WO2016128740A1

WO2016128740A1 - Modular tunnel lining system and method

Info

Publication number: WO2016128740A1
Application number: PCT/GB2016/050310
Authority: WO
Inventors: Mark Lusher
Original assignee: Mark Lusher
Priority date: 2015-02-10
Filing date: 2016-02-10
Publication date: 2016-08-18
Also published as: GB201502165D0; EP3256694A1; EP3256694B1; GB2537583A

Abstract

A modular man-entry tunnel lining system for a tunnel having a manhole access and an elongate tunnel inside surface, the system at least comprising: a plurality of sets of pre-formed radial liner sections; a plurality of elongate liner section supports; and a plurality of tensioners; wherein all of the radial liner sections, liner section supports and tensioners are transportable through the manhole access, and each set of the radial liner sections can assemble to form a length of a liner around at least a portion of the inside surface of the tunnel, and the sets of radial liner sections are supported by the elongate support sections and tensioned in place by the tensioners.

Description

MODULAR TUNNEL LINING SYSTEM AND METHOD

The present invention relates to a modular tunnel lining system and method, in particular for man-entry tunnels such as sewers.

Trenchless repair' or 'trenchless piping' is well known for the relining or renovation of small underground pipes. It commonly uses the 'cured-in-place-pipe' (CIPP) system for small bore pipes and non-man-entry sewer repair. However, CIPP is not suitable for the repair and renovation of larger tunnels such as man-entry sewers, which require more substantive work to repair.

Man-entry sewers or drains are defined in Annex B of the National Build

Standards, which is part of the Water Industry Act 1991. Generally they are defined as tunnels within which a man can enter and work, typically having a minimum diameter of 800mm, and going up to 2-3 metres a n d g r e a t e r in diameter for larger tunnels such as main sewer piping.

Currently, i t i s g e n e r a l l y n o t possible, or very uncommon, to repair and/or restore man-entry sewers using any known trenchless piping arrangement while the sewer is in use with water flowing thought it, i.e. while the sewer is in flow.

One current technique requires digging trenches and the like through the surrounding earth, road, pavement etc., and any other infrastructure, to gain direct access into the tunnel, for the passing of large size repair panels into the tunnel.

Other repair techniques, such as spiral winding, involve accessing the tunnel trough a manhole but require the water flow to be diverted, drained or Over pumped'. All these actions, especially the digging required to provide enough room to directly access the tunnel, and/or diverting or stopping the water flow through the tunnel, involves substantial time, cost and unsettlement in the relevant location.

It is an object of the present invention to provide a modular man-entry tunnel lining system, that can provide 'trenchless' repair thereto while the tunnel remains in flow.

According to one aspect of the present invention, there is provided a modular man- entry tunnel lining system for a tunnel having a manhole access and an elongate tunnel inside surface, the system at least comprising:

-a plurality of sets of pre-formed radial liner sections;

-a plurality of elongate liner section supports; and

-a plurality of tensioners; wherein all of the radial liner sections, liner section supports and tensioners are transportable through the manhole access, and each set of the radial liner sections can assemble to form a length of a liner around at least a portion of the inside surface of the tunnel, and the sets of radial liner sections are supported by the elongate support sections and tensioned in place by the tensioners.

By ensuring that all parts of the tunnel lining system of the present invention are transportable through the manhole access, 'trenchless' repair or restoration of the tunnel can be achieved.

Man-entry tunnels are known in the art and are defined above, generally having a minimum diameter of 800mm, and extending to a diameter of at least 2-3 metres. Whilst some tunnels are wholly or substantially 'circular' in cross-section or radial profile, many other cross-sectional shapes are known, including combinations of arcuate sides, straight sides, elliptical sides, and other arc-shaped sides, such 'sides' including for any defined roofs or floors. The present invention is not limited to the cross-sectional shape of the tunnel or the size of the manhole access.

Many man-entry sewers or drains have a fully circular cross-section. Others can have a partly circular cross-section with one or more straight sides such as the floor or one or more side walls. Another known cross-sectional shape has an arcuate roof, arcuate floor, or both, with straight sides, which shape is sometimes termed a 'brick-barrel' or 'barrel vault'. Manhole entries into man-entry tunnels are typically circular, and approximately 580- 600mm in diameter, but many manhole accesses to sewers and drains, especially older sewers and drains, have been non-conventionally formed or individually defined or shaped at the time, such that there is no typical 'manhole access' definition in the art, especially for older tunnels such as older sewers or drains.

In one embodiment of the present invention, the manhole access has a diameter in the range 550mm-650mm. A typical tunnel will have more than one manhole access, which may or may not have the same dimensions. I will be appreciated that the size of a manhole access can vary widely, depending on the requirements of the asset holder.

In another embodiment of the present invention, the man-entry tunnel is a sewer tunnel.

The present invention involves sets of pre-formed radial liner sections which are transportable through a manhole access, and can be assembled by one or more user within the tunnel to form lengths of the liner around the inside surface of the tunnel. Each so-formed length depends upon the length or width of the pre-formed radial liner sections, which depends upon the size of the manhole access. The user will be aware of the size of the manhole access, and form the radial liner sections appropriately to be transportable through the manhole access. Optionally, the pre-formed radial liner sections of each set able to be assembled to form a length of a liner around the inside surface of the tunnel, are regularly shaped.

