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Ten TechWall Structures to be Included in Major Retaining Wall Contract for TEXRail Project

In 2016, the Fort Worth Transportation Authority (FWTA) awarded a major construction project to Archer Western Herzog. The work is to involve the construction of a light rail system from Dallas-Fort Worth Airport to downtown Fort Worth.

While the new rail line will follow the existing Fort Worth & Western Railroad right-of-way, there was still a significant amount of bridge work required in the design, creating the need for significant retaining walls. In addition, there were also walls required where the right-of-way elevations did not support the new track profile without a wall structure.

Even though the retaining walls were predominantly Mechanically Stabilized Earth (MSE) walls, there were a number of locations where the MSE technology was not feasible. At these locations, Archer Western Herzog elected to pursue the use of the TechWall system. As with the Union Pacific Railroad Project in Mesquite, this design also considered the use of cast-in-place walls and precast stem walls. After careful analysis, the Archer Western Herzog group elected to use the TechWall system for the exact same reasons - ease of construction, schedule advantages, and cost savings.

Since that decision was made, The Reinforced Earth Company has worked closely with Archer Western Herzog, TranSystems, and Parsons Transportation to develop final designs for these walls. At this time the first walls have been fabricated, and erection will be starting very shortly.

Inspiring Bridge Innovation Through High-Performance Composites

University of Maine’s Advanced Structures and Composites Center has spent the last decade taking arch bridge design and construction to a higher level. Using high-performance lightweight Fiber Reinforced Polymer (FRP) material, they have created a solution for short and medium span bridges that is recognized as one of the great new civil engineering innovations. The composite arch has already improved infrastructure deficiencies on roadway projects in more than twenty locations in the Northeast and Midwest United States.

Under a recent partnership between their spin-off company, Advanced Infrastructure Technologies, Inc. (AIT), and  The Reinforced Earth Company (Terre Armée Group), the bridge system is fully-engineered and delivered on-site as InspirArch™. It combines the new composite arch innovation with a longstanding and thriving innovation, Reinforced Earth® Mechanically Stabilized Earth (MSE) retaining walls. The result is an efficient bridge  solution  with  a  100-year design  life.

InspirArch will accommodate a wide range of bridge geometries and site conditions, from the straight-forward to complex. The profile of the arch tube is custom-designed and fabricated to meet the geometry requirements of the bridge. They can be easily configured to allow for a skewed bridge alignment.

The materials and construction sequence are ideal for short to medium span bridges, especially when considering remote locations and accelerated bridge construction. The FRP arch units and decking are lightweight and can be installed with hand labor. The tubes are essentially pre-fabricated concrete formwork and reinforcement.

Originally known as Bridge-in-a-Backpack™, the composite arch bridge system was developed with military applications in mind, due to its lightweight and easily mobilized material. Other agencies have quickly recognized the value of the solution when applied to the Nation’s badly needed infrastructure upgrades.

The American Association of State Highway and Transportation Officials (AASHTO) has completed a review of the composite arch system and published, “AASHTO LRFD Guide Specifications for Design of Concrete-filled FRP Tubes for Flexural and Axial Members.”

The Federal Highway Administration has played an active role in the research and exploration of the use of FRP, and specifically the use of composites in bridge construction.

In addition to receiving an innovation award in 2011 from the American Society of Civil Engineers (ASCE), the composite arch system has been recognized as a “gamechanger” in ASCE’s 2017 Infrastructure Report Card.

InspirArch has proven to be the high-performance innovation needed to provide long-lasting upgrades to our transportation infrastructure.