Seismic Performance Analysis Of Super High-rise Steel Concrete Structures In Highly Seismic Region

With the development of the city, a large number of people have poured into the city. Consequently, the construction land is extremely tight and buildings are developing towards tall buildings or even super high-rises. Thus how to resist earthquakes and how to dissipate seismic energy for the super high-rise buildings in high seismic fortification intensity regions are problems faced by the designers. With the help of the project "An Analysis of The Seismic Performance of Steel Concrete Structure Super High-rises in High Seismic Regions", which is supported by the Department of Housing and Urban-Rural Development of Hainan Province, this research selects the "GH Hotel", a high-rise building (236m) in Haikou with the seismic fortification intensity of eight degrees (0.3g), as a carrier, and does some calculation and analysis on the structure with Concrete Filled Steel Tube (CFST) and Buck-ling-Restrained Braced Frame (BRB) so as to explore the seismic performance of CFST and energy dissipation effect of BRB in high intensity districts.First, this thesis theoretically introduces constitutive model of CFST as well as the devel opment and application of BRB. Then, by Superposition Response Spectrum Analysis and Elastic Time-history Analysis, the Structure model "GH Hotel" is analyzed from the perspective of different parameters to explore the seismic performance of frequent earthquake. The calculating parameters include cycle, cycle ratio, displacement, displacement angle, displacement ratio, line of defense and so on. It is concluded that CFST has a good seismic performance under frequent earthquake and it meets the design specifications and safety requirements of super high rise buildings. Finally, two contrast models of the40th story with and without BRB are set up respectively to analyze the two models under frequent earthquake and to compare the results of resist seismic parameters by Superposition Response Spectrum Analysis and Elastic Time-history Analysis so as to get the conclusion about the effect of BRB in frequent earthquake. Then, calculate the Structure model "GH Hotel" in rare earthquake and draw a conclusion of the effect of BRB under rare earthquake. Trough the analysis and calculation, it shows that both the structure and BRB are in the elastic stage under frequent earthquake and the BRB not only improves the lateral stiffness of the frame structure and but reduces the horizontal displacement. The installment of BRB on one story of the whole structure makes difference. It effects the largest structure nodes displacement of the stories above the story with BRB as well as the interlayer displacement angle of the ten stories under or above the story with BRB. Under rare earthquake, the BRB is in the elastic-plastic stress state, which can effectively absorb and dissipate seismic energy. Thus it can act as the first seismic fortification line of the structure to protect the load-bearing components from damage or at least to reduce the damage.