Unseating Prevention

Keywords epoxy resin, seismic retrofit, steel jacketing method, carbon fiber sheet jacketing method, unseating prevention... 

Unseating Prevention Devices. These structural systems complement the above seat length. The horizontal seismic design load is considered 1.5 times the vertical reaction due to dead load and the maximum design displacement for unseating prevention is 0.75xSE. 

Steel bracket, which is fixed by anchor bolts to the top surface of abutment, is utilized as an unseating-prevention device. A shock absorbing chain connected between the steel bracket at bottom of girder and that of vertical front wall of concrete abutment is also adopted in order to avoid the bridge falling. Injected liquid epoxy resin is effective to fix the anchor bolts in horizontally bored hole. 

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