GB2430948A

GB2430948A - Tunnel Lining Bracket

Info

Publication number: GB2430948A
Application number: GB0520484A
Authority: GB
Inventors: Simon Francis Klippel; Neil Frank Gill; Louise Caroline Foster; Mark Gaskell
Original assignee: Tyco European Metal Framing Ltd
Current assignee: Tyco European Metal Framing Ltd
Priority date: 2005-10-07
Filing date: 2005-10-07
Publication date: 2007-04-11
Anticipated expiration: 2025-10-07
Also published as: GB2430948B; GB0520484D0

Abstract

A bracket for attachment to the flange of a bolted section of a tunnel lining. The bracket comprises a base (fig. 1, 11) having a large aperture 15 to hook over the headed fasteners of tunnel tubing sections such as bolts 34, and upstanding flanges (fig. 1, 13) with adjustable length struts 23 for biasing the side of the aperture 15 against the fastener 34. The brackets may be mounted back to back for lateral retention, and are adjustable in angle by the struts 23.

Description

P713881GB Tunnel Lining Bracket This invention relates to an improved

bracket for the internal surface of a tunnel formed of bolted tubing sections.

Tunnel linings comprise arcuate sections fixed in a freshly bored tunnel just behind a tunnel boring machine or face shield. Many lined tunnels comprise arcuate cast iron or steel sections bolted together at adjacent internally protruding flanges. Typically, each arcuate section is about 3 00-500mm wide and has internal flanges about 150mm in depth. Bolted joints may be at 300mm or less around the circumference. Once formed, such a lining is strong and self-supporting.

A need often arises to fix components to the internal surface of the lining, for example a cosmetic or fireproof secondary lining, cables, pipes, signs and the like. To avoid breaching the lining, such components are usually suspended or anchored from the existing fixing bolts. This can be very time consuming for often the existing bolts must be removed and substituted with a different kind; furthermore access to the fixing bolts can be restricted by proximity to the circumferential wall, by the internal flanges, and by other tunnel furniture.

What is required is a bracket which is simple to fit, has no loose parts, and is adaptable to any kind of component required to be fixed to the tunnel lining.

According to the invention, there is provided a bracket for a tunnel lining comprised of sections having flanges extending generally radially of the tunnel axis and joined by headed fasteners extending therethrough generally parallel to the tunnel axis, the bracket comprising a planar base having an aperture adjacent one end and upstanding flanges at said end on either side of said aperture, said flanges having a respective through hole, the through holes having an axis generally orthogonal to the axis of said aperture, and said aperture being oversize with respect to the heads of tunnel lining fasteners.

In use the bracket is hooked over the head of a tunnel lining fastener via said aperture so as to lie generally radially of the tunnel axis, and adjustable length struts are inserted so as to bear on the tunnel wall and force the side wall of the aperture against the tunnel side of the head of the fasteners. By adjusting the respective lengths of the struts, the angle of the bracket can be varied so as, for example, to be perpendicular to the tunnel wall at the fastening location. Fine adjustments of the angle is possible.

Such a bracket is self contained and easily fitted to any tunnel lining location without regard to the kind and size of tunnel lining fastener all that is required is to ensure that the aperture is larger than the largest head likely to be found in practice. No disturbance of existing tunnel lining fasteners is necessary, and accordingly the requirement for additional spanners and different fasteners is obviated, and the difficulty of removing existing fasteners close to the tunnel wall is avoided.

Any suitable strut may be employed, for example a nut bearing on the outside face of a flange, and a set screw for the nut, and passing through the respective hole. The nut may be welded to the flange. Alternatively the flange may be threaded.

Preferably the opposite end of said base is narrowed from each side so as to give improved access to said flanges, for the purpose of adjusting said struts. The flange is preferably symmetrical about a longitudinal axis perpendicular to a line passing through said flanges.

In a preferred embodiment the aperture is circular, and the centre of the aperture is substantially on a line passing through said flanges. The end between said flanges is preferably defined by an arcuate wall, which in the preferred embodiment is semicircular and centred on said aperture.

The base may include a through hole adjacent said other end to permit back to back connection of two of said flanges via a suitable fastener. Such an arrangement gives lateral stability about a flanged tunnel joint.

Preferably, the other end of said bracket includes an upstanding wall having apertures for attachment of tunnel fixings or tunnel furniture, said wall preferably extends on the same side as said flanges, and in a parallel plane.

Other features of the invention will be apparent from the following description of a preferred embodiment, shown by way of example only in the accompanying drawings in which: Fig. 1 is a plan view of a bracket according to the invention; Fig.2 is a transverse section on line 2-2 of Fig. 1.

Fig.3 is an end elevation of the bracket of Fig. 1.

