Steel in the News
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Posted by Scott Melnick on December 5, 2007 at 12:52 PM.
The FHWA and state DOT engineers in attendance at this year’s World Steel Bridge Symposium (going on right now in New Orleans) are hot and heavy to improve the accelerated construction of bridges. “80% of bridges on the interstate system are single span, 30 m or less, and many are in need of replacement,” explained Bill Wright of the FHWA. The goal is to develop systems that offer rapid construction, 100-year durability, and are cost effective in terms of initial and life-cycle cost. And the solution they’re looking at now points towards a prefabricated system that can be quickly moved into position with minimal disruption to traffic.
During the next five years, the FHWA will spend nearly $3 million annually on a variety of projects that will directly impact the steel bridge community, including:
- Optimized welding (including robotics);
- HPS corrosion resistance;
- One-coat shop coatings;
- Innovative designs (testing and evaluating rapid bridge construction concepts);
- Precision measuring of components to eliminate the need for shop assembly to ensure fit-up correctness;
- Shop automation; and
- Technology transfer.
Some of the intriguing programs currently being researched focus on using GMAW for HPS and developing Hybrid Laser Assisted Welding (HLAW). Work on the former is being done by Yoni Adonyi up at LeTourneau University, while the latter project is being spearheaded by High Steel Structures. Innovative work also is being done by Mittal and Lehigh on advanced corrosion resistance in the next generation of high performance steel, while work at Northwestern University focuses on optimizing the current generation of HPS. Meanwhile, the FHWA is working on re-writing their standards for the use of weathering steel to further promote this product.
According to Wright, the next generation of bridges will offer integrated structure and deck so the system can be dropped in place quickly. The goal is to meet a 100 ft span with single-crane erection and a maximum erection time of one week.
A parallel effort is underway with the Transportation Research Board, which has contracted with HNTB on a program for Innovative Bridge Design for Rapid Renewal. The goal is to develop “standardized approaches to designing, constructing, and reusing complete bridge systems.” The system developed will offer the rapid replacement while the existing bridge is in-place while minimizing disruption to traffic.
Phase one, which has just started and is expected to last a year, includes a literature review and focus groups around the country. If you’d like to contribute to the project or participate in a focus group, please contact Frank Russo at email@example.com.