GB2075090A - Truss assemblies and plate beams for supporting mine roofs - Google Patents
Truss assemblies and plate beams for supporting mine roofs Download PDFInfo
- Publication number
- GB2075090A GB2075090A GB8113215A GB8113215A GB2075090A GB 2075090 A GB2075090 A GB 2075090A GB 8113215 A GB8113215 A GB 8113215A GB 8113215 A GB8113215 A GB 8113215A GB 2075090 A GB2075090 A GB 2075090A
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- Prior art keywords
- roof
- plate beam
- plate
- mine
- reinforcing rib
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- 230000000712 assembly Effects 0.000 title description 3
- 238000000429 assembly Methods 0.000 title description 3
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 58
- 230000000295 complement effect Effects 0.000 claims abstract description 6
- 239000011435 rock Substances 0.000 claims description 21
- 239000011347 resin Substances 0.000 claims description 5
- 229920005989 resin Polymers 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 3
- 230000004048 modification Effects 0.000 abstract 1
- 238000012986 modification Methods 0.000 abstract 1
- 230000015572 biosynthetic process Effects 0.000 description 13
- 238000005755 formation reaction Methods 0.000 description 13
- 238000005452 bending Methods 0.000 description 8
- 229910000831 Steel Inorganic materials 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 239000000853 adhesive Substances 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 3
- 229910001335 Galvanized steel Inorganic materials 0.000 description 2
- 238000004873 anchoring Methods 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 235000012489 doughnuts Nutrition 0.000 description 2
- 239000008397 galvanized steel Substances 0.000 description 2
- 238000005065 mining Methods 0.000 description 2
- 229910000746 Structural steel Inorganic materials 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000003137 locomotive effect Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D17/00—Caps for supporting mine roofs
- E21D17/01—Caps for supporting mine roofs characterised by the shape of the cap, e.g. of specified cross-section
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/006—Lining anchored in the rock
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D17/00—Caps for supporting mine roofs
- E21D17/02—Cantilever extension or similar protecting devices
- E21D17/03—Brackets for roof-supporting bars
Landscapes
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Roof Covering Using Slabs Or Stiff Sheets (AREA)
Abstract
An elongated plate beam (10) has a plurality of longitudinally extending downwardly directed ribs positioned in parallel spaced relation to form a pair of lateral ribs (18, 20) and a center reinforcing rib (22). The plate beam (10) is of a length to span the width of a mine passage and includes a top surface (26) for abutting the mine roof. Openings (30) are spaced along the length of the plate beam (10) and extend through the center reinforcing rib (22). A roof plate is positioned in abutting relation with the plate beam bottom surface (28) in overlying relation with each opening (30). Roof bolts extend through the roof plates and openings (30) into engagement with the walls of bore holes drilled in the mine roof. An enlarged end of each roof bolt bears against the respective roof plate to apply an upward force upon the plate beam (10) to position the plate beam in roof supporting relation with the mine roof over the entire width of the mine passage spanned by the plate beam. In a modification the roof plates each include a center rib positioned in complementary interengagement with the plate beam centre reinforcing rib to increase the surface to surface contact of the roof plates with the plate beam (10) to increase the bearing force applied by the plate beam to the mine roof. <IMAGE>
Description
SPECIFICATION
Truss assemblies and plate beams for supporting mine roofs
This invention relates to truss assemblies and plate beams for supporting mine roofs.
In underground operations, such as mining or excavating, it is a well known practice to support unsupported rock formations or roofs by wooden beams or cross timbers that are placed across a mine passage under the unsupported roof. Vertical uprights or props are positioned at the ends of each wooden beam or cross timber and extend upwardly from the mine floor to support the wooden beam or cross timber against the roof. Wooden beams having a dimension of 76mm X 203mm (3 inches by 8 inches) and up to 4.9m (1 6 feet) in length are commonly supported in this manner to prevent roof falls or cave-ins. A disadvantage of this arrangement is that the vertical props are positioned at the mine sidewalls and reduce the width of the mine passageay available for the passage of mine cars, locomotives, mining machines, and other equipment through the mine passage.
