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October 8, 2026

Less concrete, lower costs, faster construction: Geogrid-reinforced retaining structures vs. concrete cantilever walls

A comparative study shows how geogrid-reinforced retaining structures can reduce concrete use, greenhouse gas emissions, construction costs and time compared with conventional retaining walls.

Construction workers and an excavator install drainage pipes and retaining walls beside a railway embankment.
Technical cross-sections of a reinforced retaining wall showing geogrid layers, facing system, fall protection, shaft, and drainage components.
Technical cross-sections of a reinforced retaining wall showing geogrid layers, facing system, fall protection, shaft, and drainage components.
Typical cross-sections of the two options investigated: geogrid-reinforced retaining structure (left) and reinforced concrete cantilever retaining wall (right)
Typical cross-sections of the two options investigated: geogrid-reinforced retaining structure (left) and reinforced concrete cantilever retaining wall (right)

Retaining structures are often required in transport infrastructure projects to accommodate changes in ground level safely within limited space. Geogrid-reinforced retaining structures offer an alternative to conventional reinforced concrete cantilever retaining walls that can be designed using established engineering methods. A comparative study illustrates the potential differences in material use, greenhouse gas emissions, costs and construction time.

The study considered a new railway embankment with a retaining structure 100 metres long and 4 metres high. A geogrid-reinforced structure and a reinforced concrete cantilever retaining wall were compared under identical actions and railway-specific requirements. A service life of at least 50 years was assumed for both options. Environmental impacts were evaluated through a comparative life cycle assessment based on DIN EN ISO 14040, DIN EN ISO 14044 and DIN EN 15804.

Four sustainability metrics: approximately 70% less greenhouse gas emissions, 60% less primary energy demand, 59% lower construction costs, and 64% less construction time.
Four sustainability metrics: approximately 70% less greenhouse gas emissions, 60% less primary energy demand, 59% lower construction costs, and 64% less construction time.
Comparison of the construction methods considered in terms of greenhouse gas emissions, primary energy demand, construction costs and construction time
Comparison of the construction methods considered in terms of greenhouse gas emissions, primary energy demand, construction costs and construction time

In the example considered, the calculated greenhouse gas emissions of the geosynthetic-reinforced option were approximately 70% lower, and primary energy demand approximately 60% lower, than those of the reinforced concrete cantilever retaining wall. A key reason is the reduced use of concrete and reinforcing steel. In the geosynthetic-reinforced solution, however, the required load-bearing capacity is achieved primarily through the interaction between the soil and the geogrid reinforcement layers, rather than through large concrete cross-sections.

The case study also revealed significant economic differences: at approximately €350,000, the construction costs of the geogrid-reinforced option were around 59% lower than those of the reinforced concrete cantilever retaining wall. At the same time, the estimated construction period decreased from around 55 to approximately 20 working days, a reduction of about 64%.

The results of this comparison demonstrate the potential of geogrid-reinforced retaining structures for transport infrastructure and railway construction. However, a project-specific assessment remains essential: ground conditions, available space, deformation requirements, fill soil, transport distances and the construction sequence must be considered at the option appraisal stage.

Further details on the methodology, design and assessment of the two construction methods are available in the full technical article (only available in German).

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