| With the rapid development of seismic design,structural nonlinear time-history analysis method is progressively becoming a critical issue and getting a lot of attention due to its guidence in the structural design.The ground motion input is of great importance cause its uncertainty will significantly influence the structural response.How to choose suitable ground motion for nonlinear analysis input is one of the principle tasks to be solved in structural engineering.Recordings of engineering demand are inadequate in China,and the seismic activity is significantly different across different regions.Considering these problems,this paper tries to select a set of recordings for the capital cities using ground motions captured in the corresponding province with the demand of fifth zonation map.The selected results are presented in a website,which is established for users to utilize and share the related information.Then the impact of different editions of the zonation map and seismic codes for ground motion selection is discussed.The main contents are as follows:(1)This paper firstly summarizes the state-of-the-art researches and various seismic codes requirement about strong motion selection,then the recordings from Chinese National Strong Motion Observation Network System(2007 to 2015)and NGA-West2 dataset are collected and processed to establish the ground motion database for further selection.Based on the fifth seismic zonation map,several methods of selecting ground motion which commonly used in current engineering are discussed.The various methods are utilized to select recordings based on the Chinese dataset.The results indicate that these methods are not suitable for the entire situations,which significantly depends on the matching period range.For one specific region in China,they could not be implemented in the ground motion selection.(2)This paper then proposes a new multiple-period range selecting method.The least square method for spectrum-matching is applied in the different range of periods considering the possible fundamental period range of target structures.Considering the significantly different seismic activity in different regions of China,the main cities of China are divided into three categories:using records from the local province,from NSMONS and from the whole database including the NGA-West2.Then the code spectrums for these cities are established based on the seismic fortification parameters in the zonation map as target for recordings selection.Based on the ground motion selection results for different period range,one web-based interactive page is established to present the results and share related information.(3)This paper then focuses on the influence of corresponding change of target spectrum for ground motion selection in the fifth zonation map.Firstly,the change and difference between zonation map and seismic code in target spectrum is summarized and compared with each other.Then the performance of ground motion selection is evaluated under different target spectrum considering differentsite amplitude coefficientβ,long-period adjustment,and the double parameter adjustment for site condition.The results of recordings indicate that current seismic zonation map well presented the characteristics of the ground motion,that is,more suitable for ground motion selection.Related conclusions could provide reference for the modification of the seismic target spectrum in the next version of seismic code in China. |