As an alternative to supporting a mine roof by vertical props and cross beams, it is known as disclosed in United States Patent 2,667,037 to eliminate the vertical props and hold the cross beams in place by anchoring the cross beams with expansion bolts. The bolts are inserted in holes drilled up into the mine roof and are tensioned to bear against the cross beams and hold them firmly against the mine roof. The above patent discloses cross beams made of either wood or structural steel with the bolts secured in the rock formation by either an expansion shell or a quicksetting cement.
It is also well known in the art to eliminate the cross beams entirely and use roof plates spaced a preselected distance apart across the roof of the mine passage. With this method of mine roof support, elongated bolts are inserted in holes bored into the rock formation of the roof. The bolts are secured by either engagement of an expansion shell on the end of the bolt with the rock formation or adhesively bonding the bolt by a thermosetting resin injected into the bore hole. Upon setting of the resin, the bolt is united with the rock formation. A roof plate is retained on the bolt and bears against the face of the rock formation.
In the case of the mechanical anchor method the bolt is rotated to expand a shell into gripping engagement with the rock formation. Rotating the bolt having an expansion shell expands the shell to engage the rock formation. The bolt is thus tensioned and the rock strata is compressed. By adhesively bonding bolts to the rock formation, the adhesive penetrates into the rock to adhesively unite fissures in the rock and to firmly hold the bolt in the bore' hole. The bolt, however, is not tensioned when adhesively bonded to the rock formation.
Roof plates do not completely span the mine roof across a mine passage but are spaced a preselected distance apart in accordance with a center plane. Therefore, gaps of unsupported mine roof are formed between the spaced apart roof plates. Thus the roof plate system of supporting a roof support does not provide the continuous span of roof support from sidewall to sidewall provided by the conventional cross beam system.
It is known to combine the roof plate system with the continuous span system by replacing the timber beam with a galvanized steel roof mat having a preselected length and a width that generally ranges between 127mm and 254mm (5 and 10 inches) depending on the size of the roof plate which abuts against the mat. The steel mat is generally a 14 or 16 gauge galvanized steel. Bolt holes are positioned at selected intervals along the length of the mat in accordance with a predetermined distance between bolt centers.
A principal advantage of the roof mat is that it is substantially lighter in weight than a comparable length of timber beam. This permits ease of installation and decreases the time required to complete the roof bolting process.
Steel roof mats also are not subject to deterioration as are wooden beams.
While it has been suggested to support a mine roof by bolting wooden and steel cross beams to the mine roof and to use steel mat with roof bolts to provide a continuous span of roof support across a mine passage, the prior art roof support systems do not provide a non-wooden cross beam that can withstand the bending loads encountered when held in contact with the mine roof by roof plates bolted to the mine roof. Therefore, there is need to provide a mine roof truss system that utilizes non-wooden cross beams in conjunction with roof plates and bolts to provide support of a section of the mine roof in a continuous span without bending under the load of the mine roof.
According to the invention there is provided a truss assembly for supporting a roof of an underground mine, the truss assembly comprising an elongated plate beam having a plurality of longitudinally extending downwardly directed ribs, said ribs being disposed in spaced relation to form a pair of lateral ribs and a center reinforcing rib positioned between said pair of lateral ribs, said plate beam having a top surface abutting or capable of abutting a mine roof and a bottom surface, a plurality of openings spaced longitudinally along the length of said plate beam and extending through said center reinforcing rib, and anchor means extending or capable of extending through each of said plate beam openings into the mine roof for securely engaging said plate beam top surface in abutting relation with the mine roof, said anchor means each having a first end portion anchored or capable of being anchored within the mine roof and a second end portion bearing against or capable of bearing against said plate beam bottom surface so that said plate beam exerts a roof supporting force upwardly upon the mine roof along the length of said plate beam.
The invention also provides a plate beam for supporting a mine roof, the plate beam comprising an elongated channel shaped member, a plurality of longitudinally extending ribs projecting from said channel shaped member, said ribs being disposed in spaced relation to form a pair of lateral ribs and a center reinforcing rib positioned between said pair of lateral ribs, and a plurality of openings spaced longitudinally along the length of said channel shaped member and extending through said center reinforcing rib, said channel shaped member having a top surface extending the length of said channel shaped member and capable of being positioned in abutting relation with a mine roof with said ribs extending downwardly from the mine roof.
