简单形体山区桥址风场特性风洞试验研究

发布时间：2018-05-28 06:01

本文选题：山区地形 + 风场特性　；参考：《大连理工大学》2015年硕士论文

【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。
[Abstract]:In recent years, many long-span bridges have been built in mountainous areas. Wind load is one of the most important loads in long span bridges, and even plays a controlling role in structural design. Therefore, the accurate determination of wind field characteristics plays an important role in the wind-resistant design of long-span bridges in mountainous areas. In this paper, the wind field characteristics of eight typical simple two-dimensional mountain bodies (monomers) are studied by wind tunnel test. The wind field characteristics under the condition of wind deflection angle and multiple mountain disturbance are considered. The main contents and conclusions of this paper are as follows: the first chapter classifies according to the research method, from three aspects of wind tunnel test, numerical simulation and field measurement, makes a detailed and in-depth analysis on the research status of wind field characteristics of the bridge site in mountainous areas at home and abroad. Induction and summary. The second chapter mainly introduces the main research contents and related theoretical knowledge of wind field characteristics in mountainous areas from the two aspects of average wind characteristics and pulsating wind characteristics. The third chapter introduces the test model, scheme, working condition and data processing method used in the wind tunnel test in this paper. In chapter 4, the wind field characteristics of a single semi-circular mountain body are analyzed, and the wind field characteristics of several typical two-dimensional mountain bodies and the effects of different wind deflection angles on the wind field characteristics are compared and analyzed. The results show that the influence of triangle mountain and trapezoidal mountain on wind field in front and rear of mountain is greater than that in semicircular mountain, and the bigger the slope of upwind is, the more significant the influence is, and the more obvious is the blocking effect. The wind attack angle and turbulence intensity are greater, and the pulsating components behind the mountain are more. 5) in chapter 5, the wind field characteristics under the condition of multiple mountain disturbance are analyzed, and some suggestions for wind resistance design and research of mountain bridges are put forward. The results show that the acceleration effect at the top of the mountain is weaker than that of the single mountain, and the area affected by the wind speed at the back of the mountain is increased, and at the foot of the leeward near the rear mountain, the acceleration effect at the top of the mountain is weakened, and the area affected by the wind speed at the back of the mountain is increased. Wind speed and angle of attack are relatively large. The blocking effect of triangular mountain is more obvious than that of semi-circular mountain. Two mountains with a certain distance from each other have a certain influence on the wind field characteristics at a distance of 4 times the height of the mountain body in front of the mountain body. The wind speed decreases, the wind attack angle increases, and the turbulence intensity increases. Some conclusions and prospects are given.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442

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