单箱多室波形钢腹板组合箱梁桥动力特性参数分析

Parametric Analysis of Dynamic Characteristics of Multi-Cell Single-Box Composite Box Girder Bridge with Corrugated Steel Webs

为研究结构参数对单箱多室波形钢腹板组合箱梁桥动力特性的影响,以南昌市朝阳大桥非通航孔桥为工程背景,利用有限元分析软件ANSYS建立该桥的空间有限元模型,分析横隔板和横隔梁布置、钢腹板板厚、钢腹板与横隔梁连接方式、支座约束及箱梁截面形式对该桥频率及振型的影响。结果表明:端横隔板对结构基频影响较大,中横隔梁主要影响桥面板局部振动;结构各阶频率随着腹板厚度增加略微增加;腹板与横隔梁的不同连接方式对各阶频率与振型影响不大;双固定支座可以限制结构横向弯曲,延缓桥面板局部振动出现;合理选择箱梁翼缘板宽度和箱室宽度可以有效限制结构扭转变形。

To study the influences of the structural parameters on the dynamic characteristics of the multi-cell single-box composite box girder bridge with corrugated steel webs, the non-navi- gable span bridge of the Chaoyang Bridge in Nanchang City was taken as example. The analysis software ANSYS was used to build up the spatial finite element model for the bridge and the in- fluences of the diaphragm arrangement, steel web thickness, connections between the steel webs and diaphragms, bearing restraint and the box girder cross section types on the vibration frequen- cies and vibration modes of the bridge were analyzed. The results of the analysis indicate that the end diaphragms have considerable influences on the base frequencies of the structure and the mid- dle diaphragms mainly have influences on the local vibration of the deck slabs. With the increase of the web thickness, the different orders of the vibration frequencies of the structure may slight- ly increase. The influences of the different connections between the webs and diaphragms on the different orders of the vibration frequencies and vibration modes are not great. The double-fixed bearings can restrict the transverse bending of the structure, retard the occurrence of the local vi- bration of the deck slabs and the proper selection of the flange plate width and cell width of the box girder can effectively restrict the torsional deformation of the structure.