AU8279987A - Tunnel or sewer lining system - Google Patents

Description

Title: "TUNNEL OR SEWER LINING SYSTEM" BACKGROUND OF THE INVENTION

(1) Field of the Invention

THIS INVENTION relates to a tunnel or sewer lining system and is particularly suitable for lining non-circular man-entry tunnels or sewers.

(2) Prior Art

The aggressive environment found in sewers leads to deterioration in the sewer walls . To reinstate efficient flows, it is necessary to periodically reline the sewers .

SUMMARY OF THE INVENTION

Preferred objects of the present invention are to provide a method of lining tunnels or sewers which has great flexibility and which preferably has the advantages that no expensive excavation is required; irregular shapes and features can be lined; very little cross-sectional area is lost; installation is rapid; and/or there is no "blind" grouting. It is also a preferred object to provide a system of interlocking strips which are used with the grout or mortar to form a sandwich-like liner.

Other preferred objects of the present invention will become apparent from the following description.

In one aspect the present invention resides in a method for lining tunnels or sewers including: fixing a plurality of first layer strips, in side-by-side relationship, to the wall of the tunnel or sewer to be lined; applying grout to the first layer strip to a pre-selected thickness; and fixing a plurality of second layer strips to the first layer strips with the grout sandwiched there- between. Preferably the first layer strips are extruded from rigid unplasticised sewer grade P-V.C. Preferably the strips have a plurality of spaced female locking profiles which project from a perforated backing layer. Preferably there are perforations in the backing layer which allows the grout to adhere to the existing wall and key-in the plastic layer.

Preferably the grout, e.g. a mortar/cement mix, which may have a bonding additive , is sprayed on to the first layer.

Preferably the second layer strips are of the same plastic material as the first layer strips. Preferably the second layer strips are much thicker than the first, to provide a smooth liner surface, with male locking profiles to engage the corresponding female locking profiles on the first layer strips. ^"

Preferably the first and second layer strips are laid in an overlapping relationship.

In a second aspect the present invention resides in apparatus to line a tunnel or sewer including: a plurality of first layer strips to be fixed in a side-by-side relationship to the wall to be lined; grout applied to the first layer to a pre¬ selected thickness - and a plurality of second layer strips fixed to the first layer strips to grout the sandwich between the two layers. The preferred features of the apparatus are as hereinbefore described with reference to the method. BRIEF DESCRIPTION OF THE DRAWINGS To enable the invention to be fully understood, a preferred embodiment will now be described with reference to the accompanying drawings, in which: FIGS. 1, 2 and 3 show the three stages of installation of the liner, respectively;

FIGS. 1A, 2A and 3A are cross-sectional views of the wall corresponding to the three stages of FIGS. 1, 2 and 3 respectively; and

FIGS. 4 and 5 are perspective views respect¬ ively of the first and second layer strips .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The wall 10 of the tunnel or sewer 11 to be lined is cleaned and any large holes or irregularities are filled with grout. The first layer of plastic 12 is formed from a plurality of first layer strips 13 fixed side-by-side to the wall 10. Referring to FIGS. 1A, 4 and 4A, the first layer strips 13, formed of rigid .sewer grade uPVC, have a backing layer 14 with four elongate female locking profiles 15 (the central two being closely spaced) with teeth 16. The strip 13, which is formed by extrusions, has holes 17 formed in the backing layer 14 which enable the grout to adhere to the wall 10.

As shown in FIGS. 1 and 1A, the strips 13 are fixed to the wall 10 in a side-by-side relationship using masonry fasteners (not shown) applied by pneumatic fastening guns.

Masking tape 18 is laid over the female locking profiles 15 on the strips 13.

A 2:1 sand and cement mix, incorporating bond improving additives to improve the mortar's characteris- tics, is pneumatically applied over the first layer 12 to an even thickness between the female profile sections - see FIGS. 2 and 2A . As shown the mortar passes through the holes 17 to adhere to the wall 10 and so keep the strips 13 to the wall. The fresh mortar surface 19 is cut back level with the profile height before the mortar 19 has reached its final set. The protective masking tape 18 is removed.

After the mortar has set, a bead of uPVC adhesive is applied along the female locking profiles 15 and the second layer 20 is formed by locking the second layer strips 21 into engagement with the first layer strips 13 (see FIGS. 3 and 3A) . As shown in FIG. 5, the second layer strips 21 have a backing layer 2-2 with spaced male locking profiles 23 complementary to the female locking profiles 15 on the first layer strips 13. The second layer strips 21 are also extruded from sewer grade rigid uPVC and are of greater thickness than the first layer strips 13.

Referring to FIG. 3A, it will be noted that the second layer strips 21 overlap the first layer strips 13.

The second layer 2Q forms a smooth wall surface for the lined sewer or tunnel 11.

It will be readily apparent to the skilled addressee that the present invention has the advantages hereinbefore described.

The embodiments described are by way of illus¬ trative examples only and various changes and modifica¬ tions may be made thereto without departing from the scope of the present invention defined in the appended claims .^'

Claims (9)

1. A method for lining tunnels or sewers including: fixing a plurality of first layer strips, in side-by-side relationship, to the wall of the tunnel or sewer to be lined; applying grout to the first layer strip to a pre-selected thickness; and fixing a plurality of second layer strips to the first layer strips with the grout sandwiched there¬ between.

2. A method according to Claim 1 wherein: the first layer strips have a plurality of spaced female locking profiles which project inwardly from a perforated backing layer, the perforations in the backing layer enabling the grout to adhere to the wall being lined.

3. A method according to.- Claim 2 wherein: the second layer strips are of greater thick¬ ness than the first layer strips and have male locking profiles projecting outwardly from a backing layer to engage the female locking profiles, the backing layer providing a smooth liner surface.

4. A method according to Claim 3 wherein: the first and second layer strips are laid in an overlapping relationship.

5. A method according to any one of Claims 1 to 4 wherein: the grout is sprayed over the first layer strip and passes through perforations in the first layer strip to adhere to the wall being lined.

6. Apparatus to line a tunnel or sewer including: a plurality of first layer strips to be fixed in a side-by-side relationship to the wall to be lined;

. grout applied to the first layer to a pre¬ selected thickness; and a plurality of second layer strips fixed to the first layer strips to grout the sandwich between the two layers .

7. Apparatus according to Claim 6 wherein: the first layer strips have a plurality of spaced female locking profiles which project inwardly from a perforated backing layer, the perforations in the backing layer enabling the grout to adhere to the wall being lined.

8. Apparatus according to Claim 7 wherein: the second layer strips are of greater thick¬ ness than the first layer strips and have male locking profiles projecting outwardly from a backing layer to engage the female locking profiles , the backing layer providing a smooth liner surface.

9. Apparatus according to Claim 8 wherein: the first and second layer strips are laid in an overlapping relationship.