侧风下桥墩及桥塔附近桥面风环境数值模拟研究

发布时间：2018-03-01 02:13

本文关键词： 桥墩桥塔桁架主梁三维数值模拟风屏障　出处：《西南交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：处于强侧风环境中的跨海大桥,其结构绕流可能导致风速突变,对行车安全十分不利。为此本文分别以某箱梁桥和桁架桥为研究对象,探究侧风环境下桥墩、桥塔对桥面风环境的影响及该区域风屏障的作用。本文主要研究工作如下：1.利用计算流体动力学(CFD)方法,借助FLUENT软件对箱梁主梁及桥墩进行三维数值模拟。通过风速云图、三维风速分布图,初步对桥墩的影响规律进行定性分析。对比桥面上不同车道的风剖面,研究桥墩附近风屏障的防风效果。考察风速顺桥向变化,探究桥墩在顺桥向及高度方向的影响范围及规律。2.运用FLUENT软件,建立桁架主梁及桥塔的三维仿真模型。通过试算及风洞试验资料,确定合理的计算参数,计算不同工况下桥面风速。分析桥塔对公路、铁路桥面风速的影响范围,以及风屏障透风率对桥塔区域风速的影响。通过与风洞试验结果的对比,验证计算的可靠性。桥墩附近桥面风环境的研究表明：桥墩附近桥面风速出现折减,随着高度增加,桥墩对桥面风环境的影响范围缩小。来流风速的变化对桥面上方风场分布规律的影响较有限；风屏障及护栏的透风率对迎风侧车道桥面流场具有显著的影响,对背风侧车道流场影响相对较弱；风屏障弱化了风速在桥墩附近的突变效应,降低了行车高度范围内的风速；桥塔附近桥面风环境的研究表明：无风屏障时,公路桥面风速在桥塔两侧急剧增大,然后趋于平缓；离桥塔越远,风屏障有效作用高度越高；有风屏障工况下,公路、铁路桥面上桥塔对风场的影响范围分别位于顺桥向桥塔两侧25m、15m区域。铁路桥面上风屏障透风率越小,风速突变越剧烈。
[Abstract]:In the strong cross-wind environment, the structure of cross-sea bridge may lead to sudden changes in wind speed, which is very unfavorable to traffic safety. Therefore, a box girder bridge and a truss bridge are taken as research objects in this paper to explore the pier under crosswind environment. The influence of bridge tower on the wind environment of bridge deck and the effect of wind barrier on the bridge deck. The main work of this paper is as follows: 1. By using computational fluid dynamics (CFD) method and FLUENT software, the main girder and pier of box girder are simulated by 3D numerical method. Three-dimensional wind speed distribution map, preliminary qualitative analysis of the influence of piers. Comparing the wind profiles of different lanes on the bridge deck, the wind-proof effect of the wind barrier near the pier is studied, and the variation of wind speed along the bridge is investigated. This paper probes into the influence range and law of piers in the direction and height of the bridge. 2. By using FLUENT software, the three-dimensional simulation model of truss main beam and bridge tower is established. The reasonable calculation parameters are determined by means of trial calculation and wind tunnel test data. The influence range of bridge tower on highway and railway deck wind speed, and the influence of wind barrier air permeability on the wind speed of bridge tower area are analyzed. By comparing with the results of wind tunnel test, the paper analyzes the influence of bridge deck wind speed on the wind speed of bridge deck under different working conditions. The study on the wind environment of the deck near the pier shows that the wind speed of the deck near the pier is reduced, and the wind speed decreases with the increase of height. The influence of piers on the wind-environment of the bridge deck is reduced, the variation of the incoming wind speed has a limited effect on the distribution of wind field above the deck, and the air permeability of the wind barrier and guardrail has a significant effect on the flow field of the windward driveway. The wind barrier weakens the sudden change of wind speed near the pier and reduces the wind speed in the range of driving height. The study on the wind environment of the bridge deck near the bridge tower shows that when there is no wind barrier, The wind speed on the bridge deck increases sharply on both sides of the bridge tower, and then tends to be gentle; the farther away from the tower, the higher the effective height of the wind barrier; under the condition of wind barrier, the highway, The influence range of the tower on the bridge deck on the wind field is located in the area of 25m or 15m on both sides of the bridge towards the bridge respectively. The smaller the air permeability of the wind barrier on the railway bridge is, the more severe the sudden change of wind speed is.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441

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