非对称独塔斜拉桥多振型抖振等效静力风荷载计算方法

发布时间：2018-04-06 05:01

本文选题：桥梁工程　切入点：独塔斜拉桥　出处：《中国公路学报》2016年11期

【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。
[Abstract]:In view of the asymmetric single tower cable-stayed bridge structure stiffness asymmetry, its wind-induced vibration response is different from the traditional symmetrical cable-stayed bridge, taking the asymmetric single-tower cable-stayed bridge located in the coastal area as the engineering background.The equivalent static wind load of buffeting response of long span cable-stayed bridge is studied.Firstly, the dynamic characteristics of the structure are analyzed by finite element method. Secondly, the wind tunnel test of the segmental model is carried out, and the buffeting response of the structure is analyzed by using the buffeting calculation model which considers both the self-excited force and the buffeting force.Based on the above work and taking the buffeting response of the structure as the equivalent target, the equivalent static wind load calculation method of buffeting based on the structural vibration model is derived, and finally, the results of the method are compared with the exact buffeting response calculation results.The results show that the proposed buffeting equivalent static wind load calculation method based on vibration mode can consider the buffeting responses of different parts of the structure at the same time, which is compared with the method in the Code for Wind resistant Design of Highway Bridges in China.This method can reflect the characteristics of equivalent static wind load which is related to the vibration shape and mass distribution of the structure, and compared with the accurate buffeting response extremum, the errors in the key parts are less than 100.The accuracy can meet the requirements of engineering calculation.To calculate the equivalent static wind load of flexible long span bridge buffeting response, it is suggested that this method be preferred.
【作者单位】：福州大学土木工程学院;同济大学土木工程防灾国家重点实验室;
【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)
【分类号】：U441.2;U448.27

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