The Dynamic Response Of The Framed Spherical Steel Tank And Analysis Of Mid-story Seismic Isolation

In recent years, earthquakes happened frequently,especially the rare earthquake,it makes a serious threat to safeties of human life and wealth. And China is a country that earthquakes happened frequently.With the development of economy,it is inevitable that structures toward to a tendency,which large-scale and high-rise.The seismic research about high-rise structure that has long period is essential.The seismic isolation arises that based on the anti-seismic,as a new damping structure,it can extend the structural natural vibration period,effectively weaken the seismic action effect on isolation of upper structure.Seismic isolation structure according to the location is divided into two types,base isolation and mid-story seismic isolation,respectively.Both in china and foreign, many earthquakes experiences shows that adopting isolation avoided the damage under earthquake.At present, China has established hundreds of buildings used isolation technology.Steel storage tanks are widely used in petroleum, chemical industry, grain and oil, food,fire control, transportation, metallurgy, national defense and other industries, which is an important infrastructure.It’s safe to say we can’t live without tank.And the important role that tanks play in the national economic development is irreplaceable.Towering framework as a very important special structure, the application amount is large and the field of usage is wide that has in the electric power, water conservancy, post and telecommunications, tourism,municipal construction and so on.It can be seen that framed spherical tank has its unique use field, and cannot be ignored.But access to relevant data, found that China’s researches on frame spherical tank anti-seismic and isolation are less.Therefore, anti-seismic and isolation that studied for the frame spherical tank have a great significance, and hope it will provide reference for the similar engineering structures.This article mainly made time-history analysis to 1500 m3 frame spherical steel tank and the dynamic response analysis by adopting mid-story seismic isolation technology.The article main content includes:1.Based on the ADINA,this article established the model of the framed spherical steel tank,comparing and analyzing with four natural period methods at China and foreign,to certify the reliability of the model.2.Using equivalent quality method,establish three frame spherical steel tank models,which had 0%, 50% and 85% water in it,and chosen four types of field seismic wave:Qianan wave, El centro, Taft wave and Tianjin wave.Aiming at the effects of liquid sloshing on the structural,under frequent earthquake, made the time history analysis in one direction that was horizontal.It proved that the effects of liquid sloshing on the structural can not be ignored.3.For storage tank with 85% liquid, in four kinds of seismic waves, made three directions seismic time history analysis, known that under the three-directions earthquakes, the part at the bottom of the structure damaged easily.4.Determined the isolation bearings, set isolation layer in five different position.Pushing three-directions rare earthquake waves into the Isolation layer structure with 85%liquid,comparing with base isolation structure, and free of isolation structure,analyzing the dynamic response under the different isolation layers and different earthquakes.Result shows that energy absorption of isolation, not only related to isolation layer position, but also related to the characteristics of seismic wave.The energy absorption of base isolation was the best.When the isolation layer was put in lower near the bottom, the damping effect was best.