摘要
在环境激励下钢结构人行悬索桥模态频率与行人步频相近,易引起共振,影响行人的安全及舒适性。而钢筋混凝土结构阻尼比相对较大,自振频率通常不在行人舒适度范围之内。为研究钢筋混凝土结构人行悬索桥舒适度问题,以一座(25+70+25)m钢筋混凝土结构的人行悬索桥为背景。基于桥梁模态分析了不同人群密度下行人主观舒适度,对舒适度未满足规范最优水平的模态作减振处理。结合质量比的影响,确定TMD最优参数,选择调谐质量阻尼器(TMD)减振方案。对比安装TMD前后桥梁各节点最大加速度峰值,对行人舒适度进行评价。结果表明:钢筋混凝土结构的人行悬索桥横向模态频率通常不在行人敏感频率范围内。主梁上施加竖向力这一结构特性是研究该类型桥梁舒适度所要考虑的主要因素。随着人群密度的增加竖向舒适度降低,在竖向舒适度未满足要求的振型峰值位置处附加与相应模态质量比为1.2%的TMD,人致振动的减振率可达54.6%,减振效果明显。因此,安装TMD可保证钢筋混凝土结构的人行悬索桥在高人群密度下,竖向舒适度也可达到最优水平。
Under environmental excitation,the modal frequency of a steel structure pedestrian suspension bridge is similar to the pedestrian step frequency,which can easily cause resonance and affect pedestrian safety and comfort.However,the damping ratio of reinforced concrete structures is relatively high,and the natural frequency is usually not within the range of pedestrian comfort.To study the comfort level of reinforced concrete pedestrian suspension bridges,a(25+70+25)m reinforced concrete pedestrian suspension bridge is taken as the background.Based on bridge modal analysis,the subjective comfort level of pedestrians under different crowd densities was analyzed,and vibration reduction treatment was carried out for modes whose comfort level did not meet the optimal standard level.Based on the influence of mass ratio,determine the optimal parameters of TMD and select the tuned mass damper(TMD)vibration reduction scheme.Compare the maximum peak acceleration of each node of the bridge before and after installing TMD,and evaluate pedestrian comfort.The results indicate that the transverse modal frequency of pedestrian suspension bridges with reinforced concrete structures is usually not within the range of pedestrian sensitive frequencies.The structural characteristic of applying vertical force on the main beam is the main factor to consider when studying the comfort of this type of bridge.As the density of the crowd increases,the vertical comfort decreases.By adding a TMD with a mass ratio of 1.2%to the corresponding mode at the peak position of the vibration mode where the vertical comfort does not meet the requirements,the vibration reduction rate of human induced vibration can reach 54.6%,and the vibration reduction effect is significant.Therefore,installing TMD can ensure that pedestrian suspension bridges with reinforced concrete structures can achieve optimal vertical comfort under high crowd density.
作者
尖秀涛
亓兴军
米家禾
曹三鹏
巩茂康
JIAN Xiutao;QI Xingju;MI Jiahe;CAO Sanpeng;GONG Maokang(School of Civil Engineering,Shandong Jianzhu University,Jinan,Shandong 250101,China;School of Transportation Engineering,Shandong Jianzhu University,Jinan,Shandong 250101,China;Jinan Kingyue Highway Engineering Company Limited,Jinan,Shandong 250101,China)
出处
《公路工程》
2025年第1期98-103,共6页
Highway Engineering
基金
山东省交通运输厅科技计划项目(2022B06)
山东省企业技术创新项目(202160101415)。
关键词
人行悬索桥
舒适度
调谐质量阻尼器
减振
pedestrian suspension bridge
comfort level
tuned mass damper
vibration reduction
作者简介
尖秀涛(2000-),男,山东临沂人,硕士,研究方向:桥梁抗震。;通信作者:亓兴军,E-mail:qxj123@163.com。
