Shaking Table Test and Numerical Analysis of Dynamic Coupling Effect Between Suspended System and OLF1000

Earthquake damage data show that substation long-span frames (LSFs) have remained intact under many strong earthquakes, even when electric power facilities and transmission towers had sustained serious damage. Therefore, the influence of the suspended system (SS) dynamic coupling effect (DCE) on LSF seismic responses is a matter of great concern. For that reason, this study focused on seismic responses of a 1000-kV outgoing line frame called OLF1000, which is a type of LSF, as it is subjected to the SS DCE. A scaled-down experimental model of a single-span OLF1000 was tested using a shaking table. An SS showing different sag-span ratios was applied to OLF1000 to determine how DCE influenced OLF1000 seismic responses. DCE was numerically simulated and analyzed according to different site classifications and ground motion intensities. Results showed that the DCE between the SS and OLF1000 was significant. In addition, the DCE reduced OLF1000 seismic responses owing to energy consumption and elastic constraints. Moreover, the DCE was found to be an SS structural attribute and was therefore unaffected by external loads. The DCE more significantly affected the single-span OLF1000 than the three-span OLF1000.