新型大跨径连续钢桁组合梁桥设计关键技术

Key Technology for Design of New Long-span Continuous Steel Truss Composite Girder Bridge

摘要:

对于连续组合梁桥支点负弯矩区桥面板受拉是设计的关键控制点，对于大跨径钢桁组合梁桥这一点尤为突出。同时，负弯矩区桁架下弦杆的内力突变亦应引起设计的注意。以某实际工程为依托，详细介绍了新型大跨径连续钢桁组合梁桥设计的关键技术，通过制定合理的施工工序重点解决了混凝土桥面板开裂问题；通过在下弦杆灌注混凝土形成双重组合截面重点解决了下弦杆的受压稳定问题。

Abstract:

For continuous composite girder bridge, the tension of deck in negative moment area of fulcrum is the key control point of design, especially for long-span steel truss composite girder bridge. At the same time, the attention should be paid to the sudden change of the internal force of the lower chord of the truss in the negative moment area in design. Based on an actual project, the key technology for the design of new long-span continuous steel truss composite girder bridge is introduced in detail. The cracking problem of the concrete bridge deck is solved by formulating a reasonable construction process. The compression stability problem of the lower chord is solved by pouring the concrete into the lower chord to form a double composite section.