GB2171432A

GB2171432A - Underground roadway arch sections

Info

Publication number: GB2171432A
Application number: GB08604366A
Authority: GB
Inventors: Allan Richard Hilton
Original assignee: NCB
Current assignee: NCB
Priority date: 1985-02-22
Filing date: 1986-02-21
Publication date: 1986-08-28
Also published as: GB8604366D0; WO1986004952A1; AU5515986A; KR870700116A

Abstract

An underground roadway support comprises interconnected side-by-side arch sections (20, 21, 22) each constituted by a plurality of interconnected panels (23, 24, 25). Each panel comprises a plurality of arch sections butted and coupled together, the panel being of rectangular configuration and having on two opposed sides formations adapted movably or adjustably to engage complementary formations on corresponding panels of adjacent arch sections to provide mechanically flexible connections therebetween. The formation on one side of a panel is a channel (31) open outwards of the panel, while the formation on the other side of the same channel is a box section (32) adapted to engage within a channel formation of an adjacent panel to form, in effect, a knuckle joint thus to permit joined panels, and consequently joined arch sections, to accommodate earth strata irregularities or variations.

Description

SPECIFICATION An underground roadway support This invention relates to an underground roadway support.

The term "underground roadway" is intended to include, inter alia, a roadway in a mine, for example a coalmine, and a tunnel or other excavation into earth stata.

There has previously been proposed (see published United Kingdom Patent Application No. 2057034A in the name Allan Richard Hilton) an underground roadway support comprising a plurality of arch sections butted and rigidly tied or coupled together, for example by bolting, and extending along an underground roadway to provide protection for workmen within the underground roadway and a means for supporting the earth strata during roadway drivage and/or excavation.

In the aforesaid published Patent Application each arch section consists of a plurality of seperate panels butted and rigidly tied or coupled together by, for example, bolting or wedges.

The underground roadway support of the aforesaid published Patent Application is, therefore, easily and readily extendible and/or movable and each arch section can be easily and readily repaired (individual panel replacement) if necessary.

It is an object of the present invention to provide such an underground roadway support as is generally disclosed in the aforesaid published Patent Application with an in-built facility for adjacent arch sections to compensate for and/or accommodate earth strata irregularities or variations within the underground roadway.

Accordiny to the present invention there is provided a panel adapted to constitute a part of an arch section of an underground roadway support comprising a plurality of arch sections butted and coupled together, the panel being of rectangular configuration and having on two opposed sides formations adapted movably or adjustably to engage complementary formations on corresponding panels of adjacent arch sections to provide mechanically flexible connections therebetween.

Preferably, the formation on one side of a panel is a channel open outwards of the panel.

Preferably, the formation on the other side of the same channel is a box section adapted to engage within a channel formation of an adjacent panel to form, in effect, a knuckle joint.

Preferably, the formation on one side of a panel is a channel open outwards of the panel while the formation on the other side of the same panel is also a channel dimensionally smaller than said one channel whereby the other channel can be engaged within said one channel to form the knuckle joint.

Preferably, the other channel is also open outwards of the panel.

Alternatively, the other channel opens to one side of the panel.

Preferably, the said one channel which opens outwards of the panel has outwardly diverging inner faces while the box section or other channel has parallel outer faces or surfaces which abut the outwardly diverging faces to permit relative pivoting or rocking between engaged formations in the manner of a knuckle joint thus to permit joined panels, and consequently joined arch sections, to accommodate earth strata irregularities or variations.

Preferably, the free ends of each inner channel of the joint are inturned to increase the strength of the joint.

Each inner channel of the joint may be relatively shallow in its outward extension from the panel.

Each outer channel of the joint may have one relatively short limb and one relatively long limb, the latter at its free end being inturned. This configuration is considered to facilitate location of an inner channel within an outer channel to form the joint.

A preferred construction of panel is a rectangular frame of angle iron infilled with wire mesh with an inner formation, box section or channel, and an outer channel formation on two opposed sides and with the other two opposed sides (hereinafter called "fastening sides") formed or provided with means allowing same to be releasably fastened to a similar side of an adjacent panel making up an arch section.

Each fastening side is preferably provided with bolt holes so that adjacent butted panels constituting an arch section can be bolted together.

Alternatively, each fastening side of a panel has one, or preferably two, elongate slots allowing two abutting adjacent panels in an arch section to be connected together by a wedge device or a cotter device.

Where a box section is employed for the inner formation of the joint, or a channel facing to one side of the panel them is provided a three web support between adjacent panels of adjacent arch sections.

This multi-web joint, i.e. the web of the outer channel and the two parallel webs of the box section or side facing channel received within the outer channel provides simi lar strength to much larger R.S.J.'s but provides a lighter structure. The mechanical flexibility between arch sections is maintained to compensate for or accommodate earth strata settlement.

