【作者】 郭威；

【导师】 李加武；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2013， 硕士

【摘要】 随着经济发展，人们对便捷交通的需求与日俱增。在公路飞速发展的同时，桥梁也进入连岛跨海建设的新时期。大跨度桥梁行车空间具有风速高，桥塔区局部风场变化剧烈等特点，侧风环境下的行车安全问题也因此突出。大桥侧风环境下的安全行车策略不仅关系交通安全与大桥的运营效率，还牵涉到社会影响，关乎政治，经济，防灾救灾等方方面面。因此研究车辆在桥面安全行驶条件具有十分重要的现实意义。目前保障桥面行车安全的策略主要有两类：一是交通管制，如在大风天气下限制桥上行车速度甚至关闭交通；另一类是在桥面安装风障降低桥面风速。本文结合两种方法，做了如下研究：1.使用标准k–ε模型与SST k–ω模型对流线形、近流线形与钝体三类典型物体的气动力系数进行数值模拟，将计算结果与实验数据互相比较，得到两种湍流模型的准确性与适用范围。2.分析侧风环境下车辆受力状态，得到车辆是否发生侧滑与侧倾失稳判断标准。使用数值模拟方法得到典型车辆的气动力系数。提出使用侧向风速计算临界风速的方法，并与使用合成风速计算临界风速的结果进行对比。3.以分离式钢箱梁断面为研究对象，使用二维模型，研究风障高度，倾角与侧向风速大小等参数对桥面风环境与主梁气动力特性的影响。比较不同车道的有效风速大小与风剖面形式，得出大桥安全运营的临界侧风速度。4.使用三维模型对桥塔区风环境做了模拟，对比均一风障与渐变风障对桥塔区风环境的作用。更多还原

【Abstract】 Along with the economic development, the people’ demand for convenienttransportation increases. While the rapid development in roads, bridge construction is alsoentering a new era of crossing seas and connecting islands. With characters of high windspeed in driving space of large span bridge, rapid wind environment change around thebridge tower, the traffic safety becomes a prominent problem. Safety driving strategy onlarge bridge is not only related to traffic safety and bridge operational efficiency, it alsoinvolves social impact, including political, economic, and disaster prevention and relief etc.So the research for safe driving conditions of vehicles driving on bridge deck has a veryimportant practical significance.At present, there are two types of strategies to safeguard driving safety on bridge decks:the first one is traffic control, such as to limit traffic driving velocity or even closetransportation; the other type of solution is to set wind barriers to slow down wind speed ondeck. combined these two kinds of strategies, the following researches will be done in thispaper:1. Aerodynamic coefficients of streamlined body, approximate streamlined body andbluff body were numerically simulated with standard k–ε turbulence model and SST k–ωturbulence model, the results were compared to experimental data in order to evaluateaccuracy and applicable scope of two turbulence models.2. The author analyzes the force state of vehicle under crosswind environment to getcriteria to judge if vehicles would occur sideslip and roll instability. Aerodynamiccoefficients of typical vehicle were got through numerical simulation. A method to calculatecritical wind speed with crosswind speed is proposed, the result is compared with criticalwind speed got from calculation method using synthetic wind speed.3. Based on a separated beam section the influence of parameters such as wind barrierheight, dip angle and crosswind speed on bridge deck wind environment and girderaerodynamic characteristics were studied using2D models. Effective wind speed and wind profile types on different lanes were compared, and critical crosswind speed for operatingthe bridge safely was got.4. Wind field around bridge tower was simulated by3D model, and the influence ofuniform wind barrier and gradually changed wind barrier on wind field was compared.更多还原