GB2093943A

GB2093943A - Renovation of tunnels

Info

Publication number: GB2093943A
Application number: GB8106651A
Authority: GB
Original assignee: REDLAND PIPES Ltd
Current assignee: REDLAND PIPES Ltd
Priority date: 1981-03-03
Filing date: 1981-03-03
Publication date: 1982-09-08
Also published as: GB2093943B

Abstract

A method of manufacturing a tube (1) of non-circular cross-section for lining, e.g. renovating, a tunnel, sewer, pipeline or the like duct comprises the steps of deforming a pre-formed, thin walled circular cross-section pipe (22) into a deformed pipe of non-circular cross-section, wrapping reinforcing strands, e.g. in the form of helical ribs (3, 4), impregnated with a curable binder around the deformed pipe (22), and curing the binder to provide a finished tube held to a desirable non- circular cross-section by the cured binder and reinforcing strands. The invention also relates to a tube manufactured by the method and to a method of lining a tunnel, sewer, pipeline or the like duct using such tubes. <IMAGE>

Description

SPECIFICATION Renovation of Tunnels This invention relates to a method of manufacturing a tube of reinforced plastics material for use in lining, e.g. so as to renovate, a tunnel, sewer, pipeline or the like duct. The invention also relates to a method of renovating such a tunnel, sewer, pipeline or the like duct. In order to simplify the ensuing description, such ducts, whether they are situated underground, submerged in water or situated above ground, will be referred to as "tunnels".

Tunnels, whether constructed of annular members, such as end-to-end connected or abutting pipes or rings, or of arrangements of bricks, blocks or segments, undergo deterioration with the passage of time, and, in view of the high cost of renewing them, it is highly desirable to have a relative inexpensive and effective method of renovating damaged tunnels.

Many proposals have been made for the renovation of damaged or collapsed tunnels, particularly sewers, including the repointing of brick or block lines tunnels, grout sealing of pipeformed tunnels where areas surrounding the pipes have been eroded, spray coating of tunnels with sealing and water-proofing compounds, relining with reinforced concrete panels of appropriate shape, re-lining with reinforced plastics or concrete liners of similar shape to the tunnel to be renovated, relining with flexible plastics tubing which is unrolled in the tunnel and expanded into shape using fluid pressure means, or re-lining with a fixed diameter, high density polyethylene pipe of lesser diameter than the tunnel and in-filling the annular space between the pipe and the tunnel with grouting material.

All of these known proposals are successful to a degree, but are restricted in their use by the parameters imposed by the diversity of tunnel cross-sections encountered in practice. Other drawbacks to the use of some of the prior proposals are the high bulk and weight and lack of flexibility of the materials employed. For example, concrete panels are bulky, heavy and certainly lack flexibility.

The present invention aims to provide a method of manufacturing a tube for use in lining a tunnel, the tube having a desired non-circular cross-section and not having any of the drawbacks referred to above.

According to one aspect of the present invention a method of manufacturing a tube of a desired, non-circular cross-section for subsequent use in lining a tunnel having a larger, non-circular cross-section, comprises deforming a pre-formed, thin-walled pipe having a substantially circular cross-section into a deformed pipe having a desired, non-circular cross-section, applying reinforcing strands impregnated with a curable binder to the external surface of the deformed pipe, and curing the binder to provide a finished tube held to the desired, non-circular crosssection by the cured binder and reinforcing strands.

The reinforcing strands applied to the external surface of the deformed pipe ensure that the finished tube retains its deformed shape and gives the finished tube strength and rigidity.

The reinforcing strands may be applied so as completely to overlie the deformed pipe.

However, it is preferred that reinforcing strands are applied in a ribbed pattern, and in particular it is preferred that the reinforcing strands provide helical reinforcing ribs, at least one of which ribs has a different hand from the remaining rib or ribs.

The provision of helical ribs on the finished tube affords strength and rigidity to the tube without sacrificing too much of the flexibility of the tube along its longitudinal axis. In using the term "helical" to describe the ribs on the external surface of the deformed pipe, we mean. in this specification, that each rib follows a threedimensional curve with one or more turns around the longitudinal axis of the deformed pipe.

