A Study on Progressive Collapse Mechanism and Unseating Failure Control of Concrete Girder Bridges During Earthquakes


Abstract eng:
The bridge collapse failure is one of the most serious and ubiquity damages during earthquakes. Firstly, three multi-scale models of concrete continuous girder bridge, simply support-continuous girder bridge and completely simply supported girder bridge are established respectively by the finite element software ABAQUS. The nonlinear earthquake responses and collapse processes of three kinds of concrete girder bridges are numerically simulated respectively. Then, the seismic damage evolution laws and progressive collapse mechanisms of three bridges are revealed from different aspects including structural system transformation, bridge pier internal force distribution and girder-pier collision effects. Finally, a new control system for seismic unseating failure of girder bridges is proposed based on the philosophies of energy dissipation, multi-failure and damage reduction. The mechanical behaviors and transformation mode of the new unseating failure control system are investigated. The research results show that the excessive girder-pier relative displacement is the induce factor for bridge unseating and the following pier injuries from the falling span impact action lead to the bridge progressive collapse. Comparatively, for continuous girder bridge, due to the integral continuity of structure, the falling span firstly has great influence on adjacent span and the bridge failure is a whole progressive collapse process. For simply supportcontinuous girder bridge and simply supported girder bridge, considering the simply supported effect, the influence of falling span firstly on adjacent span is slight and the bridge failure is a partly collapse process. The proposed new control system for bridge unseating failure is effective in preventing span from collapsing and protecting bridge pier from damage through significantly reducing the pier-girder relative displacement with a limited increase of the force experienced by the pier.

Contributors:
Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
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Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 898.:
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