The panels may, of course, be of any configuration to suit the mining or civil engineering requirement of a particular underground roadway.

Each panel may be infilled with steel wire mesh as aforesaid, or with corrugated metal or plate welded internally or externally to the panel frame, which is preferably formed of steel.

A clamping arrangement is preferably provided to hold the joint formations in interengagement.

Preferably there are a number of clamping arrangements provided along the length of each joint between adjacent arch sections.

Preferably the clamping arrangements are releasable and re-usable.

Preferably the clamping arrangement comprises two pivotally interconnected parts defining a substantially U-shaped clamp with the limbs of the U adaped to embrace the joint and being locked against the joint by cam means.

Instead of cam means the U-shaped clamp may be locked against the joint by spring means.

The locking cam means or spring means is preferably pivoted to the U-shaped clamp.

Preferably one of the limbs of the U-shaped clamp supports a spring adapted to abut the joint and serving to compensate for variations in manufacturing tolerances in the panels and connected joint formations.

The U-shaped clamp may be recessed to engage a limb of the outer channel of the joint to ensure precise location of the clamp on the joint.

The U-shaped clamp may be formed with a hole to provide a means for hanging an article, for example a lamp or tool, from the clamp, or attaching an article thereto.

It is considered that when a number of adjacent arch sections have been assembled in jointed relationship the assembly will have sufficient inherent stability so that the clamping arrangements can be released for re-use in another part of the underground roadway support in the process of being erected.

It is to be understood that the use of the clamping arrangements is considered to be preferred but not essential to the present invention.

Also according to the present invention there is provided an arch section for an underground roadway support, the arch section being constituted by interconnected panels having opposed jointing formations as hereinbefore defined.

An arch section is preferably erected by butting the fastening sides of a number of panels together and bolting or otherwise securing them together, adjacent erected arch sections being interconnected by the knuckle joint to provide the required mechanical flexibility between such sections.

Preferably, the two lower or bottom panels of an arch section are straight, the others being curved, so that the arch section is of substantially D-section, the D lying on its flat side.

Further according to the present invention there is provided an underground roadway support constituted by a plurality of arch sections as defined in the three immediately preceding paragraphs coupled together by inner and outer interengaging joint formations to provide mechanical flexibility between adjacent arch sections.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1. is a diagrammatic perspective view of an underground roadway support according to the present invention; Fig. 2 is a fragmentary sectional view of the underground roadway support at the roof level; Fig. 3 is a fragmentary perspective view of part of an arch section showing alternative fastening means at Figs. 3A, 3B and 3C; Fig. 4 is a perspective view of adjacent panels of adjacent arch sections; Figs. 5, 6 and 6A, 7, 8 and 9 are plan views (some in section) of interengaged or interengaging panel joint formations according to the present invention; Fig. 10 is a side view of one joint clamping arrangement; Fig. 11 is a side view corresponding to Fig.

10, to an enlarged scale, of a modified joint clamping arrangement; and Fig. 12 is a fragmentary side view of another joint clamping arrangement.

The underground roadway support comprises adjacent arch sections 20, 21 and 22, each constituted by a number of interconnected panels 23, 24 and 25. Each arch section comprises two bottom straight panels 23, two intermediate long curved panels 24 and one central short curved panel 25.

The bottom panels 23 may, if desired or necessary, be supported on wooden chocks (not shown).

A different layout or arrangement of panels with staggered joints is indicated by broken lines 26.

Each panel is essentially of the same construction. It comprises a rectangular steel frame 27 (see Figs. 3 to 5) of angle iron to the outside of which is welded a steel wire mesh screen 28, the outside being that side which contacts the earth strata.

Each panel is provided on its two sides 27A parallel with the ground of the roadway with bolt holes 29 or wedge slots 30 referred to in more detail later for use in connecting panels together to form an arch section.

The other two sides 27B of the panel have welded to the outer surfaces thereof jointing formations.

In Figs. 2 to 5, these jointing formations are constituted, on one side 27B, by a channel 31 open outwards of the side 27B, and, on the other side 27B, by a box section 32.

The channel 31 and box section 32 are dimensioned so that a box section 32 of one panel is engageable within the channel 31 of an adjacent panel.

The limbs 33 of the channel 31 have outwardly diverging inner surfaces 34 while the outer faces 35 of the box section 32 are parallel.

When the box section 32 of one panel is engaged within the channel 31 of an adjacent panel there is formed, between the panels and consequently arch sections formed therefrom, knuckle joints capable of limited pivotal or rocking movement. This mechanical flexibility of the joint compensates for or accommodates variations or irregularities in the earth strata to be supported by the arch sections and consequently the roadway support.

Each of the mechanically flexible joints between adjacent panels, it will be noted, comprises three webs A to C which gives the joint substantial structural strength (compression resistance) similar to much larger R.S.J.'s while providing a much lighter, in weight, construction.

