大跨度钢桁梁桥静动力性能试验研究

以某铁路64m单线栓焊下承式钢桁梁桥为研究对象,采用数值模拟分析和现场试验相结合的方法,进行提速和扩能条件下的大桥静动力性能试验研究。结果表明:静载作用下,实测大桥杆件应力和跨中挠度均小于理论计算值,挠度、应力校验系数略大于规范通常值,挠度和应力相对残余均满足要求,上下游两片受力较为均匀;不同速度列车作用下桥梁运营性能指标基本满足规范要求,但实测数据均较大,且大于同类型双线钢桁梁桥,空重混编列车引起桥梁更大振动;桥梁基本满足承载能力和使用条件要求,结构处于良好的弹性工作状态,但桥跨结构整体刚度偏弱,安全储备较小,建议对桥梁整体刚度进行加强并对桥梁动力响应进行实时监测。

Test Research on Static and Dynamic Performances of Large Span Steel Truss Girder Bridge

Taking the 64 m through steel truss bridge as the research object,the test research on bridge static and dynamic performances is completed with numerical analysis and field test. The results show that under static load the measured stress and deflection of the bridge are less than the theoretical calculation,the deflection and the stress check coefficient are slightly larger than the standard normal values,the relative residual of deflection and stress meet the standard requirement,and the stresses of the two main trusses are in balance. The operating performance indicators under trains of different speed can basically meet the standard requirements,but the measurements are larger than that of similar double wire steel truss bridge. The empty and weight mixed trains cause greater vibration. Overall,the bearing capacity and service condition of the bridge basically meet the standard requirements and in good elastic working condition,but the bridge structure overall rigidity is weak with small emergency capacity. Thus,it is recommended that the entire bridge stiffness should be strengthened and the real-time bridge dynamic response monitored.