Study of Influences of Soil-Structure Interaction on Seismic Response of Extradosed Cable-stayed Bridge

Taking the Sifang Bridge in Yunnan Province in China as an example, this paper analysis the influences of soil-structure interaction on seismic response of extradosed cable-stayed bridge with response spectrum method. The results show that extradosed cable-stayed bridge has a shorter nature period than cable-stayed bridge, and torsional vibration mode does not happen in the first few modes as the beam has a bigger stiffness. The displacernent of the structure will be underestimated if the soil-structure interaction is ignored while the design of some parts is conservative.