Experimental Study Of Three-dimensional Multi-function Isolation Bearings

Subway transportation system, one of main city traffic methods, has many obvious advantages. In recent years, subway transportation systems have been developed rapidly in China. However, with the development of subway construction, some negative effects also appear. One of the serious problems is the impact of vibration induced by subway train to environment.During the earthquake ground motion is more weight. The present study are generally attaches great importance to the horizontal earthquake action, ignore the vertical seismic action, but the earthquake damage macroscopic phenomena show that the influence of vertical seismic action is also obvious, its value is worth attention.To solve these problems, relevant studies are carried out in this dissertation. For the purpose of reducing the vertical vibration of structure under severe earthquake damage and the vibration of adjacent buildings induced by subway, a new three-dimension multi-function isolation device is developed to reduce the buildings vibration, and its practicability and feasibility are tested and verified through theoretical research, numerical simulation, experimental test and structure response analysis. The main achievements and contents including:(1) Based on the base isolation technique a new three-dimensional multi-function isolation device is designed, which is composed of rubber beading, dish spring and viscoelastic damper. The three-dimensional multi-function isolation bearing has three to appropriate stiffness and damping performance, the rubber bearing is used in horizontal isolation of earthquake while the dish springs bearing with viscoelastic damper is in vertical isolation of vibration. In view of the various components respectively to study their performance and design methods, put forward the three-dimensional multi-function vibration isolation design and calculation methods.(2) A 3D numerical model of dish spring composite bearing is built with the help of ABAQUS (finite element analysis software). Using mature technology, the application of a wide range of lead rubber bearing, with its bearing capacity parameter for the design of composite bearing upper dish springs reference. Through the vibration isolation theory and environment of metro induced vibration characteristics analysis to determine the performance parameters of composite bearing the dish springs. Through the combination of the above theoretical analysis and numerical simulation tools, grasp the basic mechanical characteristics of disc spring composite bearing.(3) Designing and making vertical vibration isolation bearing system--dish spring composite bearing model, through the contrast test, the vertical bearing capacity, the vertical stiffness, damping performance has carried on the systematical test and research. The experimental results indicate that the vertical bearing capacity of the device can meet the design requirements and the stiffness and damp properties of these damping devices is feasible. The stiffness stabled in 15-23 kN/mm. The equivalent damping ratio can reach 11%-26%. The stiffness and loading capacity under static loads are well matched with the results of theoretical calculation.(4) Using SAP2000 structure analysis software, set up eight layer frame structure model, selection of measured subway vibration affected 3-d seismic wave, vibration isolation are calculated respectively before and after the acceleration response of the building, the evaluation of three-dimensional multi-function vibration isolation effect of isolation bearing. The analysis results show that the three-dimensional multi-function isolation bearing can not only effectively reduce the subway running adjacent existing buildings caused by vibration. At the same time under severe earthquake, bearing performance in good condition, at the same time also have a certain degree of vibration damping effect.