Response of a transmission tower-line system at a canyon site to spatially varying ground motions
MetadataShow full item record
Collapses of transmission towers were often observed in previous large earthquakes such as the Chi-Chi earthquake in Taiwan and Wenchuan earthquake in Sichuan, China. These collapses were partially caused by the pulling forces from the transmission lines generated from out-of-phase responses of the adjacent towers owing to spatially varying earthquake ground motions. In this paper, a 3D finite element model of the transmission tower-line system is established considering the geometric nonlinearity of transmission lines. The nonlinear responses of the structural system at a canyon site are analyzed subjected to spatially varying ground motions. The spatial variations of ground motion associated with the wave passage, coherency loss, and local site effects are given. The spatially varying ground motions are simulated stochastically based on an empirical coherency loss function and a filtered Tajimi-Kanai power spectral density function. The site effect is considered by a transfer function derived from 1D wave propagation theory. Compared with structural responses calculated using the uniform ground motion and delayed excitations, numerical results indicate that seismic responses of transmission towers and power lines are amplified when considering spatially varying ground motions including site effects. Each factor of ground motion spatial variations has a significant effect on the seismic response of the structure, especially for the local site effect. Therefore, neglecting the earthquake ground motion spatial variations may lead to a substantial underestimation of the response of transmission tower-line system during strong earthquakes. Each effect of ground motion spatial variations should be incorporated in seismic analysis of the structural system.
Showing items related by title, author, creator and subject.
Bai, F.; Li, H.; Hao, Hong (2010)The collapses of transmission towers in large earthquakes were partially caused by the pulling forces from the transmission lines generated from out-of-phase responses of the adjacent towers owing to nonuniform ground ...
Significance of SSI and non-uniform near-fault ground motions in bridge response II: Effect on response with modular expansion jointChouw, N.; Hao, Hong (2008)This is the second part of the study of soil-structure interaction (SSI) and ground motion spatial variation effects on bridge pounding responses. The first part [Chouw N, Hao H. Significance of SSI and non-uniform ...
Hao, Hong; Chouw, N. (2008)In this paper, numerical results from a non-linear dynamic response analysis of a 50 m long two-span RC bridge in the Perth Metropolitan Area (PMA) to simulated spatially varying seismic ground motions are presented and ...