According to preferred embodiments described in more detail below, the center reinforcing rib is connected to the oppositely positioned lateral ribs by web sections of the plate beam. The web sections each include an upstanding panel and a horizontal panel of a preselected width that forms the top and bottom surfaces of the plate beam. Inner ends of each horizontal panel are formed integral with the center reinforcing rib. Outer ends of each horizontal panel are connected, in turn, to upper ends of the upstanding panel that extends in a generally downwardly angled direction from the horizontal panel when the plate beam is positioned in abutting relation with the mine roof. A lower end of each upstanding panel is formed integral with a respective lateral rib.
Thus, in the preferred embodiments, the plate beam has a generally inverted U-channel shaped configuration. The pair of lateral ribs are vertically spaced a preselected distance below the center reinforcing rib. The center reinforcing rib extends downwardly from the top surface, which is intended to abut a mine roof, between the pair of lateral ribs.
Preferably, a roof plate is positioned in abutting relation with the plate beam bottom surface opposite the top surface, which abuts the mine roof, overlying each of the openings in the plate beam. The roof plate includes a center hole. A mine roof bolt comprising the anchor means extends through the aligned hole and opening in the roof plate and plate beam. The upper end of the roof bolt is secured to the rock formation of the mine roof by either an expansion shell or a quick setting resin to firmly hold the plate beam in compressive relation with the mine roof to support the mine roof. The openings in the plate beam are spaced a predetermined distance apart to provide selective spacing of the roof plates on the plate beam.
In one embodiment of the present invention the openings in the plate beam along the center reinforcing rib are elongated at least the length of a roof plate to permit the roof plate to abut in surface to surface contact the bottom surface of the plate beam.
In another embodiment of the present invention the openings in the plate beam have a dimension or diameter substantially equal to the diameter of the roof bolt. The roof plates are also provided with center reinforcing ribs positioned for complementary interengagement with the plate beam center reinforcing rib. This arrangement increases the surface to surface contact between the roof plates and the plate beam for urging the plate beam substantially along its entire length into roof supporting relation with the mine roof.
The preferred embodiments of the present invention described below provide a mine roof truss assembly formed by a rib reinforced plate beam supported in roof engaging relation along its entire length by roof plates abutting the plate beam and anchored securely in the mine roof. The plate beam can be used as a substitute for wooden cross timbers to support a mine roof, the plate beam being structured to withstand bending forces applied thereto by the unsupported strata of a mine roof. The center reinforcing rib provides the plate beam with increased structural strength to resist bending along its length.In one embodiment, the plate beam has a center reinforcing rib arranged to receive in complementary interengagement a center reinforcing rib of a roof plate to increase the surface to surface contact between the mine roof plate and the plate beam which is held against the mine roof by the mine roof plate.
The invention will now be further described, by way of illustrative and non-limiting example, with reference to the accompanying drawings, in which:
Figure 1 is a fragmentary, schematic isometric view of a mine roof plate beam according to a first embodiment of the invention for supporting an unsupported section of a mine roof, illustrating a center reinforcing rib and a pair of lateral ribs of the plate beam;
Figure 2 is a fragmentary sectional view in elevation of the mine roof plate beam, illustrating one of a plurality of roof plates abutting the plate beam and anchored in a mine roof by a roof bolt to firmly hold the plate beam against the mine roof;;
Figure 3 is a plan view of the mine roof plate beam connected to the mine roof by the roof plate shown in Fig. 2, illustrating an elongated opening through the center reinforcing rib and plate beam for the roof bolt and the roof plate abutting the plate beam around the opening;
Figure 4 is a schematic sectional view of the mine roof plate beam, a roof plate, and roof bolt taken along line IV-IV of Fig. 3;
Figure 5 is a fragmentary, schematic isometric view similar to Fig. 1, illustrating another embodiment of the present invention in which each roof plate is provided with a complementary reinforcing rib arranged to interengage the plate beam center reinforcing rib;
Figure 6 is a schematic exploded view of the assembly of the mine roof plate beam, the roof plate, and roof bolt shown in Fig. 5;;
Figure 7 is a plan view of the assembled mine roof plate beam, roof plate, and roof bolt shown in Fig. 5; and
Figure 8 is a schematic sectional view of the assembled mine roof plate beam, roof plate, and roof bolt taken along line Vill-Vill of Fig. 7.
