Aseismic Performance Analysis Of Assembled Shear Wall Base Isolated Structure

In early 2017,the general office of the State Council published The Opinions Of The General Office Of The State Council On Promoting The Sustainable And Healthy Development Of The Construction Industry.According to it,we should stick to intelligent application,prefabricated construction,integrated decoration,informatized management,industrialized production,standardized design.Also,we need to promote the innovation of construction methods,vigorously develop prefabricated concrete buildings,and constantly improve the use percentage of prefabricated buildings in new buildings.Therefore,this paper focus on the base isolation technology in the prefabricated shear wall consolidation structure.Then we propose different isolation schemes,and compare them to the traditional non-isolation scheme,to show the value in the engineering application.This paper is based on the building 5# of a project in Chang’an district of Xi’an,of which the assembled shear wall consolidated structure is modeled by finite element software Midas gen.Then,as we focus on isolation bearing arrangement optimization,three different base isolation schemes are designed,namely,lead-core isolation structure,rubber isolation structure and composite isolation structure.Next,the modal analysis of three proposed schemes and non-isolation structure is carried out,and the time history analysis under earthquake fortification is also conducted.For those four models,the modal period,layered-shear force,overturning moment,acceleration and layer displacement changes are studied.At last,based on the comparison and analysis,the conclusions are obtained as follows.(1)Introduces the base isolation structure of prefabricated shear wall,expounds the working principle of the base isolated structure,and designs three base isolation schemes according to the preliminary calculation results,which provides a theoretical reference for the seismic isolation design of prefabricated shear wall structure in the future.(2)The first natural vibration period of the prefabricated shear wall base isolated structure is increased by more than 90% compared with that of the non isolated structure,and the composite isolation structure has the best effect of prolonging the structural modal period.(3)The results show that the peak value of storey shear force and the peak value of overturning moment of prefabricated shear wall base isolated structure are reduced by more than 30% compared with that of non isolated structure,and that of composite isolation structure is reduced by 12.4% compared with lead core isolation structure and rubber isolation structure.The results show that the composite isolation structure can reduce the shear force and overturning moment better.(4)By comparing the story displacement peak value,floor acceleration peak value and maximum inter story displacement angle of four kinds of structures,it can be seen that the story displacement peak value,floor acceleration peak value and maximum inter story displacement angle of prefabricated shear wall base isolation structure are reduced by more than 20% compared with non isolated structure,and the reduction effect of combined isolation structure is better.(5)Based on IDA method,the incremental dynamic analysis of the assembled shear wall composite isolation structure is carried out,and the failure mode of the composite isolation structure under the action of super large earthquake is further explored,and the IDA curve is drawn.Through the IDA curve of the maximum horizontal displacement and the maximum inter story displacement angle of the isolation layer,it can be seen that the main failure control factor of the composite isolation structure is the inter story displacement angle,and the middle displacement of the structure is more easy to damage.