Fig.4 is a schematic section through a typical tunnel liming.

Fig.5 illustrates in part section the invention as applied to the arrangement of Fig.4; and Fig.6 is a part sectional end elevation of the arrangement of Fig.5.

With reference to Fig. 1, a bracket 10 comprises a planar base 11, an upstanding waIl 12 at one end, and spaced upstanding flanges 13 at the other end. The base 11 extends between the flanges 13 to define an arcuate end wall 14 which is part-boundary for an aperture 15 in the base. As illustrated, the aperture 15 is circular and centred approximately on a transverse axis coincident with the flanges 13. The base narrows towards the wall 12, as illustrated, for reasons which will become apparent.

A continuous slot 17 extends along the base 11 towards and up the wall 12, and oval mounting holes 18, 19 are provided in the wall 12 on either side of the slot 17.

Nuts 21 are spot welded to the flanges 13 coincident with suitable clearance holes 22.

The bracket is typically cut and bent from 5mm sheet steel, and may be protected from corrosion by e.g. galvanising.

Fig.4 illustrates a typical tunnel lining comprising adjacent cast iron arcuate sections 31,32 having flanges 33 held together by a suitable fastener 34 to resist the surrounding ground 35. In use the sections 31,32 form complete rings so that a continuous tube is formed as the tunnel is excavated. The flanges typically have tapering cheeks 36. The fastener 34 may be of any suitable kind, but are typically nut and bolt; as a consequence a portion of thread (not shown) may extend on one side. Many styles and size of fastener may be found.

Figs.5 and 6 illustrate an application of the invention. A pair of brackets 10 are mounted back to back about the flanged joint. Each aperture 15 is large enough to accommodate the largest fastener head which is likely, in practice, to be found. The size and shape of the apertures 15 is thus not particularly important.

Set screws 23 are inserted through the captive nuts 21 to bear upon the tunnel lining (see Fig.5), and thus urge the wall of the aperture tightly against the head of the fastener 34. It will be appreciated that by adjustment of the set screws 23, the angle of the bracket can be altered, as indicated by arrow 37.

Fig.5 illustrates that the narrowing portion of the base 11 allows relatively unobstructed access to the heads of the set screws 23, for the application of a suitable driver.

In order to provide lateral stability, the back to back brackets are connected by a bolt along axis 38 (Fig.5) and via slots 17.

Alternatively or additionally the brackets may be connected by an apertured plate 39 and bolts along axes 41 and via holes 18,19.

The plate 39 is typically provided with multiple holes and slots for the mounting of tunnel furniture. In certain circumstances the plate 39 may be substituted by a long length of material spanning several flanged tunnel joints, in which case back to back brackets are not required at every support location since one such fixing will generally provide adequate lateral stability. Other kinds of brackets may be secured, for example to support cable trays, pipes, etc. For a long length of material, and for certain tunnel furniture, precise setting of the angle of the bracket is a particular advantage.

The invention thus provides a universal means and method of securing a bracket to a tunnel lining, which does not require the existing tunnel structure to be disturbed, and which is adjustable to give a precise angle of support without special adjustment features - the means of fixing are also the means of adjustment.

Claims

1. A bracket for a tunnel lining comprised of sections having flanges

extending generally radially of the tunnel axis and joined by headed fasteners extending therethrough generally parallel to the tunnel axis, the bracket comprising a planar base having an aperture adjacent one end and upstanding flanges at said end on either side of said aperture, said flanges having a respective through hole, the through holes having an axis generally orthogonal to the axis of said aperture, and said aperture being oversize with respect to the heads of tunnel lining fasteners.

2. A bracket according to claim 1 wherein the opposite end of said base is narrowed from each side so as to give improved access to said flanges from said opposite end.

3. A bracket according to claim 1 and claim 2, and symmetrical about a longitudinal axis perpendicular to a line passing through said flanges.

4. A bracket according to any preceding claim wherein said aperture is circular.

5. A bracket according to claim 4 wherein the centre of the aperture is substantially on a line passing through said flanges.

6. A bracket according to claim 5 wherein the end between said flanges is preferably defined by an arcuate wall.

7. A bracket according to claim 6 wherein said arcuate wall is semicircular and centred on said aperture.

8. A bracket according to any preceding claim and further including an upstanding wall having apertures therein at said other end.

9. A bracket according to claim 8 wherein said upstanding wall extends on the same side of said base as said flanges.

10. A bracket according to any preceding claim, and further including an adjustable length strut in a through hole of each of said upstanding flanges.

11. A bracket according to claim 10 wherein said strut comprises a nut fixed on a respective flange against rotation, and a threaded set screw.

12. A bracket substantially as described herein with reference to the accompanying drawings.