Cut-off walls

Cut-off walls can be produced in both single-phase and two-phase systems. They perform sealing and/or screening functions and are suitable for both temporary and permanent use.

With the insertion of load-bearing elements, cut-off walls can also perform structural functions and are an inexpensive shoring solution for construction pits.

In order to seal off the bottom of the construction pit against rising groundwater, cut-off walls bond with surrounding soil layers with a low water permeability or with artificially produced sealing slabs.

Areas of application include:

• Low-cost, low-deformation temporary construction pit systems with insertion of additional load-bearing elements
• Transverse bulkheads to partition large construction pits
• Sealing dams
• Landfill enclosure
• Enclosure of contaminated land on brownfields or similar sites

• Cut-off walls provide a high degree of security due to their excellent sealing qualities.
• When combined with load-bearing elements and anchoring, this method is exceedingly low in deformation.
• Cut-off walls are an economical shoring solution that allows for a separation between structural and sealing functions.
• Huge depths of 20m to 40m are possible using the grab method.
• The construction period is shorter than that of bored pile walls, saving time and money.
• Level surfaces have several advantages for formwork and ensure economic efficiency.
• This method enjoys a high degree of acceptance among local residents because it is low-noise and vibration-free.
• It can also be executed under restricted heights (e.g. under bridges).
   

Standards and rules

Cut-off walls are designed and manufactured in accordance with DIN EN 1538 and the recommendations of the “Construction Pits” Working Group (Empfehlungen des Arbeitskreises “Baugrube”, EAB). Verification of the stability of the open diaphragm is carried out in accordance with DIN 4126.

Production

Cut-off walls are produced along the same lines as diaphragm walls, using the grab method. Guide walls are built along the route where the cut-off wall will stand beforehand to guide the grab.

A cut-off wall compound is used to stabilise the earth walls. This does not have to be replaced in the single-phase system; instead, its high cement content means that it sets in place. Precast concrete elements, HEB profiles and sheet pile profiles are used as structural load-bearing elements.

Cut-off wall thicknesses typically range between 0.45m and 1.0m, with typical depths ranging from 15m to 40m.

We ensure high execution quality with:

• Individually coordinated instructions
• Compliance with the requirements of execution standard DIN EN 1538
• Verification of the position, torsion and verticality of the diaphragm lamella with modern measuring technology such as inclinometers
• Clear processes governed by our quality management system in accordance with DIN EN 9001:201
   

The following variants are available:

• Cut-off wall with sheet-pile wall
• Cut-off wall with prefabricated concrete elements
• Cut-off wall with HEB profiles
• Cut-off wall without load-bearing elements,  for sealing purposes only