Optionally, the pre-formed radial liner sections of each set comprise radial liner sections of one or more different shapes.

For example, some liner may have substantially parallel sides, or may be formed having one or more tapered sides. In this way, a lining section in accordance with the invention when viewed in plan view, may have a square, rectangular, trapezoidal or other quadrilateral outline. Lining sections with parallel sides are particularly suited for use in lining straight or very large radius tunnels, while those with one or more tapered sides can be used to accommodate curved tunnels. The elongate liner section supports may be integral with one or more of the radial liner sections, or may be formed separately and assembled with the radial liner sections, either in advance of assembling the radial liner sections to form a length of a liner around the inside surface of the tunnel, or

simultaneously therewith, or thereafter, or a combination of same. The present invention is not limited by the order of the assembly of the elongate liner section supports with the radial liner sections.

The tensioners of the system of the present invention are able to apply a post- assembly tension to the elongate liner section supports and radial liner sections, either directly thereto, or indirectly, or a combination of same, so as to provide tension to the so-formed tunnel lining system. Such tension could be applied to each set of radial liner sections, or each length of a liner formed around the inside surface of a tunnel, or a plurality of same, or only once all of the radial liner sections and elongate liner section supports are assembled, or a combination of same.

Upon assembly and completion, the tunnel lining system of the present invention provides a tensioned liner. The tensioned liner may be free standing, or may be secured to the tunnel by the use of one or securing means such as bolts, or a combination of same at different parts along the elongate length of the lining system once assembled.

Optionally, a grout is applied in any spaces, gaps or annulus formed, between the outer surface of the so-formed tunnel lining system, and the inside surface of the tunnel. One or more injection ports could be located in the tunnel lining system to allow the injection of the grout into any spaces or annulus formed, to provide and/or increase the sealed nature of the lining system in use. It will be appreciated that the term "grout" in the context of tunnel linings refers to any suitable sealant, for example, cements, mortars, polymers and the likes.

Where the cross-sectional shape of the man-entry tunnel is a brick-barrel shape, having a vaulted roof and floor, and intermediate straight sides, it is an embodiment of the present invention that the pre-formed radial liner sections comprise at least upper and lower arcuate portions and two side panels, able together to form a length of a radial liner around the inside surface of the tunnel. Optionally, the elongate liner section supports comprise support bars locatable at or near the junctions of such upper and lower arcuate portions and two side panels, and are extendible longitudinally along the tunnel.

Further optionally, the elongate liner section supports are modular and interlock longitudinally to form longer support sections onto or into which the radial liner sections are supported and/or secured once assembled.

Where the cross-sectional shape of the tunnel is wholly or substantially circular, it is another embodiment of the present invention that the pre-formed radial liner sections comprise a series of regular circular portions, able together to form a length of a circular liner around the inside surface of the tunnel.

Optionally, the elongate liner section supports comprise raised portions at or along each longitudinal side of such circular portions, to join the circular portions together longitudinally along the tunnel.

The tensioners of the present invention may comprise any arrangement of bolts, bars, wires, etc., able to apply tension between one or more of the other parts of the tunnel lining system. This includes extending through one or more of the elongate liner section supports, and being tensionable from one end of a section support to the other. Advantageously, the tunnel lining system in accordance present invention is versatile to find use with the purposes of tunnel leaking sealing; providing tunnel semi- structural support; or providing tunnel fully structural support.

According to an other aspect of the invention there is provided a pre-formed r a d i a l lining section being a portion of the circumference of the inside surface of a tunnel in use, wherein the lining section comprises first raised end and a second raised end, w h e r e i n e xtending from the first raised end is a neck portion terminating in an expanded head, and within the second raised end there is provided a recess having a complementary but larger shape than the expanded head.

Conveniently, within the recess is located a slot within which a neck of another lining section is locatable.

In this way, the expanded head and recess provide corresponding male and female connection means.

Conveniently, the first raised end and the second raised end form the elongate liner section supports of the liner system, able to provide support between the radial liner sections once assembled.

Optionally, the first raised end is a bottom or lower raised edge, and the second raised end is a top or upper raised edge in use.

Optionally, the expanded head and the recess may be generally square or rectangular or circular in cross-section.

Conveniently, a circular aperture is provided extending through the expanded head and is adapted to receive a tensioner which extends there through in use. Optionally, at a location between the first and second raised ends, there is provided an intermediate aperture through which a tensioner extends in use.

Optionally, the intermediate aperture formed through an intermediate raised portion.

Optionally, the liner section comprises one or more apertures or removable plugs to allow annulus grouting.

Conveniently, in use the expanded head of a first liner section engages with the recess of a first circumferentially adjacent liner section on one side, with the recess of the first liner section engaging with the expanded head of a second

circumferentially adjacent liner section on an opposing side. In this way, the expanded head defines a male connection member and the recess defines a corresponding female connection member.

Optionally the second rai sed end may be formed havi ng a rem ovable l i m b wh ich defi nes one si de of the recess such that side access to the recess is possi ble . Conven iently, the rem ovable l i m b is releasably attached and secured by to the lining section by means of bolts.

