Seismic Performance Research Of Base Isolation Structure Based On The Pushover Analysis

Lead core rubber bearing base isolation structure is developing rapidly in recent years,and structure isolation technology is different from traditional anti-seismic structure of apassive suspension control technology. Lead core rubber isolation bearing which is set upbetween foundation and the main structure changed the principle of energy dissipation,extended the natural vibration period of the structure, decreased the seismic response of themain structure. In this paper, both at home and abroad about the lead rubber bearing baseisolation structure research at on the basis of according to the relevant specification, use thePushover analysis method analyze the seismic performance of lead rubber bearing baseisolation structure in theory. Modeled the engineering structure in the finite element analysissoftware Midas Gen, and run Pushover analysis to the base isolation structure compared withtraditional anti-seismic structure in seismic performance research discussion, the mainresearch results are as follows:(1) Base isolation structure is systematically presented in the paper with the fortificationtarget and performance level. According to the seismic code GB50011-2010, and combiningthe research results about fortification target and standard forms at home and abroad, theperformance of the base isolation structure level is divided into three levels. According to theimportance level of different buildings, puts forward three levels of base isolation structureseismic fortification goal, refer to the parameters of the control structure seismic performanceat home and abroad, adopts the maximum interlayer displacement angle of reinforcedconcrete frame structure limitation to quantify the fortification goal.(2) According to seismic design specification at home and abroad, introducing anelastoplastic analysis method-Pushover analysis, this paper discusses the advantages anddisadvantages of Pushover analysis, analysis of the target, basic assumption andimplementation steps, and combined with the ATC-40and FEMA356was introduced indetail for base isolation structure Pushover analysis of two kinds of lateral load loading mode,and the commonly used two kinds of Pushover analysis method.(3) Using Midas Gen program analyze the seismic performance study to a7layers leadrubber bearing isolation of reinforced concrete frame structure; run modal analysis to both thebase isolation structure and traditional anti-seismic structure, then conclude the naturalvibration period and a quality of modal participation factor in both of them; run Pushoveranalysis to both the base isolation structure and traditional anti-seismic structure, and comparethe performance between them, conclude the the base isolation structure’s seismicperformance indexes such as layer shear force and displacement, the interlayer displacementangle, the plastic hinge distribution state, conclude lead core rubber isolation bearings’ hysteretic curve and energy consumption characteristics under different earthquake levels.Then validate the rationality of Pushover analysis method for base isolation structureelastoplastic analysis.