刚构—连续组合梁桥双肢薄壁墩设计参数的分析与优化

发布时间：2018-01-12 02:07

本文关键词：刚构—连续组合梁桥双肢薄壁墩设计参数的分析与优化　出处：《兰州交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：刚构—连续组合梁桥是国内外广泛应用的桥型,它汲取了T型刚构和连续梁桥的优势,同时也彰显出自身的特点。刚构—连续组合梁桥长联、大跨,减少了桥梁伸缩装置的设置数量,使得行车舒适性增加,同时也避免了大吨位支座的使用,降低了桥梁养护工作的难度。但长联、大跨的刚构—连续组合梁桥对温度、混凝土的收缩、徐变等异常敏感,为了减小以上因素对桥梁结构的影响就必须对刚构墩的各项设计参数进行分析和优化。双肢薄壁墩是刚构—连续组合梁桥的刚构墩最常用的墩身形式。双肢薄壁墩的单肢壁厚是墩身抗推刚度的主要影响因素;双肢间距则是墩身抗弯刚度主要影响因素,因此,它们是双肢薄壁墩最重要的两个设计参数。本文以某黄河大桥为工程背景进行了以下研究:(1)研究了双肢薄壁墩的单肢壁厚及双肢间距这两个参数对刚构—连续组合梁桥内力、变形及稳定性的影响。通过对桥梁有限元模型的分析计算,得到了桥梁结构内力及变形随着单肢壁厚和双肢间距变化的规律;给出了最大悬臂状态时桥墩稳定性与单肢壁厚、双肢间距的关系,给同类型桥梁刚构墩的设计提供了参考。(2)利用CFD方法对双肢薄壁墩附近风场进行了数值模拟,分别研究了矩形截面的宽高比与阻力系数的关系,以及不同风攻角作用下双肢薄壁墩的单肢壁厚和双肢间距的变化对桥墩的气动三分力系数的影响。(3)根据双薄壁墩的结构受力情况,假定刚构墩顶的主梁刚度无穷大且双薄壁墩的双肢变形完全一致,将刚构墩顶受力与双薄壁墩的单肢受力联系起来,以墩身截面积最小为目标函数,考虑强度和稳定性约束条件,建立基于ANSYS的双薄壁墩的单肢壁厚和双肢间距的优化数学模型,通过ANSYS的优化模块实现了双肢薄壁墩的设计参数优化。
[Abstract]:Rigid-continuous composite beam bridge is widely used at home and abroad. It draws the advantages of T-type rigid frame and continuous beam bridge, but also shows its own characteristics. Rigid frame-continuous composite beam bridge has long connection and long span. Reduce the number of bridge telescopic devices, make the driving comfort increased, but also avoid the use of large tonnage support, reduce the difficulty of bridge maintenance. Long-span rigid frame-continuous composite beam bridges are very sensitive to temperature, concrete shrinkage, creep and so on. In order to reduce the influence of the above factors on the bridge structure, it is necessary to analyze and optimize the design parameters of the rigid frame pier. The two-leg thin-walled pier is the most commonly used pier for the rigid frame pier of the rigid-frame continuous composite beam bridge. The single limb wall thickness of pier is the main factor that affects the pushing stiffness of pier body. The distance between two limbs is the main factor affecting the bending stiffness of the pier body. They are two of the most important design parameters for two-leg thin-walled piers. This paper takes a Yellow River Bridge as the engineering background and makes the following research: 1). The internal force of rigid frame-continuous composite beam bridge is studied by the two parameters of single limb wall thickness and double limb spacing of two-leg thin-walled pier. The influence of deformation and stability. Through the analysis and calculation of the finite element model of the bridge, the variation of the internal force and deformation of the bridge structure with the wall thickness of the single limb and the distance between the two legs is obtained. The relationship between the stability of the pier and the wall thickness of the single limb and the distance between the two limbs under the maximum cantilever state is given. This paper provides a reference for the design of rigid frame pier of the same type of bridge. Using the CFD method, the wind field near the two-leg thin-walled pier is numerically simulated, and the relationship between the ratio of width to height of rectangular section and the coefficient of resistance is studied respectively. And under the action of different wind attack angle, the influence of the change of the wall thickness and the distance between the two limbs on the aerodynamic force coefficient of the bridge pier under the action of different wind attack angle. 3) according to the structure stress condition of the double thin-walled pier. Assuming that the stiffness of the main beam at the top of the rigid frame pier is infinite and the deformation of the double thin wall pier is completely consistent, the force on the top of the rigid frame pier is connected with the single limb force of the double thin-walled pier, and the minimum section area of the pier is taken as the objective function. Considering the constraint conditions of strength and stability, an optimal mathematical model of the wall thickness and the distance between two limbs of double thin-walled pier based on ANSYS is established. The design parameters of double-leg thin-walled pier are optimized by ANSYS optimization module.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.5

【相似文献】