AU2011244845A1 - Conduit Spacer System - Google Patents

Abstract

A method of securing a desired separation between conduits of disparate utility services in horizontally bored tunnels; said method including the steps of 5 assembling lengths of said conduits into a bundle; disparate conduits within said bundle fixed at predetermined separations by spacer elements located at intervals along the length of said bundle.

Description

P/00/009 Regulation 3.10 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Invention Title: CONDUIT SPACER SYSTEM The invention is described in the following statement, including the best method of performing it known to us: Our Reference: 112032 CONDUIT SPACER SYSTEM The present invention relates to placement of conduits 5 for infrastructure services and, more particularly, to the control of separation between conduits for different services. BACKGROUND 10 It has become an increasingly common practice to install underground services such as water, electrical and communication services in underground tunnels produced by horizontal boring to obviate the disruption' to the surface by the more traditional means of trenching. 15 Typically, after tunnelling and insertion of the required conduits, grouting is introduced to stabilise the tunnel and the conduits within it. For reasons of economy and practicality, it is desirable to keep the bore diameter to a minimum but this 20 can lead to problems with the services contained in the accommodated conduits. In particular conflicts can arise from the too close proximity of power and communication cable carrying conduits. Heat build up and electromagnetic interference can lead to corruption of data transfer and 25 even a break down in services.

Typically, after introduction of multiple conduits into a bored hole, grouting is introduced to secure the bore hole. This can lead to sagging and contacting between the various conduits, leading to the problems of 5 interference referred to above. It is an object of the present invention to address or at least ameliorate some of the above disadvantages. Notes 10 1. The term "comprising" (and grammatical variations thereof) is used in this specification in the inclusive sense of "having" or "including", and not in the exclusive sense of "consisting only of". 2. The above discussion of the prior art in the Background 15 of the invention, is not an admission that any information discussed therein is citable prior art or part of the common general knowledge of persons skilled in the art in any country. 20 BRIEF DESCRIPTION OF INVENTION Accordingly in one broad form of the invention there is provided a method of securing a desired separation between conduits of disparate utility services in horizontal boring produced tunnels; said method including the steps of 25 assembling lengths of said conduits into a bundle; disparate conduits within said bundle fixed at -- -1 predetermined separations by spacer elements located at intervals along the length of said bundle. Preferably said spacers are of unitary construction. Preferably said spacers are configured with apertures 5 corresponding to external diameters of conduits to be assembled into a said bundle. In a further broad form of the invention there is provided a method of installing a plurality of conduits for utility services; said method including the steps of: 1o a. providing an insert excavation and an exit excavation at respective ends of a utility service section, b. boring a generally horizontal tunnel between said insert and said exit excavation, 15 c. assembling one or more bundles of said conduits by passing said conduits through apertures of at least two unitary conduit spacers, and d. introducing said one or more bundles of conduits into said tunnel. 20 Preferably said method further includes the step of introducing a flowable settable material around conduits of said one or more bundles of conduits thereby to maintain tunnel integrity and maintain said conduits in a spaced apart relationship one to another. 5 Preferably said spacers are fabricated from a non-matallic material. Preferably said material is a plastics material. Preferably said material is a polymer. Preferably said material is nylon. 10 Preferably said material is a resin. Preferably said spacers are fabricated or injection moulded from High Density Polyethylene (HDPE). In a further broad form of the invention there is provided a conduit separating spacer; said spacer of unitary 15 construction formed of sheet or injection moulded HDPE; said spacer having substantially planar front and rear surfaces provided at least with apertures of diameters corresponding to conduits to be maintained at predetermined separations within a horizontally bored tunnel. 20 Preferably said spacer further includes apertures for passage therethrough of grouting material.

