A self-anchored cable-stayed suspension bridge, which includes stayed cables and possesses, combines merits of both a self-anchored suspension bridge and a cable-stayed suspension bridge, which forms a totally renewed structure mechanism. When compared to a self-anchored suspension bridge, this type of bridge gives better wind-resisting stabilities; and when compared to a cable-stayed suspension bridge, this type of bridge requires a lower tower height and does not require huge anchor bases. Hence, it is more adaptable to complex and weak geological conditions, and is therefore expected to have a more extensive developing room in the category of large-span bridges.
This research has established the numerical models and performed the detailed analysis to investigate the characteristics of earthquake response of self-anchored cable-stayed suspension bridge. By using ANSYS program and both of response spectrum analysis method and time history analysis method, this research performs the longitudinal and vertical earthquake response analysis in four different geological conditions in order to realize the characteristics of earthquake response of self-anchored cable-stayed suspension bridge in different geological condition. In addition, the influences of geometric changes and the changes in the stiffness of substructures on the earthquake response of self-anchored cable-stayed suspension bridge are also studied. The analysis results indicate that the change in the stiffness of slant cables has the largest influence on the longitudinal earthquake response, and the change in the stiffness of main cables has the largest influence on the vertical earthquake response. Moreover, the change of rise-span ratio has the largest effect in influences of geometric changes.
Finally, through time history analysis, the earthquake response of cable-stayed suspension bridge, after the installation of the metal dampers, has been analyzed and studied in this research. In addition, the influences of geometric changes and the changes in the stiffness of substructures on the earthquake response of this bridge are also studied. As a result, the device of the metal dampers can effectively reduce the energy of earthquake, joint displacement of main girder and tower, internal force of slant cables and main cables, etc.