Reducing lateral earth pressures and managing water on a bridge structure
Discover how Nidaplast RA honeycomb blocks enabled the construction of a high-performance lightweight embankment on the abutments of the Leuge viaduct in Haute-Loire (France).
An innovative solution combining mechanical strength, low density and optimal water management, while limiting lateral pressures on the structure.
10 meters
height of abutments
6,000 m3
lightweight fill volume
100 m3
installed per worker/day
Project Context and Challenges
Limiting lateral and vertical pressures on the viaduct abutments
During the design of a civil engineering structure, engineering teams must anticipate multiple factors:
- loads applied to the structure,
- lateral earth pressures,
- differential settlements,
- behaviour of the supporting soil.
For the Leuge viaduct, built near a river subject to flooding and rising groundwater, water-related risks were critical.
Identified technical constraints:
- Risk of saturation with traditional fill materials (soil, GNT, sand)
- Need to limit lateral pressures on abutments
- Management of runoff and vertical drainage during heavy rain
- Tight construction deadlines
Solution Implemented with Nidaplast
Nidaplast RA honeycomb blocks – lightweight polypropylene embankment
Nidaplast RA blocks were chosen for their very low density (50 times lighter than traditional fill) and their high mechanical strength.
Made of 95% void, they function as a draining and hydraulically transparent embankment, reducing stresses applied to the structure.
Advantages in this context:
- Significant reduction of lateral loads on abutments
- Natural drainage thanks to the honeycomb structure: water flows freely through the cells
- High mechanical strength: 500 kPa uniaxial compression
- Easy installation: lightweight blocks, no connectors, no compaction required
Technical Characteristics of the Installed Product
Block height:
520 mm
Dimensions:
2400 x 1200 mm
Weight per block:
60 kg
Dry density:
40 kg/m3
Material:
Recyclable polypropylene
Nidaplast RA
Nidaplast RA lightweight embankments are extremely light and resistant. These honeycomb structures are the recommended solution for constructing landscape embankments, road embankments, or building embankments.
View product sheetInstallation Process
1. Earthworks
Excavation and preparation of a regular formation layer, covered with an anti-contamination geotextile.
2. Laying the blocks
Placement of Nidaplast RA blocks in cross-bond pattern, both longitudinally and transversely.
3. Intermediate layer
Installation of a 30 cm GNT intermediate layer, covered with geotextile before continuing with block installation.
4. Second embankment stage
Installation of the second layer of RA blocks, followed by GNT and—depending on traffic class—by a reinforced concrete slab ensuring adequate bearing capacity for the future pavement.
Watch the installation video
Results and Benefits Observed
Major reduction of lateral and vertical pressures on the viaduct abutments
Optimal water management: infiltration and natural drainage through the Nidaplast RA honeycombs
Significant time savings (no compaction), lightweight and easy-to-handle solution
Improved long-term durability of the structure and reduced settlement risks
