AU667441B2 - Joint trenching - Google Patents

Description

1 Joint Trenching Field of the Invention This invention relates to joint or common trenching. In an embodiment it relates particularly to modular channel sections laid in a trench in an end-to-end arrangement, and through which conduits are routed. The invention thus has application in routing Utilities services such as electricity, gas, telecommunications, potable water and stormwater from residential areas. Another embo'nent has application in industrial complexes, where gaseous or liquid products need to be 10 transported. beneath the ground surface, yet still be readily accessible for inspection, maintenance or supplementation.

Background of the Invention Briefly stated, joint trenching is the practice of utilising a single trench for the routing of Utilities services. In its simplest form, this involves laying the various pipes and cables within a trench with appropriate separations. More sophisticated known forms of joint trenching use a single common channel through which the services are routed.

The advantages of joint trenching are manifold. As an example, lesser ground space is required which, in new residential subdivisions, means there is more land available for building. Adverse environmental impacts also are reduced during construction, since there is no longer a need to dig multiple trenches, thus reducing the concomitant risk of damaging adjacent services. Installation of the services should be speedier, and that saving in time can flow-on to reducing the ultimate cost of residential properties.

In this specification the term "conduit" is to be taken to include all forms of pipes, tubes, electrical cables, ducts, wires, optical fibres, bus bars and the like.

[N:\IlbklOOO56:BFD i 1 1 A A -2 A specific example in the prior art is disclosed in an article entitled "Service Pipes Eliminate Holes in the Road" published in the journal "Asian and Water Sewage, 1986, No. 12, 22-23".

Summary of the Invention Therefore, the invention discloses a Utilities channel section having one or more removable roof-forming covers, and wherein one or more sides or the base of the channel section is provided with support means intended to support conduits routing Utilities services, and the base forming a watercourse.

The invention further discloses a plurality of channel sections laid end-to-end in a trench, each channel section having one or more removable roof-forming covers, and wherein one or more sides or the base of a channel section is provided with support means intended to support conduits routing Utilities services.

The invention yet further discloses a joint trenching arrangement comprising: a trench; a plurality of prefabricated modular channel sections laid end-to-end in the trench, each channel section having support means provided on one or more sides or the base thereof, and the base forming a watercourse, the support means being for o supporting conduits routing Utilities services; 20 one or more roof-forming covers for each channel section.

S The invention yet further discloses a method of routing Utilities services S° comprising the steps of: 0Oo excavating a trench to follow the intended route of the services; laying a plurality of modular prefabricated channel sections end-to-end in the trench, each channel section having one or more roof-forming covers, and wherein one or more sides or the base of each channel section is provided with support means, and the base forms a watercourse; and with the respective covers removed, installing conduits for the Utilities services to be supported by the support means within the laid channel sections.

t tN:\Iibk]00056:BFD :~irrr;3aJr~a~lru\ A spcifc eampe intheprir at i dislosd i anartcle ntiled"Sevii Pie lmnt oe nteRa"pbihe ntejunl"sa n ae eae 198N lN:\libklOOOS6:BF Sumr of ,h mMfM Mn t J 440 OlC A -3- The invention yet further discloses a method for routing Utilities services across a roadway comprising the steps of: excavating a trench across a roadway; laying a plurality of modular prefabricated channel sections end-to-end in the trench, each channel section having one or more roof-forming covers, and the trench being of a depth such that the covers are level with, and form a part of, the roadway, and wherein one or more sides or the base of each channel section is provided with support means, and the base forms a watercourse; and with the respective covers removed, installing conduits for the Utilities services to be supported by the support means within the laid channel sections.