Alternative jointing formations are illustrated in Figs. 6 to 9.

In Figs. 6 and 6A, the jointing formations are both channels 36, 37, the larger dimensioned channel, i.e. the outer channel, being 36 whereof its limbs 38 has outwardly diverging inner surfaces 39. The limbs 40 of the inner channel 37 have parallel outer surfaces 41 and are inturned as indicated at 42 to add strength to the joint. The joint is shown separated in Fig. 6 and made in Fig.

6A. The latter Fig. illustrates the aforesaid limited pivotal or rocking movement of the joint.

Referring to Fig. 7, the jointing formations are again channels 43 and 44.

The outer channel 43 has a short limb 45 and a long limb 46 with an inturned end 47 for strength. The inner surfaces 48 of the limbs 45, 46 are outwardly diverging. The inner channel 44 has two relatively short straight limbs 49 with parallel outer surfaces 50. It is considered that this arrangement of limbs 45, 46 and 49 facilitates entry of channel 44 into channel 43. It also provides for a narrower joint between adjacent arch sections.

In Fig. 8, the outer channel 51 has limbs 52 which are outwardly divergent and which are inwardly stepped at 53. The inner channel 54 has outwardly convergent limbs 55 with inturned ends 56 for strength. This configuration of channels 51, 54 provides the aforesaid limited pivotal or rocking movement.

Finally, in Fig. 9, the outer channel 57 again has limbs 58 with outwardly divergent inner surfaces 59. The inner channel 60, in this instance however, faces to one side of the panel as shown (either side is acceptable), and provides opposed parallel surfaces 61, 62 defined respectively by the outside surface of the base 63 of the channel and the outer ends of the limbs 64 of the channel.

In this configuration of channels there are three parallel webs Al, B1 and C1 to give the joint substantial structural strength as aforesaid (see Fig. 5).

An arch section is built up by connecting panels together at their securing sides 27A which are butted together (see Fig. 3) with bolt holes 29 in register, the securement being effected by bolts 65 and nuts 66 (Fig.

3A). Where slots 30 are provided these are also registered and securement is effected by an L-shaped cotter plate 67 with a slot 68 adjacent one end and a wedge 69 (Fig. 3C) for insertion in slot 68 to secure the panels together (Fig. 3B).

When the inner and outer jointing formations are interengaged as, for example, illustrated and described with reference to Fig. 5, there is provided, as will be manifest, an extremely strong and robust box section connection and once the mechanically flexible connection between adjacent arch sections has settled to compensate for or accommodate the earth strata variations or irregularities present the adjacent arch sections are rigidly locked together due to the settlement weight of the earth strata.

Adjacent arch sections may be temporarily bound or coupled together until the aforesaid settlement occurs although this is not considered an essential requirement to the stability of the underground roadway support of the present invention.

It is also, of course, possible for adjacent arch sections to be bound or coupled together during the life of the underground roadway support.

This binding or coupling can be effected in any convenient manner but Figs. 10 to 12 illustrate preferred releasable and re-usable clamping arrangements.

The jointing formations shown in these Figs.

are those of Fig. 5, namely an outer channel 31 and an inner box section 32.

The clamping arrangement of Fig. 10 comprises two L-shaped members 70, 71 pivoted together at 72 to define a U-clamp. A pair of links 73 are connected to the U-clamp at 72, one at each side of the U-clamp, and between the links is pivoted a handle 74 having, at its clamp-adjacent end, a cam 75 adapted to act on the adjacent L-member 71. A bowed spring 76 is connected to the L-member 71 and bears against the adjacent jointing formation, the channel 31 in this instance. This spring 76 copes with dimensional differences resulting from manufacturing tolerances in the panels and their jointing formations.

Downward movement of the handle 74 causes the cam 75 to urge the L-member 71 about its pivot 72 towards the L-member 70 thus binding the jointing formations 31, 32 together.

Upward movement of the handle 74 causes the cam 75 to move to permit the L-member 71 to relax from its forced abutment with the joint thus permitting removal of the clamping arrangement.

The presence of the spring 76 resists detachment of the clamping arrangement until it is positively withdrawn from the joint by a worker.

There will generally be several such clamping arrangements spaced along the length of each joint.

In the modified clamping arrangement of Fig.

11, the L-member 71 is stepped and recessed as indicated at 77 to engage the lower limb 33 of the channel 31 to ensure a precise and positive engagement of the clamping arrangement on the joint. Here it will be seen that the bowed spring 76 bears against the panel side 27B to which the box section 32 is welded.

The L-member 71 is formed at its apex with a hole 78 for hanging an article such as a tool for example from the clamping arrangement or for attaching an article to the latter or for hanging the latter in storage.

