Discussion on the Applicability of Fu-μ Relationship in Current Design Code by Using Ground Motion Records of 2018 Hualien Earthquake

Discussion on the Applicability of Fu-μ Relationship in Current Design Code by Using Ground Motion Records of 2018 Hualien Earthquake

Current seismic design code hasn't provided a specific Fu-μ formula for near-fault pulsedliked ground motion. However, several researches have shown that the near-fault pulsed-like ground motion may induce higher ductility demand under the same strength reduction factor. Besides, the observed horizontal spectral accelerations of some periods from some strong motion stations maintained by Center Weather Bureau (CWB) are higher than the horizontal design response spectrum of the current seismic design code, and most of them are near-fault pulsedliked ground motion. Based on this point, the relationship between strength reduction factor and ductility of the near-fault pulsed-liked and non-pulse-liked ground motions observed in 2018/02/06 Hualien Earthquake are evaluated in this study to discuss the applicability of the Fuμ formula in the current seismic design code. The horizontal near-fault pulse-like ground motions as well as the pulse periods observed in 2018/02/06 Hualien Earthquake are identified by using the pulse indicator proposed by Shahi and Baker in 2014. Based on the analysis result, we preliminary concluded that the Fu-μ formula in seismic design code have a certain level of conservativism and can be applicable to near-fault pulsed-liked ground motion. The analysis result in this study can provide a reference for the revision of the seismic design code.