Brief Description of the Drawings A number of embodiments of the invention will now be described with o° reference to the accompanying drawings, in which: Fig. 1 shows a cut-away perspective view of a channel section and cover, o including installed services and terminations; Fig. 2 shows the channel section of Fig. 1 in vertical cross-section along line

A-A;

o o, Fig. 3 shows a vertical cross-sectional view of another embodiment of a channel section as installed; Fig. 4 shows a vertical cross-sectional view of yet another embodiment of a channel section as installed; Fig. 5 shows a vertical cross-sectional view of a yet further embodiment of a channel sec'ion; Fig. 6 shows a schematic arrangement, as a plan view, of a number of channel sections installed in a residential development; and Figs. 7A and 7B are vertical cross-sectional views showing two arrangements of channel section by which Utilities services to cross a roadway.

S[N:\libkI00056:BFD P. I I I L II C ~IIL CQI i0 A" 1 .L 'i ,I 0 Fig. 1 shows a cut-away perspective view of a channel section 10 for use in a joint trenching arrangement carrying a number of Utilities services. As previously noted, the services typically include electricity, telecommunications, water and natural gas.

The channel section is substantially U-shaped having two opposed vertical side walls 12,14 and a base 16. The central part of the base 16 forms a V-profiled watercourse 18, the function of which presently will be described. The channel section 10 is modular, in the sense that a number of channel sections can be laid end-to-end to o form a route for the Utilities services. The channel section is fabricated in one or more fixed lengths, typically of 1800 mm.

Each channel section 10 has one or more roof-forming covers 20. In a preferred embodiment, there are approximately five covers 20 per channel section S' 15 The covers 20 have a cross-sectional profile thicker in the mid-section than at the 00 edges, the mid-section being so for load-bearing purposes. The edges of the cover engage a ledge 22 at the top of each of the side walls 12,14. When fitted into place, the top of the cover 20 sits flush with the topmost point of the side walls 12,14.

000 Installation of the joint trenching arrangement is achieved by excavating an oversized trench (with respect to the width of the channel section), and laying a number of channel sections 10 within the trench in an abutting end-to-end arrangement, the channel sections having been prefabricated. The depth of the trench is such that the top of the side walls 12,14 of the channel section 10 are flush with the ground surface level, then the trench is back-filled to pack the space between the sides of the trench and the side walls 12,14. The channel sections 10 are symmetrical about a longitudinal mid-line, which means that no special orientation is required in the end-to-end arrangement and a channel section cannot be installed back-to-front.

[N:\libkl00056:BFD 5 A44 .j The covers 20 then are lowered into place to sit flush with the ground surface level so that there is no noticeable discontinuity. Utilities services are installed by the relevant installation personnel, this simply requiring the lifting-off of the covers thereby gaining access to the channel sections and routing the conduit(s) that are supported within each channel section by support means. The arrangement of the various services within the channel sections 10 will be described presently.

In the case of a new residential subdivision, it is usual for the channel sections and covers 20 to be installed at the time of forming the road and pathways, with the Utilities services being installed within the channel sections 10 at some later time.

°oo 10 Routing of the channel sections 10, therefore, usually follows the path of the roadways, and often may cross those roadways.

Both the channel sections 10 and the covers 20 can be fabricated from a range of suitable structural materials including reinforced concrete, fibreglass or high density plastics material. The dimensions of the covers 20 are chosen so that the resulting mass of each cover 20 is large enough to make it impossible for one (or perhaps two) adults physically to lift a cover 20 off a channel section 10. Rather, a mechanical lifting device is required. This consideration is particularly important in respect of safety, and in the: avoidance of vandalism of the services routed within the channel sections The watercourse 18 is provided for the routing of stormwater or other liquid run-off, typically to be discharged from within a network of channel sections 10 to a larger stormwater main. The ingress of stormwater to the channel section 10, and so to the watercourse 18, is by a drain, as will be described presently.

