Mareuil-les-Meaux residential development – reinforced slope with vegetated facing

Overview

In Mareuil-les-Meaux, northwest of Paris, CETP IDF – a construction company specializing in residential site development – sought an environmentally responsible and cost-effective approach for building retaining walls on a new real estate complex. The project included four residential buildings, each with one to two above-ground floors and one or two basement levels.

Originally designed with concrete retaining walls, the client opted to explore a geosynthetic-reinforced fill solution featuring a vegetated facing to reduce material use, lower costs, and minimize environmental impact. Solmax supported CETP IDF and the geotechnical engineering office BY Géotechnique in designing, modeling, and executing this alternative solution. Construction was completed in spring/summer 2025.

Challenge

The development required a reinforced embankment with a slope of 70 degrees and a maximum height of 9 m, alternating layers of soil and reinforcement. For CETP IDF, this was the company’s first experience using geosynthetic reinforcement and Polyslope-type facings.

The main challenge was technical unfamiliarity. To address this, Solmax’s engineering team provided detailed installation guides, design assistance, and on-site meetings to ensure correct handling and placement. Two slope profiles were modeled during the design phase to confirm structural stability and optimize material use.

Solution

The final design used a geosynthetic-reinforced soil structure combining three Solmax products:

• MIRAGRID^® GX 80/30 – high-strength geogrid reinforcement installed every 60 cm to provide internal stability and load distribution.

• MIRAGRID Green B – an erosion control layer for preventing soil run-off and supporting vegetation of the slope surface

• Polyslope S – a facing system designed for steep vegetated slopes, providing both aesthetic and functional performance.

This configuration offered a durable, flexible retaining system with strong mechanical performance, reduced carbon footprint, and visual integration into the residential landscape. The geosynthetic system replaced traditional concrete retaining walls, achieving significant cost savings and reduced environmental impact through lower material and transport requirements. The design’s vegetated facing contributed to local aesthetics and stormwater management, aligning with regional sustainability objectives in Île-de-France.

CETP IDF highlighted three key factors for success: responsiveness and close technical collaboration during design and construction, rapid product availability that ensured no delays on site, and comprehensive technical and commercial support from Solmax teams throughout execution.