中文摘要：

组合桥梁结构型式多种多样，但仍然不能够满足当代重要工程结构建设的需要．在组合桥梁结构发展中，需要提出新型的组合桥梁结构型式，提出一种新型组合桥梁结构钢管混凝土桁架与预应力混凝土上下翼缘板组合箱梁桥．针对该新型组合桥梁结构在设计方面资料缺失的问题，通过建立ANSYS有限元模型，研究节间高宽比和腹杆刚度这些结构参数对整体桥梁结构受力性能的影响规律．结论表明，随着节间高宽比或腹杆刚度的增加，新型组合桥梁结构跨中最大挠度非线性减小，当节间高宽比大于1．2时，梁体最大挠度变化接近零；随着节间高宽比或腹杆刚度的增加，新型组合桥梁结构的顶板和底板的受压部分的压应力逐渐变小，底板受拉部分的拉应力逐渐增大；随着节问高宽比的增加，腹杆最大轴向拉力非线性减小，腹杆最大轴向压力非线性减小，当节间高宽比大于1．2后，腹杆最大轴向拉力变化接近零．这些结论可以为该类组合桥梁结构的设计提供重要的理论参考．

英文摘要：

Though types of composite bridge structures are many, they still can＇t meet the needs of the construction of con- temporary and important engineering structures. In the development of the composite bridge structure, it is necessary to put forward new-type composite bridge structures. This paper puts forward a new-type of composite bridge structure i. e. concrete filled steel truss and prestressed concrete top and seat flange plate composite box girder bridge. To solve the problem that the meterial is deficient in design, the influence law of such structure parameters as the aspect ratio, stiff- ness of web member on the entire structure is studied through building ANSYS finite element model in this article. Re- sults show that with the increas of the ratio of internode or stiffness of web member, the maximum deflection coefficients of bridge structure is reduced nonlinearly; when the ratio of internode is more than 1.2, the change of the maximum de- flection coefficients is close to zero; with the increase of the ratio of internode or stiffness of web member, the compres- sive section of roof and floor of new-type composite bridge structure is reduced gradually, and the tensile section of floor is increased gradually. With the increase of the ratio of internode, the maximum axial tension is reduced nonlinearly, and the axial pressure is reduced linearly. When the ratio of internode is more than 1.2, the change of the maximum axial tension is close to zero. Those results provide theoretical reference for design of those similar composite bridge structures.