Optionally, the lining section is provided with a gasket groove which extends around the periphery of the said lining section adapted to receive a gasket.

Preferably, the gasket groove is disposed towards an inner in use side of the liner section, i.e. towards the intrados face of the section. Preferably, the gasket is a continuous O-ring seal.

Optionally, the intermediate aperture is adapted to receive a sleeve through which a tensioner extends in use, the intermediate aperture comprising a lip or flange formation which extends circumferentially inwardly at one end of said aperture against which one end of the sleeve abuts in use. In this way, when a bolt is subsequently inserted into said sleeve sand tightened, the sleeve reacts against the flange such that the tension imparted by the tensioner is transferred to the edge of an abutting longitudinally adjacent liner that has already been installed. In this way, the tensioning load is transferred to the adjacent faces of the lining sections rather than through the entire length of the newly installed lining section.

Optionally, the expanded head and/or recess is/are tapered along its/their respective lengths. Conveniently, the taper draws mutually engaged expanded heads and and/or recesses tightly together when slidably joined and fastened.

Optionally, the liner section is provided with one or more tongue formations extending from one side edge, and one or more groove formations provided in an opposing side edge.

According to another aspect of the present invention, there is provided a method of forming a liner around the elongate tunnel inside surface of a man-entry tunnel having a manhole access, the method at least comprising the steps of;

(a) providing a plurality of sets of pre-formed radial liner sections, elongate liner section supports; and tensioners through the manhole access into the tunnel;

(b) assembling each set of the radial liner sections to form a length of a liner around at least a portion of the inside surface of the tunnel;

(c) locating the elongate support sections with the radial liner sections;

(d) repeating step (a) and optionally step (b) to achieve the desired length of liner; and

(e) locating the tensioners in the elongate support sections and tensioning the tensioners to tension the so-formed liner. Optionally, the method comprises the steps of:

(i) providing a plurality of sets of pre-formed radial liner sections comprising at least a first lower panel, a first upper panel and two first side pieces; elongate liner section supports in the form of interlocking support beams, and a plurality of tensioners;

(ii) locating a first lower panel across the floor of the tunnel;

(iii) locating the side pieces on the sides of the tunnel upwardly from the first lower panel;

(iv) locating a first upper panel across the roof of the tunnel to reach the side pieces;

(v) locating an elongate liner section support at each junction of the first upper and lower panels and the side panels;

(vi) locating a second set of pre-formed radial liner sections onto or around the elongate liner section supports, and repeating such step to form the length of liner along the tunnel; and

(vii) tensioning the assembled radial liner sections and elongate liner section supports by tightening one or more tensioners located through the elongate liner section supports.

Optionally, the interlocking support beams are interlocking rectangular support beams.

In another embodiment of the present invention, the method comprises the steps of:

(i) providing a plurality of sets of pre-formed radial liner sections, each extending to a portion of a circular circumference, and each having elongate liner section supports formed along each longitudinal edge;

(ii) assembling the radial liner sections together by conjoining, preferably locking, the elongate liner section supports of each radial liner section together to form a length of a liner around at least a portion of the inside surface of the tunnel;

(iii) repeating step (ii) to form the length of liner along the tunnel; and

(iv) providing tensioning wires, bolts or bars through one or more of the elongate liner section supports in a longitudinal direction, and tensioning said bars, bolts or wires to tension the radial liner sections together.

It will be appreciated that the terms "liner section" and "lining section" used throughout the description are interchangeable.

The preceding discussion of the background to the invention is intended only to facilitate an understanding of the present invention. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge as at the priority date of the application.

Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of those words, for example "comprising" and "comprises", mean "including but not limited to", and are not intended to (and do not) exclude other components, integers or steps.

Throughout the description and claims of this specification, the singular

encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers or characteristics described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.

Brief Description of the Drawings

Embodiments of the present invention will now be described by way of example only, and with reference to the accompanying figures in which:

Figure 1 is a part cross-sectional, part perspective view of a brick-barrel sewer tunnel with a first radial liner section therein;

Figure 2 is a development of Figure 1 now including an elongate liner section support;

Figure 3 is a development of Figure 2 now including further radial liner sections; Figure 4 is an enlargement of a portion of Figure 3;

Figure 5 is a development of Figure 3 showing further assembly of sections and supports according to one embodiment of the present invention;

Figure 6 is a further development of Figure 5;

Figure 7 is a cross-sectional view of an assembled man-entry tunnel lining system according to one embodiment of the present invention;

Figures 8a and 8b are enlarged portions of Figure 7;

Figure 9 is a part cross-sectional part perspective view of a part assembled man- entry tunnel lining system according to one embodiment of the present invention;

Figure 10 is a cross-sectional view of a circular tunnel and a modular man- entry tunnel lining system according to another embodiment of the present invention;

Figure 1 1 is a part cross-sectional part perspective view of a circular tunnel having a number of radial liner sections therein; Figure 12 is a cross-sectional view of elongate liner section supports according to another embodiment of the present invention;

Figure 13 is perspective view of the arrangement of Figure 12 extending along the tunnel;

Figure 14 is a development of Figure 11 including a number of further radial liner sections; Figure 15 is a development of Figure 14 showing a modular man-entry tunnel lining system according to another embodiment of the present invention, including a plurality of tensioners;