BRIEF DESCRIPTION OF DRAWINGS Embodiments of the present invention will now be described with reference to the accompanying drawings 5 wherein: Figure 1 is a perspective view of a bundle of conduits assembled by means of a conduit spacer according to the invention, Figure 2 is a perspective view of a preferred 10 embodiment of a three conduit spacer according to the invention, Figure 3 is a perspective view of a preferred embodiment of a four conduit spacer according to the invention; Fig 4 is a dimensioned plan view of the spacer of Fig 2, 15 Fig 5 is a dimensioned plan view of the spacer of Fig 3. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS With reference to Fig. 1, a plurality, in this example, three service carrying conduits, in this instance 20 of equal diameters, have been assembled into a bundle by means of conduit spacers 12. Although in this example use has been made of two spacers 12 spaced apart along the length of the conduits 10, it will be appreciated that for long and flexible lengths of conduit three or more spacers 25 may be employed to secure the desired separation between the conduits. Thus for relatively flexible conduits it may - I be desirable to position spacers at three or four meter intervals. Figure 2 shows one preferred embodiment of a conduit spacer 12 which has again been provided with three main 5 equal diameter conduit apertures 14, together with some additional smaller diameter apertures 16. These may assist the flow through of grouting material introduced into a bored tunnel after a bundle of conduits is inserted, or one or more may be used to support smaller conduits. 10 Another preferred embodiment of a conduit spacer 12 according to the invention shown in Figure 3 similarly provides for a number, in this instance four, relatively large equal diameter conduit receiving apertures 18 as well as a number of smaller apertures 20 of varying diameters, 15 again suitable for passage of a flowable settable grout through the spacer, or support of additional smaller conduits. Preferably, the conduit spacers of the present invention may be fabricated from a non-metallic material, 20 more preferably a plastics material and yet more preferably from High Density Polyethylene (DDPE), 50mm sheet, or injection moulded from that or similar material. HDPE and similar material compositions are extremely durable and ideally suited to underground use, as well as being 25 resistant to attack from chemical leaching. The spacers 12 are of unitary construction; that is that they are of one - 0 contiguous piece of material. Whether fabricated from sheet or injection moulded, the spacer has substantially planar front and rear surfaces for simplicity of tooling, storage and handling. 5 Apart from the apertures required to receive the plurality of conduits and provide for the passage of grout, additional apertures may be provided to reduce weight and economize on material in the case where the spacers are injection moulded. In the example of Figure 1, it will be 10 noted that the conduits are relatively closely spaced, allowing relatively little space for additional apertures. In this arrangement the edges of the spacers may be scalloped as shown to reduce the amount of material required. 15 By use of appropriately spaced conduit spacers of the invention, conduits of any size and construction can be retained securely in any specified separation, thus ensuring the integrity of, and non-interference between, power and telecommunication cabling for example. 20 Specific of preferred embodiments of conduit spacers are shown in Figure 4 and 5. With reference to Figure 4, a conduit spacer configuration is shown for a three conduit installation, catering for conduits having an outer diameter of approximately 180mm. The apertures in the 25 conduit spacer for these conduits are 186mm, to provide approximately 2.5mm clearance all round to allow easy threading of the conduits through the apertures. Smaller diameter apertures for flow through of grout are provided in this example with a diameter of 66mm. Figure 5 shows a preferred configuration of a four 5 conduit spacer, also for conduits with an outside diameter of 180mm, and with one additional hole of 140mm diameter and four smaller 70mm diameter holes for the passage of grout. In both the three conduit and the four conduit spacer, the centre to centre spacing of the 180mm diameter 10 conduits is 255mm. It will be understood that although the above described embodiments have been specific to three and four conduit spacers, spacers according to the invention, may be configured to suit any combination of the number and 15 diameters of conduits. In Use In use, an insertion excavation and an exit excavation are prepared at respective ends of a line of a section of a utility service installation. A tunnel is prepared by 20 horizontal boring methods between the insert and the exit excavations, The one or more bundles of conduits, sufficient for the length of the section, are then assembled by passing each conduit through a designated aperture in each of the conduit spacers to be employed. The 25 spacers are then affixed to the conduits at the predetermined intervals. In one form this is carried out by plastic welding - particularly in the case where both the spacer and conduit are made from HDPE. Where other materials are used other forms of affixing sufficient to prevent dislodgement or movement of the spacer relative to 5 the conduit may be employed eg gluing. These one or more bundles are then guided into the tunnel, joining the conduits as insertion progresses as appropriate, Finally when insertion and such connections to any 10 previously installed section has been completed, a flowable settable material is injected into the.tunnel to ensure its integrity and to secure the spaced apart relationships between the conduits in the bundles. 15 In some forms and circumstances the horizontally formed tunnel may be lined either as it is being bored or subsequent to the boring step. The above describes only some embodiments of the 20 present invention and modifications, obvious to those skilled in the art, can be made thereto without departing from the scope of the present invention.

Claims (5)

1. A method of securing a desired separation between conduits of disparate utility services in horizontally bored tunnels; said method including 5 the steps of assembling lengths of said conduits into a bundle; disparate conduits within said bundle fixed at predetermined separations by spacer elements located at intervals along the length of said bundle. 10

2. The method of claim 1 wherein said spacers are of unitary construction.

3. A method of installing a plurality of conduits for utility services; said method including the steps of: 15 a. providing an insert excavation and an exit excavation at respective ends of a utility service section, b. boring a generally horizontal tunnel between said insert and said exit excavation, 20 c. assembling one or more bundles of said conduits by passing said conduits through apertures of unitary conduit spacers, and d. introducing said one or more bundles of conduits into said tunnel, e. introducing a flowable settable material around conduits of said one or more bundles of 5 conduits thereby to maintain tunnel integrity and maintain said conduits in a spaced apart relationship one to another.

4. The method of any one of claims 1 to 3 wherein said spacers are fabricated from a non-metallic material. 10

5. A conduit separating spacer; said spacer of unitary construction formed of a non-metallic material; said spacer having substantially planar front and rear surfaces provided at least with apertures of diameters corresponding to conduits to be maintained 15 at predetermined separations within a horizontally bored tunnel; said spacer further including apertures for passage therethrough of grouting material.