Rockfall protection

Passive rockfall protection

Reinforced Earth® rockfall bund withstands impact of 5000 KJ!

Terre Armée’s rockfall bund solution is the result of decades of research and development that has led to the creation of an innovative and high-performance narrow rockfall protection barrier. Most recently, full scale testing by Terre Armée in 2020 entailed releasing a giant 12.4-tonne block from a height of 41m and impacting the 3 meters thick structure resulting in an impact of 5.1 megajoules (video available below). The narrow bund successfully absorbed the energy from the impact, pushing the limits of soil-structure interaction to a new level and establishing a world-record for a reinforced soil structure.

Sheds and galleries

Rockfall sheds using TechSpan® precast arches, and TechBox™ precast boxes is gaining popularity with engineers. Adjoining retaining walls built within narrow excavation limits are often designed using TechWall™ or T-Wall®.

Rockfall protection barriers

Terre Armée’s passive rockfall protection barriers are made of metallic, non-metallic and/or composite materials. It is primarily applied to arrest and catch rocks, boulders, shooting stones or debris that can be flowing or falling due to natural causes. The rockfall protection barrier is a support solution allowing to hold these disintegrating and falling elements, subsequently avoiding damages to infrastructure and preventing disruptions such as traffic blockages. It has an ability to withstand energy impacts typically up to 5000KJ.

Terre Armée’s passive rockfall protection barrier can be used as an efficient alternative to more traditional and costly mitigation measures and presents many benefits:

• Cost efficient compared to similar rigid barriers
• Effective for confined and open channels
• Easy clean out and maintenance
• Does not affect sediment flow under non-event conditions
• Low aesthetic impact on landscape

Active rockfall protection

Rockfall protection nets

Terre Armée companies also design engineered solutions and supply materials for the construction of active protection using our wire mesh protective netting solution in combination with TerraNail™ soil nails and TerraAnchor™ soil anchors. Our protective netting solution consists of either high-tensile nets (grade > 800MPa) or generic products like gabion mesh or welded wire mesh.

Terre Armée also provides drapery rockfall protection solutions. It is a flexible membrane that supports superficial pressure generated by the potential unstable ground mass or debris flow, categorised in two types:

• High tensile mesh made of coated wires having minimum tensile strength of 1770MPa
• Rectangular mesh made of coated wires having minimum tensile strength of 400 MPa. These are available in different diameters and mesh strengths depending on the geology and geometry of the slope to be protected.

Our solutions are proven to be:

• Easy and rapid to install
• Sustainable with high safety standard
• Highly durable

Choice references

The Yeongi-gun Rockfall Shed, Chungcheong, South Korea

Due to increasing population density, the Korean government requested time-sensitive solutions to prepare for traffic increases in this area prone to rockfall. Developers launched the construction of several underpass structures with added protection against rockfall. The project’s signature guidewalls and underpass entails a 549m long precast TechWall™ section, and a 171m long precast TechBox™ protection shed for a total length of 720m.

The Jeongseon Rockfall “Arch” Shed, Gangwon-do, South Korea

TechSpan® precast arches are a cost-effective and time-saving alternative to a cast-in-place boxes due to speed of construction and with minimal or no road closures necessary during installation. Engineers realize that arches effectively disperse impact loads and thus minimize structural damage possible from rockfall impact. This example illustrates the benefits of utilizing TechSpan® for rockfall shed galleries.

The A23 Mudéjar Motorway Rockfall Shed, Huesca-Jaca, Spain

This expressway improvement connects the mediterranean coast with the central Pyrenees. A vital portion of the new link extends through rockfall-prone hillsides requiring travelers with protection from potential rockfall. Our solution was to design, manufacture and install a 232m long cut-and-cover rockfall shed gallery and TechWall™ earth retaining guidewalls.