韩江北桥主桥力学性能分析

应用大型有限元程序MIDAS/Civil,建立了韩江北桥主桥整体的空间有限元计算模型,根据钢管混凝土统一理论计算了各桥跨拱肋单元的截面特性,采用刚度、质量等效原则对复杂桥面板进行了简化模拟。依据桥梁设计规范要求对该桥梁成桥阶段的静力性能进行了详细计算。计算结果表明,当桥梁某跨上布置有汽车荷载时,其余各桥跨是否布置有汽车荷载,对该桥跨竖拱拱肋及桥面系横梁内力、变形结果影响较小。因此,在桥梁设计计算中,可大大减少作用效应组合的数量,在进行桥梁整体性能计算做作用效应最不利组合时,为简化设计计算,可仅考虑汽车荷载沿全桥各桥跨布置这一种典型情况参与组合即可计算得到足够精确的计算结果。本文计算结果已为韩江北桥主桥设计提供依据,并对同类桥梁结构设计也具有重要的参考价值。

Analysis of Mechanics Properties for the Main Bridge of the Hanjiang North Bridge

A spatial finite element model of the main bridge of the Hanjiang north bridge is established integrally using a MIDAS/Civil program.The element stiffness data and section data of the arch rib in every span are calculated according to the CFST uniform theory.The complicated plate elements on the bridge are simplified based on the stiffness equivalent principle and the mass equivalent principle.The static properties of the bridge accomplishing stage are calculated in detail comply with the bridge design criterion.The computational results indicate that internal force and deformation in the arch ribs and the crossbeams of the span on which automobile loads act are not affected notably whether automobile load act on the other spans.So in the calculation of the bridge design process,the amounts of combination for action effects can be reduced greatly.When the worst combination for action effects is considered in calculating the properties of the whole bridge,a typical combination that automobile load act on all spans in the bridge is enough for simplification and the computational results can be drawn exactly.The results have been used for the design on the main bridge of the Han Jiang north bridge and can be great benefit for the similar projects.