大的弯矩。双支承间距的增大可以提高整体刚度也同时带来了托架根部弯矩增大的问题,通过有限元分析对双支承间距合理取值进行了研究。通过实桥试验数据分析了新型结构体系的合理性及解决柔性塔多塔长跨斜拉桥体系刚度问题的有效性。 (6)基于动力特性及地震反应分析对琼州海峡大桥方案做了进一步优化。多塔斜拉桥刚度的增大,提高了结构的静力抗变形能力,但是对动力特性的影响不能一概而论。本文分析了提高桥塔刚度和改变塔梁支承体系等措施对琼州海峡大桥方案动力特性的影响,并基于静动力特性总结了多塔斜拉桥刚度合理取值的方法。 (7)探讨了采用反分析对多塔斜拉桥结构刚度参数进行优化的方法。在刚度参数敏感性分析的基础上,给定一个挠度期望值,反演分析刚度参数,使得参数优化计算更具针对性,避免需要反复调整初始参数的大量有限元试探性分析。参数优化分析时,采用Ansys软件参数化建模技术建立了琼州海峡大桥方案的有限元模型,采用Matlab语言编制了相应的参数优化模型,并通过DOS内部命令,实现两种软件之间的对口连接,使其能够相互调用,降低了编程工作量,提到了工作效率。
[Abstract]:Abstract: it has already appeared in the middle of the twentieth Century multi pylon cable-stayed bridge, but the development has been relatively slow, one of the key factors restricting the development of the overall stiffness is weak, therefore the domestic and foreign scholars carried out some research. When entering the large span cable-stayed bridge, the stiffness problem is more prominent, based on the results of previous studies, research on the key technology of multi tower cable-stayed bridge with long Department of transportation science and technology project "(project number: 2013315494011), the main systematic research on the stiffness problems related to multi tower long span cable-stayed bridge. The main work of this paper includes the following aspects:
(1) the overall stiffness index of multi tower cable-stayed bridge, cable-stayed bridge defines the vertical stiffness of the representative value and the limit value are discussed, provide a criterion for the follow-up research. On the basis of widely collected data, has been built on the cable-stayed bridge. The statistical parameters were combined with the theoretical analysis, put forward reasonable tower cable-stayed bridge span ratio range.
(2) put forward the method to calculate the deformation of the isolation structure of multi tower cable-stayed bridge structure, Matlab language and the corresponding program is designed based on improved stiffness parameter optimization of main beam live load deformation calculation efficiency. The cable-stayed bridge is different from the conventional cable-stayed bridge (based on Twin Towers or single tower cable-stayed bridge) stress characteristics and considering the calculation formula of stiffness coefficient of cable support tower beam stiffness and verified. The formula, that both sides of the middle tower girder and pier not auxiliary side span beam as a rigid beam, but has a certain flexibility, only provide a certain degree of restraint on the tower, also considered the ability to resist deformation of the tower itself, finally discusses the bridge stiffness, girder stiffness, cable stiffness and cable angle and other factors on the stiffness of cable support, the conclusion can be used to guide the design concept.
(3) to the main span of 828m of the Qiongzhou Strait Bridge of the five tower cable-stayed bridge as engineering example, studied the solving methods of multi tower long span cable stayed bridge stiffness problem. Through the sensitivity analysis of parameters, the stiffness parameters of the original scheme was optimized, gives reasonable tower beam stiffness values the matching range, determine the reasonable range of cable stiffness and column span ratio. Using various cable schemes are compared and analyzed, the Qiongzhou Strait Bridge Scheme Optimization Based on the static characteristics and the mechanical properties of calculation are given.
(4) put forward the concept of multi tower cable-stayed bridge stiffness ratio, stiffness of cable support based on the formula for calculating the corresponding mathematical expressions. Compared with the stiffness of cable, tower rigidity of cable-stayed bridge and the influence of the stiffness of the beam is larger, the degree of freedom of design is large. Starting from the angle of stiffness, the tower beam stiffness ratio will be divided into flexible cable-stayed bridge tower tower system and rigid system.
(5) proposed a new type of multi tower cable-stayed bridge structure system, an improved structure of Morandi (AMSS). To solve the flexible tower system tower (four tower and above) stiffness of long span cable-stayed bridge. The system is in the tower along the bridge on both sides of a certain distance away from the set of tower and beam the vertical bearing of cable-stayed bridge, to realize the vertical constraint between tower and beam and rotational constraints, in mechanical behavior near tower girder consolidation, and structural performance for the tower beam separation. Based on the analysis of its mechanical properties, and found that it have improved the tower beam consolidation system stiffness function, and avoid large bending moment the tower beam consolidation. Double spacing increases can improve the overall stiffness also brought the increase of bracket root bending moment problems, through the finite element analysis, the reasonable value of double spacing is studied. The new structure was analyzed by real bridge test data The validity and rationality of solving the flexible Taduota long span cable stayed bridge stiffness of the system.
(6) dynamic characteristics and seismic response analysis to optimize the scheme of the Qiongzhou Strait Bridge. Based on the stiffness increasing multi pylon cable-stayed bridge, improve the structure of the static deformation resistance, but can not be on the dynamic characteristics. This paper analyzes the impact of improving the tower stiffness and changing the tower beam support system and other measures. The dynamic characteristics of the Qiongzhou Strait Bridge project, and summarizes the methods of static and dynamic stiffness reasonable value of cable-stayed bridge based on.
(7) was studied by using inverse analysis method to optimize the stiffness parameters of cable-stayed bridge structure. Based on the sensitivity analysis of stiffness parameters, given a deflection expectations, inversion analysis of stiffness parameter optimization calculation, more targeted the parameters, avoiding the need for finite element analysis of a large number of tentative adjustment the initial parameters. Parameter optimization analysis, modeling technology to establish the finite element model of the Qiongzhou Strait Bridge scheme using Ansys software parameters, parameter optimization model is developed by the Matlab language, and through the DOS internal commands, realize the connection between the two kinds of software counterparts, which can call each other, reduce programming the workload, referred to the work efficiency.

【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U441.4;U448.27

【参考文献】