高速铁路单索面矮塔斜拉桥的静动力性能

Static and Dynamic Performances of Single Cable Plane Extradosed Bridge on High Speed Railway

赣深(赣州—深圳)高速铁路剑潭东江特大桥主桥为(136+260+136)m双塔单索面矮塔斜拉桥,结构受力复杂,本文采用有限元分析与现场测试相结合的方法研究其静动力性能。结果表明:双肢薄壁墩水平抗推刚度小,在跨度大、墩身低,主梁应力控制设计的情况下可采用此墩型;采用塔、梁、墩固结的结构体系可有效弥补单索面斜拉桥抗扭刚度的不足;测试截面加载时,中箱室的剪力滞效应比边箱室大,剪力滞系数为1.14~1.24;桥梁横向自振频率实测值略大于计算值,而竖向自振频率实测值约为计算值的1.09倍,表明桥面轨道结构能提高梁体竖向刚度;桥梁动力性能满足动车组在小于或等于设计速度运行时的相关标准要求。

The main bridge of Jiantan Dongjiang super large bridge of Ganzhou-Shenzhen high speed railway is a extradosed bridge with double-pylon and single cable plane with a span of(136+260+136)m which has complex structural stress.In this paper,the static and dynamic performancesof extradosed bridge with single cable plane on high speed railway was researched by the combination of finite element model numerical analysis and field test.The results show that the horizontal thrust stiffness of double-leg thin-walled pier is small.This pier type can be adopted under the condition of large span,small pier height and main girder stress control design.The structural system using tower,girder and pier consolidation can effectively make up for the deficiency of torsional stiffness of single cable plane extradosed bridge.When the test section is loaded,the shear lag effect of the middle box chamber is greater than that of the side box chamber,and the shear lag coefficient is 1.14~1.24.The measured transverse natural frequency of the bridge is slightly larger than the calculated value,while the measured vertical natural frequency is about 1.09 times of the calculated value,which indicates that the bridge deck track structure can improve the vertical stiffness of the girder.The dynamic performance of the bridge meets the requirements of technical standards when the EMU operates at less than or equal to the design speed.