Study On The Seismic Performance And Seismic Fortification Measures Of A Super-tall Building

Nowadays, super-tall buildings have been developing more and more rapidly, especially for those that are taller than 500 m. China has a high earthquake risk. Therefore, it is particularly important for structural engineers to better understand the seismic performance of such super-tall buildings, and to improve the seismic fortification measures. A typical super-tall building is studied in this work, including its seismic performance under maximum considered earthquake level and mega-earthquake level, and the structural design recommendations to improve the seismic performance and collapse resistance. The summary of the works is as follows:(1) Based on finite element method, the computational model of the super-tall building is set up. The elasto-plastic analysis under maximum considered earthquake level and collapse simulation under mega-earthquake level is performed. It can be concluded that the seismic responses of this building can meet the requirement of performance based design and realize the objectives of three-level seismic design with sufficient collapse resistance capacity. The neck part of the building has the largest deformation and is the most vulnerable for collapse.(2) Three control methods to satisfy the requirements of the minimal seismic shear force coefficient are proposed. Three finite element models are design accordingly. Through the comparison of the seismic performance and collapse resistance, the model whose structural stiffness was adjusted to meet the requirements of the minimal seismic shear force coefficient(such method is proposed by the Chinese seismic design code), has the largest structural stiffness and the highest cost, but shows approximate seismic response and collapse resistance with the other two models, which are better choices for this building.(3) Two computational models with different layout plan of embedded brace in the shear wall are established and analyzed. The amount of constructi on materials, seismic performance and collapse resistance of the two structures are compared. The results show that the collapse margin ratio of the structure with embedded brace in the shear wall at the neck part of the building is significantly improved with little additional steel. It is recommended to use the embedded brace to strengthen the shear wall for improving the collapse resistance of super tall buildings. This work provides a reference for the seismic design of such kind of super-tall buildings.(4) The arrangement of dual coupling beams of this building are analyzed and compared. The energy calculation method for shell element is improved and used to compare the influence of different arrangements of the dual coupling beams on the energy dissipation of the overall structure. This work provides reference for the design of coupling beams of this super-tall building.