Earthquake resistant behaviors of a complex shape super high-rise steel TV tower
LI Chun-xiang1; WANG Ying-jun1; ZHONG Qiu-yun1; QIN Ji-biao2
1.Department of Civil Engineering, Shanghai University, Shanghai, 200072; 2. First Company of Shenzhen General Institute Limited Company of Architectural Design and Research, Shenzhen, 518031
Abstract：The structural height and antenna mast height of Ningxia TV tower (NXTVT) is 216m and 104m, respectively. The shape of NXTVT resembles a small-bottom, large-top，and slender-waist-middle vase, which consists of three storey segments with 28 floors in total. The discontinuous arrangement of floors leads to the uneven distribution of mass and lateral stiffness of the structure. Thus, this structure with complex geometry requires a high demand of seismic performance. Firstly, ANSYS code is employed to analyze the dynamic characteristics of NXTVT. Simultaneously, for the purpose of comparison, the results of the structural natural frequencies using SAP2000 code are also taken into consideration. The numerical results indicate that the third and eight modes of the structure are torsional ones, and furthermore the torsional effect is considerably significant. The ratio of the first torsional period to the first translational period meets Chinese code, but close to the limiting value. Then, the responses of this building under frequent earthquakes are analyzed using both the mode superposition response spectrum and time-history method, respectively. The whiplash effect can be brought out clearly through the time-history analysis. Accordingly, the seismic performance should be evaluated based on the simultaneous considerations of the results of the aforementioned two methods. Under the multi-dimensional earthquakes, the structural deformation meets the requirements of code for seismic design of buildings. Finally, the responses of the structure under the 8 degree (0.2g), 8 degree (0.3g), and 9 degree rare earthquakes are analyzed using the dynamic elasto-plastic time-history method, in order to check both the deformation indices and development of the plastic zone of the structure. The numerical results demonstrate that the inelastic deformation meet the requirements of code for seismic design of buildings. Likewise the middle story segments is the weaker part, which is right the slender-waist of the structure. Therefore, the Ningxia TV tower can meet the requirement of no damage under frequent earthquake, repairable damages under basic earthquake, and no collapse under rare earthquakes. Through extensive numerical analysis and comparisons, the conclusions obtained herein will be much useful for the earthquake-resistant design of NXTVT or similar projects under earthquakes. Additionally, the analysis approach has reference values in the calculation of the structures with complex geometry utilizing commercial finite element program.
李春祥;汪英俊;钟秋云;秦季标. 复杂形体超高钢结构电视塔抗震性能分析研究[J]. , 2011, 30(10): 61-72,1.
LI Chun-xiang; WANG Ying-jun;ZHONG Qiu-yun;QIN Ji-biao. Earthquake resistant behaviors of a complex shape super high-rise steel TV tower. , 2011, 30(10): 61-72,1.
2011, Vol. 30 
