摘要
为了及时发现结构异常、保障桥梁安全运营,以新光大桥健康监测系统为背景,提出了"多指标两级预警"的在线结构预警体系,确定了预警指标、预警阈值和预警流程,并重点对承载能力利用率、年疲劳损伤度、疲劳车辆荷载、跨中竖向变形及固有频率变化率等预警指标进行了研究。提出了基于实测静应力的应力分离方法并计算了构件的承载能力利用率,利用实测法计算了构件的年疲劳损伤度,同时进行其他预警指标的计算。结果表明,在当前荷载作用下新光大桥构件的承载能力利用率较低,构件承受活载能力的富余程度较高,年疲劳损伤度微小,其他预警指标的结果亦正常,满足使用要求。所提出的预警体系已成功应用于新光大桥长期健康监测,该体系可及时发现结构异常,对保障桥梁安全运营具有较大的实用价值。
To timely find out the structural abnormality and to ensure the safe operation of bridges ,the structural health monitoring system of the Xinguang Bridge was taken as the research object and an online structural early warning system of “multi‐index and two‐level warning” was proposed .The early warning indices ,thresholds and workflow were determined and the warning indices ,such as the bearing capacity utilization rates ,annual fatigue damage degrees ,fatigue vehi‐cle loads ,midspan vertical deformation and the change rates of natural frequencies ,were particu‐larly studied .The stress separation method based on the measured static stress was developed and the bearing capacity utilization rates of the components were calculated .The annual fatigue damage degrees of the components were calculated by the measurement method and meanwhile ,the other warning indices were calculated as well .The results of the research demonstrate that under the current load circumstances ,the bearing capacity utilization rates of the components of the Xin‐guang Bridge are low ,the margin of live load borne by the components is high ,the annual fatigue damage degrees are slight ,the results of the other warning indices are normal and the components can meet the operation requirements .The proposed early warning system herewith has been suc‐cessfully applied to the long‐term health monitoring of the Xinguang Bridge ,the system can time‐ly find out the structural abnormality and is of important practical application value to the safe op‐eration of bridges .
出处
《桥梁建设》
EI
CSCD
北大核心
2015年第3期44-50,共7页
Bridge Construction
基金
国家自然科学基金项目(51078150)
华南理工大学亚热带建筑科学国家重点实验室基金项目(2013ZA01)~~
关键词
桥梁结构
健康监测
结构预警
预警指标
预警阈值
承载能力
疲劳损伤
bridge structure
health monitoring
structural early warning
early warning in-dex
early warning threshold
bearing capacity
fatigue damage
