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Title:Field and Analytical Study for Deteriorating Precast Double-Tee Girder Bridges
Authors:Junwon Seo, Brian Kidd, and Nadim Wehbe
University:South Dakota State University
Publication Date:Jan 2021
Report #:MPC-21-426
Project #:MPC-565
TRID #:01766485
Keywords:bearing capacity, deterioration, dynamic loads, field tests, girder bridges, live loads, load and resistance factor design


This project discusses the performance of deteriorating double-tee (DT) girder bridges that have been in service for many years. This included field testing of two single-span DT girder bridges in South Dakota for live load distribution factors (LLDFs) and dynamic load allowance (IM). The LLDFs and IM were determined using strain data measured during the tests. When calculating LLDFs, nearly all the measured LLDFs were below the American Association of State Highway Transportation Officials (AASHTO) values. While analyzing the data, it was found that the stems on the same girder did not always have similar strain quantities. Hence, newly proposed stem and joint approaches to calculate the LLDFs were investigated and compared with the conventional girder approach. These results were also compared with those determined according to AASHTO Standard and Load and Resistance Factor Design (LRFD) specifications. It was found that both the AASHTO LRFD and Standard specifications were conservative when estimating IM, compared with the test results for both bridges. Analytical models for both bridges were then created in CSi Bridge to perform parametric studies with variance in DT bridge design parameters. It was concluded that the AASHTO LRFD values are typically conservative for the studied parametric bridges.

How to Cite

Seo, Junwon, Brian Kidd, and Nadim Wehbe. Field and Analytical Study for Deteriorating Precast Double-Tee Girder Bridges, MPC-21-426. North Dakota State University - Upper Great Plains Transportation Institute, Fargo: Mountain-Plains Consortium, 2021.

NDSU Dept 2880P.O. Box 6050Fargo, ND 58108-6050