Figure 16a is a is a detailed exploded view of a length of tunnel liner formed from a set of liner sections in accordance with an embodiment of the invention;

Figure 16b is an end elevation of the view of Figure 16a;

Figure 16c is a development of Figure 16b showing in detail the connection between circumferentially adjacent lining sections in accordance with an

embodiment of the invention;

Figure 16d is a schematic cross section showing an sleeve inserted into a lining section in accordance with an embodiment of the invention;

Figures 17a, 17b and 17c are detailed views of a liner section of Figures 16a, 16b and 16c;

Figure 18 is a schematic illustration showing a tongue and groove connection means provided on liner sections of Figure 16;

Figure 19a is a cross section of the connection between circumferentially adjacent lining sections with locking bolts inserted in accordance with an embodiment of the invention;

Figure 19b is a cross section of the connection between circumferentially adjacent lining sections in accordance with an alternative embodiment of the invention;

Figure 20 is a schematic illustration of a tunnel lining system formed from a plurality of liner section rings wherein adjacent liner section rings are shown rotated / offset with respect to each other;

Figure 21 is a schematic illustration of a tensioner adapted for use of a liner section in accordance with an embodiment of the invention; and

Figures 22a and 22b show exemplary respective parallel and curved lining systems incorporating lining sections in accordance with the invention.

Description of the Preferred Embodiments

Referring to the drawings, Figure 1 shows a part cross-sectional part perspective view of a brick-barrel sewer tunnel 2 having a vaulted or arcuate roof 4, a vaulted or arcuate floor 6, and two vertical sides 8 thereinbetween.

Figure 1 shows a first lower pre-formed radial liner section 10 having a arcuate shape adapted to wholly or substantially match the arcuate shape of the floor 6, and two upwardly extending sleeve portions 12 discussed hereinafter. The user is aware of the dimensions of the manhole access (not shown) to the sewer tunnel 2, and has therefore already determined the size of possible radial liner sections that are transportable through the manhole access to be assembled within the tunnel 2. Figure 2 shows a development of Figure 1 , wherein two elongate liner section supports 14 have been assembled to fit or slide within the apertures of the sleeves 12 of the lower radial liner section 10. As can be seen in more detail in Figure 3, the elongate liner section supports 14 can optionally also be modular, being formed of individual length sections 16 which can be assembled together to form a longer liner section support 14. With reference to Figure 3, ach individual section 16 optionally also includes one or more means or arrangements to conjoin and fit with further individual sections 16, such as having a male-female arrangement or tongue-in-slot arrangement or similar. In this way, either the elongate liner section supports or each individual liner section can be

transportable through the manhole access for assembly and/or location in the tunnel by one or more users. Figure 3 also shows a first roof or upper pre-formed radial liner section 20 having an outer surface intended to wholly or substantially match the inner surface of the roof 4 of the tunnel 2. Where the roof 4 and floor 6 are wholly or substantially similar, it may be that the upper and lower radial liner sections 10 and 20 are wholly or substantially similar or the same. The upper radial liner section 20 includes two depending sleeve portions 22 (only 1 shown in Figure 3) at each end.

Figure 3 also shows a first side panel 18 locatable between the first upper and lower radial liner supports 10, 20. Preferably, as shown in Figure 4, the first side support 18 extends behind at least a portion of the sleeves 12, 22 of the upper and lower radial liner sections 10, 20. In the arrangement shown in Figure 4, the end of the sleeve 22 is shown to locate the first side section 18 between the end of the sleeve 22 and the side wall 8 of the tunnel 2, and help form an enclosure able to accommodate an elongate liner section support. Figure 5 shows a development of Figures 1-4 wherein a further, now upper, elongate liner section support 24 is now added through the sleeve 22 of the upper radial liner section 20. Optionally, the upper liner section support 24 is also modular, and formed in a series of sections as discussed hereinabove in relation to the first liner section support 14.

Figure 6 shows the addition of a second side panel 26 beside the first side panel 18.

With the addition of similar side panels (not shown) on the other side wall in an equal and opposite arrangement, the assembly of the first upper and lower radial liner sections 10, 20 and the first side panels 18 form a length of a liner around the inside surface of the tunnel, which are supported by the elongate support sections 14, 24.

The skilled man can see that the user can now add further radial liner sections in sets to form further lengths of a liner around the inside surface of the tunnel to the length necessary or desired along the inside surface of the tunnel 2.

Optionally, the user can slide one or more further liner sections along the free ends of the elongate support sections 14, 24 now located to assist each assembly and coordination of the radial liner sections together in extending the length of the liner along the tunnel. Where the elongate support sections 14, 24 are also modular, the user can build the length of the elongate liner section supports 14, 24 to suit the assembling of the radial liner supports thereinafter in the best manner suited for the work in hand, which may be dependent upon the nature of the tunnel, its inside surface, and/or the nature of the repair or restoration required.

The skilled man can also see that the user is not limited in the order of the addition of the radial liner sections and liner section supports, such that one or more of these may be added in a different order to that shown in Figures 1-6, and still forming the liner along the tunnel 2.

