大跨度曲线简支钢箱梁设计及受力分析

Design and stress analysis of long span curved simply supported steel box girder

城市跨线桥设计,随着路网密度的不断发展,难免出现在已修建的高速路或城市快速路上方修建跨越式桥梁,但该类桥梁的构建,又往往会受到桥下构造物的影响。为了减少对桥下跨越道路交通的影响,加快施工进度,大都倾向于采用自身重量小、高跨比小、结构轻盈且施工简便的钢箱梁桥。基此,以一座跨越城市快速路的58m简支钢箱梁桥为工程实例,采用Midas/Civil软件建立单梁模型,并对其纵向、横向、刚度及抗倾覆验算分析。工程实践结果表明,钢箱梁可以较好适应道路线型,相较于预应力梁桥,高跨比小、受力简单,尤其适应小半径桥梁。

With the continuous development of road network density,the design of urban overpass bridges inevitably appears in the built expressway or urban expressway,but the construction of such bridges is often affected by the structure under the bridge.In order to reduce the impact on the road traffic under the bridge and speed up the construction progress,most of them tend to adopt the steel box girder bridge with small weight,small height span ratio,light structure and simple construction.Based on this,taking a simple steel box girder bridge of 58m across the urban expressway as an example,a single girder model is established by MIDAS/civil software,and its longitudinal,transverse,stiffness and anti overturning checking calculation analysis are carried out.The results of engineering practice show that the steel box girder can adapt to the road line better.Compared with the prestressed girder bridge,the high span ratio is small and the stress is simple,especially for the small radius bridge.