摘要
以某62m钢管混凝土曲弦桁架桥为研究对象,依据其加固方案,运用通用有限元软件ANSYS建立其加固前后的空间有限元模型,计算该类型桥梁加固前后的自振频率,采用动态时程分析法对比分析其抗震性能。分析结果表明:加固后桥梁的频率值有不同程度的增大,特别是桥梁竖向与扭转频率增幅明显。加固前后桥梁上弦内力中轴力最大,剪力和弯矩较小,内力最大值基本上都出现在上弦两端位置处,此位置应作为桥梁抗震薄弱环节予以重视。在相同工况下,与加固前相比,桥梁加固后的轴力减小约30%,桥梁加固后的位移均有不同程度的减小。加固措施对桥梁横向刚度有所改善,对桥梁竖向刚度有明显提高,特别是对桥面系刚度提高显著。该类型桥梁宜用Taft波动态时程分析结果进行抗震截面验算,用EI-Centro波动态时程分析结果进行挠度验算。
Taking a 62 m concrete-filled steel tube bridge with curved string truss as the research object,according to its reinforcement scheme,the spatial finite element models of the bridge before and after reinforcement are established by using the general finite element software ANSYS.The natural frequencies of the bridge before and after reinforcement are calculated,and the seismic performance of the bridge is analyzed by using the dynamic time history method.The results show that the frequencies of the reinforced bridges increase in varying degrees,especially the vertical and torsional frequencies.Before and after reinforcement,the maximum axial force in the upper chord of the bridge is the largest,and the shear force and bending moment are small.The maximum internal force basically appears at the two ends of the upper chord.This position should be regarded as the weak link of the bridge seismic resistance.Under the same working conditions,the axial force of the bridge after reinforcement is reduced by about 30%compared with what before reinforcement,and the displacement of the bridge after reinforcement is reduced in varying degrees.The reinforcement measures can improve the lateral and vertical stiffness of the bridge,especially the stiffness of the deck system.For this type bridge,it is advisable to use the Taft wave for seismic section verification,and EI-Centro wave for deflection verification.
作者
陈代海
薛小风
张国臣
马凤瑞
Chen Dai-hai;Xue Xiao-feng;Zhang Guo-chen;Ma Feng-rui(School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,China)
出处
《工程抗震与加固改造》
北大核心
2019年第6期80-88,共9页
Earthquake Resistant Engineering and Retrofitting
基金
国家自然科学基金项目(51408557)
中国博士后科学基金(2013M541995).
关键词
钢管混凝土曲弦桁梁桥
桥梁加固
自振特性
地震波
动态时程分析
concrete-filled steel tube beam bridge with curved string truss
bridge reinforcement
natural vibration characteristic
seismic wave
dynamic time history analysis
