Smoothing Out Overpass Issues

June 27, 2014
Ohio county road project benefits from communication, convenience

The Ohio Department of Transportation (ODOT) wanted to bridge Delaware County’s heavily traveled County Road 124 over the existing CSX railway and was looking for an economical solution for the proposed retaining walls. Tight budgets and limited backfill options presented challenges to the success of the project. Because the type of aggregate that is required for steel reinforcement was not locally available and would have to be hauled in, additional transportation and material charges would be incurred. A tight site envelope was required, since the overpass was being constructed directly adjacent to the existing road and in front of an active railroad. Also, the close proximity of utilities associated with the railroad required the contractor to alter the construction sequence.

The ARES retaining wall system from Tensar was specified as an approved mechanically stabilized earth (MSE) wall solution, and Trucco Construction Co. Inc. ultimately chose it for use with the project. Many factors went into the decision to install the ARES walls, but the primary advantage of using them was the ability to use locally available backfill material with the extremely inert polymer geogrids, providing a cost savings for the project.

“By utilizing the Tensar ARES retaining wall system, we were able to take advantage of backfill material from a local source,” said Randy King, vice president of Trucco Construction. “The ability to use this local material enabled us to be more competitive at bid time. We trucked in approximately 100,000 tons of granular backfill, which equated to around 5,000 loads. Given this quantity, utilizing less trucking was definitely a key component to the success of the project.”

Two retaining walls totaling 45,000 sq ft, with maximum heights reaching 40 ft and combined lengths of approximately 1,600 linear ft, were designed for the site. Among the challenges of the project were double rows of tightly spaced piles supporting the bridge abutments, as well as a specified plain smooth form finish for the panels. Smooth panels can be a challenge for any MSE retaining wall, mainly because there is so little room for error aesthetically. The panels can be damaged easily, and the slightest misalignment—even if the wall remains within tolerance—is visually apparent.

The onsite assistance provided by Tensar proved to be a valuable aspect of the installation process. “A line item was set up in the proposal which enabled Tensar to send a technical representative, Jeremiah Riggio, to the site for five days,” said King. “This created a team atmosphere in which Trucco Construction, along with ODOT, could work closely with Tensar to ensure that the walls were being constructed per the plan requirements, as well as the manufacturer’s specifications. It resulted in a smooth process for all parties.”

“Trucco’s overall professionalism and attention to detail during every stage of construction was impressive and resulted in one of the best ARES installations I’ve seen,” said Riggio.