双箱单室波形钢腹板组合箱梁设计研究

The design on composite box girder with twin-box single-chamber corrugated steel webs

深圳南山大桥上部结构为双箱单室波形钢腹板PC组合箱梁,对这种新型结构进行了缩尺试验,并建立了空间实体有限元模型,探讨其受力全过程,分析了横梁对这种组合箱梁的影响。研究结果表明,双箱单室组合箱梁的受力性能与单箱单室组合箱梁相似,其弹性阶段内的截面应变满足"拟平截面假定";小横梁的设置在一定程度上改善了顶板的受力状况,但对增强两箱整体性的作用不大;大横梁加设小横梁形式在小幅度增加自重的情况下,可增强两箱的整体性,并有效地改善箱梁顶底板的受力状态。

The up structure of Nanshan Bridge in Shenzhen is composed by PC composite box girder with twin-box single-chamber corrugated steel webs.A reduced scale experiment is performed to test this new structure,the spatial finite element model is established,and the whole stress process has been discussed.The influence of the cross girder on this combination box has been analyzed.The results show that the mechanical property of twin-box single-chamber box girder is similar to that of single box single-chamber box girder.The strain on the section corresponds with 'the assumption of plane section'within its flexibility stage.The setting of the small cross girder improves the loading state of the top flange,but with less strength in the integrity of two boxes.The form of large cross girders added in small cross beams can strengthen the integrity under the situation of a small increase of weight,and effectively improve the stress state on the top and the bottom plate of the box girers.