铁路简支梁桥动力响应数值分析与实测验证  

Numerical Analysis and Field Measurement Validation of Dynamic Characteristics of Simply-supported Beam Railway Bridge

作　　者：张一鸣 王飞球 金顺利 谢以顺[1,2] 王浩 ZHANG Yi-ming;WANG Fei-qiu;JIN Shun-li;XIE Yi-shun;WANG Hao(School of Civil Engineering, Southeast University, Nanjing 210096, Jiangsu, China;China Railway 24th Bureau Group Co., Ltd., Shanghai 200071, China)

机构地区：[1]东南大学土木工程学院,江苏南京210096 [2]中铁二十四局集团有限公司,上海200071

出　　处：《建筑科学与工程学报》2019年第4期87-93,共7页Journal of Architecture and Civil Engineering

基　　金：国家重点基础研究发展计划(“九七三”计划)项目(2015CB060000);江苏省重点研发计划项目(BE2018120);中国铁路总公司科技研究开发计划重点项目(2017G002-K)

摘　　要：以某铁路简支梁桥为工程背景,基于有限元软件ANSYS实现了列车荷载作用下简支梁桥自振特性分析与动力响应计算,并利用现场实测加速度响应对有限元计算结果进行了验证。基于验证后的有限元模型,研究了跨径、车速及车重等关键因素对铁路简支梁桥动力响应的影响,采用移动荷载模型分析该简支梁桥在列车荷载作用下的动力响应。结果表明:简支梁桥自振频率及加速度特征值与有限元计算值总体上吻合较好,但由于现场实测存在多种环境因素干扰,局部对比结果存在差异;有限元计算的加速度平均值大于现场实测值,但幅值相差不大且都呈周期性变化;桥梁1阶及3阶自振频率的实测值与有限元计算值较为接近;跨径、车速及车重等关键因素均对桥梁动力响应产生一定影响,随着列车车速的提高,简支梁桥动力响应明显增加,列车驶离桥梁后,桥梁自由振动的振幅随车速的提高显著增大;简支梁桥跨径与车重均对跨中截面挠度影响显著,在设计过程中应予以重视;所得结论可为铁路桥梁的动力性能评价提供参考。A simply-supported beam railway bridge was employed as an example,the vibration responses of natural vibration frequency and dynamic characteristics were calculated based on ANSYS.The reliability of the calculated results was validated by the field measured acceleration response.On the basis,some key factors which influence the dynamic characteristics of bridges,including bridge span,velocity and train weight were analyzed based on the finite element model.The dynamic response of the simply supported beam bridge was analyzed based on moving load model.The results show that the measured natural frequency and acceleration can match well with the calculated results in general.However,some of the calculated results deviate from the measured ones due to the interference of external factors.The average acceleration calculated value by finite element method is larger than measured value,but the difference in amplitude is small and periodic.Bridge span,velocity and train weight have an influence on dynamic characteristics,and the bridge deflection increases remarkably with the increasing of these factors.With the increase of train speed,the vibration response of simply supported beam bridge is obvious.The bridge vibration increases significantly with the increase of train speed,when the train leaves the bridge.The bridge span and train weight have significant influence on the deflection of bridge midspan,which should be paid more attention to in the design process.The results can provide references for the vibration performance evaluation of railway bridges.

关 键 词：铁路桥梁 简支梁桥 动力响应 现场实测 数值计算 

分 类 号：U24[交通运输工程—道路与铁道工程]