Comparison of the earthquake response of super-high-rise structures based on different seismic design spectra

  • Jing Zhou
Keywords: long-period ground motion, design spectra, modal decomposition response spectrum method, dynamic time-history analysis method, damping ratio

Abstract

To evaluate the reliability of seismic design spectra in the long-period segment, two super-high-rise structures with long-period national vibration period are analyzed using response spectrum superposition method and dynamic time-history analysis method. The maximum displacement response of the structural top and the maximum earthquake shear response of the structural base are compared. According to the long-period segment spectrum stipulated in the Japanese and Chinese seismic design codes, the displacement spectra calculated based on a quasi-spectral relationship obviously amplify with the increase of the vibrational period. This is not consistent with the statistical attenuation characteristics of the displacement response spectrum. When following the design spectrum of the Japanese or Chinese seismic design codes, the maximum displacement response calculated by the response spectrum method is significantly higher than the average result calculated using a dynamic time-history analysis method. However, the difference between the maximum displacement response calculated in accordance with the design spectrum stipulated in US seismic design codes and our proposed design spectrum and the average results calculated by the time-history analysis method is significantly smaller. Therefore, the proposed design spectrum and the US seismic design codes are more reliable in this regard. The maximum base earthquake shear force calculated in accordance with the response spectrum method in the proposed design spectrum is consistent with the average results calculated by the dynamic time-history analysis method, as well as the results calculated according to the design spectrum methodology in China and the seismic design codes utilized in the US. However, the proposed design spectrum better characterizes the shear response of the long-period structures of high-order vibration modes. For large long-period structures, the maximum displacement response calculated in accordance with the design spectrum in the Chinese seismic design codes increases with the structural damping ratio. The amplitude variation of the maximum shear force of the structural base is very small. This indicates that the long-period segment in the design spectrum stipulated in the Chinese seismic design code is not very reasonable. For large long-period structures, as the damping ratio increases, the increasing ratio of the damping force to the structural system’s internal force cannot be ignored. Therefore, the reduction ratio of the damping force in the long-period segments of the response spectrum should be appropriately selected. 

References

ASCE, 2010. Minimum design loads for buildings and other structures. American Society of Civil Engineers, Reston, Virginia, USA.

Chen, Y. & Yu, Y., 2007. Adaptability of long-period portion of multi-damping-ratio-spectra in the code for seismic design of buildings (GB50011-2001). Earthquake Research in China 23(2):131-140.

Fang, X., Wei, L. & Zhou, J., 2014. Characteristics of earthquake response for long-period structure and response spectrum. Journal of Building Structures 35(3): 16-23.

GB 50011, 2010. Code for seismic design of buildings, China academy of building research. China Architecture & Building Press, Beijing, China.

Liang, X., Dong, Z., Wang, Y., et al., 2009. Damage to tall buildings in areas with large epicentral distance during M8.0 Wenchuan earthquake. Journal of Earthquake Engineering and Engineering Vibration 29(1):24-31.

Luo, K. & Wang, Y., 2011. Researches about the response spectra with different damping ratio. Building Structures 41(11):16-21.

Luo, K. & Wang, Y., 2006. Research on conversion relationship among the parameters of ground motions in seismic design codes of China, America and Europe. Building Structures 36(8): 103-107.

Mistumasa, M., Izuru, O., Masanori, I., et al., 2003. Performance-based seismic design code for buildings in Japan. Earthquake Engineering and Engineering Seismology 4(1):15-25.

Sun, Y., Zhao, S. & Ye, L., 2011.Comparative study of seismic design method for reinforced concrete structures in China and Japan. Building Structures 41(5): 13-19+32.

Takewakii, I., Murakami, S., Fujita, K., et al., 2011. The 2011 off the Pacific coast of Tohoku earthquake and response of high-rise buildings under long-period ground motions. Soil Dynamic and Earthquake Engineering 31(11):1511-1528.

Yu, Y. & Wang, S., 1997. The long period ground motion response spectra of southern Yellow Sea earthquake, November 9, 1996. Earthquake 17(4):364-370.

Zhou, F., Gui, H., Shigetake, A., et al., 2012. Inspection report of the disaster of the East Japan earthquake by Sino Japanese joint mission. Building Structures 42(4): 1-20.

Zhou, J., Fang, X. & Mao, W., 2017. Attenuation power index and damping reduction factor of seismic design spectrum for long-period ground motions. Journal of Building Structures 38(1): 62-75.

Published
2019-11-20
Section
Civil Engineering (1)