GB2103675A

GB2103675A - Drainage headwall support

Info

Publication number: GB2103675A
Application number: GB08123855A
Authority: GB
Inventors: John Kenneth Hoare
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-08-04
Filing date: 1981-08-04
Publication date: 1983-02-23
Also published as: GB2103675B

Abstract

A one-piece headwall support for a drainage outfall pipe discharging into a ditch comprises a rear face plate portion 1 connected to a front flange 3, adapted to be flush with the bank of the ditch, by integral walls 4 and 5 of which the lower wall 5 forms a cill. The rear face 1 has an aperture for the outfall pipe and, for anchorage purposes, a loop 6 of polypropylene cord, twine or strand is cast into one of the walls 4 for attachment of an anchor line itself attached to a more or less remote anchor. <IMAGE>

Description

SPECIFICATION Headwall support This invention relates to headwall supports.

Various forms of headwall supports have been commercially available for some time. They consist of precast concrete items which need to be assembled after excavation and followed up by backfilling.

In most cases this work is acceptable as part of the economic price for the job but in some cases, particularly fitting of headwalls to existing outfalls at frequent intervals along a ditch or channel, the cost is too great.

I have previously proposed a one piece structure which can be mounted with a minimum of excavation and backfilling. That structure, which form the subject of my application 801 6804, comprises a headwall support formed in one piece and comprising a face plate portion having an outfall aperture, or a portion in which such an aperture can be cut, the face plate portion being solid with a pair of limbs arranged to be extended into the ditch or channel wall, and with a cill or base on the side of the face plate portion remote from the limbs.

Such a structure is satisfactory for many applications but where the outfall pipe makes an angle of less than about 65 with the ditch wall, the rigid anchoring arms are difficult to locate in the bank or wall of the ditch.

According to the present invention, there is provided a head-wall support comprising a face plate portion having an outfall aperture, or a portion in which an outfall aperture may be readily pierced, and an integral cill or base on an external side of the face plate portion, the said headwall support also being provided with means for attachment of an anchor line to be buried into a ditch bank and attached to an anchor, also buried.

The attachment means may for instance be a loop formed of a cord, twine or strand having its ends set into the material of the headwall support.

The cord, twine or strand may be of polypropylene or similar rot-resistant material.

The headwall support is preferably of glass reinforced concrete and may be formed by a spraying process or by casting.

The anchor may for instance be a short bar of concrete, e.g. 6 inches (15 cm) long and 3 inches (7.5 cm) square in section, having the anchor line case into it. The anchor line may again be a suitable strand, cord or twine of polypropylene, or similar rot-resistant material.

Alternatively the anchor may be a thick sheet of galvanised steel having means for attachment for the anchor line.

The invention will be further described with reference to the accompanying diagrammatic drawing, in which: Figure 1 is a front elevation of a form of headwall support in accordance with one form of the invention; and Figure 2 is a side elevation of the headwall support of figure 1.

The drawings show a headwall support having a face plate portion 1 which is arranged to be embedded some way into the bank of a ditch and it is provided with an outfall aperture 2 through which an outfall pipe may be projected. An outer flange 3 is connected to the face plate 1 by means of intermediate integral walls 4, and the lowermost integral connecting wall 5 is formed as a cill or base to receive and direct flow from the outfall.

The headwall support illustrated is of integral construction and is formed from glass-reinforced concrete either by casting or by a spraying technique.

In order to anchor the headwall support within the bank of a ditch, a loop 6 of rot-proof material, such as a cord, twine or strand of polypropylene, is embedded in the upper wall 4 as it is formed. To this loop 6 there is then attached an anchor line (not shown), which may be a twine, cord or strand of polypropylene, having its other end embedded in or attached to an anchor buried directly behind the headwall support at an appropriate distance, with the anchor line taut, and also buried.

By this means the anchoring may be achieved with a minimum of additional excavation. The anchor may for instance be in the form of a short bar of concrete cast solid with the anchor line.

Alternatively, the anchor may be a sheet of galvanised steel provided with a securing point of the anchor line.

Since the headwall support may be buried in ditch walls of various angles, the angle of incidence of the outfall may vary considerably in relation to the face plate 1. In order to provide a reasonable degree of conformity between the aperture 2 and the outfall, the face plate 1 may be provided with perforated knock-out sections to provide a choice of shape.

Alternatively, an elliptical cast hole may be provided and additional plugs may be made available to close the ends of the aperture 2 when a nearer circular form is required.

Various modifications may be made within the scope of the invention.

1. A headwall support comprising a face plate portion having an outfall aperture, or a portion in which an outfall aperture may be readily pierced, an integral cill or base on an external side of the face plate portion, the said headwall support also being provided with means for attachment of an anchor line to be buried into a ditch bank and attached to an anchor, also buried.

