Method of supporting mine walls and installing a mine stopping

Information

  • Patent Grant
  • 6715961
  • Patent Number
    6,715,961
  • Date Filed
    Friday, February 1, 2002
    23 years ago
  • Date Issued
    Tuesday, April 6, 2004
    20 years ago
Abstract
A method of supporting opposite first and second walls of a mine passageway includes providing an elongate beam having opposite first and second ends and a longitudinal axis. The beam is configured to have substantial columnar strength for bearing a substantial longitudinal load applied to the beam generally longitudinally of the beam and substantial bending strength for bearing a substantial transverse load applied to the beam generally transversely of the beam. The method further includes selecting first and second locations on the first and second walls, respectively, providing suitable areas for supporting the first and second walls, and positioning the first end of the beam at the first location and the second end of the beam at the second location so that the beam extends between the first and second walls of the mine passageway.
Description




BACKGROUND OF THE INVENTION




This invention relates to a method of supporting mine walls in a mine passageway and to a method of installing a mine stopping.




Mine stoppings are widely used in mine passageways to stop off the flow of air therethrough. A conventional metal stopping shown in U.S. Pat. No. 4,483,642 comprises a plurality of elongate extensible panels


7


extending vertically from the floor to the roof of the mine passageway and positioned in side-by-side relation across the passageway. (See FIG. 1 of the patent.) The mine walls of the passageway tend to shift over time (especially coal mine walls), generally moving closer together from the weight of the overburden. Shifting tends to cause cracking and sloughing off of large portions of the mine walls, which can result in the leakage of air past the aforementioned stopping. Such leakage increases the operating cost of a mine, since more fresh air must be pumped into the mine.




A conventional metal stopping as disclosed in the aforementioned patent is typically constructed by embedding ends of elongate bars


3


in the mine walls. The bars include two or more overlapping steel angles which are slidable relative to one another and held in place by ties or tape. (See

FIG. 2

of the patent). The telescoping panels are positioned side-by-side so that they are in contact with the bars. An upper member


17


of each telescoping panel


7


is extended relative to a lower member


13


of the panel so that it engages the roof of the mine, and the upper and lower members are held in place by wire ties


9


secured to the bars


3


.




The elongate bars of the conventional metal stopping provide little or no support to the mine walls. The ends of the bars are typically either embedded in holes in the walls or placed on shelf formations on the walls. In either case, the cross-sectional area presented by the ends of the bars is too small to provide significant lateral support to the walls. Moreover, since the frictional forces exerted by the wire ties is relatively small, the bars will slide relative to one another when subjected to relatively small compressive loads (e.g., 500 pounds are less). These loads are not sufficient to provide significant support to the walls, as during a mine convergence. Some prior art angles are bolted together so that the angles cannot slide. (See FIG. 1 of U.S. Pat. No. 2,729,064.) However, such non-yielding angles simply penetrate the mine walls upon convergence, thereby providing little or no support to the mine walls.




SUMMARY OF THE INVENTION




Among the several objects of this invention may be noted the provision of a method that inhibits cracking and sloughing off of opposing mine walls; the provision of such a method that reduces ventilation air leakage in the mine; the provision of such a method that provides yieldable support to the mine walls; the provision of such a method that is cost effective; and the provision of such a method which involves the installation of a mine stopping.




The present invention is also directed to a method of installing a mine stopping that is easy to perform, and the provision of such a method wherein the mine stopping is adapted to withstand significant loading caused by air pressure and by convergence of the mine walls.




In one aspect, the invention is directed to a method of supporting opposite first and second walls of a mine passageway including providing an elongate beam having opposite first and second ends and a longitudinal axis. The beam is configured to have substantial columnar strength for bearing a substantial longitudinal load applied to the beam generally longitudinally of the beam and substantial bending strength for bearing a substantial transverse load applied to the beam generally transversely of the beam. The method further includes selecting first and second locations on the first and second walls, respectively, providing suitable areas for supporting the first and second walls, and positioning the first end of the beam at the first location and the second end of the beam at the second location so that the beam extends between the first and second walls of the mine passageway. The method also includes securing the first end of the beam to the first wall at the first location and the second end of the beam to the second wall at the second location so that the beam is positioned for supporting the first and second walls.




