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在很多设计规范中,桥面上移动车辆的动态影响一般被处理为动力系数(动态影响系数)。由于既有桥梁路面的退化,根据现场测量所计算的影响系数比设计规范中规定的值高。建立3维车辆-桥耦合模型,用以模拟桥和车辆之间的相互作用以及研究多肋混凝土梁桥的影响因子。对桥的跨度、车速、路面条件对影响因子的影响进行了检测。对影响因子进行了卡方试验。试验显示:在相同路面条件下获得的影响因子遵循极值-I分布。最后,提出适用于新桥和既有桥计算影响因子的简化表达式。对5个桥影响因子的相应置信水平研究显示:破旧路面的短跨桥、旧桥,采用AASHTO标准时,将低估了影响因子。所提表达式能够用于AASHTO标准的修正。
In many design specifications, the dynamic effects of a moving vehicle on a bridge deck are generally treated as a dynamic coefficient (dynamic influence coefficient). Due to the degradation of existing bridges and pavements, the coefficient of influence calculated according to field measurements is higher than the values specified in the design specifications. A 3-D vehicle-bridge coupling model is established to simulate the interaction between the bridge and the vehicle and to study the influence factors of the multi-ribbed concrete bridge. The influence of bridge span, vehicle speed and pavement condition on influencing factors was tested. The impact factor was chi square test. The test shows that the influence factors obtained under the same road conditions follow the extreme-I distribution. Finally, a simplified expression suitable for calculating the influence factor of Xinqiao and existing bridges is proposed. The research on the corresponding confidence level of five bridge influence factors shows that: short-span and old bridge on worn roads, the AASHTO standard will underestimate the impact factor. The proposed expression can be used for AASHTO standard amendments.