To quantitatively evaluate the destructive capacity of ground motions for Chinese seismic design, a method to rank the ground motion based on a new comprehensive intensity measure is proposed. A total of 5535 ground motions from NGA-West2 database were used as the input ground motions for dynamic time history analysis to four typical reinforced concrete structures. By performing correlation analysis on the ground motion intensity measures (IMs) and structural response parameters, two optimal IMs, including the peak ground velocity and the relative input energy, are first selected to represent the damage capacity of ground motion. Through regression analysis, a new comprehensive IM is proposed to quantitatively describe the destructive capacity of ground motions. Then based on the proposed comprehensive intensity measure, all ground motions are ranked from first to last. Finally, the comparison with other methods proves the feasibility of the proposed ranking method in quantitatively describing the destructive capacity of ground motions.

To rank the pulse-like ground motions based on the damage potential to different structures, the internal relationship between the damage potential of pulse-like ground motions and engineering demand parameters (EDPs) is analyzed in this paper. First, a total of 240 pulse-like ground motions from the NGA-West2 database and 16 intensity measures (IMs) are selected. Moreover, four reinforced concrete frame structures with significantly different natural vibration periods are established for dynamic analysis. Second, the efficiency and sufficiency of the IMs of ground motion are analyzed, and the IMs that can be used to efficiently and sufficiently evaluate the EDPs are obtained. Then, based on the calculation results, the principal component analysis (PCA) method is employed to obtain a comprehensive IM for characterizing the damage potential of pulse-like ground motions for specific building structures and EDPs. Finally, the pulse-like ground motions are ranked based on the selected IM and the comprehensive IM for four structures and three EDPs. The results imply that the proposed method can be used to efficiently and sufficiently characterize the damage potential of pulse-like ground motions for building structures.

To study the intrinsic relationship between the structural response of long-span suspension bridges and the intensity measures (IMs) and to select the optimal IM to reduce the discreteness in the prediction of structural responses, this paper uses the Incremental Dynamic Analysis (IDA) method to amplitude adjust near-fault pulse-like ground motions and analyzes the response using the curvature at the base of the tower as the structural response index. Then uses the four evaluation indices: efficiency, sufficiency, practicality, and proficiency to evaluate the intrinsic relationship between the structural response and the IMs. The study results indicate that, according to the four evaluation indices, the velocity-related IMs all performed well, while those displacement-related IMs performed the worst. Among them, the effective peak velocity (EPV) performed the best, being optimal in all evaluation indices except for the sufficiency relative to magnitude, which was lower than the maximum incremental velocity (MIV). Therefore, the EPV can be considered the best ground motion IM for predicting the dynamic response of long-span suspension bridges under the action of near-fault pulse-like ground motion. This result can provide a basis for the selection of IMs and structural response prediction for near-fault long-span suspension bridges, considering the impulse effect. Doi: 10.28991/HIJ-2025-06-01-07 Full Text: PDF

The relative input energy of a ground motion is used to quantitatively estimate the destructive capacity of ground motion to a structure, which reflects the deformation capacity and energy dissipation capacity of a structure. The destructive capacity of a ground motion on a structure is known to be relevant to the structural period. Because ranking the destructive capacity of ground motion at all periods is not practical, rationally dividing period ranges should be performed before ranking ground motions according to their destructive capacity and a new method to divide period ranges based on the relative input energy is proposed. According to the correlation coefficient of the relative input energy at adjacent structural periods, the structural periods from 0.2 s to 10 s are divided into several representational period ranges, which include a recommended period within each period range to represent the whole range. Only the ground motion ranking sequence at the recommended period is used in this period range. The rationality of the ranking sequence of ground motions based on destructive capacity is verified by a series of structural seismic response analyses. The results of this paper are compared with those of existing methods, and the results show that the relative input energy index is able to better quantitatively describe the destructive capacity of ground motion.

The constant-strength ductility spectrum is a nonlinear response spectrum that is commonly used to establish the demand curve of the seismic response during performance-based seismic design. It is affected by many factors. In this paper, to evaluate the effect of the major influencing factors, including the structural parameters and seismic factors, the constant-strength ductility spectrum is calculated under different conditions based on 5535 ground motion records. Conclusions are drawn based on the mean constant-strength ductility spectra. (1) With respect to the effects of structural factors, the variation trend of the ductility spectra is highly consistent with increasing T, and the ductility spectra are usually larger for larger ζ and smaller C_y and k₂. (2) With respect to the seismic factors, the ductility spectra show obvious differences in different periods; however, some parameters, such as PGA, have no influence on the ductility spectra. The results of this study can provide a theoretical basis for the calculation of ductility demand in the seismic design of structures.