TechBox™

TechBox™, a state-of-the-art solution for building large box bridges, culverts and rockfall protection shelters.

TechBox™ is an engineered site-specific solution for building robust “box-type” bridging of single or multi-span underpasses, small bridges and cut-and-cover passageways.

These structures are built using precision-made segmental precast concrete sections that are assembled at the jobsite. The use of pre-engineered forming moulds, quality-controlled manufacturing, and pre-planned installation procedures reduce jobsite work duration. The TechBox™ solution results in quicker, safer and more efficient completion at the jobsite as compared with the unpredictable nature of cast-in-place alternatives.

Applications

• Roadway and railway underpasses and overpasses
• Cut-and-cover tunnels of all types
• Large culverts
• Waterway channeling
• Rockfall protection shelters

Design

The design is carried out using the finite element modelling method (FEM). Through this method, the concrete section sizes and reinforcement designs are optimized resulting in the thinnest, yet most durable sections possible. The FEM modelling analyses consider the following, but not limited to:

• Self weight of precast elements
• Applied bearing pressure
• Capacity of the foundation soils
• The sequence of installation
• Fill cover height effects
• Static loads and live loads
• Service life requirements

Manufacturing

Reinforced Earth engineers and project managers are specialists in developing, manufacturing, handling and delivery procedures for precast concrete solutions on a worldwide basis. Precasting operations are performed in a quality-controlled plant environment, either offsite requiring transport, or performed at the jobsite.

Our engineers will normally manage the design and fabrication of the specific precast forming moulds to precisely match with the optimized design of the TechBox™ sections. We analyze the project site conditions, schedule constraints, working crew sizes, and availability of equipment, among other factors when developing the manufacturing activity sequence.

Installation

The units required to assemble a TechBox™ bridging section normally consist of three precast segmental units: two full-height side wall units and a roof slab unit. The full-height side walls closely resemble our TechWall™ solution, although modified to include side stitch beams. The general steps for constructing TechBox™ include:

• Installation of full-height side wall units
• Placement of top “roof” slab units
• Casting or connecting the base slab
• Application of waterproofing, joint protection
• Staged backfilling up to the stitch level
• Casting of the side and top stitch beams
• Completion of backfilling and finishing

Since earth retaining structures are normally required for wing walls or spandrels, these are often built using Reinforced Earth®, TechWall™, T-Wall® or other retaining wall solutions designed and furnished by Terre Armée and our subsidiaries.