摘要
针对非对称独塔斜拉桥结构刚度不对称以致其风振响应异于传统对称斜拉桥的状况,以位于沿海地区的某非对称独塔斜拉桥为工程背景,对大跨度斜拉桥抖振响应等效静力风荷载进行了深入研究。首先,采用有限单元法分析了结构的动力特性;其次,进行了节段模型风洞试验,并采用同时考虑自激力和抖振力的抖振计算模型对结构的抖振响应进行了分析,并在上述工作的基础上,以结构的抖振响应为等效目标,推导了基于结构振型的抖振等效静力风荷载计算方法;最后,将该方法与精确抖振响应计算结果进行了比较。结果表明:所提出的基于振型的抖振等效静力风荷载计算方法可以同时考虑结构不同部位的抖振响应,与中国《公路桥梁抗风设计规范》中的方法相比,能够体现等效静力风荷载与结构振型和质量分布相关的特性;该方法的计算结果与精确抖振响应极值相比,在关键部位的误差均小于10%,精度满足工程计算的要求;对于柔性大跨度桥梁抖振响应等效静力风荷载计算,建议优先采用该方法。
Because of the asymmetric stiffness of asymmetric cable-stayed bridge with single tower, the wind induced dynamic responses are different from which of the traditional symmetric cable-stayed bridge. Based on one asymmetric cable-stayed bridge with single tower which is located in coastal area, buffeting equivalent static wind loading （ESWL） of long span cable-stayed bridges was investigated in depth. Firstly, the dynamic characteristics of the bridge were analyzed through finite element method. Secondly, sectional model wind tunnel tests of the bridge deck were conducted and buffeting responses of the bridge were analyzed through the buffeting calculation model with the consideration of buffeting forces and self-excited forces. On the basis of the above work, a buffeting ESWL calculation method based on the mode shapes was derived by taking the buffeting response of the structure as equivalent object. Finally, the results of proposed method were compared with those of accurate buffeting response calculation method. The results show that buffeting responses of different parts of the bridge can be simultaneously considered by the proposed method. Compared with the method in wind-resistent design specification for highway bridges of china, the proposed method can represent the relationships between distribution of ESWL and mode shapes and mass distribution. Comparing the results of the proposed method and the extreme values of accurate buffeting response calculation method, the errors at critical nodes of the bridge deck are smaller than 10%, which meet the required accuracy of the practical engineering. For the buffeting ESWL calculation of flexible long span bridges, the proposed method is recommended.
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2016年第11期108-115,共8页
China Journal of Highway and Transport
基金
国家自然科学基金项目(51508107)
桥梁结构抗风技术交通行业重点实验室开放基金项目(KLWRTBMC14-03)
中国博士后科学基金项目(2016M590592)
关键词
桥梁工程
独塔斜拉桥
多振型抖振分析法
抖振等效静力风荷载
振型
bridge engineeringl single tower cable stayed bridge
buffeting analysis method con-sidering multi-modes
buffeting equivalent static wind loading
mode shape
