The John E. Mathews Bridge in Jacksonsville, Fla., spans the St. Johns River and supports an active transportation thoroughfare. When a cargo vessel clipped the undercarriage of the bridge in Sept. 2013, it severed a major cord supporting the superstructure. The Florida Department of Transportation stepped into high gear as they pulled in the construction and engineering teams needed to safely and quickly repair the bridge.
The construction team contracted with Strickland Supplies Inc. to provide the scaffolding system that would allow crews safe access to the repair site. Strickland determined that the Safedeck truss system, manufactured by Next Generation Scaffold Services, would provide the necessary durability to facilitate the repair process. Because DH Glabe & Associates had been integral in the engineering, design, and testing of the Safedeck product, Strickland contacted them to provide engineering design and support.
“We got the call on Thursday afternoon,” remembered Jared Thompson, president of DH Glabe & Associates. “This was the first commercial application of the Safedeck truss system, and they gave us until Tuesday to engineer a working access solution.”
Zach Forster, P.E., senior engineer at DH Glabe & Associates, worked continuously through the weekend with FDOT and lead engineering firm, RS&H, to complete the feasibility study and design on time. “They needed to safely fit the suspended scaffold stages under the bridge so the repair work could begin," he said. "The major limitation was how much additional load could be added to the damaged structure without bringing down the bridge. The scaffolding also had to span the maximum dimensions of the bridge without overloading the trusses. Regardless of the various limitations, the platform still had to provide the strength to support the workers and equipment required during the repairs.”
After multiple design iterations, DH Glabe & Associates was successful in delivering the scaffolding design before the deadline, and the repair project began in earnest. Florida DOT crews worked tirelessly over the following weeks, and eventually reopened the bridge in just 34 days.