大跨度铁路钢桥疲劳损伤修正系数研究  

Study and Formulation of Fatigue Damage Correction Factor of Long-span Railway Steel Bridges

作　　者：王丽 张玉玲 WANG Li;ZHANG Yuling(Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;State Key Laboratory of High-Speed Railway Track Technology,Beijing 100081,China)

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [2]高速铁路轨道技术国家重点实验室,北京100081

出　　处：《铁道标准设计》2023年第9期96-100,141,共6页Railway Standard Design

基　　金：中国国家铁路集团有限公司科技研究开发计划系统性重大项目(P2019G002)。

摘　　要：损伤修正系数是疲劳设计中的一个关键参数,与桥梁跨度和设计寿命期内运营列车密切相关,研究针对远期年运量为1500万t情况下,影响线长度在20~1100 m之间桥梁杆件的疲劳损伤修正系数进行计算分析,并提出取值建议。对国内外规范中疲劳损伤修正系数进行调研分析;以国内一座千米级大跨度悬索桥为背景,根据桥梁所在线路的运营特征,制定了典型疲劳列车,验证了简化为简支梁计算损伤修正系数的方法对于桥梁杆件的适应性;计算得到典型疲劳列车与列车荷载图式作用下的荷载效应比频谱,依据荷载效应比频谱得到损伤修正系数计算值。计算结果表明,在线路远期年运量为1500万t、机车轴重为25 t、货车轴重为23 t的情况下,20~1100 m影响线长度杆件的损伤修正系数计算值在0.476~0.725之间,随跨度增加损伤修正系数呈降低的趋势,当跨度增加至一定程度时,损伤修正系数基本不变。结合计算结果及现行规范规定,建议20~1100 m影响线长度杆件的设计损伤修正系数取值在0.6~0.9之间,大于600 m时按0.6计算。The damage correction factor is a key parameter in fatigue design,which is closely related to the bridge span and the operating trains during their designed life.The fatigue damage correction factor of bridge members with an influence line length of 20-1100 m under the condition of annual traffic volume of 15 million tons are calculated and analyzed,and values are proposed.The fatigue damage correction factors in domestic and foreign codes are investigated and analyzed.A domestic kilometer long-span suspension bridge is taken as research object and a typical fatigue train is formulated according to the operation characteristics of the line where the bridge is located.The adaptability to bridge members of the method simplified to calculate the damage correction coefficient of simply supported beams is verified.The load effect ratio spectrum of typical fatigue train is calculated,and the calculated value of damage correction factor is obtained.The calculation results show that when the long-term annual traffic volume of the line is 15 million tons,the axle load of locomotive is 25 tons and the axle load of freight car is 23 tons,and the calculated value of the damage correction factor of members is between 0.476-0.725.The damage correction factor decreases with the increase of span.When the span increases to a certain extent,the damage correction factor remains unchanged.Combined with the calculation results and the current codes,it is suggested that the design damage correction factor of 20-1100 m influence line length should be between 0.6-0.9,and when influence line is greater than 600m,the factor is 0.6.

关 键 词：大跨度桥 铁路桥 钢桥 疲劳设计 疲劳损伤修正系数 

分 类 号：U24[交通运输工程—道路与铁道工程] U448.36[建筑科学—桥梁与隧道工程]