Application Of Thick Rubber Bearing In Vibration Isolation For Metro Surrounding Building Structures

The rapid development of subway system has strongly supported theextension of the cities and provided the urban population a fast and efficientcommuting choice. But at the same time, environmental vibration induced bytrains has become a serious environmental pollution and social nuisance, whichhas great impact for the residents living or working alongside the subway line.The subject of this research is to reduce the vibration of metro surroundingbuildings using base isolation method. Rubber bearings are used as the baseisolation solutions. Compared to the traditional rubber bearings, the thick rubberbearings may have better isolation effect but haven’t been studiedcomprehensively and systematically. So the main contents of this research are asfollows:1) Several on-site measurements are carried out on several representativelocations or buildings near subway lines in Beijing. The results are studied toreveal the basic law of the distribution of the environmental vibration and thebuilding response. The measurements can also help to evaluate the actual needof vibration control for the metro surrounding buildings. The data can be used asthe excitation resource of the following isolation analysis.2) Compression tests and shearing tests are carried out for rubber bearingsto investigate the physical mechanical properties under subway inducedvibration. The temperature dependency and other dependency tests are carriedout to evaluate the stability of the compression and shearing properties. Thetensile tests and extreme shearing tests are conducted to analysis the safety ofthe isolation buildings under earthquake excitations.3) A scale model test is conducted in the lab. The isolation effect ofdifferent types of rubber bearings are tested under various compressive stresses,testing frequencies and excitation intensity. The transfer functions are converted to fitful for the full size specimens to evaluate the real isolation effect in realvibration environment.4) Base on a real metro surrounding project in Wuhan, the time-historyanalysis is carried out for the building before isolation by FEM analysis. Thebuilding is then designed to be isolated using thick natural rubber bearings. Thetime-history is carried out again for the building after isolation, and the isolationeffect is demonstrated by compared to the former results.