THE INFLUENCE OF GROUND MOTION SPATIAL VARIATION EFFECT ON SEISMIC RESPONSE OF LONG SPAN TRUSSED ARCH

Ground motion spatial variation effects on seismic response of an actual long span trussed arch structure are investigated. Intensive numerical simulations of the responses of the trussed arch subjected to ground motion excitations are carried out. The ground motion spatial variations associated with wave passage effect, coherency loss effect and different local site effect are considered. The effects of non-uniform ground motion wave apparent velocity, coherency loss and local site conditions on structural responses are discussed. In numerical calculations, the simulated spatially varying ground motions are individually compatible with the response spectrum defined in Chinese Seismic Design Code, and are compatible with an empirical coherency loss function between each other. Numerical results indicate that each factor of ground motion spatial variations has a significant effect on the dynamic response of the structure, and neglecting ground motion spatial variations in analysis may lead to the underestimation of structural responses. To obtain an accurate structural response assessment and a better design of long span trussed arch structure, a reliable ground motion spatial variation model is essential. The results obtained could provide useful reference for practical design of trussed arch structures.