Study On The Effects Of Super High Rise Structre On Deep Soft Sites Under The Long Period Ground Motion Considering Soil-Structre Interacting

In recent years,with the development of economy and the increasing urban population,super high-rise buildings in the center of the city has developed fast.Many large and middle-sized cities located in sedimentary basin and seaside,covering these areas usually has the characteristics of deep soft sites.Super high-rise buildings belongs to the long period structure,sensitivity to the long period ground motion,prone to class resonance response.Moreover,soil-structure dynamic interaction based on soft soil foundation may cause adverse effects in the structure.At present,most countries including China specification in order to simplify the design,generally be safely using the rigid ground assumption and not included in the influence of SSI effect.By using finite element ABAQUS,four typical super high-rise buildings on deep soft soil layer of different natural vibration period(4s,6s,8s and 10s)are numerically simulated.Based on the four typical super high-rise buildings,The finite element model of considering SSI effect or without considering SSI effect was established.By using the selected three long-period seismic waves and one reference seismic wave,four typical super high-rise buildings are analysed.Based on seismic time-history analysis,the effects of super high rise structure on deep soft sites under the long period ground motion considering soil-structre interacting were obtained.For this purpose,The theoretical foundation and necessity for the performance or displacement based seismic design and Performance based seismic evaluation was Proposed.The main conclusions of this study are:Interlaminar deformation of structure under seismic action is the Main Effect Factor.Based on inter-story displacement,Example 1,2,3 and 4 considering SSI effect after the upper structure of maximum displacement between layers are not considering the effect of SSI 1.001,1.06,1.32,0.97,0.91,0.97,0.92,0.86,0.89,0.81,1.01,0.81 times and 0.91,0.83,0.90,0.83 times under Aqaba – Had era.EW wave,OSKO080508161146.EW,JIJI wave and ELCENTROL wave.This implies that the peak inter-story displacement upper structure that consider SSI effect are smaller than not consider SSI effect in example one,and are bigger than the other examples.It implies that SSI effect can be weakened the Seismic response of super high-rise buildings on deep soft soil layer.When the nature vibration period of upper structure is close to the nature vibration period of site,resonance vibration is easy to happen,It can magnify the Seismic response of super high-rise buildings on deep soft soil layer;With the increase of the upper structure first natural vibration period,the upper structure of inter-story displacement are weakened under the action of four seismic waves that consider SSI effect or not consider SSI effect.In the four examples,the peak acceleration response at the top of upper structure that consider SSI effect are smaller than not consider SSI effect,The peak acceleration amplitude under ELCENTROL wave is smaller than the other Seismic waves.This implies that SSI effect can be weakened the Seismic response of super high-rise buildings on deep soft soil layer,and response under the Far-field long-period ground motions are more significant;With the increase of the upper structure first natural vibration period,the upper structure of the top peak acceleration decreases under the action of four seismic waves that consider SSI effect.In the four examples,compared with the action of reference wave,the lateral displacement of upper structure,inter-story displacement and the peak acceleration amplitude became bigger under the three long-period seismic waves.This implies that the far-field long-period ground motions can magnify the Seismic response of super high-rise buildings on deep soft soil layer.