基于悬索桥修正成桥线形的索夹弯曲应力分析  

Analysis of Flexural Stress of Cable Bands Based on Modified Completed Bridge Geometric Shape of Suspension Bridge

作　　者：阮坤[1] 陈作银 陈冠桦[2] 

机构地区：[1]北京建达道桥咨询有限公司,北京100016 [2]贵州省交通规划勘察设计研究院,贵州贵阳550001

出　　处：《世界桥梁》2011年第6期46-49,共4页World Bridges

摘　　要：为较精确地分析悬索桥成桥线形下索夹对主缆弯曲次内力的影响,基于成桥状态下的分段悬链线理论,考虑索夹的套箍作用修正成桥线形,使其更接近于实际线形。修正后的成桥线形近似为各段悬链线与短直线段交替连续的混合线形。以三汊矶大桥为例,利用有限元法计算出索夹端面处主缆的主拉应力及索夹相对转角,代入WYATT公式,计算出主缆在各个索夹端部的二次弯曲应力及索夹在吊杆力作用下的纵向弯曲应力。计算结果表明:桥塔附近索夹端部主缆二次应力较大;当荷载作用于一个边跨或半中跨时,加载跨索夹端部主缆二次应力较大;各索夹纵向弯曲应力分布较稳定,均符合结构实际受力特点。To accurately analyze the influence of cable bands on the secondary flexural internal force of main cable under the condition of completed bridge geometric shape of suspension bridge,the completed bridge geometric shape was modified to make it closer to the actual geometric shape according to the segmental catenary theory of the completed bridge and in consideration of banding effect of the cable bands,and the modified geometric shape was approximated as the alternatively continuous mixed geometric shape of each segment of the centenary and short straight line.By way of example of the Sanchaji Bridge,the finite element method was used to calculate the principal tensile stress of the main cable at the end surfaces of the cable bands and to calculate the relative rotation angles of the cable bands.The calculated tensile stress and rotation angles were substituted into the formula WYATT and the secondary flexural stress of the main cable at each end of a cable band and the longitudinal flexural stress of the cable bands under the action of suspender forces were calculated.The results of the calculation show that the secondary flexural stress of the main cable at the end surfaces of the cable bands nearby the tower is great and when load acts on one side span or on half a central span,the secondary flexural stress of the main cable at the end surfaces of the cable bands of the loaded span is great,the distribution of longitudinal flexural stress of each cable band is rather stable and is agreeable with the actual force condition characteristics of the structure.

关 键 词：悬索桥 成桥线形 悬链线 索夹 弯曲应力 有限元法 

分 类 号：U448.25[建筑科学—桥梁与隧道工程] U441.5[交通运输工程—道路与铁道工程]