Anti-seismic Collapse Performance Analysis Of Steel Frame Concrete Core Tube Structure In Low Intensity Area

Many regions of China subjected to frequent earthquake activities,and a large areas of low design seismic fortification intensity of 7 degrees or below exist except for areas of frequent high intensity.With the rapid development of China’s economy,more and more high-rise buildings appeared in the low seismic intensity area,and the high-rise buildings located in the low intensity area did not experience theoccurance of earthquake,besiedes,on the one hand,there are some deviations in our vibration parameters for seismic design,on the other hand,potential of sufferingfrom 2 ～ 3 degree higher seismic fortification intensity in low intensity zonesdoes exist.Therefore,it is necessary to perform seismic capacity assessment for these buildings,to avoid huge economic losses and casualties caused by the earthquake.In this context,this paper selected a building of steel frame concrete core tube structure as the research object in 6degree fortification areas,and conductedthe analysis of seismic collapse resistance of the building with the method of increment of time history analysis,and evaluated the seismic performance of the structure.The main work is as follows:(1)The researches of anti-progressive collapse progress and some engineering applications at home and abroad wereintroduced in this paper briefly.The seismic collapse mode,analysis method and failure criterion of collapsewere discussed in this paper,and ultimately,lateral incremental collapse mode was chosen as the research direction,and according to the collapse criterion of American Standard FEMA350(recommended seismic design criteria Vol.1),the incremental history analysis method was adopted to analyze and calculate the selected structure model.(2)A building of steel frame concrete core tube structure in 6 degree fortification areas waschosen as the prototype,and the finite element analysis model wasestablished in SAP2000 after simplification,and the anti-seismic collapse analysis on the structure based on the incremental dynamic analysis methodwas performed to obtain the earthquake collapse rate in different seismic fortification intensity,and evaluated the seismic collapse resistance of the structure in quantitatively.(3)The influence factors of anti-collapse behaviorsof the structure was analyzed and comparison was undertaken in terms of the thickness of the floor slab,axial compressionratio ofthe bottom column and the thicknessof bottom core wall.Therefore,a total of 10 analysis models in three groups,were designed and anti-collapse analysis was conducted one by one with the method of incremental dynamic analysis,to obtainthe structure collapse rate under different seismic fortification intensity of rare earthquake,and according to the calculation results,the suggestive value for these three parameters values was proposed.