The pre-formed, thin-walled pipe employed in the method in accordance with the invention is preferably made of reinforced plastics material and preferably has a wall thickness of from 3 to 6 mm, and may have a plurality of layers containing different reinforcing materials. The plastics material may be any commercially available resin, for example polyester resin, and the pipe may comprise an inner layer reinforced with glass fibre tissue having a thickness of from 0.5 to 1 mm and one or more outer layers reinforced with chopped glass strands each having a thickness of from 1 to 1.5 mm. The tissue used for reinforcing the inner layer preferably consists of E glass continuous filaments laid randomly in a mat and held together with a suitable binder. Such tissue is capable of taking up a large amount of resin, so that the inner layer of the pipe is resin rich.The chopped glass strands used for reinforcing the outer layer or layers of the pipe may be made from E glass and have a length of about 5 cm. The strands are suitably prepared in the form of a mat in which the strands are randomly laid and held together with a suitable binder, for example starch.

The reinforcing strands applied to the external surface of the deformed pipe may be formed from bundles of continuous E glass filaments impregnated with synthetic resin.

It will be appreciated that the method according to the invention affords a versatile manufacturing method. When a tunnel is desired to be lined, a pre-formed pipe of appropriate diameter is selected from a store of previously manufactured pipes having different diameters.

The method according to the invention is then performed, the selected pipe being deformed to a suitable shape, e.g. to have a rectangular, barrelshaped, eliptical or egg-shaped cross-section, to conform to the shape of the tunnel to be lined.

When the finished tube has been manufactured, it is introduced into the tunnel to be lined and the space between the external surface of the tube and the internal surface of the tunnel is filled with grouting material.

The pipe may be deformed so as to have the desired, non-circular cross-section, by any suitable mechanical deforming means positioned inside the pipe. In its simplest form the mechanical deforming means may comprise a plurality of templates made, for example, of plywood. Alternatively the mechanical deforming means comprises an inflatable and deflatable air bag arrangement. Preferably, however, the mechanical deforming means comprises a variable geometry mandrel incorporating a plurality of expandible and contractible jacks. e.g.

screw-actuated jacks.

In certain applications the length of the tunnel to be lined and the course it takes will be such that only a single tube need be manufactured to line the tunnel. However in most applications it will be necessary to provide a tubular lining in the form of a plurality of lining tubes joined end-toend. In this latter case, one end of each tube may be manufactured with a socket to enable adjacent tubes to be joined by means of a spigot and socket connection. Conveniently the socket is formed by positioning a flexible collar-mould adjacent the said one end of the pipe and forming a collar defining the socket at the said one end of the pipe. The collar is typically formed by applying a reinforced, settable plastics material over the said one end of the pipe and the collar-mould and subsequently curing the settable plastics material.

The reinforced, settable plastics material may be the same material as the said curable binderimpregnated reinforcing strands and may be applied at the same time as the latter are applied to the external surface of the deformed pipe.

According to another aspect of the present invention, a method of renovating a tunnel comprises the steps of introducing into the tunnel a tubular lining made up of at least one tube manufactured according to said one aspect of the invention, and filling the space between the external surface of the tubular lining and the internal surface of the tunnel with a grouting material.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which~ Figure 1 is a perspective view of a tube manufactured by a method in accordance with the invention, Figure 2 is a schematic sectional view of a tunnel in the course of being renovated by the insertion of a plurality of tubes, each as shown in Figure 1, joined end-to-end, Figure 3 is a sectional view, on an enlarged scale, of a portion of the tunnel of Figure 2 after having been renovated, Figure 4 is a schematic sectional view, taken on the line lV-lV of Figure 5, of one embodiment of apparatus for manufacturing a tube by a method in accordance with the invention, Figures 5 and 6 are 'schematic sectional views, taken on the lines V-V and VI-VI, respectively, of Figure 4, respectively prior to and after a pipe supported on the apparatus has been deformed to have a desired cross-sectional shape, Figure 7 is a longitudinal sectional view through the wall of part of a preferred embodiment of tube manufactured by the method in accordance with the invention, and Figure 8 is a schematic perspective view of part of another embodiment of apparatus for manufacturing a tube by a method in accordance with the invention.

The tubular lining, generally designated by the numeral 1, shown in Figure 1 comprises a thinwalled tube 2 made from reinforced plastics material, for example polyester resin reinforced with glass fibre material. The external surface of the tube 2 is formed with two helical ribs 3, 4 formed from bundles of glass filaments impregnated with plastics material. The ribs 3, 4 have a helix angle in the range of from 450 to 700, and one of the ribs is of opposite hand compared with the other. As a result, the ribs 3, 4 cross one another to define, on the external surface of the tube 2, a plurality of diamondshaped areas 5 bounded on two opposed sides by the rib 3 and on the other two opposed sides by the rib 4.

