Underwater concrete foundations perform an important sealing function against the surrounding ground water as well as a load-bearing function, regardless of whether it is a temporary foundation or, in combination with a waterproof, reinforced platform, it remains permanently in place to absorb the uplift forces of the ground water.
Underwater concrete foundations can be installed with or without anchoring. The key factor for the choice of foundation is the hydrostatic pressure. In the case of foundations with anchoring, we deploy injection piles, vibratory piles and pre-stressed ground anchors. Lifting chocks are also often installed in the walls of the sheeting.
Before installing underwater concrete foundations, the excavation base must be free of sediment sludge and the walls of the sheeting free of adhering material in order to ensure complete watertightness. In the case of foundations with anchoring, the anchor plates with lock nuts must be attached to the anchors at the required height prior to installation of the concrete foundations.
Underwater concrete foundations are installed solely using the following contractor technique: (procedures)
- Installation with pump, delivery hose and pump tube
- Installation with pouring pipe and hopper (tremie)
- Installation with floating tube (hop dobber)
- Installation with compressible drop hose (hydrovalve)