GB2186656A

GB2186656A - Improved sewer or tunnel lining

Info

Publication number: GB2186656A
Application number: GB08703122A
Authority: GB
Inventors: Gordon Elliott; Stephen Elliott
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-02-13
Filing date: 1987-02-11
Publication date: 1987-08-19
Also published as: GB8603540D0; GB8703122D0

Abstract

A sewer or tunnel lining comprises at least two sheets of material (2,4) of arcuate shape in transverse section the longitudinal edges (8) of adjacent sheets (2,4) abutting one another to define a hollow lining the cross-section of which conforms substantially with that of the sewer to be lined, each sheet of material (2,4) having one or more flanges (6) formed thereon extending longitudinally of the associated edge region. The lining further comprises connections means (14) eg. stainless steel clips embracing adjacent flanges to interconnect adjacent sheets with one another. <IMAGE>

Description

SPECIFICATION Improved sewer linings This invention relates to linings for sewers, tunnels and the like (hereinafter referred to as sewers).

Many underground sewers have been in existence for several decades in locations where the stresses and strains applied thereto by modern-day activities are far greater than were anticipated at the date of installation. Consequently, it is now well-established practice to reinforce existing sewers by introducing liners therein, usually of glass-reinforced plastic or like material, and grouting the liners in position within the sewers.

Such liners commonly consist of a series of interconnected lengths each of two-piece construction, comprising a lower trough portion and an upper crown portion each of generally semi-circular shape in transverse section with their longitudinal edges interconnected by tongue and groove arrangements, gaskets sometimes being provided at the longitudinal joints.

Once located in the sewer, the volume between the inner face of the original sewer and the outer wall of the lining is filled with grout to retain the lining in position, and further to reinforce the existing structure.

These known arrangements suffer from a number of disadvantages. The tongues and grooves on the components of the lining have to be machined quite accurately to ensure a good fit therebetween-thus manufacturing tolerances must be carefully adhered to. The tongues and the walls of the grooves of the connection are often quite thin and are therefore prone to damage on transportation and installation. Further, once installed in a sewer, said tongues and grooves are often not capable of withstanding external lateral forces applied thereto such as are present when the linings are grouted in position within the sewer-thus it is often necessary to introduce buttressing within the linings to counter the external forces applied by the grout. This results in the expending of additional time and expense in installation.

It would be desirable to be able to provide a sewer lining less prone to damage, more capable of withstanding external forces thereon and capable of manufacture to much wider tolerances than heretofore.

According to the present invention, there is provided a sewer lining comprising two or more sheets of material each of substantially arcuate shape in transverse section, the adjacent longitudinal edges of adjacent sheets abutting one another to provide a hollow lining the cross-section of which conforms substantially with that of the sewer, each sheet of material having formed thereon one or more flanges extending longitudinally of each edge region thereof, the lining further comprising connection means adapted to embrace adjacent flanges of adjacent sheets to interconnect said sheets with one another.

In a preferred lining, the longitudinal edges of each sheet are substantially planar and the flanges are located externally of the lining whereby the hollow interior of the lining has a smooth inner surface thereto.

Preferably a continuous flange is formed along each edge region of a sheet, each flange lying closely adjacent to, and being spaced slightly outwardly of, the associated edge region to define a gap between the sheet of material and the flange. In such a case the connection means conveniently comprises, for each pair of abutting edges, a resilient, elongate clip member of generally Cshape in transverse section adapted to be a sliding force fit over the associated pair of flanges to embrace said flanges and urge the edges of the sheets into abutting engagement with one another.

In a preferred embodiment, the sheets are of glassreinforced plastic and the clip members are of a corrosionresistant metal such as stainless steel.

A preferred sewer lining comprises two sheets of material, one sheet being of generally semi-circular shape in transverse section and the other sheet being of subsstantially Ushape in transverse section to define a lining of generally egg-shape in transverse section.

Conveniently one end of each lining is of increased diameter and incorporates therein an internal circumferential seal, said one end of one lining being adapted to receive therein, in substantially sealing engagement, the other end of another lining.

By way of example only, an embodiment of the invention will now be described in greater detail with reference to the accompanying drawings of which: Fig. 1 is an exploded view, in transverse section, of the components of a sewer lining according to the invention; Fig. 2 is a schematic transverse section through a lining according to the invention grouted into a sewer, and Fig. 3 shows a detail of Fig. 2 to a larger scale.

Referring to the drawings, the illustrated lining comprises a lower, or trough portion 2 of glass-reinforced plastic of generally semi-elliptical shape in transverse section, and an upper, or crown portion 4 of glass-reinforced plastic of generally semi-circular shape in transverse section.

The free longitudinal edges of both portions 2 and 4 are each integrally moulded with corresponding flanges 6 extending the full length of the lining, each flange 6 comprising a planar face 8 defining an end edge of the associated lining portion and a reflex body portion 10 spaced from the associated trough portion 2 or crown portion 4 of the lining and con nected thereto by a reduced thickness neck portion 12.

