Self-closing sheet for encapsulating and dumping a bulk of material

Abstract

The invention relates to a sheet (1) to be placed in relation to a split barge (100) for encapsulating a bulk of material (101) to be dumped when the bulk of material is released, the sheet comprising a material containing portion (4) and at least one material free portion (3) extending from at least two opposed sides of the material containing portion, wherein that the immersed sheet encapsulating the bulk of material comprises an encapsulated body (20) encapsulated by the material containing (4) portion and a self-closing portion (22) being at least a part of the material free portion (3) both extending from an assembly point (21), wherein a closing length of the self-closing portion (22) correspond to at least 5% of the circumventing length of the encapsulated body (20), the circumventing length extending from the assembly point (21) to the assembly point (21). The invention further relates to a method of encapsulating a bulk of material by means of a sheet.

Description

FIELD OF THE INVENTION[0001]The invention relates to a sheet to be placed in relation to a split barge for encapsulating a bulk of material to be dumped when the bulk of material is released, the sheet comprising a material containing portion and a material free portion extending from at least two opposed sides of the material containing portion. The invention further relates to a method of encapsulating a bulk of material by means of a sheet.BACKGROUND OF THE INVENTION[0002]Dredging—the excavation of materials such as sediment of soil, sand, clay, slit and / or rocks from beneath bodies of water such as rivers and oceans—is a large global industry that makes marine construction projects possible, and supplies a large portion of the world's sand consumption.[0003]The industry reuses a large portion of the 9 billion cubic meter of matter it excavates every year for construction purposes, coastal feeding or landfilling. However not all material is suitable. Somewhere between 22-25% of t...

AI Technical Summary

Benefits of technology

[0057]The material containing portion of the inner sheet may be configured for being folded, for example zig-zag folded, when being placed in the split barge. Folding parts of the inner sheet arranged along the inside surface of the split barge, may facilitate a degree of extendibility of the inner sheet. The provided excess material of the inner sheet may unfold during immersion of the bulge of material. The unfolded excess material of the inner sheet may provide an extendibility of the self closing portion of the inner sheet.

[0058]The outer sheet may be configured to withstand the peak forces in / on the sheet occurring when the bulge of material squeezes through the split barge when being opened. The outer sheet may be configured to protect the inner sheet from being teared up by sharp or rough surfaces and / or edges or other irregularities in / on the split barge. The outer sheet may be a TenCate® sheet or the like. The inner sheet may be configured to withstand the forces imposed on the sheet during descent toward the sea bed. The inner sheet may thereby be made of a material having a lower strength than when only using one sheet.

[0059]The cost of manufacturing the sheet is related to the requirements on the material strength. The advantage of using a sheet comprising the inner sheet and the outer sheet is that the inner sheet, which may be configured for single use, may require a relative low material strength and thereby have a relative low manufacturing cost. The outer sheet requiring a higher material strength and thereby a higher manufacturing cost may be reusable.

Problems solved by technology

However not all material is suitable.

Somewhere between 22-25% of the annual dredged volume comprises dredge spoils and fine sediments which requires disposal, as its small grain size makes it unusable for practical uses.

The fine sediment is therefore instead dumped offshore where it may disturb the aquatic ecosystems, often with adverse long term effects, as the dumped sediment can remain in the water column for up to half a year where it may kill small organisms and in some cases cause deoxygenation.

Due to the potential hazards of oceanic dumping, the dredging industry is being met with increasingly high dumping costs, both through rising environmental fees and though the increased difficulty in finding suitable dumping sites close to excavation sites.

But as the geotextile bag does not encapsulate the material some sediment pollution may still take place.

A disadvantage of the known operations for sealing the flexible containers is that they are rather time-consuming.

Developers and contractors who hire dredging companies on the other hand, are encountering higher raw material costs, as the price of raw materials such as rocks, gravel and sand is rising due to demand and depletion of these resources in certain regions.

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