【作者】 沈国辉；

【导师】 孙炳楠；

【作者基本信息】 浙江大学 ， 结构工程， 2004， 博士

【副题名】屋盖结构的表面风压、风致响应和等效风荷载研究

【摘要】 大跨度屋盖结构由于具有优美的外形和能提供尽可能大的无内柱空间等特点，近年来被广泛地应用于机场、体育馆等大型公共建筑中。随着大跨度屋盖结构向着长大化和轻质化方向发展，风荷载逐渐成为其主要的控制荷载。但是大跨度屋盖结构的风荷载理论却未能随之发展而发展，各国规范中关于大跨度结构风振方面的内容几乎是空白。本文提出建筑结构风致响应和等效风荷载的标准(standard)解法和模态(model)解法，并把这两套方法应用于大跨度屋盖结构中，同时对大跨度屋盖结构表面风压的分布特征进行了分析。 首先，对于大跨度屋盖结构的表面风压，本文提供了一套具体的分析思路，分四周封闭体型和整体敞开体型对大跨度屋盖结构进行风洞试验方法和风压分布规律的分析，并讨论了大跨度屋盖结构的干扰效应和抑风措施。 同时，本文首次提出建筑结构风致响应和等效风荷载的标准解法。对于风致响应的背景分量和共振分量，分别采用方差分析法和振动分析方法来求解；对于等效风荷载的背景分量和共振分量，分别采用LRC法和惯性力法来求解。求得各分量后，按响应分配的原则获得总的风致响应和等效风荷载。在大跨度屋盖结构中应用标准解法时，分主次梁体系屋盖和空间整体体系屋盖进行讨论。分析两种体系屋盖的常见实例，可以发现背景分量占主要地位，共振分量占较小的比例。 再次，本文提出建筑结构风致响应和等效风荷载的模态解法，首次澄清了模态交叉项和非交叉项对于背景分量和共振分量的贡献。将非交叉项的贡献分为背景分量和共振分量，将交叉项的贡献确定为背景分量，从而将模态交叉项和非交叉项的贡献与背景分量、共振分量确立起对应的关系。在主次梁体系屋盖中应用模态解法时，对于风致响应，模态解法与标准解法得到的结果一致，但对不同的响应类型，模态解法须计算不同的模态阶数；对于等效风荷载，模态解法得到的结果是标准解法结果的逼近和近似，当模态解法采用的模态阶数越高，两种方法得到结果间的差异就越小。在空间整体体系屋盖中应用模态解法时，对于风致响应，两种方法的结果基本一致；对于等效风荷载，两种方法得到的结果差异较大。 最后，本文还提出求解背景响应等效风荷载的简便算法，即荷载—升力—相关(LLC)法。相比LRC法，LLC法具有计算简便、物理意义明确的特点，同时LLC法还将用于结构整体设计和围护结构设计的风荷载计算公式进行统一。更多还原

【Abstract】 Due to theirs beautiful shapes and capacities of providing huge space without inner columns, long span roofs have been greatly constructed recently as large-sized public buildings such as airport terminal buildings and stadiums. When long span roofs tend to more flexible and light, the wind loads, among all kinds of loads, become dominating. But the theory of wind-induced response and Equivalent Static Wind Load (ESWL) on long span roofs isn’t well developed and in most countries few Codes are presented to regulate the dynamic wind loads on long span roofs. Considering such embarrassed condition, the present study puts forward two theories, which is Standard Solution and Model Solution, to obtain the wind-induced response and ESWL on civil engineering buildings. By applying the above-mentioned two solutions, the wind-induced dynamic problems on long span roofs can be solved. And the characteristic of wind pressures on long span roofs is also investigated.Usually long span roofs can be categorized as closed and open type regarding whether their inner surface suffers from wind directly or not. According to these different types, different ways of wind runnel test are given to obtain the wind pressures on long span roofs. And the characteristic of wind pressure distribution on each type of long span roofs is discussed with regard to the roof shapes. The interfering effect and ways to reduce the wind pressures on roofs are also investigated in present study.The Standard Solution is put forward to obtain the wind-induced response and ESWL on civil engineering structures. Here the methods of Covariance Analysis and vibration analysis are employed to obtain the background and resonant component of wind-induced response. And the methods of Load-Response-Correlation and inertial force are used to obtain the background and resonant component of ESWL. When the background and resonant components are derived, the total response and ESWL can be calculated based on the proportions, which indicate the participating degree of the corresponding response. The Standard Solution is employed to solve the wind-induced dynamic problems on long span roofs, which is categorized as beams supporting type and structurally integrated type according to their dynamic properties. After analyzing the common examples of wind effect on long span roofs, it can be found that the background component occupies prevailing proportion of the totality,while the resonant component only occupies small proportion.The Modal Solution, which is based on modal dynamic analysis, is presented to obtain the wind-induced response and ESWL on civil engineering structures. The contribution of modal cross-correlation items is considered as background component, while that of modal non-cross-correlation items is separated as background and resonant component. After summing up the background component in these two items, the background and resonant components of wind-induced response and ESWL can be decided. The Modal Solution is applied to obtain the wind-induced response and ESWL on beams supporting roofs. As for wind-induced response, the accordance will be found between the results of the Standard Solution and Model Solution. As for ESWL, the results of the Model Solution are just an approximation and tendency of those obtained from the Standard Solution. When higher mode is taken in the Model Solution, the smaller disparities can be predicted between the results of these two Solutions. When applying the Model Solution to structurally integrated roofs, the accordant results will be found for wind-induced responses and the large disparity will be found for ESWL.A new method, which is the Load-Lift-Correlation (LLC), is put forward to simplify the calculation on ESWL of background response. Compared with LRC method, the LLC method has virtues of briefness in calculating and definitude in physical significance. And the LLC method also can unify the wind load equations for main structure design and shielding system design.更多还原