||A diaphragm wall is a reinforced in-situ concrete wall that is cast in panels excavated into the ground. The trench is held open by the use of a supporting bentonite slurry during excavation, installation of reinforcement and concreting.
Diaphragm walls provide a safe and cost effective solution to construct permanent or temporary retaining structures. They are particularly suitable to protect excavation carried out below the water table and they can be installed in close proximity to existing structures with minimal loss of support to existing foundations.
Various other techniques such as precast diaphragm walls and cut-off walls, that are derivatives of diaphragm wall technology, are also commonly used in ground engineering:
- Precast diaphragm walls are very similar to conventional diaphragm wall but instead of pouring concrete into an in situ trench, precast reinforced concrete elements are lowered into the trench. The bentonite cement slurry which is used as excavation fluid seals the prefabricated elements into the ground.
- Cut-off walls are cast in situ non-structural hydraulic barriers that are chemically resistant. In this application, a bentonite cement mix forms a hydraulic barrier.
For diaphragm wall and cut-off walls, Bachy Soletanche has developed a wide range of construction techniques and equipment. These include the Complete Water Stop (CWS) watertight seal, the KS3000 hydraulic grabs and the Hydrofraise reverse circulation trench cutter.
KS3000 Hydraulic Grab, Hydrofraise and Compact Hydrofraise