Finally, in Fig. 12, the clamping arrangement is held in place on an inter-arch section joint by a spring lock formed of wire and comprising a locking or clamping U-member 79 having inturned ends engaging in apertures defined by a U-member having arms 80 pivotally engaging the L-member 71 at 81 and integral with the arms 80 a lever portion 82. The dotted lines show the spring lock in clamping position while the dot-dash lines show the spring lock in released position.

It is to be understood that the cooperating surfaces of the interengaging jointing formations need not be as described above provided they are such as to permit the aforesaid limited pivotal or rocking movement whereby mechanical flexibility is achieved between adjacent arch sections to compensate for irregularities or variations in the supported earth strata and to cope with settlement of the latter.

For example the inner surfaces of the outer channel may be parallel and the outer surfaces of the inner box section or channel converging or diverging to give the required mechanical flexibility. Other configurations of adjacent surfaces may be employed provided mechanical flexibility is achieved.

Claims

1. A panel adapted to constitute a part of an arch section of an underground roadway support comprising a plurality of arch sections butted and coupled together, the panel being of rectangular configuration and having on two opposed sides formations adapted movably or adjustably to engage complementary formations on corresponding panels of adjacent arch sections to provide mechanically flexible connections therebetween.

2. A panel as claimed in claim 1, in which the formation on one side of a panel is a channel open outwards of the panel.

3. A panel as claimed in claim 2, in which the formation on the other side of the same channel is a box section adapted to engage within a channel formation of an adjacent panel to form, in effect, a knuckle joint.

4. A panel as claimed in claim 1, in which the formation on one side of a panel is a channel open outwards of the panel while the formation on the other side of the same panel is also a channel dimensionally smaller than said one channel whereby the other channel can be engaged within said one channel to form the knuckle joint.

5. A panel as claimed in claim 4, in which the other channel is also open outwards of the panel.

6. A panel as claimed in claim 4, in which the other channel opens to one side of the panel.

7. A panel as claimed in any one of claims 4 to 6, in which the said one channel which opens outwards of the panel has outwardly diverging inner faces while the box section or other channel has parallel outer faces or surfaces which abut the outwardly diverging faces to permit relative pivoting or rocking between engaged formations in the manner of a knuckle joint thus to permit joined panels, and consequently joined arch sections, to accommodate earth strata irregularities or variations.

8. A panel as claimed in any one of claims 5 to 7, in which the free ends of each inner channel of the joint are inturned to increase the strength of the joint.

9. A panel as claimed in claim 5, in which each inner channel of the joint is relatively shallow in its outward extension from the panel.

10. A panel as claimed in claim 9, in which each outer channel of the joint has one relatively short limb and one relatively long limb, the latter at its free end being inturned.

11. A panel as claimed in claim 1, comprising a rectangular frame of angle iron infilled with wire mesh with an inner formation, box section or channel, and an outer channel formation on two opposed sides and with the other two opposed fastening sides formed or provided with means allowing same to be releasably fastened to a similar side of an adjacent panel making up an arch section.

12. A panel as claimed in claim 11, in which each fastening side is provided with bolt holes so that adjacent butted panels constituting an arch section can be bolted together.

13. A panel as claimed in claim 11, in which each fastening side of a panel has elongate slots allowing two abutting adjacent panels in an arch section to be connected together by a wedge device or a cotter device.

14. An assembly of two side-by-side panels as claimed in any one of claims 1 to 13 wher eof adjacent complementary formations are interengaged comprising a clamping arrangement provided to hold the joint formations in interengagement.

15. An assembly as claimed in claim 14, in which the clamping arrangement comprises two pivotally interconnected parts defining a substantially U-shaped clamp with the limbs of the U adaped to embrace the joint and being locked against the joint by cam means.

16. An assembly as claimed in claim 15, in which instead of cam means the U-shaped clamp is locked against the joint by spring means.

17. An assembly as claimed in claim 16, in which the locking cam means or spring means is pivoted to the U-shaped clamp.

18. An assembly as claimed in any one of claims 15 to 17, in which one of the limbs of the U-shaped clamp supports a spring adapted to abut the joint and serving to compensate for variations in manufacturing tolerances in the panels and connected joint formations.

19. An assembly as claimed in any one of claims 15 to 18, in which the U-shaped clamp is recessed to engage a limb of the outer channel of the joint to ensure precise location of the clamp on the joint.

20. An arch section for an underground roadway support, the arch section being constituted by interconnected panels having opposed jointing formations as claimed in any one of claims 1 to 13.

21. An underground roadway support constituted by a plurality of arch sections as claimed in claim 20 coupled together by inner and outer interengaging joint formations to provide mechanical flexibility between adjacent arch sections.

22. An underground roadway support as claimed in claim 21 in which selected panels of adjacent arch sections are clamped together by clamping arrangements as claimed in any one of claims 14 to 19.