大跨屋盖结构抗风类型划分方法及应用

根据风振响应中平均响应、背景响应和共振响应之间的关系，初步提出划分结构抗风类型的思想，将大跨屋盖结构分为4类抗风类型，并给出具体的划分方案，以简化风振响应和等效静风荷载的分析过程．在此基础上，以拱作为研究对象，在工程常用的参数范围内，通过风洞试验，确定屋面风荷栽，对矢跨比分别为1／8和1／4的大跨拱结构的抗风类型进行系统的参数分析，研究风荷载基本参数和结构参数（矢跨比、跨度、结构截面刚度和屋面质量）对拱结构抗风类型的影响．分析结果表明：基频小于4Hz的绝大多数拱结构，脉动风响应明显大于平均风响应，脉动风响应不可忽略，属于背景响应可以忽略、共振响应占主导地位的结构抗风类型．

Classification and application of wind-resistant type of long-span roof structures

According to the relationship among the mean response, background response and resonant response of wind-induced response, an idea is advised to classify long-span roof structures into four wind-resistant types, and the detailed classification criterions are developed. Systematic parameter analysis of wind-resistant types of long-span arch structures is performed with the presented method in this paper, by considering some parameters of wind loading and arch structures, such as mean wind velocity, roof mass, rise-span ratio and section properties of the arch, where wind pressure loads are obtained by wind tunnel test. The results show that： the parameters of the wind loads and the struc- ture have important effect on structural response for long-span arch structures. The fluctuating wind- induced response can＇t be ignored, and most arch structures, whose first natural frequencies are lower than 4Hz, belong to the wind-resistant type that resonant response is more predominant than back- ground response.