Research On Reaction Of Base Isolation System In Earthquake

Base-isolation of building is one of the most important technical progress in the field of civil engineering for about twenty years. After discussed by hundreds of administrative and technical specialists from design institute and university and confirmed by construct ministry, the technique has been wrote into the "Code of Earthquake-Resistance Design(GB50011-2001) and have been applied in 2001.First, the paper brings forth the menace brought by earthquake and the significance of base-isolation compared with traditional earthquake-resistance. So ascertains the mainly research content of the paper.Second, the paper analyses the cybernetics principle of base-isolation, expatiates its detailed development process and its concrete appliance actuality, makes further analysis to its working theories and classifies it. In allusion to relatively mature status of folded rubber layer isolation, the paper introduces the conception of slippage base-isolation , which affords theory foundation for the sixth chapter's test .Additionally, simplified analyzed model of many freedoms base-isolation system is established based on basic presupposition. The movement equation of base-isolation structure system is deduced. Recur to the damp theory knowledge , equivalent damp matrix is also deduced. Vibration equation is made out ,from which we get relevant equation of velocity,acceleration and displacement.In allusion to analyzed means of earthquake reaction ,the paper lists two mainly method :time history analysis method and reaction table method. Toward Runge-Kutta method which is used frequently in time history analysis method, Relatively detailed integral steps are listed.At last, because the shearing force between two floors which induces the destruction of the structure is the important parameter ,the analysis of acceleration "a"in time history is important .Via dynamical examination ,in the sixth chapter we get acceleration data. Via programming and "matlab", we get twelve teams of contrasting diagrams of acceleration time history which consists of isolation state and resistance state. Via "visio", we get two teams of contrasting diagram of peak value of acceleration .because top structure energy "E" leads to direct damage of structure , the time history analysis of velocity "v" is more important. In the sixth chapter six teams of time history contrasting diagram of velocity are also listed. Via "visio", two visualized teams of velocity peak value diagrams are a listed, too. Predominant velocity, predominant period and isolation's ratio are figured out. Been convenient for contrast, the paper presents three teams of acceleration wrap- diagram and three teams of velocity parcel- diagram by the knowledge of curve's drawing up. Refer to a series of data and diagrams, in aspect of decrease damage of earthquake, isolation system of structure precedes resistance system greatly.Base-isolation is a kind of isolation measure which is applied in practice relatively early. But it is not well extend .it can not bring its latency advantage into play in front of great earthquake calamity. Along with attaching more importance to it and making more research to it, base-isolation must bring great operation into play.