2. A headwall support as claimed in claim 1, in which the attachment means is a loop formed of a cord, twine or strand having its ends set into the material of the headwall support.

3. A headwall support as claimed in claim 2, in which the cord, twine or strand is of polypropylene.

4. A headwall support as claimed in claims 1, 2 or 3, which is manufactured of glass-reinforced concrete by casting or by a spraying process.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Headwall support This invention relates to headwall supports. Various forms of headwall supports have been commercially available for some time. They consist of precast concrete items which need to be assembled after excavation and followed up by backfilling. In most cases this work is acceptable as part of the economic price for the job but in some cases, particularly fitting of headwalls to existing outfalls at frequent intervals along a ditch or channel, the cost is too great. I have previously proposed a one piece structure which can be mounted with a minimum of excavation and backfilling. That structure, which form the subject of my application 801 6804, comprises a headwall support formed in one piece and comprising a face plate portion having an outfall aperture, or a portion in which such an aperture can be cut, the face plate portion being solid with a pair of limbs arranged to be extended into the ditch or channel wall, and with a cill or base on the side of the face plate portion remote from the limbs. Such a structure is satisfactory for many applications but where the outfall pipe makes an angle of less than about 65 with the ditch wall, the rigid anchoring arms are difficult to locate in the bank or wall of the ditch. According to the present invention, there is provided a head-wall support comprising a face plate portion having an outfall aperture, or a portion in which an outfall aperture may be readily pierced, and an integral cill or base on an external side of the face plate portion, the said headwall support also being provided with means for attachment of an anchor line to be buried into a ditch bank and attached to an anchor, also buried. The attachment means may for instance be a loop formed of a cord, twine or strand having its ends set into the material of the headwall support. The cord, twine or strand may be of polypropylene or similar rot-resistant material. The headwall support is preferably of glass reinforced concrete and may be formed by a spraying process or by casting. The anchor may for instance be a short bar of concrete, e.g. 6 inches (15 cm) long and 3 inches (7.5 cm) square in section, having the anchor line case into it. The anchor line may again be a suitable strand, cord or twine of polypropylene, or similar rot-resistant material. Alternatively the anchor may be a thick sheet of galvanised steel having means for attachment for the anchor line. The invention will be further described with reference to the accompanying diagrammatic drawing, in which: Figure 1 is a front elevation of a form of headwall support in accordance with one form of the invention; and Figure 2 is a side elevation of the headwall support of figure 1. The drawings show a headwall support having a face plate portion 1 which is arranged to be embedded some way into the bank of a ditch and it is provided with an outfall aperture 2 through which an outfall pipe may be projected. An outer flange 3 is connected to the face plate 1 by means of intermediate integral walls 4, and the lowermost integral connecting wall 5 is formed as a cill or base to receive and direct flow from the outfall. The headwall support illustrated is of integral construction and is formed from glass-reinforced concrete either by casting or by a spraying technique. In order to anchor the headwall support within the bank of a ditch, a loop 6 of rot-proof material, such as a cord, twine or strand of polypropylene, is embedded in the upper wall 4 as it is formed. To this loop 6 there is then attached an anchor line (not shown), which may be a twine, cord or strand of polypropylene, having its other end embedded in or attached to an anchor buried directly behind the headwall support at an appropriate distance, with the anchor line taut, and also buried. By this means the anchoring may be achieved with a minimum of additional excavation. The anchor may for instance be in the form of a short bar of concrete cast solid with the anchor line. Alternatively, the anchor may be a sheet of galvanised steel provided with a securing point of the anchor line. Since the headwall support may be buried in ditch walls of various angles, the angle of incidence of the outfall may vary considerably in relation to the face plate 1. In order to provide a reasonable degree of conformity between the aperture 2 and the outfall, the face plate 1 may be provided with perforated knock-out sections to provide a choice of shape. Alternatively, an elliptical cast hole may be provided and additional plugs may be made available to close the ends of the aperture 2 when a nearer circular form is required. Various modifications may be made within the scope of the invention. CLAIMS

5. A headwall support as claimed in any of the preceding claims in which the anchor is a short bar of concrete having one end of the anchor line cast into it.

6. A headwall support as claimed in any of claims 1 to 5, in which the anchor is a sheet of corrosion resistant material, such as galvanised steel, having means for attachment of the anchor line.

7. A headwall support as claimed in any of the preceding claims, in which the anchor line is a strand, cord or twine of polypropylene.

8. A headwall support substantially as hereinbefore described with reference to the accompanying drawings.