城市整孔预制波腹箱梁研究

Research on Whole Span Prefabricated BoxGirder with Corrugated Web in Cities

城市中小型跨径桥梁中,横向分块的预制T梁和小箱梁存在稳定性差、工序复杂、视觉效果差等缺陷,而整体现浇箱梁存在地基处理成本高、交通与环保压力大等问题。本研究采用波形钢取代混凝土腹板,设计出一种重量仅471t的整孔预制波腹箱梁,相比于单幅现浇箱梁,自重减轻30.74%,刚度却增加23.45%。分析表明,整孔预制波腹箱梁在架设和成桥阶段的力学特性符合相关规范要求,通过对高速铁路架桥设备进行轻型化改装,可以完成整孔预制波腹箱梁的架设。经济性分析表明,整孔预制波腹箱梁造价比单幅现浇箱梁、工字钢梁组合梁造价分别降低6.18%、30.30%。从施工效率、城市美观、环保特性、经济性方面综合考虑,整孔预制波腹箱梁是一种用于城市中小跨径梁桥的较为理想的桥型。

The transverse block precast T-beam and small box girder in small and medium-sized spanbridges in cities have kinds of defects,such as poor stability,complex process and poor visual effect,whilethe whole cast-in-place box girder has problems such as high foundation treatment cost,heavy traffic andenvironmental protection pressure.In this paper,the corrugated steel is used to replace the concrete webs,and a kind of single precast box girder with corrugated web is proposed,which weighs only 471t.Compared with single cast-in-place box girder,the dead weight is reduced by 30.74%,while the stiffnessis increased by 23.45%.The analysis shows that the mechanical characteristics of the single line precastcorrugated box girder in the erection and the operation stages conform to the relevant specificationrequirements.Through the light modification of high-speed railway bridge equipment,the erection of thesingle line precast corrugated box girder can be completed.The economic analysis shows that the cost ofthe single line precast corrugated box girder is 6.18%and 30.30%lower than that of single cast-in-placebox girder and I-steel composite beam.From the comprehensive consideration of construction efficiency,urban aesthetics,environmental protection characteristics and economy,the single line precast wave-beltedbox girder is an ideal bridge type among the small and medium span girder bridges in the city.