Referring to the drawings and particularly to
Figs. 1 and 5 there is illustrated an elongated mine roof plate beam generally designated by the numeral 10 that when used in conjunction with a plurality of mine roof plates 1 2 and roof bolts 1 4 forms a roof truss assembly generally designated by numeral 1 6 for supporting the roof of an underground mine. For purposes of illustration only a singls mine roof plate 1 2 is shown with the plate beam 1 0.
The mine roof plate beam 10 extends transversely across a mine passage at the mine roof in a continuous span from sidewall to sidewall ot the mine passage. A first embodiment of the roof truss assembly 1 6, in accordance with the present invention, is illustrated in Figs. 1-4. A second embodiment of the roof truss assembly is illustrated in Figs. 5-8.
Now referring to Fig. 1 in which like numerals refer to like parts in Figs. 1-8, the plate beam 10 is elongated and has a preselected length as predetermined by the width of a mine passage, i.e. the width between the sidewalls or ribs of a mine passage or mine entry. To this end the plate beam 10 may have a length for example of 4.9m (16 feet).
The plate bearn 10 has a channel shaped configuration formed by a plurality of longitu- dinally extending ribs that include a pair of lateral ribs 1 8 and 20 and a center reinforcing rib 22 positioned between -the pair of lateral ribs 18 and 20.The ribs 18 27 are positioned in spaced parallel relation and extend the length of the plate beam 1 0. With the plate beam 10 in its operative position abutting a mine roof, the ribs 18-22 extend outwardly from the mine roof thereby forming a generally inverted U-shaped recess generally designated by the numeral 24 in which the recess 24 extends the length of the plate beam 10. The plate beam 1L includes a top surface 26 designed to engage in abutting relation the surface of a mine roof and a bottom surface 28 that is designed to receive the roof plates 1 2.
The plate beam 10 includes along its entire length a plurality of elongated openings 30, only one of which is illustrated in Figs. 1-3.
The openings 30 or slots are spaced longitudinally the entire length of the plate beam 10 and extend through the center reinforcing rib 22. The openings 30 have a preselected length, as illustrated in Fig. 2, to permit the roof plate 1 2 to be positioned in abutting relation with the bottom surface 28 of the plate beam 10 without obstruction by the center reinforcing rib 22.
The roof plates 1 2 may be of either a square or rectangular configuration as shown in Fig. 2, and may be of the doughnut-type as illustrated in Figs. 2-4. However, it should be understood that any conventionally known type of mine roof support or bearing plate can be used or adapted for use with embodiments of the present invention.
The representative roof plasm 1 2 shown in Fis. 2-4 includes a center opening (not shown) thorough which the roof bolt 14 LiC ex- tends. As well known in the art, the roof bolt 14 has an elongated shank 32 of a prese elected length and an enlarged end portion 34 that serves to retain the bolt 14 on the roof plate 1 2. The shank portions 32 of the bolts 14 are inserted in holes previously drilled in a mine roof 36, illustrated in Fig. 2, at suitable spacings.
The upper ends of the bolt shank portions 32 are not shown, and it should be understood that in one embodiment expansion shells, as disclosed in United States Patent 4,160,614, are used on the ends of the bolt shank portions to grip the wall of the drilled bore holes at the top ends of the holes. The expansion shell, after being positioned in the drilled bore hole, is expanded by rotating the bolt enlarged end portion 34. This places the roof bolt 1 4 in tension and thereby applies compressive forces upon the strata of the rock formation above the mine passage. Also, as illustrated in Fig. 2, a washer 38 is positioned in abutting relation with the bolt enlarged portion 34 between the enlarged end portion 34 and the recessed portion formed by a doughnut embossment 35 surrounding the center hole of the roof plate 1 2.
It should also be understood, in accordance with the present invention, that the bolt 14 may be adhesively bonded in the bore hole drilled in the mine roof. As illustrated and described in United States Patents 3,324,662 and 3,394,527 the components of the bonding material are advanced into the bore hole ahead of the roof bolt 14. When the roof bolt 1 4 or rod is rotated the components of the adhesive material are admixed and penetrate into the surrounding rock formation to adhesively unite the rock strata and to firmly hold the bolt 1 4 in position in the bore hole. The adhesive mixture fills the annulus between the bore hole and the roof bolt 14 along a substantial length of the bolt 14.
