窄悬索桥加劲梁选型

Selection of Stiffening Girder for Narrow Suspension Bridge

清江特大桥主桥为420m单跨双铰悬索桥,主缆中心距离13.3m,宽跨比仅为1/31.6,桥位处基本风速31m/s,桥梁抗风性能成为设计中重要控制因素。初步设计阶段分别拟定混凝土板式结构、钢混叠合板式结构、钢箱梁、钢桁架4种加劲梁型式,对各种加劲梁型式分别进行了抗风颤振稳定性、桥梁竖向刚度、施工便利性、综合造价等方面比较,从而得出合理的加劲梁型式。

The main bridge of Qingjiang River Bridge is a 420-m single-span double-hinge suspension bridge. The center distance of main cable is 13.3 m. The width-span ratio is only 1/31.6. The basic wind speed at the bridge position is 31 m/s. The bridge wind-resistant property becomes the important control factor in the design. Four kinds of stiffening girder of concrete plate structure, steel-concrete combined plate structure, steel box girder and steel truss are separately proposed in the preliminary design stage. The article separately compares these four kinds of stiffening girders in the aspects of wind-resistant flutter stability,bridge vertical rigidity, construction convenience and comprehensive construction cost so as to select the reasonable stiffening girder.