In another aspect of the invention, a method of supporting opposite first and second walls of a mine passageway includes providing an elongate beam having opposite first and second ends and a longitudinal axis wherein each end of the beam has a bearing member thereon for bearing against a respective wall. The bearing member has a bearing surface area greater than the cross-sectional area of the beam. The beam is configured to have columnar strength for bearing a longitudinal load of at least 800 pounds applied to the beam generally longitudinally of the beam and bending strength for bearing a transverse load caused by an air pressure of at least two inches water gauge and applied to the beam generally transversely of the beam. The beam includes a central beam and a slide member slidable relative to the central beam. The method further includes selecting first and second locations on the first and second walls, respectively, providing suitable areas for supporting the first and second walls. The first end of the beam is positioned at the first location and the second end of the beam is positioned at the second location by sliding the slide member relative to the central beam to adjust the length of the beam to correspond to the distance between the first and second walls so that the beam extends between the first and second walls of the mine passageway. The bearing member of the first end of the beam is secured to the first wall at the first location and the bearing member at the second end of the beam is secured to the second wall at the second location so that the beam is positioned for supporting the first and second walls.




In yet another aspect of the invention, a method of installing a mine stopping between the first and second walls of a mine passageway includes providing an elongate beam having opposite first and second ends and a longitudinal axis. The beam is configured to have substantial columnar strength for bearing a substantial longitudinal load applied to the beam generally longitudinally of the beam and substantial bending strength for bearing a substantial transverse load applied to the beam generally transversely of the beam. The first end of the beam is positioned at a first location on the first wall and the second end of the beam is positioned at a second location on the second wall so that the beam extends between the first and second walls of the mine passageway. The method further includes securing the first end of the beam to the first wall at the first location and the second end of the beam to the second wall at the second location so that the beam is positioned to take a substantial longitudinal load. A stopping is erected to extend between the first and second walls after the beam has been secured to the walls. The erecting step includes securing the stopping to the beam so that a load applied to the stopping due to an air pressure differential across the stopping is transferred to the beam as a transverse load.




Other objects and features will be in part apparent and in part pointed out hereinafter.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a fragmentary perspective view of a mine stopping in a mine with the stopping having a plurality of reinforcing braces secured thereto with optional side channels shown exploded;





FIG. 2

is a perspective view of a reinforcing brace;





FIG. 3

is side elevation view of a reinforcing brace;





FIG. 4

is an enlarged sectional view of the reinforcing brace taken alone the line


4





4


of

FIG. 3

;





FIG. 5

is a perspective view of a stopping with a door unit with one side channel shown exploded;





FIG. 6

is an enlarged fragmentary sectional view taken along the line


6





6


of

FIG. 5

showing details of a lintel;





FIG. 7

is an enlarged fragmentary view of the lintel and column shown in

FIG. 5

;





FIG. 8

is a enlarged fragmentary end sectional view of another embodiment of the brace and stopping system;





FIG. 9

is an enlarged fragmentary sectional view of the stopping system taken along the line


9





9


of

FIG. 7

; and





FIG. 10

is a fragmentary perspective view of a brace of another embodiment.











Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.




DESCRIPTION OF THE PREFERRED EMBODIMENT




Referring to

FIG. 1

, the numeral


1


generally designates a high pressure stopping system of an embodiment of this invention adapted for use in mines to at least partially close a mine passageway


3


. The system can be used to substantially or partially seal the passageway against air flow therethrough. In this embodiment, the stopping system


1


is used to substantially seal against air flow creating a pressure differential across the stopping system


1


with a normally high pressure side


8


and a normally low pressure side


9


. This pressure differential applies force to the stopping system


1


in the direction of the higher pressure side


8


toward the lower pressure side


9


. In use of the system, it is to be understood that the high pressure side


8


and the low pressure side


9


may switch under certain circumstances but are normally in one orientation. Sealing can be accomplished by having the top edge


4


, side edges


5


,


6


and bottom edge


7


of the stopping system adjacent to the top or roof


12


, opposite side walls


14


,


15


and the floor


16


, respectively, and having suitable sealing material


17


(e.g., polymeric foam such as polyurethane and polystyrene) therebetween.




