Study On Seismic Performance And Continuous Collapse Resistance Of A Long-span Cantilever Structure

As society progresses day by day,people's aesthetic level is getting higher and higher,and many buildings with beautiful shapes were created,among which cantilever structure is the most popular.However,the cantilever structure is not evenly distributed in mass and stiffness,it has a complex body type,and it is extremely sensitive to vertical static load,and the vertical seismic action cannot be ignored.Therefore,it is necessary to conduct seismic analysis on such structures to control their dynamic characteristics.Because the cantilever structure lacks sufficient constraints,the sensitivity of structural components is relatively high,so it is necessary to carry out anti-collapse analysis to ensure a certain safety guarantee.This paper takes hubei province city landmark public service-oriented architecture as the research object.Firstly,mechanics model of the structure was established by using finite element software MIDAS,using method of characteristic vector and Ritz vector method analysed structure modal,it was found that the latter can make the structure more quickly meet the specification requirements of effective mass participation coefficients.And under the seismic condition and non-seismic conditions,the deflection,natural vibration period and internal force of different stressed steel truss schemes and side sealing truss schemes were compared and analyzed.The final structural scheme were determined according to the uniformity and rationality of stress on the structure and the requirements of using space on the building;Secondly,the dynamic characteristics of the structure were controlled by the elastic time-history analysis of the selected structure.The response of the structure under the action of horizontal earthquake and three-direction earthquake were compared and analyzed,for summaring the dynamic response characteristics of the structure.Finally,the method of alternate path was used to analyze the collapse resistance of the cantilevered steel structure for finding out load transfer path.It was found that the stress ratio was greater than 1 in the beam element members of steel truss and part of coordinated steel beam members,but they all met the requirements of no continuous collapse in the code,and the structure had enough redundancy.