叠层厚橡胶支座力学性能及其震振双控性能分析

Mechanical Properties of Thick Rubber Bearing and Its Earthquakeand Subway-Induced Vibration Control Analysis

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。

In order to achieve the control of earthquake-and subway-induced vibration in over-track buildings,thick rubber bearings(TRBs)are used in their structural transfer floor.Compared to conventional rubber bearings,the thickness of each rubber layer of TRBs is increased to isolate the horizontal earthquakes and mitigate the vertical vibration caused by subway.To evaluate the effects of TRBs in over-track buildings,an isolator with a first shape factor of 6.82 was designed in this study.Physical testing,including compression,shear,tension,and stability tests under large vertical loads,was conducted on a full-scale isolator.The effects of vertical compression stress,shear strain,and loading frequency on the mechanical properties of this TRB were explored.Performance properties,such as compressive stiffness,horizontal equivalent stiffness,equivalent damping ratio,and tensile stress were identified for the isolation design.Then,based on the identified parameters,numerical models of over-track buildings supported by fixed base,conventional rubber bearings and TRBs were established,respectively.Finally,time-history analyses were carried out by inputting selected seismic waves and three-direction subway vibration measured from field tests.TRBs were verified to provide effective subway and earthquake vibration control,and thus they represent a technical support for overtrack buildings.