以净跨180m的上承式钢管混凝土拱桥为例,在考虑车桥耦合振动的基础上,引入振动加速度峰值和振动感觉指标,研究车辆荷载作用下桥梁的振动控制问题,给出了舒适度的评价方法。评价结果表明,该桥在设计车速下条件下比值小于0.61,满足舒适度标准,但结构刚度并非象挠度检算表明的那么富裕,在稍微超速的情况下即以超限。由此可见,活载挠度限值并不能有效地控制桥梁结构的振动,为了确保桥梁安全和舒适性,建立我国桥梁振动判断标准势在必行,并使以人为本的设计理念得到真正的落实。
Taking one deck-type CFST arch bridge with 180 m clear span for example, considering coupled vehicle-bridge vibration, vibration peak acceleration and vibration sensory indicators were introduced to research the bridge vibration control under vehicle load and comfort evaluation methods were presented. Evaluation results indicate that (1) VG value is less than 0.61 at the vehicle design speed and the bridge satisfies the criterion of comfort evaluation; (2) structure rigidity is not as sufficient as the defection check, the bridge inclines to over the prescribed limit with little over-speed and thus it can be seen that the limited live load deflection cannot control the bridge structural vibration effectively. Establishment of national bridge vibration criteria is imperative to ensure bridge safety and comfort as well as fulfill the people-oriented design concept.