Analysis Of Seismic Response Of Multi-story Isolated Structure Under Near Fault Ground Motion

Seismic isolated structure’s vibration period has increased through settingisolation layer effectively avoiding the site predominant period, while the energydissipation device of isolation layer also can absorb and consume the energy of theground motion input structure thus it could reduce the seismic response of thestructure. Seismic isolation technology in engineering tries to use up from the20thcentury20generations to now, after nearly a century of development, has to mature.Now, isolated buildings have been designed and built in thousands of above in theUnited States, Japan and other developed countries.With frequent earthquake in recent years, people more and more realized the nearfault earthquake to the damage of the structures might be more serious than the farfield earthquake, and due to the human the earth science and technology development,at the time of the earthquake also more and more seismic waves were recorded. All ofthese provide favorable conditions for studying the response of the structure under theeffect of near fault earthquake. Long-period components of near fault seismic wavestend to be strengthened and it is likely to bring the same long isolation vibrationperiod structure adverse effects. So the study of structure response under the seismicaction in recent fault is very necessary.In this article, through the analysis of an engineering example it comparesacceleration response and layer drift of isolation structure and non-isolation structureunder near fault earthquake and far-field earthquake. And then gets the followingconclusion:(1) Isolation structure still can have the effect of reducing seismic response undernear fault ground motion.(2) Isolation layer and layer displacement response of seismic isolated structureunder near fault earthquake is bigger than under far-field earthquake.Acceleration ofisolation structure under near fault earthquake is more variable.(3) Lead plug rubber bearing with low shear modulus of elasticity has bettervibration isolation effect.