The operation involves sewing or patching a geotextile tube that has been damaged by an external element (piece of wood, boat, etc.).
For this, the divers use whipping twine as well as geotextile of the same composition as the tube itself.
For perfect performance of sewn pieces, a special stitch is made every 1cm with a stitch at most every 10cm.
This task involves removing the old bolts and replacing them with new ones on the geoports.
For the removal of bolts, a set of specific keys has been manufactured by our company to access the bolt heads inside the geoports. It is imperative, however, to clear the periphery of a quantity of sand at the level of the geoports before carrying out this task. Regular cleaning of the geoports makes it unnecessary to change bolts.
This operation consists in replacing the 8 mm black PVC blind flange that serves as a closure for the geoports. A diver removes the flange to be replaced and bolts the new flange. Special attention is paid to cleaning the span of the flange before replacing the new one. Regular cleaning of the geoports makes it unnecessary to change blind flanges.
A request may be made to add a buoy. For this operation, as with the change of the deadman, a boat equipped with a hydraulic arm is used to launch the body.
If the visual inspection has not enabled an identification, before the geotextile tube is emptied of all or part of its sand, it is possible to replace the latter.
The anchorage of the boats implemented will be four deadmen of 1 ton marked by buoys used to anchor the boat arm.
Once the boat is put in place, teams of divers cut the upper part of the geotextile tube using pneumatic (grinder, chainsaw, jigsaw) or mechanical (knife, cutter, etc.) equipment.
Once the upper part is completely cut, it is slung and stored on the boat arm.
Sand pumping is done using a Toyo pump equipped with jetting if necessary in order to decompress the sand.
The use of a Toyo pump allows us to pump the sand without capturing the geotextile composing the lower part of the tube as well as the anti-scouring mat.
Once the sand has been pumped, the geotextile tube is moved and pulled out of the water by the boat’s crane. After storage on the boat for dewatering, the geotextile is removed to watertight bins for removal to the approved landfill. It can thus be replaced.