Seismic Analyses of Long Span Steel-Concrete Composite Bridge

  • Dr Kai Wei, State Key Laboratory for Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China, China
  • Engr Yongguang Xiong, Urban Infrastructure Construction and Development Center,Hangzhou 310000,China, China
  • Engr Yi Fu, Urban Infrastructure Construction and Development Center,Hangzhou 310000,China, China
  • Dr Xinjian Cao, State Key Laboratory for Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China, China
  • Prof, Dr Wancheng Yuan, State Key Laboratory for Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China, China

Motivated by a need to investigate the characteristics and major problems in seismic design of long span steel-concrete composite bridges, many parameters of some existing bridges were analyzed statistically and seismic demands of different design strategies for a typical continuous bridge were compared. The results show that composite bridges have lower seismic demands than concrete bridges. Seismic analyses of composite bridges were conducted for study seismic traveling wave effect and pounding effect at expansion joints. These analyses are performed for earthquake motions about 3% chance of being exceeded in 100 years by performing nonlinear time history analyses on three-dimensional finite element model of an 1855m composite bridge. The major conclusions are that, traveling wave and pounding effect are negative on bearing deformation and relative displacement between girders. Furthermore, a new cable seismic bearing for long span composite bridge was introduced. The seismic response of bridge with these new bearings was analyzed. It is determined that cable seismic bearings are effective measure for reducing the seismic vulnerability of composite bridges.