The stopping system


1


of this embodiment includes a plurality of stopping panels


18


positioned in side-by-side relation and extending vertically in the mine passageway


3


. The stopping panels


18


can be of any suitable style, e.g., each one can be fabricated as a single piece panel or as a pair of panel sections


19


and


20


(

FIG. 1

) which are preferably channel shaped (

FIG. 9

) in transverse cross section. The panel sections


19


and


20


are slidably or telescopically connected, i.e., one fits within the other and can move coaxially relative to one another to form a telescoping stopping panel


18


as exemplified in U.S. Pat. Nos. 4,547,094, 4,820,081 and 4,911,577, which are incorporated herein by reference. As best seen in

FIG. 9

, the panel sections


19


,


20


have a channel-shaped transverse cross section with a panel web portion


22


, opposing flanges


23


and inturned legs


24


. The panel sections


19


and


20


are preferably of the same shape with one being smaller than the other so the smaller one will fit within the larger one for connection and telescoping movement. Preferably, the panels


19


,


20


are metal, preferably steel.




When the panels


18


are installed in a mine, they are positioned in side-by-side relation and are extended in length to provide the desired height. The panels


18


are suitably secured in position in the mine passageway


3


in side-by-side relation. Such securement can be by any suitable means and helps prevent substantial relative movement between adjacent side-by side panels


18


. As shown in

FIG. 1

, rib angles or bars


28


are placed against the legs


24


of the panels


19


,


20


and are secured thereto as for example by twist wires


30


or any other suitable means. Note that the bars


28


may be omitted if the stopping is constructed by first installing a brace, as further described below. Others of the panels


18


are secured using rib members attached to braces described below.




Referring now to

FIGS. 1 and 2

, the stopping system


1


includes one or more horizontal reinforcing braces


35


which are preferably extensible or variable in length. In one embodiment, each brace


35


includes a compression chord (generally, elongate beam) designated generally


31


, a tension chord designated generally


32


and a web designated generally


33


extending between the compression chord


31


and the tension chord


32


. Alternatively, as described in parent application Ser. No. 09/464,808, the brace may include only the compression chord


31


. When more than one horizontal brace


35


is used in a stopping system


1


, the braces are spaced apart vertically and are preferably generally parallel. Anchor means


38


is preferably provided for mounting or securing the brace


35


to the mine wall. However, the anchor means may be omitted without departing from the scope of this invention.




Each compression chord


31


has opposite first and second ends and a longitudinal axis L. The compression chord


31


comprises at least one central support member or central beam


37


. In the embodiment of

FIGS. 1-10

, there is one central beam


37


. Length adjustment or variation is provided by having at least one slide member


41


mounted on the central beam


37


for telescoping movement. As shown, the central beam


37


is tubular having a rectangular transverse cross section with inside dimensions. The slide member


41


has a corresponding rectangular transverse cross section with outside dimensions slightly smaller than the inside dimensions of the central beam


37


and is slidably received therein for telescoping movement. It is to be understood that the cross sectional shape of the central beam


37


can vary, e.g., it may have an I-beam shape. Moreover, the central beam


37


may be sized smaller in cross section than the slide members


41


so that the central beam is received in ends of the slide members. The shape of the slide member


41


preferably corresponds to the central beam, but may differ therefrom within the scope of this invention. Preferably a slide member


41


is mounted in each of the two opposite ends of the central beam


37


permitting length adjustment or variation of the compression chord


31


at both ends of the central beam


37


. The illustrated embodiment shows the use of two slide members


41


in a central beam


37


; however, only one slide member may be used. The length of the slide members


41


should be such that they will accommodate the maximum amount of mine wall divergence without disengaging from the central beam


37


. During cycles of mine wall convergence and divergence, the central beam


37


could work completely to one side of the mine passageway. Thus, the slide member


41


on the opposite end of the central support member is preferably long enough to prevent disengagement from the central beam


37


. Additionally, sufficient lengths of the slide members


41


are preferably disposed in the central beam


37


to provide the necessary strength for the brace


35


to support the anticipated loads on the brace.




