Abstract: Taking a hex-pylon cable stayed bridge at home as the research object，the method and technology for calculating the overall vehicle load response were introduced． And then the characteristics response and response duration of the overall performance of the control structure under diverse traffic conditions were analyzed． The calculation results were compared with those in the vehicle load value of current bridge criterion ( JTG D 60—2004) ． Ｒesults show that: the extreme response values of the researched hex-pylon pylon cable stayed bridge under diverse traffic conditions are obviously smaller than those in the current bridge criterion，and it is of sufficient reserve of the vehicle load for the researched bridge in the term of current design; vehicle load response characteristics of multi-pylon cable stayed bridge are closely related with the daily traffic volume and the ratio of truck; different responses indicate different sensitiveness for the vehicle load modes and values． So， in order to reflect the actual vehicle load response，the vehicle load model with multi-level of multiple parameters is proposed to be established，which can optimize the design of multi-pylon cable stayed bridge．

Key words: multi-pylon cable stayed bridge, vehicle load response, vehicle load model, system optimization

摘要： 以国内某6塔斜拉桥为分析对象，引入汽车荷载实际响应计算的方法与技术，分析了不同交通运营状况下控 制结构总体性能的特征效应响应时程。并将计算结果与JTGD60—2004《公路桥涵设计通用规范》汽车荷载计算 结果进行了比较研究。结果显示:该多塔斜拉桥在不同交通运营状况下响应极值均显著小于规范计算值，依照现有 设计本桥对汽车荷载有很大安全储备;多塔斜拉桥的汽车荷载响应特征与日均交通量及重车混入率密切相关;不同 效应呈现出对汽车荷载加载方式及取值不同的敏感性能。为此，可以尝试建立反映实际负荷状况的多级别多参数 汽车荷载模型，优化多塔斜拉桥设计。

关键词: 多塔斜拉桥, 汽车荷载响应, 车辆荷载模型, 结构体系优化