基于吊杆损伤的斜靠式拱桥动力特性分析

The Analysis on the Dynamic Properties of Double X-shape Arch Bridge with Damaged Suspenders

根据平顶山市城东河路湛河桥主桥———斜靠式拱桥的结构特点,借助M IDAS/C ivil桥梁通用有限元程序,建立该桥的空间精细FEM,对不同吊杆损伤工况进行结构动力特性分析。通过与桥梁完好状态下的桥梁动力特性对比,可以得出结论:吊杆损伤对斜靠式拱桥的低阶自振频率总体影响较小,但对桥梁整体竖向自振频率和扭转自振频率相对影响较大,吊杆损伤导致桥梁竖向和扭转自振频率降低;主拱比稳定拱吊杆损伤对该桥的自振频率影响敏感,跨中比1/4跨处吊杆损伤对该桥自振频率影响大。

According to the structural characteristics of the main bridge of Zhanhe bridge,a double X-shape arch bridge,over Chengdong River in Pingdingshan City,the bridge＇s spatial mechanical computational FEM was erected by Finite element software MIDAS/Civil.By calculating and comparing the bridge＇s dynamic properties in the different degree damage of the suspender,it can be concluded that it has a slightly influence on the bridge＇s low order natural frequencies with the damages of suspenders,but has a great reduction on the frequencies of vertical and torque vibration.Compared with the damages of outboard suspenders,the damages of inside suspenders exert more influence on the bridge＇s natural frequencies;and by comparing with the damages of outboard suspenders in 1/4 span position,the damages of suspenders in span center have more influence on the bridge＇s natural frequencies.