湖北国际物流枢纽中心配套工程:不同垂度四主缆悬索桥约束体系研究

Supporting Project of Hubei International Logistics Hub Center:Research on Restraint System of Four Main Cable Suspension Bridge with Different Vertices

燕矶长江大桥作为湖北国际物流枢纽中心配套工程,首次采用了不同垂度四主缆悬索结构,为了确保该结构在特定的约束体系下具有最佳的受力状态,文章提出多种约束方式组合,通过有限元模型分析,揭示各种约束体系下结构的受力及变形特性。结果表明:不同垂度四主缆悬索桥约束体系对主缆和吊索的受力影响不大;不同垂度四主缆悬索桥约束体系对桥塔和主梁受力、结构纵向变位影响较大,因而在设计中应充分模拟支座非线性力学特性;纵向半漂浮约束方式对减少桥塔弯矩及结构偏位有较大影响;竖向塔连杆约束方式可以过塔连杆的转动在一定程度上满足加劲梁纵向位移要求,且对解决支座的耐久性与更换问题有现实意义;在不同垂度四主缆悬索桥设计中,如要避免采用较大的伸缩缝,建议结构设置纵向限位装置。

Yanji Yangtze River bridge,as a supporting project of Hubei international logistics hub,has adopted a four-cable suspension structure with different sag for the first time.In order to ensure that the structure has the best stress state under a specific constraint system,this paper proposes a combination of multiple constraint modes,and reveals the stress and deformation characteristics of the structure under various constraint systems through finite element model analysis.The results show that the restraint system of four-main cable suspension bridge with different sag has little influence on the stress of main cable and sling;the restraint system of four-main cable suspension bridge with different sag has great influence on the stress of the tower and main beam and the longitudinal displacement of the structure,so the nonlinear mechanical characteristics of the support should be fully simulated in the design;the longitudinal semi-floating restraint mode has great influence on reducing the bending moment and structural deflection of the bridge tower;the restraint mode of the vertical tower connecting rod can meet the longitudinal displacement requirements of the stiffening beam to a certain extent through the rotation of the tower connecting rod,and has practical significance for solving the durability and replacement of the support;in the design of four-main cable suspension bridges with different sag,if large expansion joints are to be avoided,it is recommended that the structure be equipped with longitudinal limit devices.