The Utilities services shown in Fig. 1 include a potable water pipe 24 and a recycled water pipe 26. Both these pipes 24,26 are supported from the base 16 by means of scallop-shaped footings 28. High voltage and low voltage electricity cables are supported from the side wall 14 by a longitudinally extending tray and cover 32 mounted by appropriate means to the inside of that side wall 14. In a similar manner, [N:\libkl00056:BFD i i I^ I I -6telecommunications cables 34 are mounted from a tray fixed to the inside of the other side wall 12.

A gas pipeline 36 is shown mounted to the outside of the side wall 14 and supported by anothL ,igitudinally extending tray 38. The tray 38 is affixed to the outside of the side wall 14 by any appropriate means. Another gas pipeline 40 is shown in phantom mounted to the outside of the other side wall 12. This signifies that a gas pipeline can be located on either or both sides of a channel section 10. The gas pipelines 36,40 have been chosen to be placed to the outside of the channel section in this embodiment for reason of isolating the flammable gas from the other services.

1o Even so, it is equally possible to route the gas pipelines 36,40 within the channel o° o section *00 oIn the instance of the Utilities services being routed by a network of channel sections 10 about a residential subdivision, it is necessary to make those services 0o 0 available for connection to each residential property. For this purpose, a termination 0 15 box 42 is mounted to the side of the channel section 10. The termination box 42 also oO O-0 has a removable cover 43, thus allowing access to the terminated water, 0 telecommunications, electricity and gas services for interconnection to the residential property. Each of these services are communicated to the termination box 42 from within the channel section 10 by appropriate cables and pipes. These cables and pipes are supported across the span of the channel section 10 by a tray 44.

It is also often necessary to provide an above-ground servicing point for maintenance personnel. In that case, a pillar 46 is mounted to the cover 20, into which one of the electrical cables 30 is jointed, passing through the cover 20. In this way, service personnel can perform work on the reticulated electricity supply. Note, however, that connection of the electricity supply to a residential property is via the termination box 42.

Fig. 2 shows the joint trenching arrangement of Fig. 1 in a vertical crosssection along line A-A. Like-items shown in Fig. 1 are represented by the same [N:\Iibk]OOO56:BFD I I r III 7 reference numerals. Fig. 2 particularly shows the terminating arrangement of the services to the termination box 42. The interconnecting cabling and piping between the respective services and the termination box 42 is otherwise conventional. Fig. 2 also shows the exit point 48 from the termination box 42, in this case being for the further routing of the services to residential premises.

Fig. 3 is similar to Fig. 2. In Fig. 3, the channel section 10 is arranged to be directly adjacent a curb 50 which, in turn, forms the wall of the gutter 52, extending outward to a roadway 54. Any stormwater run-off along a gutter 52 is diverted to the channel section 10 by an ingress drain 56. The drain 56 discharges water to the inside S 10 of the channel section 10, which then flows along the watercourse 18, to a stormwater main (not shown). The presence of water within the channel section 10 does not create any difficulties beyond those experienced by conventional reticulation techniques. The cables and pipes 24,26,30,34 within the channel section 10 are appropriately insulated ;oo ~against ingress of water, or otherwise are not affected by the water.

15 Fig. 4 shows another arrangement in which the channel section 10 is butted-up o0o0 to the edge of the gutter 52, with the roadway 54 extending from the opposite side thereof. In this configuration, the cover 20 is required to be sufficiently reinforced to cope with the anticipated dynamic loading of vehicular traffic along the roadway 54, of o"oo which the cover 20 and buried channel section 10 form a part. By incorporating the channel section 10 into the roadway, land usage for the residential properties within a subdivision can be maximised. Furthermore, the existing services laid under footpaths can be relocated into the channel section within the roadway, thus allowing rehabilitation of the footpaths, and avoiding continual digging-up of the footpath in the event of needing to maintain or supplement the services.