In this manner the bolt 14 is securely anchored in the mine roof but is not maintained in tension as is the case with a roof bolt mechanically anchored by an expansion shell in the mine roof. Known anchor systems that combine both expansion shells and a quick-setting resin can be used or adapted for use in embodiments of the present invention.
However, with ail the available methods of anchoring the roof bolts 14 in the mine roof 36, the roof plate 1 2 bears against the plate beam bottom surface 28 to maintain the plate beam upper surface 26 in abutting relation with the mine roof 36. With this arrangement the plate beam 10 exerts a roof supporting force upon the mine roof 36 the entire length of the plate beam 1 0. It should also be understood that the openings 30 in the plate beam 10 can be dimensioned to receive the roof bolt enlarged end portion 34 to secure the plate beam 10 to the mine roof 36 without the provision of a roof plate 1 2.
The center reinforcing rib 22 and the lateral ribs 1 8 and 20 are preferably positioned in spaced parallel relation where the center reinforcing rib 22 is connected to the oppositely positioned lateral ribs 1 8 and 20 by web sections generally designated by the numerals 40 of the plate beam 10. The web sections 40 each include an upstanding panel 42 and the substantially horizontal panel 44 that has a preselected whip that forms the top and bottom surfaces 26 and 28 of the plate beam 10. As illustrated in Figs. 1 and 4, the center reinforcing rib number 22 is generally Vshaped and extends downwardly from the mine roof 36 when the plate beam top surface 26 is positioned in abutting relation with the mine roof 36.
The web horizontal panels 44 each include inner ends 46 formed integral with the V legs of the center reinforcing rib 22. The outer end 48 of each web horizontal panel 44 is connected to the upper end of the respective upstanding panel 42. Each of the web upstanding panels 42 extends in a generally downwardly angled direction from the respective horizontal panel 44 when the plate beam top surface 26 is positioned in abutting relation with the mine roof 36. The lower end of each upstanding panel 42 is formed integral with a respective lateral rib 1 8 and 20.
As illustrated in Fig. 4 the lateral ribs 1 8 and 20 are also generally U-shaped. The lateral ribs 1 8 and 20 include free end portions 50 that extend upwardly and outwardly from the web upstanding panels 42.
With the above described arrangement the plate beam 10 has a generally inverted Uchanneled shaped configuration where the pair of lateral ribs 1 8 and 20 are vertically spaced a preselected distance below the center reinforcing rib 22. This facilitates positioning the bolt enlarged end portion 34 in the recess 24 to protect the bolt enlarged end portion 34 from being sheared off by contact with a piece of equipment moving through the mine passage. Also with the illustrated and described configuration of the rib reinforced, recessed plate beam 10, a low profile mine roof plate beam is provided making available more head room in the mine passage in comparison with the head room reduced by - conventional wooden timbers and cross beams where the bolt end portions protrude from the bottom surface of the cross beam.
An exposed bolt end portion is subject to being sheared off if contacted with sufficient force by equipment traveling through the mine passage beneath the cross beam.
As illustrated in Figs. 1-3 the openings 30 in the center reinforcing rib 22 are sufficiently elongated to permit the roof plates 1 2 to abut in surface contact the length of the roof plate the bottom surface 28 of the plate beam 1 0.
In this manner a conventional roof plate can be used in conjunction with the plate beam 10 having the V-shaped center reinforcing rib 22. The anchored roof plate 1 2 exerts an upward force upon the plate beam 10 to urge the plate beam 10 substantially along its entire length into roof supporting relation with the mine roof 36. In this manner the plate beam 10 provides a continuous span of roof support across an unsupported section of the mine passage.
The center reinforcing rib 22 has been found to substantially increase the structural strength of the plate beam 10 to resist the bending stresses applied to the plate beam 10 by the unsupported mine roof. In tests conducted with a 4.9m (16 foot) plate beam it has been found that the plate beam 10 of the present invention having the center reinforcing rib 22 has the equivalent strength of a 76mm X 203mm (3 inch X 8 inch) wooden timber. However, the plate beam 10 has a lower profile than a 76mm X 203mm (3 inch X 8 inch) wooden timber and protectively positions the bolt end portion 34 within the recess 24. This prevents the bolt end portion 34 from being sheared off.
