Temporary system allows for continuous flow of heavy traffic on ramp connecting I-285 and I-75
(Parsippany, New Jersey) – 23 October 2017 – Acrow Bridge, a leading international bridge engineering and supply company, has announced that it designed and provided a temporary “straddle bent” support structure to the Georgia Department of Transportation for use during construction of an interstate ramp in Atlanta as part of the larger Northwest Corridor Project.
The Northwest Corridor Project is currently under construction and will eventually add nearly 30 miles of express and toll lanes along I-75 and I-575 designed to ease traffic congestion in the northwestern suburbs of metro Atlanta. It was begun in 2014 and is expected to be completed in 2018.
When construction was considered for the ramp from I-285 eastbound to I-75 northbound, it was determined that neither a detour nor a full closure would be possible, owing to the heavy amount of traffic it carries. Instead, contractor Northwest Express Roadbuilders rented a temporary support system from Acrow that supported four girders during the staged erection sequence for the flyover over the ramp. The system included two 70-foot-high towers and an 85-foot-long straddle bent pier.
The project posed numerous challenges. Situated in a highway interchange, access to the site was very limited. Also, because it was not possible to use guy wires, the towers and straddle bent were required to be a moment frame. However, since the shoring tower was in the same location as future overhead signage, Acrow was able to adapt the footings to also be used as the footings for the shoring tower. The construction of the straddle bent and the staged erection of the girders had to be conducted during nighttime hours because of the extremely high traffic volume on the ramp, and Acrow’s engineers had to factor into the superstructure design load of the girders and the deflection caused by the load to ensure the girders were at the correct elevation.
“Acrow’s temporary straddle bent support structure was the perfect solution for this challenging project,” said Will Smith, Southeast Regional Manager, Acrow Bridge. “While this was a difficult job, it was ultimately very rewarding to be a part of this very complex road improvement project.”
Added Bill Killeen, President and CEO of Acrow Bridge, “Like all Acrow products, our support systems are completely customizable and durable enough for the most demanding applications, and our engineers excel at unique solutions to the most difficult projects.”
About Acrow Bridge
Acrow Bridge has been serving the transportation and construction industries for more than 60 years with a full line of modular steel bridging solutions for vehicle, rail, vessel, military and pedestrian use. Acrow’s extensive international presence includes its leadership in the development and implementation of bridge infrastructure projects in over 80 countries, covering Africa, Asia, the Americas, Europe and the Middle East. For more information, please visit www.acrow.com.