Research On Seismic Response Of Track-bridge System Considering Wave Passage Effect

High-speed railways have been playing increasingly important role in the economicdevelopment of society. To meet the need of track structure in high-speed railway lines, moreand more bridges are adopted. China is a country seriously suffered by earthquake disasters.As a result of that many high-speed railways pass through seismic zones. Therefore, seismicperformance of track-bridge system has become the focus. Based on the existing research inboth China and abroad, a model of typical high-speed railway bridge with ballastless tack isestablished to build the dynamic balance equation of seismic response of track-bridge systemconsidering wave passage effect under absolute coordinate system. Corresponding simulationprogram called TBDAUE is worked out. By taking a common multi-span simply supportedgirder bridge as the research object, seismic performance of track-bridge system underuniform excitation and non-uniform excitation is studied. The main research results are asfollows:1．While under a three-dimensional earthquake wave, because of rotational displacementat the top of piers causing by longitudinal earthquake, there are vertical dislocations of tracknear the beam crevice of simply supported girder bridge. But the horizontal displacement oftrack is simply as same as rigid body translation. The horizontal deformation of track is little.Therefore, research on seismic response of track-bridge system should pay attention tolongitudinal earthquake wave.2. In every span, seismic responses of beam and track are nearly the same except phaseunder earthquakes with different shear wave velocities.3. Under seismic excitation considering wave passage effect, the horizontal deformationsof bridge and track are mainly causing by phase difference of land displacement time history.While the vertical deformations of bridge and track are mainly causing by both phasedifference of land displacement time history and rotational displacement at the top of piers.4. The length of pier has little effect on horizontal deformations of bridge and track buthas great effect on vertical deformations of bridge and track under seismic excitationconsidering wave passage effect.