Diaphragms are underground walls made in situ and executed as a trench by using bentonite mud. The excavation is completed by installing a steel reinforcement and flushing out bentonitic mud by the concrete flux.
A diaphragm wall is commonly used as support before an excavation, as a structural foundation or to retain underground water to flow inside the trench. Diaphragm walls are very much used in underground constructions since they can be executed with a very limited grade of interference. To make the panels, the trench is then filled with concrete from the bottom up, using tremie pipes. The joint between two panels can be constructed using a CWS steel formwork section that will provide a sealing system between the panels and will provide guidance for the excavation grab.
ENTECO products include diaphragm wall application with telescopic Kelly hydraulic grabs to be applied to any piling rig of the range with excavation up to 50 meters panels depth.
The assembly is composed of a single long bar or multiple telescopic bars, friction and interlocking type, sliding along the base unit drilling mast and connected to it by suitable cradles maneuvered by a crowd/extraction winch. The bars guide a hydraulic grab which is suitable with interchangeable valves and guides to excavate different sizes of panels using the same grab body.
Since the system is fully hydraulic, hoses recovery reels and grab rotation system to guarantee perfect panel verticality are provided.
- Soft earth close to open water or with a high ground water table
- Execution in areas that already built and as completion of existing works
- Water tightening of underground soil formations
- Enhanced verticality control
- Full control of piles verticality by means of electronic devices