North Tarrant Express - Mega Project Successfully Wraps Up

North Tarrant Express - Mega Project Successfully Wraps Up

Construction of Managed Toll Ramps over General Purpose Lanes
Precast MSE Retaining Walls
Tarrant County, TX
Bluebonnet Contractors, LLC (Ferrovial / WW Webber JV)
The Reinforced Earth Company

The North Tarrant Express (NTE) project is along one of the most congested highway corridors in the Dallas-Fort Worth region. This multiple-phased project will improve the mobility along I-35W, I-820 and SH 121/183 Airport Freeway. While the project adds four managed toll lanes, it also rebuilds the existing main lanes and frontage roads. The first segment of this Public-Private Partnership (P3) project was awarded to NTE Mobility Partners (NTEMP), a consortium of Cintra US, Meridiam Infrastructure, the Dallas Police and Fire Pension System, and W.W. Webber, LLC for a price of $2.05 billion.

In 2011, The Reinforced Earth Company (RECo) was contracted by Bluebonnet Contractors, LLC (Ferrovial/W.W. Webber JV) to design and supply over 2,200,000 square feet of MSE walls, 25,000 square feet of fascia panels, 49,000 lineal feet of precast coping, and 95,000 lineal feet of precast half-connector to support traffic barriers on top the MSE walls. RECo’s previous experience with large design-build projects was instrumental in managing this project. From the onset RECo and Bluebonnet Contractors (BBC) had many meetings regarding the execution of design, project management, material fabrication and delivery.

The monthly delivery demand was 60,000 square feet; and it was to be sustained over a 36 month duration. This rate required the fabrication of panels to begin immediately; but due to the design-build nature of the project, the design of individual walls was not released yet. Therefore, through close coordination between RECo and BBC, standard panels were cast to inventory in advance of final approval of individual walls. This proved to be a major benefit to the contractor, as RECo could respond immediately to panel deliveries. It also allowed RECo to still meet BBC’s demand when wall priorities changed.

Midway through the project, BBC requested a significant increase in panel deliveries. Through production adjustments made at RECo’s precast plant in Waco, shipping levels in excess of 160,000 square feet were achieved for several consecutive months. As of February 2014, panel production is over 95% complete, and the final panel shipments should be completed during the first half of 2014.

RECo’s technical expertise was called upon by BBC on several instances. One instance stemmed from an existing RECo wall that was erected in the late 1990’s. That wall restricted the placement of the reinforcing strips that would support a new 40’ tall wall. Among the solutions presented by RECo to BBC, was a Shored Reinforced Earth Wall (SREW). That technology had previously been developed by RECo for similar conditions. Through the use of soil reinforcements and attachments from the new wall to a permanent wire wall, SREW would allow the construction of the new wall without the need for removal of the existing wall. BBC selected this option and the final design was completed and approved in a few weeks. As a further benefit to BBC, RECo already possessed a form liner that matched the existing structure and allowed the wall to be erected within BBC’s tight schedule.

The original aesthetic treatment to the precast MSE panels was a smooth steel finish, which was painted with a pleasing color that matched the other painted structures within the project. After discussion between BBC and the six communities through which the project passed, an enhanced architectural finish was agreed upon whenever the walls faced the cities. The chosen finish was an ashlar stone panel broken up by a smooth pilaster panel every 100’. The ashlar stone finish was painted the same color as the smooth panels; however the pilaster panel was painted a darker shade, which helped break up the finish throughout the length of the wall. BBC provided RECo with the aesthetic treatments for each wall in order to detail the proper finish requirements. The clear distinction of finishes shown on our plans helped our precast plant fabricate and supply the correct finish types per wall, while providing the contractor information on which panel finishes were required for each wall.

Even though the project is still under construction, anyone who drives through this corridor can see the substantial contribution that RECo has made to this project in terms of retaining walls. Overall, the close relationship that has been developed through RECo and BBC has enabled a seamless flow of coordination, design, material fabrication, material delivery and response to construction related issues. The project is scheduled for substantial completion in 2015.