Figure 7 shows a cross-sectional view of a modular man-entry tunnel lining system according to one embodiment of the present invention. Section A of Figure 7 is expanded into Figure 8a, and section B of Figure 7 is expanded into Figure 8b. In more detail, Figures 8a and 8b show four tensioners 30 in the form of wires or bars, two each located longitudinally along the length of the elongate liner section supports 14 and 24. The tensioners 30 can be tensioned from each free end, optionally extending within, at or beyond the ends of the elongate liner section supports 14, 24, to provide tension to the elongate liner section supports 14, 24, and thereby provide tension to the radial liner sections, and the complete lining system. The skilled man is aware of suitable tensioners, including the use of winding mechanisms, threads, threaded nuts, etc., at one end of a tensioning wire or tensioning bar, which can be tightened, usually through rotation, to provide tension along the length of the tensioning wire or bar 30. Figures 8a and 8b also show the addition of screws or bolts 32 to assist fixing of the radial liner sections 10, 20 and elongate liner section supports 14, 24 together.

Figure 7 and Figures 8 and 8b also show, in exaggerated form, an annulus 34 between the outside surface of the lining system and the inside surface of the tunnel 2. Preferably, the lining system includes one or more ports or apertures or entries, though which a suitable grout can be injected to fill the annulus 34 and to thereby provide, optionally increase, the sealing effect provided by the lining system within the tunnel 2.

The skilled man is aware that the length of the lining system may be any length, and the radial liner sections and elongate liner section supports preformed to a length and/or shape to suit the overall length of lining system desired, and the internal shape of the tunnel inside surface.

The skilled man is also aware that the present invention as shown by the embodiment in Figures 1-8 is not limited to the shape of the tunnel 2 as shown, but can be adapted to suit other internal tunnel shapes. Figure 9 shows a different perspective view of a part assembled liner system of Figure 5.

Figure 10 shows a circular tunnel 40 having an inside surface 42 which is wholly or substantially circular in cross-section form, and a modular man-entry tunnel lining system 44 according to another embodiment of the present invention. Figure 10 also shows, possibly in exaggerated form, an annulus 46 between the lining system 44 and the inside surface 42, which could be filled with a suitable sealant in a manner as described hereinabove. Figure 1 1 shows a plurality of pre-formed radial liner sections 48, each being a regular arcuate portion of the circumference of the inside surface 42 which, when assembled together, form a length of the liner 44 around the insider surface of the tunnel 42. Figure 12 shows a cross-sectional view of the bottom or lower raised edge 50 of a first radial liner section 48a, engaging with the top or upper raised edge 52 of a second radial liner section 48b. Extending from the bottom 50 is a neck portion 54 and an expanded tubular head 56. Within the upper edge 52 of the second radial liner section 48b is a recess 58 having a complementary but larger shape than the expanded head 56. Within the recess 58 is located a sleeve 60 having an upper slot within which the neck 54 is locatable. In this way, expanded tubular head 56 and recess 58 provide corresponding male and female connection means.

The lower and upper edges 50, 52 form the elongate liner section supports of the liner system, able to provide support between the radial liner sections 48a, b (and all of sections 48) once assembled. Optionally, the distance of the neck 54 from the outer surface of the upper radial liner section 48a is offset, such as by one or a few millimetres, from the distance of the recess 58 from the outer surface of section 48b, or at least the access in the sleeve 60, such that the conjoining of the enlarged head 56 in the sleeve 60 is not 'loose', but causes tension between the upper and lower radial liner sections 48a, 48b, when conjoined, increasing the locking together and tensioning between the radial liner sections 48 in general.

Figure 12 also shows seals 62 located on each side of the neck 54 to increase the sealing effect in the junction area between the radial liner sections 48a, 48b in use, especially once the fully formed circular arrangement of the lining system is created, which will squeeze at least the inner seal 62 in a manner to increase its sealing effect, and thereby the overall sealing of the lining system.

Figure 13 is a perspective view of the arrangement in Figure 12, wherein the raised portions of the lower and upper edges 50, 52 of the upper and lower radial liner sections 48a, 48b are shown longitudinally, extending along the length of the radial liner sections 48a, 48b in use. The raised portions are analogous with the sleeves 12 the embodiment of the liner section discussed above.

It will be appreciated that the expanded tubular head 56 and the respective complementary recess 58 may have alternative shapes to those shown by way of example in Figures 12 and 13. For example, they may be generally square or rectangular in cross-section, as shown in the embodiment of Figures 16a, 16b, 16c. Figure 14 is a development of Figure 10, showing a number of further radial liner sections 48 located around the inside surface of the tunnel 40, each set of radial liner sections 48 forming a length of a liner along the inside surface of a tunnel.

Figure 15 shows a continuation of the development of the liner system shown in Figure 14, and the addition of tensioning bars 66 located through the apertures 56 shown in Figure 12, which tensioning bars 66 can then be tensioned in a manner known in the art in order to tension in place the elongate support sections and radial liner sections.

Figure 16a is a is a detailed exploded view of a length of tunnel liner formed from a set of pre-formed radial liner sections 480 in accordance with an embodiment of the invention. Each radial liner section 480 is preferably a regular arcuate portion of the circumference of the inside surface of a tunnel when assembled together. Figure 16b is an end elevation of the view of Figure 16a. Figure 16c is a

development of Figure 16b showing in detail the connection between

circumferentially adjacent lining sections as described generally below.