Fig. 5 shows another embodiment of a channel section 100. In this case, there is no watercourse along the base 16 of the channel. This means that services conduits otherwise supported from the walls 12,14 now can be supported along the base 16, and hence the depth of the channel section 100, and hence also of the depth of trench to be [N:\Iibk]00056:BFD i r I I 8 .444 <(00.0 t, J' 4 excavated, can be reduced. This is evident from a comparison between the channel sections of Fig. 4 and Fig. 5. As shown in Fig. 5, the various services conduits 24,26,30,34,40 are supported from a common footing 28. A number of such footings are located in spaced-apart arrangement along the length of the channel section 100. In this embodiment, it usually would not be the case that an inlet duct for stormwater u.sually would not be provided.

Fig. 6 is a plan view of a joint trenching installation utilising the configuration shown in Fig. 4, in that the channel sections 10 form a part of the roadway 54. Grates 58 are located periodically along the gutter 52, and coincide with the location of the ingress drains56. The termination boxes 42 each service two residential properties.

The particular teiT;nination box 42 located on the opposite side of the roadway to the channel sections 10 requires that the services be routed underneath the roadway 54.

Both Figs. 7A and 7B relate to possible configurations for crossing a roadway.

The channel sections 10 in both Figs. 7A and 7B are provided beside the roadway 54.

15 In the case of Fig. 7A, the services are routed beneath the roadway 54 by open excavation, placement of ducting pipes and backfilling to provide communication between the channel sections 10 at either side of the roadway 54. In Fig. 7B, the span of the roadway 54 is occupied by two (or more)arrangement along the length of th channel sections 10, which thus shown in Fig. 4, in constitute the roadway at that point. In this way, the cables and pipes carrying the ervic58 are continue to be routed as previously described, and wholly within the channel sections at all times.

The embodiments described provide numerous benefits or advantages. In terms of construction and maintenance associated won the opposith routing of Utilities services, excavations are not left open for long periods be routed underneplaced at night for54.

wo Bork that carries over to the next day. Coordination of the installation process isa roadway.

simplified over conventional methodologies, and surrounding areas of the trench can be54.

easily restored before the services are installed.

N:\ibkroadway 54 is occupied by two (or more) channel sections 10, which thus0056:BFD iJi 0 -9- Ground settlement following excavation, and the amount of backfill required, are reduced over conventional methodologies. Also, maintenance can be undertaken without the need for excavation, and similarly, the diagnosis of faults is far easier, simply requiring removal of covers.

By virtue of pipes, cables and the like being laid in the channel sections, they are not subjected to adverse stresses from soil movements, or to external corrosion from soil action or ground water, and therefore should have a greater life expectancy.

Additional services can be easily incorporated by reason of there being spare capacity. A further consequence of having a void within the cover channel sections is 0. 0 10 that monitoring systems can be incorporated and can easily and quickly detect leaks or 00. Sdamages. The ready access provided by removable covers can reduce the time and Scosts associated with installation and maintenance.

There are also a number of positive safety implications, in that workers can see o the exact placement, position and condition of all services and so determine whether 15 there is an obvious fault without the need to excavate. The danger of inadvertently severing or damaging services is similarly reduced. Maintenance personnel also have 0 far improved access, in that the channel sections can be stood in, and further, there is no chance of a cave-in trapping workers within the channel section.

exa By way of example of modifications and alterations falling within the broad scope of the invention, the cross-sectional shape of the channel sections can include shapes other than a such as one or more or 'V'-shaped profiles. Further, the channel sections can include reinforcing webbing or flanging along their length.

i [N:\]ibl000 56 BFD

Claims (16)

1. A Utilities channel section having one or more removable roof- forming covers, and wherein one or more sides or the base of the channel section is provided with support means intended to support conduits routing Utilities services, and the base forming a watercourse.

2. A channel section as claimed in claim 1 that is substantially U-shaped in cross-section.

3. A channel section as claimed in either one of claim 1 or claim 2, further comprising an inlet means formed in a wall or a cover of the channel section, the inlet means allowing ingress of liquid.