A further advantage of the plate beam 10 over the conventional wooden timber and other known types of beam supports is that the plate beam 10 is designed to yield under the stresses exerted by an unsupported mine roof before it fails. A wooden timber does not yield before it fails, but cracks without giving advance warning that its load limit is about to be exceeded. The plate beam 10 has an ultimate strength to resist bending comparable to that of a conventional wooden timber but has a substantially greater factor of safety because it yields before it ultimately fails, thereby giving advance warning of a potential roof fall or cave-in.
As illustrated in another embodiment of the roof plate beam 10 in Figs. 5-8 the plate beam 10 is provided with a generally circular opening 52 having a dimension substantially equal to the diameter of the roof bolt 14. In accordance with the second embodiment of the present invention, the roof plate beam 10 is used in conjunction with a roof plate 1 2 having center reinforcing ribs 54 that extend along the longitudinal axis of the plate 1 2.
The roof plate center reinforcing ribs 54 extend outwardly from a doughnut embossment 56 surrounding a center hole 58 in the roof plate 14.
In assembling the roof plate 1 2 on the roof plate beam 10, as illustrated in Fig. 6, the center reinforcing ribs 54 of the roof plate 1 2 are positioned in parallel overlying alignment with the plate beam center reinforcing rib 22.
The roof bolt 14 extends through the aligned opening 52 and hole 58 into the mine roof.
The washer 38 on the roof bolt 1 4 surrounds the roof plate hole 58 and receives the bolt enlarged end portion 34.
Once the bolt 1 4 is securely anchored in the drilled bore hole of the mine roof, the plate beam and roof plate center reinforcing ribs 22 and 54 are urged into overlying abutting relation. Thus it will be apparent that the roof plate center reinforcing ribs 54 are constructed for complementary interengagement with the plate beam center reinforcing rib 22. This arrangement increases the surface to surface contact between the roof plate 1 2 and the plate beam 1 0.
The roof plate 1 2 with the ribs 54 has an increased area of contact with the plate beam 10. This increases the bearing force exerted by the roof plate 1 2 upon the plate bearn 10.
By increasing the bearing force upon the plate beam 10, the plate beam 10 is maintained in greater contact with the mine roof 36. The surface contact of the plate beam 10 with the mine roof 36 is substantially along the entire length of the plate beam 1 0. Consequently a continuous span of roof support is provided by the plate beam 10 from sidewall to sidewall of the mine passage.
By ensuring that the plate beam 10 is substantially maintained in contact with the surface of the mine roof 36 along its entire length, uniform roof support is provided along the continuous span of the plate beam 10.
This enables the plate beam 10 to more effectively resist concentrated bending stresses applied at specific points by the rock strata on the plate beam 1 0. This feature, in addition to the provision of the plate beam center reinforcing rib 22, substantially increases the structural strength of the low profile plate beam 10 to resist bending stresses applied thereto by unsupported rock strata. Thus a mine roof truss assembly 1 6 is formed that is easily installed to provide a mine roof control having a greater factor of safety than encountered with the conventionally known roof support systems and particularly cross beam and wooden timber supports which are subject to deterioration by rotting and the like.
Claims (14)
1. A truss assembly for supporting a roof of an underground mine, the truss assembly comprising an elongated plate beam having a plurality of longitudinally extending downwardly directed ribs, said ribs being disposed in spaced relation to form a pair of lateral ribs and a center reinforcing rib positioned between said pair of lateral ribs, said plate beam having a top surface abutting or capable of abutting a mine roof and a bottom surface, a plurality of openings spaced longitudinally along the length of said plate beam and extending through said centere reinforcing rib, and anchor means extending or capable of extending through each of said plate beam openings into the mine roof for securely engaging said plate beam top surface in abutting relation with the mine roof, said anchor means each having a first end portion anchored or capable of being anchored within the mine roof and a second end portion bearing against or capable of bearing against said plate beam bottom surface so that said plate beam exerts a roof supporting force upwardly upon the mine roof along the length of said plate beam.