Similar to those shown in Figure 11 , each section 480 comprises a first raised end 500 and second raised end 520. At a location between the first and second raised ends, there is provided an intermediate aperture 562 through which a tensioner 490 extends in use. Intermediate aperture 562 is optionally formed through a

intermediate raised portion 510. Conveniently, the first raised end 500, the second raised end 520, and the intermediate raised portion 510 form the elongate liner section supports of the liner system in use, able to provide support between the radial liner sections 480 (and all of sections 480) once assembled. Optionally, a liner section 480 may have one or apertures or removable 486 plugs to allow annulus grouting

With reference to Figures 17a, 17b and 17c, extending from the first raised end 500 is a neck portion 540 terminating in an expanded head 560 having a box section. The box section may be a square box or rectangular box, with the aperture 561 extending through the expanded head 560 being circular and adapted to receive a tensioner 490 which extends therethrough in use. Within the second raised end 520 is a recess 580 having a complementary but larger shape than the expanded head 560. Wthin the recess 580 is located a slot within which the neck 540 is locatable.

In use, the expanded head 560 of a first liner section slidably engages with the recess 580 of a first circumferentially adjacent liner section 480 on one side, with the recess 580 of the first liner section engaging with the expanded head 560 of a second circumferentially adjacent liner section on an opposing side as shown in Figures 16a, 16b and 16c. In this way, the expanded head 560 defines a male connection member and the recess 580 defines a corresponding female connection member.

As shown in Figure 19b, the recess 580 of the second raised end 520 m ay be formed havi ng a removable l i m b 581 wh ich defi nes one si de of the recess such that si de access to the recess 580 is poss i ble. I n thi s way, when the l i m b 581 i s removed or is absent, engagement can be made with an expanded head 560 which is hooked onto the recess. Once the limb 581 is attached and secured by bolts 590a and 590b, the expanded head 560 is fixed within recess 580. In this way, circumferentially adjacent liner sections can be attached together by insertion, or slidable engagement as described above. It will be appreciated, that slidable engagement of the expanded head 560 with a recess 580 is still possible with the removable limb 581 variant. It will be appreciated that as the limb is elongate (i.e. it extends across the length of the lining section) it has the form of a removable panel. With reference to Figures 17b, 17c, 18 and 19a, each liner section 480 is provided with a gasket groove 483 which extends around the periphery of the said liner section (i.e. around the side edges and around the first and second raised ends) and is adapted to receive a gasket 484 (shown in Figure 16a). Preferably, the gasket groove 483 is disposed towards an inner in use side of the liner section, i.e. towards the intrados face of the section. Preferably, the gasket 484 is a continuous O-ring seal.

When circumferentially and longitudinally adjacent liner sections 480 are joined together as described above, the gasket 484 provides a water tight seal between said adjacent liner sections. As shown in Figure 19a, this seal also prevents ingress of water into the join between expanded heads 560 and recess 580 of

circumferentially adjacent liner sections. As shown in Figure 19a, to augment the fastening of the respective circumferentially adjacent connected expanded heads 560 and recesses 580, they may be bolted together in use. To enable bolting, one or more apertures 591 for receiving a lock bolt 590a are provided through the each recess 580, which align with corresponding apertures provided through the neck portion 540 of the expanded head 560.

The tensioners used to secure longitudinally adjacent liner sections 480 together preferably comprise elongate sleeve bolts 490, which are shown in detail in Figure 21. Each bolt 490 comprises a head 491 , a shank 492 and a threaded (male) terminal end 493. Head 491 is adapted to receive a hexagonal drive 495 and is internally threaded with a female thread 494. Bolts 490 are inserted in use through intermediate aperture 562 and aperture 561 of an expanded head 560 of the lining section 480 as shown in Figure 16a. The sleeve bolts 490 are of a length such that their male threaded terminal ends 493 are able to screw threadedly engage with the internal female threads 494 of a bolt 490 provided in a longitudinally adjacent lining section. In this way, the sleeve bolts of longitudinally adjacent lining sections interconnect. Optionally, sleeve bolts 490 may be inserted through a sleeve 496 (Figure 16) which is in also inserted through an aperture 561 of the lining section.

As shown in Figure 16d, the sleeve 496 is a cylindrical metal sleeve that can be inserted into an intermediate aperture 562 and/or aperture 561 of an expanded head 560 of a lining section. When inserted, an end of the sleeve 496 abuts against a lip or flange formation 563 which extends circumferentially inwardly at one end of aperture 561 , 562. When a bolt 490, 491 is subsequently inserted into said sleeve and tightened, the sleeve reacts against flange 563 such that the tension imparted by the tightening bolt 490 is transferred to the edge of the abutting longitudinally adjacent liner that has already been installed (not shown). In this way, the tensioning load is transferred to the adjacent faces of the lining sections rather than through the entire length of the newly installed lining section. Optionally, to improve the stiffness of a ring formed from a plurality of liner sections 48, 480, the expanded heads (56, 560) and recesses (58, 580) (i.e. male and female connection members) may be tapered along their respective lengths.

