Abstract:
The earthquake of Mw7.8 magnitude that occurred in Turkey on February 6, 2023 (TK), resulted in significant human casualties and economic losses. Similarly, the Wenchuan earthquake (WC), with a magnitude of Mw7.9, caused immeasurable damage and losses in several regions of China. To investigate the characteristic differences between these two earthquakes and their impact on the seismic response of subway station structures, this study selects 12 seismic records with similar epicentral distances from both TK and WC earthquakes. The seismic records are analyzed in terms of record time history, response spectrum, and seismic intensity indexes to examine the characteristics differences. Additionally, A finite element model of a two-story, three-span subway station considering soil nonlinearity and concrete structure damage is established. The seismic response differences of the subway station structure under typical records from both earthquakes are analyzed, and its fragility curves under TK and WC earthquakes are provided. The results indicate that: The main feature of TK earthquake is the presence of velocity pulses, while the main feature of the WC earthquake is the presence of double-plateau in the seismic records; The interstory displacement ratio (IDR) of the subway station structure is related to the accumulated damage of the structure, and the velocity pulse causes the IDR of the structure to increase instantaneously, resulting in a larger accumulation of damage. At loading levels below 0.3
g, the probability of minor damage to the subway station structure is greater in the TK earthquake. At loading levels above 0.3
g, the second plateau in the WC earthquake significantly increases the peak IDR and residual displacements, resulting in the greater probability of severe damage or even collapse of the structure.