【作者】 周晶；

【导师】 许福友；

【作者基本信息】 大连理工大学 ， 桥梁与隧道工程， 2015， 硕士

【摘要】 近年来,在山区修建了很多大跨度桥梁。风荷载是大跨度桥梁的一项非常重要的、甚至对结构设计起控制作用的荷载。因此,山区风场特性的准确确定对山区大跨度桥梁施工和运营阶段的抗风设计起着至关重要的作用。本文采用风洞试验方法,研究了八种典型简单二维山体(单体)干扰条件下的风场特性,考虑了风偏角以及多重山脉干扰条件下的风场特性。本文主要工作内容和结论如下：(1)第一章按研究方法进行分类,从风洞试验、数值模拟、现场实测三个方面,对国内外山区桥址风场特性的研究现状进行了详细深入的分析、归纳和总结。进而简要介绍了本文研究内容及意义。(2)第二章主要从平均风特性和脉动风特性两方面介绍了山区风场特性的主要研究内容和相关理论知识,为后文研究提供了理论支持。(3)第三章介绍了本文风洞试验中采用的试验模型、试验方案、试验工况以及试验数据处理方法,并进行了试验误差分析。(4)第四章分析了单个半圆形山体的风场特性、对比分析了多种典型的二维山体的风场特性以及不同风偏角对山体风场特性的影响。分析结果表明,三角形山体和梯形山体对山体前、后方一定区域内风场特性的影响大于半圆形山体,且迎风面坡度越大,影响越显著,表现为遮挡效应更显著、风攻角和紊流强度更大,山体后方的脉动成分更多。(5)第五章分析了多重山脉干扰条件下的风场特性,并提出了进行山区桥梁抗风设计与研究的几点建议。分析结果表明,相比单个山体,两个相距2倍山体高度的山体,山顶处的加速效应有所减弱、山体后方风速的遮挡效应影响区域有所增大；在靠近后方山体背风面山脚处,风速和风攻角脉动相对较大。三角形山体比半圆形山体遮挡效应更显著,范围也更大。两个相距一定距离的山体,后方山体对其前方4倍山体高度距离处的风场特性有一定的影响,表现为风速减小、风攻角增大,紊流强度增大。(6)最后进行了总结,给出了相关的结论和展望。更多还原

【Abstract】 In recent years, there have been built lots of long-span bridges in the mountain areas. For the long-span bridges, the wind loading is very important and even control the structure design. The accurate determination of the characteristics of wind field in mountainous area plays an important role in wind resistant design of long-span bridges for both construction and operation stages.The wind field characteristics of eight typical simple two-dimensional hills, the effects of different wind yaw angles and the interference effect of multiple mountains are investigated by using wind tunnel tests in this article. The major contents and conclusions of the researches are as follows:(1) The first chapter introduces the research status of the wind field characteristics in mountain areas at home and abroad from the wind tunnel test, numerical simulation and field measurements three aspects. And then introduces the contents and significance of the article.(2) The second chapter describes the research contents and several related theories of the average wind and fluctuating wind characteristics. And it provides theoretical support for the later research.(3) The third chapter introduces the test model, the test plan, the test cases and the data processing method. And the test errors are analyzed.(4) The forth chapter investigates the wind field characteristics of a single semicircle hill, different kinds of hills and the effects of different wind yaw angles. It shows that, for the impact of the wind field characteristics in front and behind of the hill, the triangle and trapezoid hill is bigger than the semicircle hill, and the bigger the slope, the greater the impact, mainly in the more significant wind barrier effect, the larger wind attack angle and the turbulence intensity.(5)The fifth chapter investigates the interference effect of multiple hills, and puts forward several suggestions on wind resistance design and research of bridges in mountainous terrain. It shows that, when two hills twice the height of the mountain apart, speed-up effect is less, the wind barrier effect is greater than that of a single hill, the wind speed standard deviation and the wind attack angle are greater in the lee side foot. And the wind barrier effect of triangle hills is greater than the semicircle hills. When two hills some distance apart, the wind speed decrease, the wind attack angle increase and the turbulence intensity in front of the second hill. (6) Finally, the related conclusions are summarized and the prospects are addressed.更多还原