城市轨道交通上盖不同类型结构振动特性对比

Comparison of Vibration Characteristics in Over-Track Buildings with Different Structural Types

为了研究城市轨道交通上盖不同结构类型建筑的振动特性,以上海市徐泾车辆段上盖钢框架结构和钢筋混凝土(reinforced-concrete,简称RC)框架结构为研究对象,进行了轨道车致激励下不同结构类型振动测试,并采用Z振级、1/3倍频程和均方根加速度总量等对比振动响应。结果表明:两类结构底部楼层的振动响应基本接近,而盖上钢结构中上部楼层的车致振动响应较盖上钢筋混凝土结构大;钢筋混凝土结构的上部结构存在竖向高频成分(100~180 Hz)的振动;各楼层振动响应满足规范要求,针对盖上钢结构,后续设计可适当提高中上部楼层板的厚度,以提高楼层舒适度。该研究为城市轨道交通上盖不同结构类型的建筑开发提供数据支撑。

The comprehensive development of urban over-track areas is promoting the intensive progress of metropolises,and thus there are numerous buildings with different structural types increasingly emerging above the metro depots in these cities.However,the interaction between subway vehicles and tracks may induce vibrations to affect the comfort in over-track buildings.It is necessary to perform a comparative study of vibration characteristics in over-track buildings with different structural types.The research subjects of this paper are the steel frame and reinforced concrete frame buildings in the Shanghai Xujing metro depot.Field tests are carried out in these two buildings with different structural types.Comparisons of vibration responses are performed using evaluation indexes including the Z vibration level,one-third octave plumb vibration level,total root-meansquare acceleration,etc.The results show that the vibration responses of the first story in these buildings are almost the same,while the responses of the mid and top stories of the steel building are larger than those of the reinforced concrete building.There are high-frequency(100~180 Hz)vibrations existing in the reinforced concrete building.Besides,their vibration responses meet the limits of different codes.To further improve the floor comfort of over-track steel buildings,the design thickness of the mid and top stories can be appropriately increased.This study can provide data support for the development of over-track buildings with different structural types.