为了研究随机车流制动状态下斜拉桥的结构纵向响应以及黏滞阻尼器的振动控制效果，结合采集的交通荷载数据与交通流关键参数统计，建立3种车流密度的随机车流模型。其次基于车-桥系统耦合关系，利用改进折半查找法确定单主梁模型车辆荷载加载方法，编制单主梁模型车-桥耦合分析模块。通过建立的随机车流制动模型，对斜拉桥制动工况下结构纵向响应、纵向黏滞阻尼器振动控制效果和制动影响因素进行分析。结果表明：随机车流制动工况下，会产生相反方向的制动响应，且桥梁结构响应大于正常随机车流；纵向黏滞阻尼器可有效控制结构纵向位移，速度指数α越小，阻尼系数C越大，控制效果越突出，控制效率最大可达到90%左右；桥梁后半段制动响应和制动系数明显大于前半段的制动响应；制动车道越多，制动响应和制动系数越大；对于车流密度，制动产生的响应和制动系数大小规律为——密集流>适中流>稀疏流。

Here, in order to study longitudinal response of cable-stayed bridge under braking state of random traffic flow and vibration control effect of viscous damper, firstly, combining the collected traffic load data and the key parameters statistics of traffic flow, random traffic flow models with 3 kinds of traffic flow density were established.Secondly, based on the vehicle-bridge system coupled relation, the improved half search method was used to determine the vehicle loading method of single girder model, and the vehicle-bridge coupled analysis module of the single girder model was compiled.Finally, longitudinal response of a cable-stayed bridge under braking condition, vibration control effect of longitudinal viscous damper and braking influencing factors were analyzed using the established random traffic flow braking model.The results showed that under braking state of random traffic flow, the braking response in opposite direction can be produced, and the bridge structure response is larger than that under normal random traffic flow; longitudinal viscous damper can effectively control the bridge’s longitudinal displacement, the smaller the speed index α, the larger the damping coefficient C and the more prominent the control effect, the maximum control efficiency can reach about 90%; the braking response and braking coefficient of the bridge’s second half are obviously larger than those of the first half; the more the braking lanes, the larger the braking response and braking coefficient; for the traffic flow density, the law of the braking response and braking coefficient is: dense flow > moderate flow > sparse flow.