Method for performing a dredging operation and installation of underwater dredging.

摘要

Method for performing a dredging operation in a water body by means of a drag head, comprising the bottom (29) of said body of water a compressed bottom material particles (33) which enclose pores which are filled with pore water, comprising said drive head at least one cutting element (8) for cutting the bottom material, jet means (36) connected to a duct (26) supplied with pressurized water for treating the bottom material by at least one jet water, and suction means for removing the material cut line, said method comprising the steps of: - dragging the drag head along the bottom (29), - exerting a cutting force on a parcel (34) of material background compressed by the cutting element (8), causing said cut force increasing the mutual distance of at least a portion of said particles (33) of the parcel of bottom material and thereby causing one r elicitation pore pressure in the water filled pores between said particles (33), - directing at least one water jet (30) towards said parcel (34) of bottom material to introduce a water flow into said pores between said particles (33) and thereby at least partly eliminating the pressure reduction in said pores caused by the said displacement of bottom material, resulting in that elimination one specific cutting force reduced, - subsequently cutting said parcel (34) the bottom material by the cutting element (8), - where the water flow is generated at or near the cutting member (8).