下部结构刚度对梁拱组合桥静力性能的影响

Influence of Substructure Stiffness on Static Performance of Arch-beam Composite Bridge

结合工程实例,介绍了群桩基础采用等代双柱模型以考虑上下部结构共同作用的模拟方法,给出了等代双柱的参数换算公式,并在此基础上研究了下部结构整体刚度和桥墩转动刚度变化对上承式梁拱组合桥静力性能的影响。研究结果表明:下部结构整体刚度对梁拱结合段主梁弯矩影响较大、对主梁轴力影响较小、对成桥水平推力和年温差水平推力影响较大。桥墩群桩转动刚度对成桥内力几乎没有影响、对成桥推力和年温差水平推力影响较小。

With a practical engineering case, the simulation method for pile group foundation with equivalent column model considering the composite action of superstructure and substructure was introduced. Transformation formulas for the equivalent columns were given. On this basis, the influences of the changes of overall stiffness of superstructure and rotational stiffness of the group piles on the static performance of deck arch-beam composite bridge were studied. The result reveals that （1） the overall stiffness of the substructure has great influence on the bending moment of the main girder at the arch-beam combined se^Tnent and has less influence on axial force of the main girder; （2） the overall stiffness of the substructure im＇luences both horizontal thrust force at completion stage and temperature caused horizontal thrust force greatly; （3） the rotational stiffness of the group piles has little influence on the internal force＇s at completion stage and has less influence on the thrust force at completion stage and temperature caused horizontal thrust force.