2. A truss assembly according to claim 1, wherein said anchor means includes a roof plate having a center hole aligned or capable of being aligned with a respective one of said openings in said plate bearn, and a roof bolt extending through or capable of extending through said aligned hole and opening, said roof bolt having an inner end enchored within or capable of being anchored within a bore hole in the mine roof and an outer end abutting against or capable of abutting against said roof plate to urge said roof plate into abutting relation with said bottom surface so that said top surface bears against the mine roof to provide a continuous span of roof support along the length of said plate beam.
3. A truss assembly according to claim 2, which includes a center rib positioned on said roof plate and extending on opposite sides of said center hole, the roof plate center reinforcing rib having a configuration capable of being positioned in complementary interengagement with said plate beam center reinforcing rib to increase the surface to surface contact between said roof plate and said plate beam.
4. A truss assembly according to claim 1, claim 2 or claim 2, which includes a channel shaped recess extending the length of said plate beam between said pair of lateral ribs, said center reinforcing rib being positioned within said channel shaped recess.
5. A truss assembly according to claim 1, wherein said anchor means includes an elongated bolt extending through or capable of extending through each of said openings in said plate beam and into the mine roof, said elongated bolt having an enlarged end applying or capable of applying an upward bearing force upon said plate beam bottom surface and an upper end positioned or capable of being positioned in the mine roof, and an expansion shell positioned on said bolt upper end and operable upon rotation of said bolt to expand into gripping engagement with the rock strata of the mine roof to thereby anchor said bolt in the mine roof.
6. A truss assembly according to claim 1, wherein said anchor means includes an elongated bolt extending through each of said openings in said plate beam and into the mine roof, said elongated bolt having an enlarged end applying an upward bearing force upon said plate beam bottom surface and an upper end positioned in the mine roof, and a resin material mixed and cured in surrounding relation with said bolt enlarged end in the mine roof to anchor said bolt to the rock strata of the mine roof.
7. A truss assembly according to any one of the preceding claims, which includes a plate web section connecting said center reinforcing rib to each of said pair of lateral ribs, said plate web section including a horizontal panel forming said plate beam top and bottom surfaces and an upstanding panel, said horizontal panel being formed integral at one end with said center reinforcing rib and at the opposite end with one end of said upstanding panel, and each of said lateral ribs being formed integral with the opposite end of said respective upstanding panel so that said lateral ribs are vertically spaced a preselected distance from said center reinforcing rib.
8. A truss assembly according to claim 7, wherein said upstanding panel is positioned at an angle with respect to said horizontal panel and said upstanding panel is arranged to extend downwardly from said horizontal panel when said plate beam top surface is positioned in abutting relation with a mine roof.
9. A truss assembly according to any one of the preceding claims, wherein said center reinforcing rib has a V-shaped configuration extending downwardly from said plate beam bottom surface to provide a vertical dimension between said bottom surface and said lateral ribs greater than the vertical dimension between said bottom surface and said center reinforcing rib.
10. A truss assembly for supporting a roof of an underground mine, the truss assembly being substantially as herein described with reference to Figs. 1 to 4 or Figs. 5 to 8 of the accompanying drawings.
11. A plate beam for supporting a mine roof, the plate beam comprising an elongated channel shaped member, a plurality of longitudinally extending ribs projecting from said channel shaped member, said ribs being disposed in spaced relation to form a pair of lateral ribs and a center reinforcing rib positioned between said pair of lateral ribs, and a plurality of openings spaced longitudinally along the length of said channel shaped member and extending through said center reinforcing rib, said channel shaped member hav- ing a top surface extending the length of said channel shaped member and capable of being positioned in abutting relation with a mine roof with said ribs extending downwardly from the mine roof.
12. A plate beam according to claim 11, wherein said lateral ribs are positioned in spaced parallel relation and vertical spaced from said top surface to form a channel shaped recess extending the length of said member, and said center reinforcing rib is positioned within said channel shaped recess.
1 3. A plate beam according to claim 11 or claim 12, which includes a web section connecting said center reinforcing rib to each of said pair of lateral ribs, said web section including a horizontal panel forming said channel shaped member top surface and an upstanding panel, said horizontal panel being formed integral at one end with one end of each of said upstanding panels, and each of said lateral ribs being formed integral with the opposite end of said respective upstanding panel so that said lateral ribs are vertically spaced a preselected distance from said center reinforcing rib.
