Title:
Full-Scale Evaluation of a Repair Measure of Earthquake Damaged Bridge Column
Author(s):
A K M Golam Murtuz
Publication:
Web Session
Volume:
Issue:
Appears on pages(s):
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DOI:
Date:
10/17/2021
Abstract:
The Cascadia Subduction Zone (CSZ) earthquake is expected to damage the existing bridges in the Pacific Northwest and spread geographically throughout the region. A rapid repair method to restore mobility along the lifeline route should be implemented quickly as part of the earthquake damaged bridge repair and replacement. A repair method incorporating semi-permanent installation is being developed anticipating the need for such quick measures. The presentation will outline the development of the repair methodology, analytical design approach and results from a full-scale cyclic test validating the performance for seismically substandard concrete bridge substructure. Seismically substandard bridges in the region will undergo damage ranging from concrete core crushing to reinforcement bar buckling/fracture following CSZ earthquake. While the conventional repair methods are effective in restoring the strength in the damaged zones, often lead to higher stiffness and strength that would likely result in shifting the failure to other part of the structure under future earthquake or aftershock demands. The proposed repair methodology uses the capacity design principles to protect the reminder of the bridge into future earthquake and eradicates the need for establishing rebar continuity resulting in less labor-intensive repair method. The adopted concept is to utilize U-shaped metallic plates as externally attached ductile fuses to be anchored with the non-damaged part of the column and hence bypassing the damaged zone to restore the lateral capacity. The damaged zone can then be repaired with strips of fiber reinforced polymer (FRP) sheets to provide lateral confinement preventing any further damage to the core concrete. A typical substandard reinforced concrete column-to-footing subassembly was damaged during a full-scale cyclic test under CSZ loading protocol.