The cross-sectional shape of the tube 2 of the lining shown in Figure 1 is chosen to suit the cross-sectional shape of the tunnel it is desired to renovate with the lining. Thus, although the tube 2 shown is of generally ovoidal shape, it will be appreciated that it can have any other shape conforming to that of the tunnel in which it is to be inserted.

Figure 2 shows the tubular lining 1 being inserted into an underground tunnel 6, for example a sewer, which is formed from a plurality of end-to-end connected pipes 7. A hole 8 is excavated in the ground to uncover one end of a portion 9 of the tunnel 6 that has to be renovated, and a part of the tunnel is removed in this region to leave a gap 10 therein. The numeral 1 1 designates a man-hole 11 giving access to the tunnel 6 at the end of the tunnel portion 9 which is remote from the hole 8.

The interior of the tunnel portion 9 is first cleaned and any debris and broken parts removed. A section 12 of the lining 1 is then introduced into the tunnel portion 9 at the gap 10 and the leading end of the section 12 is connected by a rope 13 to a winch 14 located in the man-hole 1 1. By actuating the winch 14, the lining section 12 is drawn along the tunnel portion 9 until the leading end of the section reaches the man-hole 1 To facilitate movement of the lining section 12 along the tunnel, the leading end of the section may be provided with a conical end closure 15.

Since the tunnel portion 9 has a length greater than each tube 2, the lining section 12 comprises a plurality of tubes 2 connected together end-toend. One such connection is shown in Figure 3 by employing an H-section jointing member 16. In Figure 3, the joining member 1#6 is shown connecting tube 2 to a further tube 2a. The two sections 2, 2a would usually be connected together with the jointing member 16 before the trailing end of the tube 2 entered the tunnel portion 9. This connection is conveniently effected above ground or in the hole 8, the adjacent ends of the two tubes being secured in the jointing member 16 with a suitable adhesive.

As an alternative to employing the jointing member 16 for connecting together adjacent tubes, one end of each tube 2 may be formed with a socket to enable adjacent tubes to be connected together by means of a spigot and socket connection. The method of forming a socket at one end of a tube will be described in detail hereinafter with reference to Figures 5 to 7.

Figure 3 shows the tubular lining 1 installed in the tunnel portion 9 with the gap 17 between the internal surface of the tunnel portion 9 and the external surface of the lining 1 filled with a grouting material 18, for example cement grout.

The grouting material 18 may be introduced into the gap 17 from inside the lining 1. To this end, the lining 1 may be provided with holes 19 through which the grouting material 18 may be injected under pressure. Alternatively, the grouting material 18 may be introduced into the gap 17 from above the tunnel portion 9, via holes 20 bored through the tunnel portion 9 and the ground overlying the tunnel portion. Temporary supports 21, shown in chain lines, may be arranged in the lining 1 to support the latter while the grouting material 18 sets. These supports are removed when the grouting material has set.

Due to the thin-walled construction of the lining 1 and its external helical reinforcing ribs 3, 4, it is found that the lining has a degree of flexibility enabling it to be moved along at least gently curved sections of the tunnel to be renovated, yet at the same time it provides a strong and rigid lining when finally grouted into the tunnel.

The tubular lining 1 is manufactured in two distinct stages. In the first stage of manufacture, a thin-walled pipe 22, of circular cross-section, is formed by applying resin impregnated glass fibre material to a rotatable, circular-cylindrical mandrel (not shown) using conventional techniques. The pipe 22 is then placed in a curing chamber, or passed through a tunnel drier, to cure the resin.

In the second stage of manufacture, there is employed apparatus generally designated 23 (see Figures 4, 5 and 6). The apparatus 23 comprises a mandrel 24 rotatable about its longitudinal axis on shafts 25, 26 supported in bearings 27, 28, respectively. A plurality of radially expandible and contractible jacks 29a, 29h and 29c are mounted on the mandrel 24 so as to be spaced apart along its length. Although any number of jacks may be provided in any suitable arrangement, in the embodiment of apparatus 23 shown in Figures 4 and 5, there are five jacks 29a arranged to occupy a first axial plane, five jacks 29b arranged to occupy a second axial plane, and five jacks 29c arranged to occupy a third axial plane; the first, second and third axial planes being equally spaced apart with respect to the longitudinal axis of the mandrel 24.All of the jacks 29a, 29b and 29c are radially expandible and contractible by turning screw-threaded rods 30, 31 and 32, respectively, and carry at their radially outer extremities curved forming plates 33, 34 and 35, respectively.

