Seismic Fragility Analysis And Isolation Design Of Connected Structure With Large Span Special-shaped Steel Corridor

As a complex building structure,the large span special-shaped steel corridor connected structure can not only meet the requirements of the use function,but also take into account the appearance of the building structure at the same time,so it has become more and more popular among architects in recent years.However,due to its special system,significant torsion effect,and complicated stress,it is prone to serious damage under earthquake.Therefore,in order to study the seismic performance of the large span special-shaped steel corridor connected structure and to use seismic isolation technology in similar engineering design,this paper conducted the shaking table test and research on the large span special-shaped steel corridor connected structure in the early stage of the research group and on the basis of seismic fragility analysis,24 three-dimensional seismic records were first selected to analyze the three-dimensional seismic response of the large span special-shaped steel corridor connected structure;then,Seismic isolation design was carried out,and the maximum inter-story drift ratio of the main building and affiliated building Ⅰ,the shear strain at the end of the rubber bearing,the damage factor of the embedded anchor end,the shear strain of the base-isolation were taken as the seismic demand parameter of each local structure,and the peak ground acceleration of the ground motion is selected as its strength index.Finally,the incremental dynamic analysis of the isolated structure under three-dimensional seismic excitation is carried out.The local structure and overall seismic fragility curve of the large span special-shaped steel corridor connected structure after isolation are compared with that of the large span special-shaped steel corridor connected structure before isolation.And the overall structure of the local seismic fragility curves were compared.The main conclusions of this article are as follows:(1)For the three-dimensional seismic response of the connected structure,the calculation result of the canonical response spectrum method is less than the time history analysis method,and the calculation result of the time history analysis method with amplitude modulation according to the specification ratio is the largest,and the difference between the calculation result of the response spectrum method The maximum is 31.6%,indicating that the calculation result of the time-history analysis method of amplitude modulation according to the standard ratio is more unfavorable.(2)The seismic isolation layer can effectively reduce the horizontal seismic response of the main building and affiliated building I,and can significantly reduce the torsional effect of the main building and affiliated building I,so that the main building and affiliated building I basically move in the same direction;meanwhile,the base-isolation can not change the complex stress state of the embedded anchor end in the connected structure,but it can effectively reduce the force.(3)Under the rare intensity level of degree 8,the main building,affiliated building I,the rubber bearing end of the corridor,the embedded anchor end of the corridor,the base-isolation bearing of the main building and the base-isolation bearing of the affiliated building I reach the probability of destruction The values are: 0%,0%,0%,1.51%,3.99%,and 8.29%.The damage of the isolation structure mainly occurs in the isolation support of the main building and the isolation support of the affiliated building I,so it is in similar engineering design.Attention should be paid to the damage of the base-isolation bearing.(4)The damage order of each local structure after isolation is basically the same as that of the connected structure before isolation,and the damage degree is as follows: rubber bearing end,affiliated building I,main building and pembedded anchor end.However,since the seismic isolation layer cannot change the complex stress state of the embedded anchorage end of the corridor,it can only reduce its stress.Therefore,in the similar connected structure,it is still necessary to pay attention to the damage of the embedded anchor end.(5)Under the rare intensity level of degree 8,the upper and lower bounds of the probability of damage to the connected structure after isolation are reduced by 72.56% and82.62% respectively,which indicates that the base-isolation significantly reduces the probability of damage to the large span special-shaped steel corridor connected structural system improves its seismic performance.Therefore,it is recommended to use the base-isolation technology in the design of similar connected structures.