Research On Shaking Table Test For Seismic Response Of High-speed Railway Bridges Considering Track Constraints

High-speed railway bridge orbit system makes all the bridge spans have stronger overall coupling correlation, at the time of the earthquake is bound to a certain impact on seismic response of the bridge. However, the seismic analysis model in the existing specifications can not consider the effect of the track constraints, must study seismic calculation model and seismic design method considering the track constraints. This paper uses the combined method of shaking table test and numerical simulation, modified single pier model considering track constraints was proposed, and a shaking table test was carried out. And the influence rule on seismic response of the high-speed railway bridge track constraints was discussed. The main research contents are as follows:(1) On the basis of reading a large number of domestic and foreign literatures, combining with the characteristics of earthquake damage of railway bridges, high-speed railway bridge structure features and the shortage of the existing specifications, from theoretical research and shaking table test two aspects introduced the research progress and existing problems of track constraints effect on the dynamic characteristics and seismic response of railway bridges.(2)Prototype bridge is CRTS ? slab ballastless track high-speed railway simply supported box girder bridge. Traditional analysis model, bridges and track joint action model and single pier model was established. After comparative analysis modified single pier model considering track constraint was proposed.(3)Shaking table test model of similarity relation was designed using the similarity theory, and made the test model of geometric similarity ratio of 1:20, two kinds of test model are considering track constraints and not considering track constraints.(4)Through shaking table test, the dynamic characteristics of two kinds of test model was tested, displacement response and pier bottom reinforcement stress reaction under the action of different seismic wave and acceleration.(5) By analysis the dynamic characteristics of two kinds of test model data, discussed track constraints effect on dynamic characteristics of the structure. By analysis seismic response test data of two kinds test model, discussed track constraints effect on seismic response of the structure under the action of different seismic wave and acceleration. On the basis of summarizing the pier seismic response change rule, evaluated the influence of track constraints on seismic performance of bridge piers.(6)Setted up the numerical calculation model with corresponding two kinds of test model, the seismic response of the model bridge piers is analyzed by using the time history analysis method, and with the shaking table test results are compared. The analysis results show that the calculated value are in good agreement with those obtained with the test value, the correctness of the calculation model is verified.