초록 ▼

Subsoil drain strip or sheet elements comprising a core surrounded by a polymer or glass fibre filter cloth. The core has a generally planar configuration with hollow formed-in flat topped projections on one or both sides which create internal volume for flow of water as well as supporting the filte

Subsoil drain strip or sheet elements comprising a core surrounded by a polymer or glass fibre filter cloth. The core has a generally planar configuration with hollow formed-in flat topped projections on one or both sides which create internal volume for flow of water as well as supporting the filter cloth against imposed soil loads. The depth of the supporting projections on each side of the core and their relative spacing is to be such that the surrounding filter cloth is restrained against being forced into the hollow interiors of the projections so that adequate longitudinal flow of water can take place in the strip without the need for additional drainage tubes to be provided. The depth of the projections may be greater than one quarter of their closest spacing. Additionally, the average diameter of the projections may be between 0.2 and 0.35 of their closest spacing.

대표청구항 ▼

An essentially continuous subsoil sheet drainage element comprising: a core sheet of generally planar configuration having on at least one side of a plane regularly spaced, hollow, equal depth supporting projections each having a base and a flat top, said plane located at the base of each projection

An essentially continuous subsoil sheet drainage element comprising: a core sheet of generally planar configuration having on at least one side of a plane regularly spaced, hollow, equal depth supporting projections each having a base and a flat top, said plane located at the base of each projection; and a covering of geotextile filter cloth surrounding said core; the depth of projections on one side of said plane and the spacing between adjacent projections permits the core sheet to be tightly folded upon itself without damage or significant loss of water carrying capacity.