Smithville, Tennessee’s Hurricane Bridge carries State Route 56 over Center Hill Lake, a route that serves as a major connector for all of mid-Tennessee. This includes logging companies and the region’s nearly 300 nurseries – McMinnville, located just 30 minutes south along Route 56, is also known as the “Nursery Capital of the World.” Originally built during the World War II era, this four span cantilever deck truss bridge has served the area for more than 70 years. Like many bridges of this vintage, the Hurricane Bridge was reaching the end of its lifecycle and was in need of modernization in order to meet current design and safety standards.
In 2009, the Tennessee Department of Transportation (TDOT) turned to bridge engineers Modjeski and Masters (M&M) to conduct an evaluation of the bridge. The bridge was previously rated structurally deficient, resulting in a posted limit of 15 tons. Heavier vehicles were forced to take a 30-mile detour, which proved to be an enormous inconvenience for local industries. Modjeski and Masters determined that a full rehabilitation was needed in order to upgrade the bridge to support current and significantly heavier AASHTO live load requirements. This included substantial strengthening of the truss members and rebuilding of the superstructure’s floor system members. M&M was awarded the design contract in October of 2009, and the $26.9 million construction phase commenced in January of 2011. The project was completed in October of 2013 – a remarkable turnaround given the complexity of the rehabilitation challenge.
The project involved a complete superstructure overhaul of the Hurricane Bridge: all stringers were replaced and the floor beams, truss members and select gusset plates were all strengthened. Pins were replaced at select truss rocker bearings which were no longer able to displace due to corrosion build-up. The design also called for a complete re-decking of the 1,786-ft long bridge. The continuous truss construction necessitated very specific construction staging load patterns and intensities in order to prevent unacceptable stress reversal, and to limit the magnitude of temporary stresses and loads on truss members and gusset plates. At the forefront of the engineer’s concern was prevention of a disaster similar to what occurred on I-35W in Minneapolis Minnesota. M&M conducted a comprehensive, 3D finite element analysis study to determine permissible load combinations on the structure during construction.
Like many of its era, the original structure contained lead based paint, which both needed to be removed and safely contained in order to protect workers and the nearby community during repainting. The contractor, OCCI, Inc., used both conventional tarps and innovative Safespan™ under-bridge decking to prevent the release of lead into the atmosphere, the waterway and soil. The under-bridge decking system also helped to ensure worker safety and mobility during the construction process.
The decision to modernize and rehabilitate the 70-year-old Hurricane Bridge rather than replace it entirely meant upgrading the bridge with modern features that were still congruent with those of the original. The new decking is made of lightweight concrete, which weighs 20 percent less than normal weight concrete. This lightweight concrete also features a special mix design that significantly reduces the permeability and intrusion of water and deicing salts. This innovative design application should help increase the service life of the new deck and minimize future maintenance of the superstructure.
Throughout all of the major construction phases, alternating single-lane traffic was in effect. Once the superstructure strengthening and concrete deck replacement were completed, the bridge was fully opened to two-lane traffic. In August of 2013, the 30-mile detour was finally lifted, allowing for heavier traffic to re-enter the bridge. All remaining work was completed by October 31, 2013, allowing the Hurricane Bridge to reclaim its place as a crucial route for Dekalb County and all of the surrounding region.
Dr. John Kulicki, PE, SE (Project Principal)
Michael Irwin, PE (Project Manager)
Christopher Ahlskog, PE (Bridge Engineer)
Todd Stephens, PE (Bridge Engineer)
Chad Clancy, PE (Bridge Engineer)
Edward Wasserman, PE (Bridge Engineer)
Adnan Kurtovic, PE (Bridge Engineer)
Hiep Bui, PE (Bridge Engineer)
Christopher Ellis (Bridge Inspector)
Milton Greer (Resident Engineer)
James VasKorlis, PE (Asst. Resident Engineer)
Judy Stone (Contract Specialist)
Anthony Temeles, PE, SE (Bridge Engineer)
Richard Coyne, PE (Bridge Engineer)
Thomas Rogers, PE (Bridge Engineer)
Dr. Nohemy Galindez, PE (Bridge Engineer)
Jeffrey Kaplan, PE (Bridge Engineer)
Don Price (Technician)
Earl Seibert (Technician)
Ryan Johnson (Technician)