Research On Factors Influencing The Torsion Of Base Isolation Structure

Base isolation technology is a damping control technology that is relatively mature applicationin the word at present, what is more, base isolation has been extensively studied home and abroad.However, the research of factors crossing torsion problems and torsion control indicators of baseisolation structure is not sufficient. In this paper, the above problem is studied by theoreticalderivate the torsional effects based on a base isolation model, we also select an engineering practiceexamples for analysis.The first chapter describes the causes of structure torsion and then gives the researchobjectives, content and ideas of this paper to twist control base isolated structure. The secondchapter gives the analysis model and data processing methods to reverse isolation studies. The thirdchapter theoretical derivate the torsional effects based on a simplified model and contrast theformula of the theoretical with the numerical simulation, finally, using data processing method ofnumerical tests to study influence degree of torsion structure caused by seismic intensity, theratio,eccentricity well as their interaction. In the fourth chapter, we choose a typical base isolationprojects to study the relationship between the ratio and the eccentricityThe results of this study show that the ratio as well as the eccentricity have a significantimpact on the torsion of the structure. When the ratio of translational period and torsional period ofthe base isolated structure change from0.7to1.0and the eccentricity of the isolation layer changefrom0.08to0.32,the ratio have more influence than the eccentricity. When the ratio changes from0.78to0.84and the eccentricity change from0.01to0.04, the eccentricity has more effect.However, when the eccentricity of the isolation layer of the base isolated structure is relativelysmaller, he ratio of translational period and torsional period can not be greater than0.82. When theratio is less than0.85, the eccentricity should be less than0.03; if the eccentricity can be controlless than0.04, the ratio should be controlled at0.82.