独柱支承连续曲线梁桥的稳定性研究以及支座优化设计

发布时间：2018-02-13 21:03

本文关键词： 独柱支承曲线梁桥受力特性抗倾覆稳定性支座优化　出处：《兰州交通大学》2016年硕士论文　论文类型：学位论文

【摘要】：曲线梁桥的“弯—扭”耦合效应使得其在对称荷载作用下也会产生很大的扭转变形,在偏载作用下,效应更为明显。尤其对于中间点铰支座不传递扭矩的独柱支承曲线梁桥来说,其梁端扭矩极其巨大,过大的扭转变形必将导致该类桥梁的稳定性储备不足的问题。因此,在独柱支承曲线梁桥的设计过程中,如何改善其受力状态以及提高结构的稳定性是首要解决的问题。再者,通过支座优化设计可以有效改善该类桥梁的受力状态。本文根据已有理论的基础上,采用数值模拟的方法对影响曲线梁桥受力特性的主要因素进行分析,并对独柱支承曲线梁桥支座优化设计进行深入的研究。主要完成的工作如下:(1)阐述了曲线梁桥的应用概况以及工程事故概况,进一步提出了独柱支承曲线梁桥存在的问题;(2)通过建立曲线梁微段的平衡方程、几何方程以及曲线梁内力与变形的关系推导出三个用位移分量表示的曲线梁平衡微分方程,进一步得出影响结构受力特性的主要因素;(3)通过建立相同跨径组合的直线梁桥以及曲线梁桥的有限元模型,对其内力、变形以及支反力进行对比,得到曲线梁桥独有的受力特点;通过对曲线梁桥抗倾覆稳定性验算依据的相关介绍以及验算方法的对比,得出一种偏于安全的验算方法;(4)通过设置曲率半径及跨中横隔梁数为参数,改变其取值,研究曲率半径对曲线梁桥受力特性的影响以及横隔梁布置对减小截面畸变作用的贡献,最后探讨二者对结构抗倾覆稳定性的影响;(5)介绍曲线梁桥常用的三种支座设置方法,通过改变其支承形式,对比不同支承形式对结构受力特性以及抗倾覆稳定性的影响;(6)介绍支座偏心调整独柱支承曲线梁桥扭矩的原理及方法;通过设置中支点预偏心距和端支座横向间距为参数,改变其取值,分析中支座预偏心及端支座横向间距对结构受力特性及抗倾覆稳定性的影响;并得出不同曲率半径独柱支承曲线梁桥支座优化目标的确定原则。
[Abstract]:The coupling effect of "bending and torsion" of curved girder bridge makes it also produce great torsional deformation under symmetrical load, and under the action of partial load, The effect is more obvious. Especially for the single-column supported curved girder bridge with untransmitted torque, the torsional moment at the end of the beam is extremely huge, and the excessive torsional deformation will inevitably lead to the shortage of the stability reserve of this kind of bridge. In the design process of single-column supported curved girder bridge, how to improve the stress state and the stability of the structure is the most important problem to be solved. The stress state of this kind of bridge can be effectively improved by the support optimization design. Based on the existing theories, the main factors affecting the stress characteristics of curved beam bridges are analyzed by numerical simulation method in this paper. The main work is as follows: (1) the application of curved girder bridge and the general situation of engineering accidents are expounded. Furthermore, the problem of curved beam bridge supported by single column is put forward. By establishing the equilibrium equation, geometric equation and the relationship between the internal force and deformation of the curved beam, three differential equations of equilibrium of curved beam expressed by displacement components are derived. Furthermore, the main factors affecting the mechanical characteristics of the structure are obtained. By establishing the finite element model of the linear beam bridge and the curved beam bridge with the same span combination, the internal force, deformation and supporting reaction force of the bridge are compared. The unique stress characteristics of curved girder bridge are obtained, and the relative introduction and comparison of checking calculation methods for the overturning stability of curved girder bridge are given. By setting the curvature radius and the number of mid-span transverse beams as parameters, we can change the values, study the influence of curvature radius on the stress characteristics of curved girder bridges and the contribution of the layout of the transverse beams to the reduction of cross-section distortion. Finally, the influence of the two on the overturning stability of the structure is discussed. (5) the three kinds of support setting methods used in curved girder bridges are introduced, and the supporting forms are changed. This paper introduces the principle and method of supporting eccentric adjustment of torsion of curved girder bridge supported on single column by comparing the influence of different supporting forms on the mechanical characteristics and overturning stability of the structure, and sets the pre-eccentricity of support point and the transverse distance of end support as parameters, and introduces the principle and method of adjusting the torque of curved girder bridge supported by single column by eccentricity. The influence of eccentricity and lateral distance between end and end supports on the mechanical characteristics of the structure and the stability against overturning are analyzed, and the principle of determining the optimal support objective of curved girder bridge with different curvature radius is obtained.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U441;U448.21

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