14. A plate beam according to claim 13, wherein said upstanding panel is positioned at an angle with respect to said horizontal panel and said upstanding panel is arranged to extend downwardly from said horizontal panel when said top surface is positioned in abutting relation with a mine roof.
1 5. A plate beam according to any one of claims 11 to 14, wherein said center reinforcing rib has a V-shaped configuration extending downwardly from said top surface to provide a vertical dimension between said top surface and said lateral ribs greater than the vertical dimension between said top surface and said center reinforcing rib.
1 6. A plate beam for supporting a mine roof, the plate beam being substantially as herein described with reference to Figs. 1 toX or Figs. 5 to 8 of the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US14580280A | 1980-05-01 | 1980-05-01 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2075090A true GB2075090A (en) | 1981-11-11 |
| GB2075090B GB2075090B (en) | 1984-04-18 |
Family
ID=22514621
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8113215A Expired GB2075090B (en) | 1980-05-01 | 1981-04-29 | Truss assemblies and plate beams for supporting mine roofs |
Country Status (4)
| Country | Link |
|---|---|
| AU (1) | AU6967981A (en) |
| CA (1) | CA1168459A (en) |
| GB (1) | GB2075090B (en) |
| ZA (1) | ZA812674B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU721400B2 (en) * | 1998-01-14 | 2000-07-06 | Fci Holdings Delaware, Inc. | Channel and bearing plate assembly |
| CN102200020A (en) * | 2011-04-26 | 2011-09-28 | 山东大学 | Yielding type special-shaped beam anchor rope truss roadway support system |
| US20120034037A1 (en) * | 2010-08-06 | 2012-02-09 | Fci Holdings Delaware, Inc. | Curved Mine Roof and Rib Support |
| CN108361053A (en) * | 2018-03-13 | 2018-08-03 | 山东里能鲁西矿业有限公司 | A kind of roadway support front cantilever apparatus and method |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU585675B2 (en) * | 1985-12-03 | 1989-06-22 | Arnall's Engineering Pty. Limited | Service line roof strap |
| WO1993008371A1 (en) * | 1991-10-16 | 1993-04-29 | PINK, Elizabeth, Anne | Support device for services |
| AU668524B2 (en) * | 1991-10-16 | 1996-05-09 | Buffier, Brian Lesley Joseph | Support device for services |
| CN102518459B (en) * | 2011-12-15 | 2014-04-30 | 湖南科技大学 | High-strength anchor rope steel channel beam capable of yielding automatically for deep well coal roadways |
| CN108119173B (en) * | 2017-12-29 | 2020-04-28 | 山东里能鲁西矿业有限公司 | Self-moving type telescopic front canopy and supporting method thereof |
-
1981
- 1981-04-16 CA CA000375647A patent/CA1168459A/en not_active Expired
- 1981-04-21 AU AU69679/81A patent/AU6967981A/en not_active Abandoned
- 1981-04-23 ZA ZA00812674A patent/ZA812674B/en unknown
- 1981-04-29 GB GB8113215A patent/GB2075090B/en not_active Expired
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU721400B2 (en) * | 1998-01-14 | 2000-07-06 | Fci Holdings Delaware, Inc. | Channel and bearing plate assembly |
| US6146056A (en) * | 1998-01-14 | 2000-11-14 | Jennmar Corporation | Channel and bearing plate assembly |
| US20120034037A1 (en) * | 2010-08-06 | 2012-02-09 | Fci Holdings Delaware, Inc. | Curved Mine Roof and Rib Support |
| CN102200020A (en) * | 2011-04-26 | 2011-09-28 | 山东大学 | Yielding type special-shaped beam anchor rope truss roadway support system |
| CN108361053A (en) * | 2018-03-13 | 2018-08-03 | 山东里能鲁西矿业有限公司 | A kind of roadway support front cantilever apparatus and method |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2075090B (en) | 1984-04-18 |
| ZA812674B (en) | 1982-06-30 |
| AU6967981A (en) | 1981-11-05 |
| CA1168459A (en) | 1984-06-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |