Analysis of risk-targeted decision parameters of seismic ground motions based on seismic design code and ground motion zonation map of China

In this paper, the analysis of risk-targeted decision parameters of seismic ground motions for common buildings were conducted based on the GB 50011-2010 'Code for seismic design of buildings' and the GB 18306-2015 'Seismic ground motion parameters zonation map of China'. The values of the target collapse risk, the logarithmic standard deviation of the fragility, and the conditional collapse probabilities of the maximum considered earthquake (MCE), the design basis earthquake (DBE), and the very rare earthquake (VRE) were discussed. The risk-targeted ground motion decision based on the ground motion intensity in the seismic design code and the ground motion zonation map of China were used to verify the rationality of the analysis results of decision parameters, and the risk-targeted decision parameters of both singular and group structures in China were given and analyzed. The results indicate that, for singular structure, the values of the target collapse risk, the conditional collapse probabilities of the MCE, the DBE, and the VRE are equal to 1.0%, 10.0%, 0.04%, and 54.7% respectively when the logarithmic standard deviation is equal to 0.3, while they are equal to 1.0%, 11.0%, 0.2%, and 44.6% respectively when the logarithmic standard deviation is equal to 0.4. For group structures, the logarithmic standard deviation, the conditional collapse probabilities of the MCE, the DBE and the VRE are equal to 0.6, 10.4%, 1.1%, and 30.2% respectively when the target collapse risk is equal to 1.0%, while they are 0.6, 3.6%, 0.2%, and 13. 2% respectively when the target collapse risk is equal to 0.4%. Through the analysis, it could be found that: when the logarithmic standard deviation is not large than 0.6, with the increase of the logarithmic standard deviation, the conditional collapse probabilities of the DBE, and the VRE increase and decrease gradually respectively, while the conditional collapse probabilities of the MCE does not change significantly; given the same logarithmic standard deviation, the conditional collapse probabilities of the MCE, the DBE, and the VRE all increase gradually with the increase of the target collapse risk. © 2020, Editorial Office of Journal of Building Structures. All right reserved.