The lining further includes a pair of resilient, elongate clips 14 of stainless steel, each of generally C-shape in transverse section and each substantially the length of the associated linings.

The trough and crown portions 24 of a lining can be interconnected as follows. The planar faces 8 of corresponding flanges 6 on the two portions are positioned abutting one another, and the clips 14 are hammered over, along the length of, said flanges to effect a secure, substantially sealed connection therebetween. More particularly, the internal, embracing volume within a clip 14 in its natural state is slightly smaller than the correspondingly-shaped, combined configuration of abutting flanges 6 such that the resilient nature of the clip permits their location over, to embrace,the associated flanges, and, on hammering of the clips 14 along the length of the seam, the free end edges of the clips 14 chew into the neck portions 12 of the flanges 6.

On installation in an existing sewer to be reinforced, the completed lining is chocked into position as shown schematically in Fig. 2, grout 16 is pumped into the space between the lining and the sewer wall and the grout 16 is allowed to set.

The clips 14 of the linings comprise structural components thereto which provide immediate support to the lining capable of withstanding the pressures applied to the lining by the liquid grout prior to hardening (typically 5 psi).

Thus there is no need to provide internal buttressing within the lining to counter the external forces of the grout.

Further, the presence of the clips 14 prevents any grout entering the lining, thus eliminating the necessity for specific sealing means between the portions of the lining.

Being external of the lining, the clips 14 are never in contact with effluent and the like flowing through the sewer, while, once the grout sets, the clips 14 are embodied therein.

The configurations of the lining portions 2 and 4 are such as to provide a smooth unobstructed internal surface thereto, while the flanges 6 can be manufactured to quite broad tolerances without interfering with effective connection between the trough and crown portions 2,4. Further, the flanges 6 are ofa substantial nature and are not therefore as prone to damage during transportation and installation as the connection means of known arrangements.

A typical lining according to the invention may comprise glass-reinforced plastic of thickness within the range of 3mm to 20mm, the internal dimensions commonly being 900mm high by 600mm wide (but dependent upon the dimensions of the sewer being lined) and the length of the lining being of the order of 1.5 metres. One end of the lining may be of increased-diameter to comprise a bell-end thereto housing an internal circumferential seal, adjacent linings being interconnected to form a continuous length by inserting the other end of one lining into the bell-end of the adjacent lining to form a sealed joint therebetween prior to grouting the interconnected lengths in position in the sewer to be lined. Alternatively, linings may be interconnected by providing co-operating circumferential tongues and grooves on the opposed ends of the linings.

Although described as being of glass-reinforced plastic, the portions 2,4 of the lining may be of other suitable materials, while the clips 14 may be other than stainless steel.

Clearly the particular configuration of the assembled lining is chosen to conform with that of the sewer to be lined, typically generally egg-shaped.

The linings may comprise more than two interconnected portions each provided with flanges such as 6; for example there may be three portions, a trough portion such as 4 with the crown portion 2 being divided into two components each of 900 arcuate extent.

Other variations and modifications from the described arrangement will be apparent to those skilled in the art.

Claims

1. A sewer lining comprising two or more sheets of material each of substantially arcuate shape in transverse section, the adjacent longitudinal edges of adjacent sheets abutting one another to provide a hollow lining the crosssection of which conforms substantially with that of the sewer, each sheet of material having formed thereon one or more flanges extending longitudinally of each edge region thereof, the lining further comprising connection means adapted to embrace adjacent flanges of adjacent sheets to interconnect said sheets with one another.

2. A sewer lining as claimed in claim 1 in which the longitudinal edges of each sheet are substantially planar and the flanges are located externally of the lining whereby the hollow interior of the lining has a smooth inner surface.

3. A sewer lining as claimed in claim 1 or claim 2 in which a continuous flange is formed along each edge region of a sheet, each flange lying closely adjacent to, and being spaced slightly outwardly of, the associated edge region to define a gap between the sheet of material and the flange.

4. A sewer lining as claimed in claim 3 in which the connection means comprises, for each pair of abutting edges, a resilient elongate clip member of generally C-shape in transverse section adapted to be a sliding force fit over the associated pair of flanges to embrace said flanges and to urge the edges of the sheets into abutting engagement with one another.

5. A sewer lining as claimed in claim 4 in which the sheets are of glass-reinforced plastic and the clip members are of a corrosionresistant metal.

6. A sewer lining as claimed in any one of claims 1 to 5 and comprising two sheets of material, one sheet being of semi-circular shape in transverse section and the other sheet being of substantially U-shape in transverse section to define a lining of generally egg-shape in transverse section.

7. A sewer lining as claimed in any one of claims 1 to 6 in which one end the lining is of increased diameter and incorporates therein an internal circumferential seal whereby said one end of one sewer lining can receive therein, in substantially sealing engagement, the other end of another sewer lining.

8. A sewer lining substantially as described with reference to and as illustrated by the accompanying drawings.