Preservation of a Historical Timber Bridge in California

摘要

The Albion River Bridge consists of a timber deck, a steel truss superstructure, approach timber trusses, four-legged R/C piers for the steel trusses, timber-braced towers to support the approach timber trusses, and R/C pile caps with R/C or timber piles. The 2013 condition ratings of the deck, superstructure, and substructure are "good," i.e., 7 out of 9 based on the FHWA National Bridge Inspection Standards, which makes the bridge "structurally not deficient." However, the latest (2015) Structure Inventory and Appraisal Report by Caltrans has incorrectly assigned a rating of 3 out of 9 to the substructure, and declared the bridge "structurally deficient." This paper discusses the studies conducted by the author to preserve the bridge. The efforts by the author and the Albion community have resulted in the listing of the bridge, in May of 2017, on the National Register of Historic Places of the U.S. Department of the Interior.