Advantageously, the taper draws the mutually engaged male and female connection members tightly together when slidably joined and fastened by bolts 490. The taper causes tension between the liner sections 48 , 480 when conjoined, increasing the locking together and tensioning between the radial liner sections 48, 480 in general. This taper is shown by way of example in exaggerated form in Figure 18 whereby one end of a male connection member 560A has a reduced width and height when compared to the opposing end 560B.

With reference to Figures 16a and 18, a liner section 580 may optionally be provided with one or more tongue formations 481 extending from one side edge, and one or more groove formations 482 provided in an opposing side edge. The respective tongue 481 and groove 482 formations of adjacent sections of adjacent rings of sections engage when brought into proximity with each other in use. In this way, longitudinally adjacent or abutting sections 480 are able to interlock along their respective side edges. Advantageously also, the respective tongue 481 and groove 482 formations assist in the correct co-location of longitudinally adjacent panels when arranged side by side in use, and ensures that the respective apertures through which bolts 490 are located are in correct alignment with each other.

In Figures 16a and 16b, the ring of liner sections 480 joined end to end in this way comprises four liner sections, each section representing an arc of 45 degrees.

However, it will be appreciated that a ring of liner sections may comprise any suitable number of liner sections.

Conveniently, when joined together, the first raised ends 500 and second raised ends 520 of circumferentially adjacent liner sections fo rm th e supports of the liner system, able to provide support between the radial liner sections 480 (and all of sections 480) once assembled. In this way, a liner system formed from liner sections 48, 480 is fully self-supporting.

It will be appreciated that adjacent rings of lining sections of a liner system may be connected conventional alignment, or offset with respect to each other to improve ring stiffness. In the former case, the respective intermediate raised sections 510 of each lining section 480 are aligned with each other. In the latter case, the adjacent rings of lining sections are radially offset such that intermediate raised sections 510 of each lining section 480 are aligned with the joints between first and second raised ends 500, 520 of longitudinal adjacent lining sections as shown in Figure 20.

It will be appreciated also that while the illustrated lining sections 48, 480 are shown having substantially parallel sides as shown by way of example in Figures 20 and 22a, they may be formed having one or more tapered sides as shown in Figure 22b. In this way, a lining section 480 when viewed in plan view, may have a trapezoidal 480a or other quadrilateral outline. In this way, lining sections with parallel sides are particularly suited for use in lining straight or very large radius tunnels, while those with one or more tapered sides can be used to accommodate curved tunnels.

Suitable materials for the lining system include, but are not limited to, steel, stainless steel, glass fibre reinforced plastics (GRP), Aluminum or carbon fibre composite material. It is envisaged that in some applications the support beams and panels will be formed from stainless steel. In other applications, the support beams and panels may be formed from carbon fibre composite. In other applications, either stainless steel or carbon-fibre composite may be used for either the support beams or the panels.

The present invention is able to provide a liner in a man-entry tunnel, based on a modular lining system using sections, supports and tensioners able to be transported through a manhole access. Using the manhole access achieves a 'trenchless' system, avoiding the digging conventionally required to provide access into man- entry tunnels.

Furthermore, present invention is able to provide a liner in a man-entry tunnel able to be transported through a manhole access and able to be installed while the tunnel is in flow, i.e. with water flowing trough said tunnel, up to a depth of around 600mm or more the water depth of 600mm being the typical depth a person can reach to below the water level. This is possible because unlike the prior art methods of tunnel lining, the junction area between the radial liner sections is unaffected by grit and debris in the flowing sewage. For example, in the spiral winding technique such grit and debris would enter the joints of the spirally wound lining thereby compromising the interlock between the windings. Similarly, the normal panel lining technique requires dry conditions as grout is applied to provide a seal between adjacent panels and this cannot be carried out under water.

The parts of the lining system of the present invention can easily be assembled and tensioned in place to form the liner within the tunnel by one or more users in a manner as described herein, or a variation of such. The modular man-entry tunnel lining system of the present invention allows each length of the liner to be formed, supported and then tensioned in place, by a series of matching or locking, optionally interlocking, parts, to extend as desired along the part of the tunnel to be repaired and/or restored, without overly reducing the dimensions of the tunnel.

Claims

1. A modular man-entry tunnel lining system for a tunnel having a manhole access and an elongate tunnel inside surface, the system at least comprising:

a plurality of sets of pre-formed radial liner sections;

a plurality of elongate liner section supports; and

a plurality of tensioners; wherein all of the radial liner sections, liner section supports and tensioners are transportable through the manhole access, and each set of the radial liner sections can assemble to form a length of a liner around at least a portion of the inside surface of the tunnel, and the sets of radial liner sections are supported by the elongate support sections and tensioned in place by the tensioners.

2. A system as claimed in claim 1 , wherein the manhole access has a diameter in the range 550mm-650mm.

3. A system as claimed in claim 1 or claim 2, wherein the man-entry tunnel is a sewer tunnel.

4. A system as claimed in any one of the previous claims wherein the pre- formed radial liner sections comprise at least upper and lower arcuate portions and two side panels able to form a length of a radial liner around the inside surface of the tunnel.

5. A system as claimed in claim 4, wherein the elongate liner section supports comprise support bars locatable at or near the junctions of the upper and lower arcuate portions and two side panels, and extendible

longitudinally along the tunnel.

