城市交通枢纽混凝土楼面动力放大系数实测研究

城市交通枢纽混凝土楼面的动力荷载效应不可忽视,现有结构设计规范尚未给出相应规定。以某大型城市公共交通枢纽为研究对象,开展了楼面结构在重载公交车辆作用下多个行车工况的现场测试,获取了不同行车速度下楼面结构的应变、挠度等动力响应,在此基础上计算了楼面结构的动力放大系数。结果表明:结构由动力荷载产生的响应明显大于静力荷载产生的响应;随行车速度的增加,动力放大系数先增大后减小;结构应变响应的动力放大系数比位移响应的动力放大系数取值范围大。研究成果可为大跨混凝土楼面板动力放大系数的取值提供参考。

The Study on the Field Measurements of Dynamic Amplification Factor of Urban Transportation Hub Concrete Floor Slab

The dynamic load effect of the concrete floor slab in urban transportation hub cannot be ignored, and the existing structural design codes have not givencorresponding provisions. The in-site tests were carried out on the concrete floor slabs of a large-scale urban transportation hub under the action of heavy-loaded public transit vehicles. The dynamic responses including structural strain and displacement were collected and then the dynamic amplification factor(DAF) was estimated. The experimental results show that the tested dynamic responses of displacement and strain were obviously higher than that induced by the same loads which were statically placed on the floor slab. The DAF increases first and then decreases with the driving speed of the public transit vehicles. The results also show that the range of DAF derived from strain measurements islargerthan that of the displacement measurements. The study based on the field measurements can provide knowledge for DAF estimationof the large-span concrete floor slabs.