The pre-formed, cured pipe 22 is then positioned over the apparatus 23 with the forming plates 33 to 35 bearing against the internal surface of the pipe 22. A flexible, annular collar 36, e.g. of rubber or rubber-like material, is positioned at one end 37 of the pipe 22. The collar 36 has a first outer cylindrical surface 38 which bears against the internal cylindrical surface of the pipe 22 and a second outer cylindrical surface 39 which forms an extension of the one end 37 of the pipe 22.

The rods 30, 31 and 32 are then turned radially to expand or contract the jacks 29a, 29b and 29c, respectively, so that the forming plates 33 to 35 deform the pipe 22 so that the latter has a desired cross-section (for example the substantially oval cross-section shown in Figure 6). The periphery of the deformed pipe 22 has a length substantially the same as the circumference of the undeformed pipe 22. It will be appreciated that the deformation of the pipe 22 also causes the flexible annular collar 36 to be deformed, as shown in Figure 6, so as to adopt substantially the same cross-sectional configuration as the deformed pipe 22.

A bundle 40 (see Figure 6) of continuous glass filaments is then fed through a bath (not shown) of uncured resin and the resin-impregnated bundle 40 of continuous glass filaments is laid in a helix around the deformed pipe 22. Prior to their application to the pipe 22, the bundle 40 of glass filaments may be twisted to give a rope-like configuration to the bundle. Conveniently a feed head (not shown) is employed to lay the bundle 40 of glass filaments, the feed head traversing along the apparatus 23 in the direction from the support 28 to the support 27 as the mandrel is rotated in the direction of the arrow 41 so that the resin-impregnated bundle 40 of glass filaments is laid as a helical rib 3 on the external surface of the deformed pipe 22. When the rib 3 has been laid on the deformed pipe 22 up to the end 42 of the latter remote from the end 37, the direction of motion of the feed head is reversed, so that it moves back towards the support 28. During this movement of the feed head, a further helical rib (not shown) of opposite hand to the rib 3 is laid on the external surface of the deformed pipe 22.

At the end 37 of the pipe 22, the speed of movement of the feed head is reduced and the bundle of glass filaments is closely wound around the end 37 of the pipe 22 and over the second outer cylindrical surface 39 of the collar 36 to form a socket 43 (see Figure 7) adjacent the end 37 of the pipe 22. After the two helical ribs and the socket 43 have been formed in this way, the bundles of filaments may be coated on their outer surfaces with further resin. After application of the helical ribs and the socket 43 to the external surface of the pipe 22, the lining is placed in a curing chamber, or passed through a tunnel drier, to cure the resin and form the finished tube 2. The reinforcing ribs ensure that the tube 2 retains its deformed shape when the tube is removed from the apparatus 23.

Figure 7 shows a preferred construction of the tube 2 shortly before being cured and prior to the removal of the collar 36. The tube 2 has an inner layer 50 surrounded by layers 51 and 52. The inner layer consists of polyester resin reinforced with the aforementioned tissue of continuous glass filaments having a thickness of 0.5 mm, and the layers 51 and 52 consist of the same polyester resin each reinforced with a mat of the aforementioned chopped glass strands, each mat having a thickness of 1 mm. In one example of such a tube 2, the pipe 22 had a wall thickness of 3 mm and the helical ribs 3, 4 of the tube 2, each composed of the same polyester resin reinforced with continuous glass filaments 53, had a height of 2 mm.

The tubes may be made in any convenient length, for example 5 to 10 m, and may be manufactured from thin-walled, reinforced, circular-cylindrical pipes having a wide range of diameters, for example from 0.5 to 2.5 m, so that the tubes can be employed for lining tunnels of a wide range of sizes. It will also be appreciated that pipe 22 of different diameters can be deformed to virtually any desired cross-section on the single apparatus 23.

In use, a plurality of pipes 22 is ma ufactured and stored until required to be used. Shortly before use, when the dimensions of a tunnel to be lined are known, the required number of pipes 22 are converted into finished tubes 2 of non-circular cross-section in the manner previously described.

Other apparatus may be employed for supporting a pipe 22 in a deformed condition. For example Figure 8 schematically illustrates apparatus 60 comprising a rotatable shaft 61 having a plurality of templates 62 (only one of which can be seen in Figure 8) made, for example of plywood, fixed along its length. The pipe 22 is deformed and slipped over the templates 62, the templates 62 serving to retain the pipe 22 in its deformed condition. Alternatively inflatable and deflatable air bags (not shown) may be employed to deform the pipe 22.

