United States Department of Transportation
i
Development of Depreciation Models Utilizing the NBI Condition Ratings Over 25 Years
-
2019-06-01
[PDF-6.75 MB]
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Edition:Final; September 2018 – June 2019
-
Corporate Publisher:
-
Abstract:The Georgia Department of Transportation maintains an inventory of approximately 15,000 bridges and culverts across the state. These bridges and culverts have been inspected biennially since 1992, yielding over 25 years of bridge condition rating (CR) data from the National Bridge Inventory (NBI). Condition ratings are assigned on a discrete 0-9 scale during bridge inspection, and in this study, they are used to calculate deterioration rates for culverts and the three major components of bridges, namely deck, superstructure, and substructure. This study uses the Markov chain approach to generate long-term (100 years) depreciation models and considers key attributes (e.g., material types and geographic locations) influencing bridge performance. Therefore, CR data is divided into 39 analysis groups including 3 culvert and 36 bridge groups. The three culvert groups are formed by the three geographic locations of Georgia (Northern, Central, and Coastal regions). In these three regions, bridge groups are divided into 5 deck and 5 superstructure subgroups according to 5 material types, as well as 2 substructure subgroups based on the presence of waterways. A Chi-square test is conducted to confirm the alternative hypothesis that the depreciation models developed in this study are reasonably correlated with the deterioration models created in a long-term bridge performance study. The results indicate that the depreciation models presented in this report are reliable and thus are used to determine the expected service life and condition ratings of culverts and bridges in Georgia for the next 100 years. The depreciation models established in this report will be implemented in a long-term bridge asset management program (e.g., the AASHTO BrM software) in order to complete a life-cycle analysis of bridges/culverts.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
