强弱非平稳风速对大跨桥梁抖振响应影响研究  

Research on the Effects of Buffeting Responses of a Long-span Bridge Subjected to Weak and Strong Non-stationary Wind Events

作　　者：苏延文 黄国庆[2] 曾永平[1] SU Yanwen;HUANG Guoqing;ZENG Yongping(China Railway Eryuan Engineering Group Co.Ltd,Chengdu,Sichuan 610031,China;Research Center for Wind Engineering,Southwest Jiaotong University,Chengdu,Sichuan 610031,China)

机构地区：[1]中铁二院工程集团有限责任公司,成都610031 [2]西南交通大学风工程试验研究中心,成都610031

出　　处：《铁道工程学报》2019年第12期41-47,共7页Journal of Railway Engineering Society

基　　金：四川省科技计划资助(2018GZ0052)

摘　　要：研究目的:为探究非平稳风速对大跨桥梁抖振响应的影响机理,以两组实测非平稳风速样本为例,首先提出建立非平稳风速模型的三层次方法;其次通过递归图分析获得一种有效衡量风速非平稳强弱程度的定量指标;然后采用快速CQC方法(虚拟激励法)建立非平稳瞬态风-桥梁结构抖振随机响应的计算方法;最后以某座山区悬索桥为工程背景,针对强弱两组风速对大跨桥梁抖振响应的影响进行对比与总结。研究结论:(1)非平稳性弱的实测风速样本可简化为平稳抖振理论进行分析,可显著提高风致响应的计算效率;(2)脉动风速非平稳性越强,大跨桥梁振动响应越远离稳定状态;(3)对于非平稳指标较强的实测风速样本,常规的平稳处理(10 min常值平均风速+平稳脉动风速)将会低估桥梁的抖振响应,需要进行精细化的非平稳瞬态响应分析;(4)本研究成果可为大跨径桥梁精细化的风致响应快速求解和抗风设计提供技术支撑。Research purposes:To investigate the buffeting response effect mechanism of long-span bridges subjected to non-stationary wind speed,taking two sets of observed non-stationary samples as examples,an three-layer accurate modeling method for non-stationary wind events was firstly proposed,then a quantitative indicator that can effectively measure the degree of non-stationarity was obtained by the recurrence plot.Furthermore,the fast CQC method(i.e.,pseudo excitation method)was adopted to establish the buffeting analysis method of time-varying wind-bridge system subjected to non-stationary winds.Finally,taking a mountain suspension bridge as an engineering background,the similarities and differences of buffeting responses of long-span bridges under strong and weak wind speeds were compared.Research conclusions:(1)The weak non-stationary winds can be simplified as stationary buffeting theory that can significant improve computational efficiency.(2)The more rapid variation rate of the wind fluctuation indicates that the structural vibration response is further away from its steady-state.(3)Traditional stationary treatment for the strong non-stationary winds(10 min constant mean plus stationary wind fluctuation)may underestimate the bridge buffeting responses,thus refined transient analysis may be required.(4)The research results can provide technical support for refined wind-induced dynamic response and wind-resistance design of long-span bridges.

关 键 词：桥梁工程 随机振动 非平稳 抖振响应 递归图 

分 类 号：U441+.3[建筑科学—桥梁与隧道工程]