6. A system as claimed in claim 5, wherein the elongate liner section supports are modular and interlock longitudinally.

7. As system as claimed in any one of claims 1 to 5, wherein the elongate liner section supports are formed integrally with one or more pre-formed radial liner sections.

8. A system as claimed in any preceding claim, wherein the pre- formed radial liner sections comprise a series of regular circular portions able to form a length of a circular liner around the inside surface of the tunnel.

9. A system as claimed in claim 7, wherein the elongate liner section supports comprises a first raised end and a second raised end at respective o p pos i n g longitudinal sides of each liner section.

10. A system as claimed in claim 9, wherein e xtending from the first raised end is a neck portion terminating in an expanded head, and within the second raised end there is provided a recess having a complementary but larger shape than the expanded head.

11. A system as claimed in claim 10, wherein within the recess is located a slot within which a neck portion of circumferentially adjacent lining section is locatable in use.

12. A system as claimed in claim 1 1 , wherein an aperture is provided extending through the expanded head, the aperture being adapted to receive a tensioner which extends there through in use.

13. A system as claimed in any one of claims 7 to 12, wherein at a location between the first and second raised ends, there is provided an intermediate aperture through which a tensioner extends in use.

14. A system as claimed in claim 13, wherein the intermediate aperture is formed through an intermediate raised portion.

15. A system as claimed in claim 13 or claim 14, wherein intermediate aperture comprises a lip or flange formation which extends circumferentially inwardly at one end of said aperture and against which one end of a sleeve abuts in use.

16. A system as claimed in any one of claims 9 to 15, wherein the second raised end is formed havi ng a rem ovable l i m b whi ch defi nes one si de of the recess .

17. A system as claimed in any one of claims 10 to 16, wherein the expanded head and recess of each liner section are tapered along their respective lengths.

18. A system as claimed in any preceding claim, wherein on or more liner sections comprise one or more apertures or removable plugs to allow annulus grouting.

19. A system as claimed in any preceding claim, wherein one or more liner sections is/are provided with a gasket groove which extends around the periphery of the said lining section adapted to receive a gasket.

20. A system as claimed in any preceding claim, wherein one or more liner sections is provided with one or more tongue formations extending from one side edge, and one or more groove formations provided in an opposing side edge.

21. A method of forming a liner around the elongate tunnel inside surface of a man-entry tunnel having a manhole access, the method at least comprising the steps of:

(b) assembling each set of the radial liner sections to form a length of a liner around at least a portion of the inside surface of the tunnel; (c) locating the elongate support sections with the radial liner sections;

(e) locating the tensioners in the elongate support sections and tensioning the tensioners to tension the so-formed liner.

22. A method as claimed in claim 21 comprising the steps of:

(i) providing a plurality of sets of pre-formed radial liner sections comprising at least a first lower panel, a first upper panel and two first side pieces; elongate liner section supports in the form of interlocking rectangular support beams, and a plurality of tensioners;

(ii) locating a first lower panel across the floor of the tunnel;

23. A method as claimed in claim 21 comprising the steps of:

(ii) assembling the radial liner sections together by conjoining, preferably locking, the elongate liner section supports of each radial liner section together to form a length of a liner around the inside surface of the tunnel;

(iii) repeating step (ii) to form the length of liner along the tunnel; and

(iv) providing tensioning wires, bolts or bars through one or more of the elongate liner section supports in a longitudinal direction, and tensioning said bolts, bars or wires to tension the radial liner sections together.

24. A radial liner section comprising a first raised end and a second raised end located at respective o ppos i n g longitudinal sides of said liner section.

25. A radial liner section as claimed in claim 24, wherein e xtending from the first raised end is a neck portion terminating in an expanded head, and within the second raised end there is provided a recess having a complementary but larger shape than the expanded head.

26. A radial liner section as claimed in claim 25, wherein within the recess is located a slot within which a neck portion of circumferentially adjacent liner section is locatable in use.

27. A radial liner section as claimed in claim 25 or claim 26, wherein an aperture is provided extending through the expanded head, the aperture being adapted to receive a tensioner which extends there through in use.

28. A radial liner section as claimed in any one of claims 24 to 27, wherein at a location between the first and second raised ends, there is provided an

intermediate aperture through which a tensioner extends in use.

29. A radial liner section as claimed in claim 28, wherein the intermediate aperture is formed through an intermediate raised portion.

30. A radial liner section as claimed in claim 28 or claim 29, wherein intermediate aperture comprises a lip or flange formation which extends circumferentially inwardly at one end of said aperture and against which one end of a sleeve abuts in use.

31. A radial liner section as claimed in any one of claims 24 to 30, wherein the second raised end i s form ed havi ng a removable l i m b wh ich defi nes one si de of the recess .

32. A radial liner section claimed in any one of claims 24 to 31 , wherein the expanded head and the recess of the liner section are tapered along their respective lengths.

33. A radial liner section as claimed in any one of claims 24 to 32, wherein the liner section comprises one or more apertures or removable plugs to allow annulus grouting.

34. A radial liner section as claimed in any one of claims 24 to 33, wherein the liner section is provided with a gasket groove which extends around the periphery of the said lining section and is adapted to receive a gasket.