三跨钢-混混合连续梁桥结合段传力性能研究

G318国道长桥大桥主桥为三跨钢—混混合连续梁航道桥,该桥钢—混结合段在预应力混凝土箱梁侧预埋钢接头与钢箱梁焊接.为研究该桥钢—混结合段传力性能,采用有限元软件MIDAS FEA建立钢—混结合段有限元模型,对结合面钢箱梁侧腹板、结合部分混凝土及预埋钢板顶底面、钢接头部位进行应力分析.分析结果表明:该桥钢—混结合面钢箱梁侧腹板处于较好的工作状态；钢—混结合部分传力性能良好；钢—混结合部分传力机理为当弯矩荷载传递到钢垫板时,荷载主要由预埋钢接头的上、下缘承担,然后荷载通过钢板传递到混凝土,钢接头中的PBL开孔板及钢横隔板传力作用不明显.

Study of Force Transmitting Behavior of Joint Section of a Three-Span Steel and Concrete Continuous Hybrid Girder Bridge

The main bridge of the Changqiao Bridge on the National Road G318 is a three-span steel and concrete continuous hybrid girder shipping channel bridge.The design of the steel and concrete joint section of the bridge is that a steel joint is embedded on one side of the prestressed concrete box girder and is then welded with the other side of the steel box girder.To study the force transmitting behavior of the joint section,the software MIDAS FEA was used to set up the finite element model for the section and the stress in the webs of the steel box girder at the joint surface,in the concrete and bottom and top of the embedded steel plates of the joint part and in the steel joint was analyzed.The results of the analysis reveal that the webs of the girder are in good working conditions and the force transmitting behavior of the join part is satisfactory.The force transmitting mechanism of the joint part is that as the bending moment load is transmitted to the steel padding plate,the load is mainly shared by the upper and lower flanges of the embedded steel joint,the load is in turn transmitted to the concrete via the steel plates and the action of the force transmitting of the PBL perforated plates in the steel joint and of the steel diaphragm is not obvious.