Cut-off walls for levees, landfills and contaminated sites
A cut-off wall is an impermeable cement-bentonite barrier built into the ground. It stops seepage under a levee, contains landfill leachate and isolates a contaminated site. Building one takes the same machines as a foundation diaphragm wall, which has been our business for more than 40 years.
- 2 methods single-phase and two-phase
- 1 supplier for mixing, storage and desanding
- 40+ years with bentonite slurry
Foundation contractors already know these machines: they are the ones they use for diaphragm walls and piles. What changes is the purpose of the work and, in part, the mix.
We supply the plant behind the wall: preparing and storing the bentonite or the mix, pumping it and, with the two-phase method, desanding the slurry so it can be reused.
Where they are used
River levees
Against seepage and piping under the embankment.
Earth dams
As an impermeable cut-off in the foundation.
Landfills
To enclose the waste and contain the leachate.
Contaminated sites
To isolate the source of contamination and protect groundwater.
Single-phase or two-phase: what the site needs
Single-phase: self-hardening slurry
The trench is excavated while supported by the cement-bentonite mix itself, which stays in place and hardens.
Two-phase: excavate under slurry, then replace
The trench is supported with bentonite slurry, which is then replaced with the plastic mix. During excavation the slurry picks up sand: it has to be desanded and recycled, as in a foundation diaphragm wall.
What we supply
We supply the machines and size them with you. Your engineer designs the wall and the contractor builds it: the mix recipe remains the one in the design.
The machines
We size the plant on the daily output of the wall.
Mixers and turbomixers
To prepare bentonite and mix.MixersBentonite tanks
To hydrate the slurry and keep it ready next to the trench.TanksMixture plants
For sites with higher daily output.Mixture plantsSD desanders and desilters
To clean and recycle the slurry in the two-phase method.Mud treatment
Public programmes and incentives
- €1 billion against flood risk: Decree-Law 65/2025 funds an extraordinary programme of works in Emilia-Romagna, Tuscany and Marche from 2027 to 2038, approved in six-year tranches.
- Remediation and landfills: Italy has more than 16,000 active remediation procedures (ISPRA) and 42 Sites of National Interest. Vertical barriers are one of the techniques used to contain landfills and sources of contamination.
- Incentives for machinery: hyper-depreciation 2026–2028 for goods that meet the 4.0 requirements, Nuova Sabatini for SMEs, and the ZES Unica tax credit for investments in southern Italy.
Why SAICI
- 40+ years on diaphragm wall and pile sites: bentonite slurry is our everyday work.
- One supplier for mixing, storage, pumping and desanding.
- Wear-resistant parts: every part subject to wear is made from wear-resistant materials, selected and tested for the duty.
- Spare parts shipped within 24 hours of the order, for all our machines: a plant or a site standing idle while it waits for a part is expensive.
- Designed and built in Forlì: you deal directly with the people who know the machine.
Frequently asked questions
Why does the two-phase method need a desander?
During excavation the bentonite slurry picks up sand and loses its properties. Desanding it lets you reuse it several times and reduces the slurry to dispose of.
Do you carry out the works?
No, we supply the machines. The wall is built by the foundation or remediation contractor.
What do you need for a quote?
Length and depth of the wall, the method (single- or two-phase), the expected daily output and the soil type.
Let's talk about your project
Send us this information and we'll propose the plant:
- length and depth of the wall
- method: single-phase or two-phase
- expected daily output
- soil type
In some cases rental is also possible: if you're interested, ask us.