高层建筑风振问题的研究

【作者】 葛楠；

【导师】 周锡元；

【作者基本信息】 中国建筑科学研究院 ， 结构工程， 2006， 博士

【摘要】 随着建筑物高度的增加，风荷载对结构的作用特别是横向作用与扭转方向的作用变得越来越重要。目前在我国的《建筑结构荷载规范(GB5009-2001)》中只考虑了建筑物顺风向脉动风荷载与圆形截面横向风荷载的作用；在《高耸结构设计规范(GBJ135-90)》中也考虑了圆形截面塔桅结构横向风荷载的作用；在《高层民用建筑钢结构技术规程JGJ99-98》规定了顺风向与横风向最大风振加速度的计算方法，主要是用来验算钢结构高层建筑的舒适度，而对具体的横风向风荷载则没有做出规定；风振扭转的研究也不多见。但在结构的设计阶段需要准确地确定作用在结构上的全部风荷载及他们对结构的作用效应。为结构方案的选择与设计提供准确的依据。 本文研究工作的重点是作用在高层建筑结构上的横风向风荷载、结构在横向风荷载作用下的动力反应以及结构在顺风向风荷载及横向风荷载联合作用下的扭转方向动力反应。另外从湍流基本理论出发得出了作用在结构上横风向脉动风荷载谱密度函数的解析公式。本文中主要的研究内容和创新性的成果如下： 1 根据顺风向Davenport脉动风速谱密度函数及日本建筑结构荷载规范给出的横风向脉动风压谱系数函数，分别模拟了顺风向脉动风压与横风向脉动风压时程，经过适当的滤波处理后，得出了谱特性与Davenport脉动风速谱与日本建筑结构规范中横风向风力谱相吻合的顺风向脉动风压时程与横风向脉动风压时程。 2 将高层建筑简化为一端固定，另一端自由的悬臂梁模型，根据模拟得出的顺风向与横风向脉动风压时程求出了建筑结构的顺风向风振动力反应时程、横风向风振动力反应时程及扭转动力反应时程。对于结构风振控制计算来说，有些阻尼器模型随着振动时间的延长，应考虑由于阻尼器温度升高而使风致振动可能表现为非平稳的过程，而时程分析可以反映出非平稳过程的特点。结果表明：建筑结构的横风向风振与扭转振动也主要表现为共振振动，这与顺风向风振研究中得出的结论是一致的。横风向风振的时程分析结果与日本规范公式(谱分析法)的计算结果相吻合。而扭转振动的时程分析结果也与本文提出的谱分析结果相吻合。 3 在未考虑建筑物刚度偏心、质量偏心及平扭耦联振动的情况下导出了扭转风振动力反应的谱分析计算公式。将顺风向脉动风压谱密度函数与横风向脉动风压谱度函数作为输入函数，得出了结构扭转风振反应谱密度函数。在后续的研究工作中，若需考虑建筑物的更多还原

【Abstract】 With the increasing of the height of buildings, wind load effects will become more and more important, especially in the across wind direction and in the torsion direction. At present time, in Chinese design code about load "Load code for the design of building structures GB5009-2001", only the wind load in the along wind direction and in the across wind direction for circular cross section and their effects have been specified. On the other hand in "Design code for tall and slender structures (GBJ135-90)" the fluctuating wind load on tower -mast structure with circular cross section both in the along wind direction and in the across wind direction has been specified. While in "Technical specification for steel structure of tall buildings JGJ99-98", specification about the evaluation for the maximum accelerations both in the along wind direction and in the across wind direction have been made for the approximation of body comfort index. But there is little research work about the fluctuating wind load either in the across wind direction or in the torsion direction on high rise buildings with non-circular cross section. Non specification has been made about such kind of wind load in the across wind direction. It is usually necessary to evaluate the wind load in all directions and their effects on the structure in the designing stage so as to provide more accurate reference for the structure scheme selection and the design work.This dissertation is devoted to the research work of the fluctuating wind load in the across -wind direction and the structure dynamic response both in the across wind direction and the torsion direction. under the jointed action of wind load in the along wind direction and that in the across wind direction. The turbulence fluctuating wind load has been derived from the basic equation of turbulence movement. The main research content and outcomes of this work are:1. The time history of the wind load fluctuating both in the along wind direction and in the across- wind direction have been simulated according to Davenport’s spectrum density function and the spectrum density function specified in Japanese building code. Through the effective filters, the time history of the wind load possess the same statistics properties as that of Davenport’s spectrum and Japanese spectrum density function.2. Regarding the high rise building as an cantilever model which is fixed at one end and free at another end, the time history of its dynamic response in the along wind direction, across wind direction and torsion direction could all be evaluated under all the fluctuating wind load. In the更多还原