In order to overcome the apparent characteristics as a flexible structure of a long-span single-tower cable-stayed bridge and the excessive axial force of the main girder, and to exert the advantages of cable-stayed arch cooperative system bridges, this paper proposes a new type of single-tower cable-stayed arch cooperative system bridge. On the premise of the same amount of steel, the new cooperative system bridge can have a greater stiffness than the existing cable-stayed arch cooperative system bridge with the same span. The new system bridge uses the main girder as the rigid tie bar to balance the arches’ thrusts, which enables the main girder to have a smaller axial force and makes the cable-stayed arch cooperative system bridge a thrustless structure. The proposed bridge is assembled by the following method: (a) constructing a cable-stayed bridge with a steel box girder to bear part of the dead load and to act as a construction platform firstly; (b) then installing arch structures and fixing they with the girder to bear the remaining dead load; and, (c) adding web members between the arch ribs and the girder to form a variable-height truss structure with the arch ribs as the upper chords and the girder as a lower chord to bear most of the live load at last. The underlying mechanical principles were explained, and the mechanical properties of the cooperative system bridges were calculated with the finite element method in this paper. The stiffness and axial forces in the girders are analyzed by the finite element method and compared with those of the conventional bridges. The FEA results show that the new cooperative system bridge has the truss structure’s characteristics, which shows apparent advantages of stiffness and much smaller axial force in the main girder.

为了克服大跨度单塔斜拉桥的柔性结构的明显特征以及主梁的轴向力过大，并发挥斜拉拱协作系统桥的优势，提出了一种新型的单塔斜拉拱合作系统桥。在钢量相同的前提下，与具有相同跨度的现有斜拉拱协作系统桥相比，新的协作系统桥可以具有更大的刚度。新的系统桥使用主梁作为刚性拉杆来平衡拱的推力，这使得主梁具有较小的轴向力，并使斜拉拱协作系统桥成为无推力的结构。拟议的桥梁是通过以下方法组装的：（a）用钢箱梁建造斜拉桥，以承担部分自重，并首先用作建筑平台；（b）然后安装拱形结构，并用大梁将其固定，以承受剩余的静载荷；（c）在拱肋和梁之间增加腹板构件以形成高度可变的桁架结构，其中拱肋为上弦，而梁为下弦，以最终承受大部分活荷载。解释了基本的力学原理，并使用有限元方法计算了协作系统桥梁的力学性能。大梁的刚度和轴向力通过有限元方法进行分析，并与传统桥梁的刚度和轴向力进行比较。