4. A channel section as claimed in claim 3, further comprising a termination box located above or to the side of a channel section, and there being communication between the termination box and the channel so that Utilities services o "can exit from the channel section to a termination point in the termination box. o 15

5. A plurality of the channel sections as claimed in either one of claim 1 or claim 2, whereby, in use, the channel sections are laid end-to-end in a trench.

6. A plurality of channel sections as claimed in claim 5, whereby the channel sections are arranged in the trench so that the covers coincide with the ground level.

7. A plurality of channel sections as claimed in either one of claim 5 or claim 6, wherein one or more of the channel sections has inlet means formed in a wall or a cover of the channel section, the inlet means allowing ingress of liquid, and whereby the bases of the laid channel sections form a watercourse.

8. A plurality of channel sections as claimed in claim 7, wherein one or more of the channel sections further comprises a termination box located above or to the side thereof, and there being communication between the termination box and the channel so that Utilities services can exit from the channel section to a termination point in the termination box. RA4,, g1 x [N:\IibkO00056:BFD r -11-

9. A plurality of channel sections as claimed in claim 8, wherein the trench forms a pathway, part of a verge to a roadway, a roadway curb or a part of a roadway.

A joint treiching arrangement comprising: a trench; a plurality of prefabricated modular channel sections laid end-to-end in the trench, each channel section having support means provided on one or more sides or the base thereof, and the base forming a watercourse, the support means being for supporting conduits routing Utilities services; and one or more roof-forming covers for each channel section.

11. A joint trenching arrangement as claimed in claim 10, further comprising inlet means formed in a wall oi cover of one or more of the channel sections for the ingress of iquid.

12. A joint trenching arrangement as claimed in either one of claim 10 or 1 5 claim 11, further comprising a termination box located above or to the side of one or o more of the channel sections, and there being communication between the termination S.box and the channel so that Utilities services can exit from the channel section to a termination point in the termination box. o

13. A method of routing Utilities services, the method comprising the S: 20 steps of: excavating a trench to follow the indented route of the services; laying a plurality .of modular prefabricated channel sections end-to-end in the trench, each channel section having one or more roof-forming covers, and wherein one or more sides or the base of each channel section is provided with support means, and the base forms a watercourse; and with the respective covers removed, installing conduits for the Utilities services to be supported by the support means within the laid channel sections. N b f iNT O (N:\IIbklO005S:BFO [N:\LIBW]039i6:BFD -12-

14. A method as claimed in claim 13, wherein the laid channel sections and respective covers form a pathway, part of a verge to a roadway, a roadway curb or a part of a roadway.

A method for routing Utilities services across a roadway comprising the steps of: excavating a trench across a roadway; laying a plurality of modular prefabricated channel sections end-to-end in the trench, each channel section having one or more roof-forming covers, and the trench being of a depth such that the covers are level with, and form a part of, the roadway, and wherein one or more sides or the base of each channel section is provided with support means, and the base forms a watercourse; and with the respective covers removed, installing conduits for the Utilities services to be supported by the support means within the laid channel sections.

16. A Utilities channel section substantially as herein described and as shown in the accompanying drawings. o DATED this Fifteenth Day of January 1996 Sydney Water Corporation Limited Patent Attorneys for the Applicant 00 SPRUSON FERGUSON N:\11bk100056:BFD Abstract Joint Trenching A joint trenching arrangement for the routing of Utilities services such as electricity, gas, telecommunications, potable water and stormwater is described. A U- shaped channel section (10) has a watercourse (18) in its base (16) and a number of roof-forming covers A number of channel sections (10) are laid end-to-end in a trench along a desired route. Utilities services are supported within the channel sections (10) by supporting m..,ns such as footings (28) and wall-mounted trays (34). Termination of the services from the channel sections (10) is by a termination box (42) mounted from the side of a channel section (Fig. 1) ao 0 0 0 o c 0 0 t [N:\llbk]00061:BFD L i e~ Ir I