Seismic Responses Analysis of a Self-Anchored Cable-Stayed Suspension Bridge

As a new type of bridge, self-anchored cable-stayed suspension bridge has the advantages of both cable-stayed suspension bridge and self-anchored suspension bridge. It enjoys good structural performances, remarkable technical and economical benefits, therefore has been adopted by the engineering filed so far. However, there is little research on the dynamic behavior of this type of bridge. With the engineering background of Zhuanghe Construction Bridge, this article studies the dynamic characteristics and seismic responses of this new structural system, and the main research work covers the following aspects: Natural vibration frequencies and principal modes of the bridge. The standard seismic response spectrum is inputted from longitudinal, transverse and vertical directions respectively. With structural geometric nonlinear factors considered, the artificial earthquake wave is inputted from longitudinal, transverse and vertical directions respectively to get the response time histories of internal force and displacement of control-section such as main beam and tower. The effect regulation is discussed in detail. Three structural restriction patterns are analyzed and compared, from which the one with the best aseismatic qualities is sorted out, namely the elastic restriction structural system composed of towers and beams. This paper also analyzes the influence of longitudinal elastic restriction on dynamic character and seismic response.