Claims

1. A method of manufacturing a tube of a desired, non-circular cross-section for subsequent use in lining a tunnel (as hereinbefore defined) having a larger, non-circular cross-section, comprising deforming a pre-formed, thin-walled pipe having a substantially circular cross-section into a deformed pipe having a desired, noncircular cross-section, applying reinforcing strands impregnated with a curable binder to the external surface of the deformed pipe, and curing the binder to provide a finished tube held to the desired non-circular cross-section by the cured binder and reinforcing strands.

2. A tube manufactured according to the method claimed in claim 1.

3. A method of renovating a tunnel (as hereinbefore defined) comprising the steps of introducing into the tunnel a tubular lining made up of at least one tube as claimed in claim 2, and filling the space between the external surface of the tubular lining and the internal surface of the tunnel with a grouting material.

New Claims or Amendments to Claims filed on March 2, 1982 Superseded Claims 2 and 3 New or Amended Claims:~ 2to24

2. A method according to claim 1, in which the reinforcing strands are applied in a ribbed pattern.

3. A method according to claim 1 or 2, in which the reinforcing strands are applied as helical (as hereinbefore defined) reinforcing ribs.

4. A method according to claim 3, in which at least one of said helical reinforcing ribs has a different hand from the remaining helical reinforcing rib or ribs.

5. A method according to any of the preceding claims, in which the said thin-walled pipe is deformed into a deformed pipe by mechanical deforming means positioned inside the pipe.

6. A method according to claim 5, in which the mechanical deforming means comprises a variable geometry mandrel incorporating a plurality of expandible and contractible jacks.

7. A method according to claim 5, in which the mechanical deforming means comprises inflatable and deflatable air bag means.

8. A method according to claim 5, in which the mechanical deforming means comprises a plurality of axially spaced apart templates.

9. A method according to any of the preceding claims, comprising forming a socket at one end of the tube to enable a similar tube to be joined thereto by means of a spigot and socket connection.

10. A method according to claim 9, in which the said socket is formed by positioning a flexible collar mould adjacent, so as to be positioned partly inside, the said one end of the undeformed, thin-walled pipe, the subsequent deformation of the thin-walled pipe into its deformed state causing a similar deformation of the flexible collar mould, applying a reinforced, settable plastics material over the said one end of the pipe and a portion of the collar mould projecting from the said one end, curing the settable plastics material, and removing the flexible collar mould.

11. A method according to claim 10, in which the said reinforced, settable plastics material is the same material as the said curable binderimpregnated reinforcing strands.

12. A method of manufacturing a tube of a desired, non-circular cross-section, the method being performed substantially as herein described with reference to Figure 1 and Figures 3 to 7, or Figures 1, 7 and 8, of the accompanying drawings.

13. A tube manufactured according to any of the preceding claims.

14. A tube according to claim 13, in which the said thin-walled pipe is made of reinforced plastics material.

15. A tube according to claim 13 or 14, in which the said thin-walled pipe has a wall thickness of from 3 to 6 mm.

16. A tube according to any of claims 13 to 15, in which the said thin-walled pipe comprises an inner layer reinforced with a tissue made of filamentary material and at least one further layer surrounding the inner layer and reinforced with chopped glass strands.

17. A tube according to claim 16, in which said inner lining has a thickness of from 0.5 to 1 mm.

18. A tube according to claim 16 or 17, in which the or each further layer has a thickness of from 1 to 1.5 mm.

19. A tube according to any of claims 16 to 18, in which the tissue used for reinforcing said inner layer consists of E glass filaments randomly laid in a mat and held together with a binder.

20. A tube according to any of claims 16 to 19, in which the chopped glass strands used for reinforcing the or each further layer are made from E glass and have a length of approximately 5 cm.

21. A tube according to any of claims 16 to 20, in which said reinforcing strands applied to the external surface of the deformed pipe are formed from bundles of continuous E glass filaments impregnated with synthetic resin.

22. A tube according to any of claims 16 to 21, in which the reinforcing strands are applied as helical (as hereinbefore defined) ribs, each of said helical ribs having a helix angle of from 450 to 700.

23. A method of lining a tunnel (as hereinbefore defined) comprising the steps of introducing into the tunnel a tubular lining made up of at least one tube according to any of claims 16 to 22, and filling the space between the external surface of the tubular lining and the internal surface of the tunnel with a grouting material.

24. A method of renovating a tunnel (as hereinbefore defined) comprising the steps of introducing into the tunnel a tubular lining made up of at least one tube according to any of claims 16 to 22, and filling the space between the external surface of the tubular lining and the internal surface of the tunnel with a grouting material.