Bridge Column Footing Performance and Seismic Retrofit Evaluation Considering Soil-structure Interaction

The objectives of this research are to improve the experimental basis for assessing bridge column-footing performance with and without retrofits subject to SSI and to provide clear design guidance for the evaluation of retrofit/replacement alternatives, with full consideration of the moment capacity at the top of the columns as well as the evolution of the force flow within the spread footing. The proposed experiments will be coupled with numerical modeling to extend the experimental work, inform design guidance, and show the effect of various foundation soil conditions. Although the focus of this work is on spread footings, the outcomes may be applicable to retrofits of timber pile-supported substructures, if the pile caps can be retrofitted similar to spread footings under the assumption that deteriorated timber piles make the pile cap act like a spread footing under an extreme seismic event. The development and implementation of these guidelines in the BDDM and GDM will allow for improved, less conservative design recommendations and the potential for improved cost savings as Oregon Department of Transportation (ODOT) improves the seismic resilience of its transportation network.