In-situ experimental investigation of the influence of structure characteristics on subway-induced building vibrations

Many types of buildings have been widely constructed in the vicinity of subway lines in China.Normal life and business activities are hampered by excessive subway-induced vibrations.This study aims to determine the influence of structure characteristics on structure-borne vibrations,generally based on experimental results.Vibration measurements were performed in four typical sites in Wuxi,China,involving over-track buildings,along-track buildings,frame structure buildings and a masonry building.Special structure designs like structure transfer floor were also included.Then,the captured data was analyzed in the time domain and the frequency domain.Furthermore,the influence of building location,structure type and structure layout was investigated.Finally,vibrations were evaluated with ISO and Chinese criteria and structure optimization for vibration attenuation was proposed.It is found that over-track buildings are more severely affected than along-track buildings.Higher frequency contents(20‒60 Hz)in over-track buildings and lower frequency contents(0‒10 Hz)in along-track buildings should be seriously considered in vibration control.Weaker structure member joints and lower material strength would be beneficial to over-track buildings while the inverse situation would be beneficial to along-track buildings.The application of structure transfer floor‒generally stiffer structure members and structure discontinuity‒is also beneficial.

叠层厚橡胶支座力学性能及其震振双控性能分析

为实现地铁上盖建筑的震振双控效果,可将叠层厚橡胶支座用于该类结构体系转换层。与普通橡胶支座相比,叠层厚橡胶支座的单层橡胶厚度较大,既可用于水平隔震,又可减小上部结构的竖向振动。为准确评估其在地铁上盖建筑中的效果,设计了第一形状系数为6.82的叠层厚橡胶支座,并对足尺支座开展竖向压缩、水平剪切、竖向拉伸和高面压稳定性能试验。探究了竖向压应力、剪应变和加载频率等对支座力学性能的影响规律,得到了设计阶段叠层厚橡胶支座竖向压缩刚度、水平等效刚度、等效阻尼比和拉应力值等性能指标。基于试验力学性能指标,建立了固接模型、普通橡胶支座和叠层厚橡胶支座的地铁上盖结构模型,分别以选取的地震波和实测三向地铁振动为激励,通过时程响应分析,验证了叠层厚橡胶支座的震振双控效果,为地铁上盖建筑的震振双控提供技术方案。