Soil-mix wall (CSM panels or columns)
Soil-mix wall (CSM panels or columns)
A soil-mix wall blends the in-situ soil with a cement grout to form a continuous wall that is both retaining and water-tight. It can be built from overlapping columns or from longer panels (CSM — Cutter Soil Mix). Reinforcement is provided by steel profiles or reinforcement cages. The process is fully low-vibration and low-noise — a strong fit for urban environments.
When to use
- Excavations in sand, silt, soft or firm clay up to about 20 m deep
- Works below the water table combining retention and cut-off
- Urban environments with strict vibration and noise constraints (fully vibration-free)
- No preliminary dewatering required
- CSM panels: longer elements mean fewer joints — useful in layered soils
What we deliver
- Column diameter / panel thickness, spacing and reinforcement design (steel profiles or reinforcement cages)
- Binder content, target UCS and permeability specification
- Stability and deformation analysis to Eurocode 7, with reduced section accounted for
- Layout, sections, calculation report and a quality-control programme
Technical notes
- Soil suitability: excellent in sand, good in silt and soft clay, limited in firm clay — caution in coarse gravel, peat and organic soils
- Overlap: ≥ 6 cm between columns (D/8 for silo/cut-off); ≥ 10 cm between panels
- Curing times: 6 h between primary series, 8 h between primary and secondary; minimum 10 days before excavation
- Quality control: 1 core per 150 m³ for retention only, 1 per 75 m³ (minimum 12 cores) for cut-off or bearing — UCS, E-modulus and inclusions < 20 vol%
- Tolerances: 25–50 mm horizontal, ±100 mm vertical, 1.3 % tilt (0.5 % for silo/cut-off)
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