超大跨桥梁主梁风致效应的定常吸气流动控制机理

By integrating theoretical analysis, numerical simulation and wind tunnel test, this project will focus on the characteristics of wind-induced flow field around super long-span suspension bridge girders with steady suction, and the structural wind-induced static and dynamic properties, in order to reveal steady air-suction flow control mechanism in improving the characteristics of wind-induced flow field around bridge deck sections, optimizing the structural wind-induced static and dynamic properties, and increasing wind-resisting ability. This project attempts to develop the steady air-suction method which based on flow control to increase wind-resisting ability of super long-span bridges. First, the steady suction control mechanism of flow field around bridge decks is studied. Secondly, the load characteristics of bridge decks under inflow and steady suction flow are studied. Thirdly, the steady suction control mechanism based on flow characteristics of inflow coupling with suction around deck sections is studied. Fourthly, the steady suction control mechanism based on load characteristics of inflow coupling with suction around deck sections is studied. Last，the steady suction control design method for wind-induced effects on super long-span bridge girders is studied. The project will provide a theoretical basis and a technical reserves for solving key wind-resisting problems for developing cross-sea level of super long-span bridges. Research results will further enrich and develop wind engineering theory, and it is of great significance to improve the ability of disaster prevention and mitigation for major projects in China.

本项目综合运用理论、数值以及实验研究手段，紧紧围绕定常吸气作用下的超大跨悬索桥箱形主梁断面风致绕流场特性，以及结构风致静、动力特性，揭示定常吸气对于改善主梁断面风致绕流场特性，优化主梁风致静力特性及风致涡振、颤振、驰振动力特性，以及提高超大跨桥梁抗风能力的作用规律与流动控制机理，旨在发展基于流动控制方式提高超大跨桥梁抗风能力的定常吸气方法。首先，研究断面风致绕流场定常吸气控制机理；之后，研究来流与定常吸气气流共同作用下的主梁荷载特性；然后，研究基于断面来流-吸气耦合流场特征的主梁风致作用流动控制机理；之后，研究基于主梁断面来流-吸气耦合作用荷载的主梁风致作用流动控制机理；最后，研究超大跨桥梁主梁风致效应的定常吸气控制设计方法。本项目研究将为解决跨海级超大跨桥梁发展所面临的抗风难题提供理论基础与技术储备，研究成果将进一步丰富和发展风工程理论，对提升我国重大工程防灾减灾能力具有重要意义。

本项目综合运用理论、数值以及实验研究手段，紧紧围绕定常吸气作用下的超大跨悬索桥箱形主梁断面风致绕流场特性，以及结构风致静、动力特性，揭示了定常吸气对于改善主梁断面风致绕流场特性，优化了主梁风致静力特性及风致涡振、颤振、驰振动力特性，以及提高了超大跨桥梁抗风能力的作用规律与流动控制机理，发展了基于流动控制方式提高超大跨桥梁抗风能力的定常吸气方法。首先，研究了断面风致绕流场定常吸气控制机理；之后，研究了来流与定常吸气气流共同作用下的主梁荷载特性；然后，研究了基于断面来流-吸气耦合流场特征的主梁风致作用流动控制机理；之后，研究了基于主梁断面来流-吸气耦合作用荷载的主梁风致作用流动控制机理；最后，研究了超大跨桥梁主梁风致效应的定常吸气控制设计方法。本项目研究为解决跨海级超大跨桥梁发展所面临的抗风难题提供了理论基础与技术储备，研究成果进一步丰富和发展了风工程理论，对提升我国重大工程防灾减灾能力具有重要意义。