Computational Analysis And Research On Relevant Parameters Of Isolation Layer And Seismic Response Based On Base-isolated Benchmark Building

The base isolation technology is the most representative seismic technology, and its varioustheories have been gradually developed and perfected. Therefore, in order to provide acommon platform for studying and comparing the various types of isolation program, controlalgorithm, control devices and control effect, it is very important to establish a standard andwidely accepted isolated structure model and propose a system of evaluation indicators aboutcharacteristics of this type of structures. So, the American Society of Civil Engineers (ASCE),Gavin (Duke University) and Johnson (University of Southern California), proposed the base-isolated Benchmark model. In order to make this model better used in theoretical research,and provide a new basis for isolation scheme design. The main research works were done inthis paper.Take the base-isolated Benchmark model as the research object, the characteristics of thismodel were evaluated, describe movement characteristics of this model with three freedomdegrees of each particle, motion equations were established under bidirectional earthquakeexcitation and the seismic response of dynamic calculation methods and calculationprocedures were established. The calculations show that the proposed calculation method isreasonable and reliable. It shows that base isolation can significantly reduce the variousseismic response and meet seismic design requirements, through comparing calculations ofnon-isolation scheme and two isolation schemes under8degrees rare earthquake.Idealized stiffness of the isolation layer was set up on the basis of the base-isolatedBenchmark model. Making the stiffness center of isolation layer moves in the mass centerand the first mode mass center by adjusting stiffness distribution parameters of the isolationlayer. The torsional effect of Benchmark model is minimal when the stiffness center ofisolation layer coincides with mass center. With the stiffness center of isolation layergradually deviated from the mass center, the isolation effect of translational directionbecomes better, and the isolation effect of torsional effect becomes worse. And three isolationschemes were used to further verify the impact of horizontal stiffness of isolation layer ontorsional and translational of the superstructure.To study the relationship of flexion weight ratio of isolation layer between isolation layerdisplacement and the superstructure reaction on the basis of the base-isolated Benchmarkmodel, through calculating the seismic response under all levels of fortification intensity inrare earthquake. In the7degrees fortification, the isolation layer can without lead in theory.In8degrees fortification, flexion weight ratio of the isolation layer about3%is appropriate.In9degrees fortification, flexion weight ratio of the isolation layer about4.8%is appropriate.