Challenge
The Blennerhassett Island Bridge carries U.S. Route 50 over the Ohio River and historic Blennerhassett Island. As the longest bridge in West Virginia, the 4,008’-9” network tied arch structure is a critical transportation link between Ohio and West Virginia. The bridge carries four lanes of traffic and supports significant daily volumes, making it vital to regional mobility, commerce and public safety.
Under the State’s Six-Year Bridge Inspection Program, the bridge receives an inspection every year in accordance with federal requirements. These inspections include detailed condition assessments and documentation to ensure long-term safety and serviceability.
For reporting and analysis, the structure was divided into three primary sections: the Ohio approach spans, Spans 1 through 3, the Main Span, Span 4, and the West Virginia approach spans, Spans 5 through 13.
The Ohio approach is a three-span steel girder unit with span length totaling 489’-9” and the main span is an 878’-6” network tied arch that crosses the main channel of the Ohio River. The West Virginia approach consists of an eight-span steel girder unit totaling 2,624’-10½”.
Given the complexity of the tied arch system and the size of the structure, both inspection and load rating required a highly coordinated and technically advanced approach.
Solution
Routine Bridge Inspections
TRC completed recurring inspections over a four-year period and performed the first comprehensive load rating of the structure. Eight inspectors were assigned across the three sections to conduct hands-on, element-level evaluations.
To access the structure safely and efficiently, TRC deployed two UB-60 under-bridge inspection units. We secured above-deck access using 185-foot and 150-foot manlifts. The interiors of the arch ribs and tie girders, end floor beams and main span floor beams were accessed through technical rope climbing. Approach stringers, floor beams, piers and abutments were inspected visually from under-bridge units, a boat and ground access points.
For the special inspection of the Nonredundant Steel Tension Members floor beams, we eliminated the need for traffic control by utilizing certified rope access technicians. This approach minimized disruption to the traveling public while maintaining full inspection coverage.
First-Ever Load Rating Analysis
In addition to inspection services, our practitioners performed the first load rating of the bridge. The client’s objective was to integrate the bridge into AASHTOWARE BrR for statewide load rating management. However, due to the structural complexity of the tied arch system, conventional BrR modeling alone was not sufficient.
TRC developed a detailed analytical model using LARSA 4D to accurately represent the tied arch behavior. We created an equivalent model for implementation within AASHTOWARE BrR. This required customized 3D modeling techniques and innovative analytical strategies to bridge the gap between advanced arch analysis and standardized rating software. The result was a reliable, fully integrated load rating solution aligned with the client’s statewide objectives that allows for integration into the client’s automated overweight permit vehicle rating system.
Results
With the inspections completed and the load rating successfully integrated into AASHTOWARE BrR, the bridge now supports accurate evaluation of any legal or permit truck configuration. The client gained a defensible, software-compatible rating model for one of the state’s most complex and significant bridge structures. The innovative approach to rating the tied arch behavior can now be considered by other departments of transportation to improve their bridge asset management approach.
The project enhanced long-term asset management capabilities while ensuring continued safety and reliability for the traveling public.
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