The Simulation And Analysis Of Three-dimensional Base Isolation Structure

Base-isolated structure is a system different from traditional resistance structure,which can consume seismic energy effectively by setting the isolated layer betweenthe basis and the upper structure. As a method of passive structural control, baseisolation has been a practical method. However, its application is almost limited to thefield of horizontal isolation.A large number of earthquake damage records indicate that, the vertical seismiccan not be ignored for many building structures, which including the construction ofthe highly seismic region, important buildings near the epicenter, large span structures,irregular complex building etc. China’s current Code for seismic design ofbuildings(GB50011－2010) provides that the large span and long cantilever structurein the8,9degree area should be calculated considering vertical seismic action, andadditionally, the base-isolated structure in8,9degree area should also considervertical seismic action in accordance with the relevant norms.The impact of vertical ground motion produced near the epicenter or earthquakefault tend to exceed the level of seismic action. At present, the base isolationtechnology is increasingly mature which can mainly solve the problem of horizontalseismic shock. But according to strong motion records of isolated building both athome and abroad show that, the vertical seismic response of building has not beenweakened. Among the base isolation technology applications at present, the basicisolation layer can not provide the relative movement of the vertical isolation orreduce the effects of vertical seismic. Therefore it can not play a role in isolation orreduce the vertical seismic effect. In these buildings, with the effective control ofhorizontal seismic action, vertical seismic action may become a major factor in thebuilding structure damage.The major studies are as follows:1. On the basis of reading a lot of domestic and foreign literature, fullyunderstand the basic principle, main types of isolation system and the performance ofcontrol system, master the situation about horizontal isolation structure andthree-dimensional base isolation, and put forward the main research contents of thispaper;2. Proposing a new kind of three-dimensional seismic isolation structure systemand describing its the preliminary simplified design method; 3. Using SAP2000finite element software to modeling and analysis, contrast theresponse of the non-isolated structure with isolated structure and three-dimensionalseismic structure which has the same structure as the non-isolated structure. Then wecan get a reasonable mechanical parameter of isolation layer about three-dimensionalseismic isolation structure.4. Establish a simplified mechanical model of three-dimensional seismicisolation structure system to analyze its performance of anti-overturning, and have apreliminary study on the influence of several important mechanical properties ofisolation layer to limit value of depth-width ratio;5. Have a preliminary study on the catastrophe control method ofthree-dimensional seismic isolation structure with a strong shock;6. Describe the findings and make a prospect about the research.