UC San Diego

Fiber reinforced polymers (FRP) are increasingly used for seismic retrofit of undamaged bridge columns. The addition of a confining jacket increases overall strength and ductility of the column. However, FRPs can also be used for repair of a damaged bridge column after a seismic event. This research project explores the application of FRPs for retrofit of damaged circular columns. A decision tree for the emergency repair of damaged columns is presented. The decision tree aids field engineers first in assessing the extent of damage to a column from a seismic event, impact or any other source of damage. Once the level of damage is specified, the decision tree can be used to determine the feasibility of FRP retrofitting. If an FRP jacket is a viable option, suggested simplified design guidelines can be used to determine the design thickness and type of required FRP jacket that should be used for the emergency repair of the column. The project included detailed evaluation of existing confining models and a proposition of a new model based on a large database of previously tested specimen columns. Several design equations were also evaluated in order to find the most accurate yet simple approach for the design thickness. The end result is a step-by-step simplified guide for engineers to use in the field for emergency repair of damaged circular bridge columns