时速400 km高速铁路预应力混凝土简支梁竖向基频下限探讨  

Discussion on Lower Limit of Vertical Fundamental Frequency of Prestressed Concrete Simply-supported Girder of 400 km/h High Speed Railway

作　　者：陈星宇 徐昕宇 郑晓龙[1] 周川江 CHEN Xingyu;XU Xinyu;ZHENG Xiaolong;ZHOU Chuanjiang(China Railway Eryuan Engineering Group Co.Ltd,Chengdu 610031,China)

机构地区：[1]中铁二院工程集团有限责任公司,成都610031

出　　处：《铁道建筑》2022年第2期79-82,共4页Railway Engineering

基　　金：国家自然科学基金高铁联合基金(U1934207);中铁二院工程集团有限责任公司司控项目(KSNQ202052)。

摘　　要：以24~40 m典型跨度简支梁为研究对象,通过有限元计算分析,确定不同跨度桥梁及不同列车荷载的简支梁容许动力系数。基于移动荷载列-桥梁动力仿真模型,探究列车移动荷载列形式、列车时速、简支梁跨度、竖向基频对梁体动力响应的影响规律。结合梁体振动加速度、容许动力系数和规范要求,确定时速400 km高速铁路预应力混凝土简支梁桥竖向基频下限值。结果表明:跨度为24~40 m时,梁体最大竖向动力响应均随简支梁跨度的减小而增大,24 m跨度简支梁的基频共振现象最显著;CRH3列车移动荷载列引起的桥梁动力响应普遍大于CRH380,相差约15%;对于时速400 km的CRH3和CRH380列车,24 m跨度简支梁的竖向频率下限建议值均为5.5 Hz,40 m跨度简支梁均为2.7 Hz,而32 m跨度简支梁的建议值分别为5.0、3.0 Hz。Taking the simple-supported girder with typical span of 24~40 m as the research object,the allowable dynamic coefficients of simple-supported girder with different span bridges and different train loads were determined through finite element calculation and analysis.Based on the dynamic simulation model of moving load train bridge,the influence laws of train load train form,train speed,simply-supported girder span and vertical fundamental frequency on the dynamic response of girder were studied.Combined with the girder vibration acceleration,allowable dynamic coefficient and code requirements,the lower limit of vertical fundamental frequency of prestressed concrete simplysupported girder bridge of 400 km/h high speed railway was determined.The results show that when the span is 24~40 m,the maximum vertical dynamic response of the girder increases with the decrease of the simply-supported girder span,and the fundamental frequency resonance of the simply-supported girder with a span of 24 m is the most significant.The bridge dynamic response caused by CRH3 train load is generally greater than CRH380,with a difference of about 15%.For CRH3 and CRH380 trains with a speed of 400 km/h,the recommended lower limit of vertical frequency of simply-supported girders with a span of 24 m is 5.5 Hz,that of 40 m is 2.7 Hz,and that of simplysupported girders with a span of 32 m is 5.0 Hz and 3.0 Hz respectively.

关 键 词：铁路桥梁 竖向基频 数值计算 混凝土简支梁 时速400 km 移动荷载列 

分 类 号：U237[交通运输工程—道路与铁道工程] U411.3