The anchor means


38


is operable to retain the brace


35


in position relative to the side walls


14


,


15


when the walls converge and diverge causing load to be applied to the stopping


1


. The anchor means


38


is affixed to an exteriorly positioned free end of each of the slide members


41


in a manner that will allow tension and compression to be applied to the slide member from the side walls


14


,


15


. The anchor means


38


is preferably operable to allow for or effect both expansion and contraction of the length of the brace


35


and maintain the brace secured to the mine walls. The anchor means


38


is secured to a mine wall to prevent movement of the brace


35


relative to or along the mine passageway. In one embodiment, the anchor means


38


includes a plate


45


connected or secured to the exteriorly positioned free end of each of the slide members


41


. The plate


45


lies in a plane that is generally perpendicular to the longitudinal axis of the respective slide member


41


. As shown in

FIGS. 1 and 2

, the plate


45


has a bearing surface area significantly greater than a cross-sectional area of the slide member


41


and of the central beam


37


. The plate


45


typically has a surface area between about 0.25 and 2.5 square feet and such area is about 2 to 25 times greater than that of the slide member


41


and beam


37


. The plate


45


may have apertures


46


for receiving appropriate fasteners


47


, such as anchor bolts, conventional roof bolts, or threaded studs. The fasteners


47


are inserted into the apertures


46


and into holes in the side walls


14


,


15


. If threaded studs are used, the plate


45


is hung on the studs, and nuts are threaded onto respective studs to retain and secure the plate. Rather than separable fasteners, the plate may include a claw (not shown) for extending into the side walls


14


,


15


. Other forms of anchor means


38


could be used, and the plate


45


may be omitted, e.g., if the cross-sectional area of the beam is sufficient to support the wall. The bearing surface area in contact with the wall is preferably at least about 16 square inches, more preferably at least about 40 square inches, and even more preferably at least about 300 square inches. If the plate


45


is omitted, the exteriorly positioned end of the slide member


41


or of the brace


35


(if the slide member is omitted) may be secured directly to the walls


14


,


15


by fasteners


47


. The fasteners


47


of the anchor means


38


can also include brackets, clamps, claws or the like that are secured to the brace


35


and the mine walls


14


,


15


. Further, the plate member


45


could have a separable clevis type mount (described more fully in the parent application). It is contemplated that the fasteners be made integral with the brace


35


, e.g., by making the fasteners integral with the plate


45


.




Retaining means is also provided to restrict telescoping movement of the slide members


41


in the central beam


37


. As shown, the retaining means preferably comprises friction lock means including, in one embodiment, T-handled set screws


49


that are threadably mounted in the central support member


37


. When the set screws


49


are tightened, they engage respective slide members


41


and frictionally retain the slide members


41


in their initial adjusted position or a subsequent position due to wall movement. The friction between the set screws


49


and the slide members


41


resists relative telescoping of the central beam


37


and slide members


41


so that the compression chord


31


is configured to have substantial columnar strength for bearing a substantial longitudinal load (i.e., axial or eccentric loading relative to the longitudinal axis L) applied to the chord. Thus, the brace is sufficiently unyielding so as to provide substantial support to the side walls


14


,


15


. Substantial convergence or divergence of the side walls


14


,


15


overcomes the frictional force causing telescoping movement of the slide members


47


relative to the central beam


37


. The slide member


41


is locked relative to the central beam


37


such that the slide member will resist a substantial longitudinal load without yielding or sliding relative to the central beam. More specifically, the slide member will resist without yielding under a longitudinal load of at least about 800 pounds, more preferably at least about 4000 pounds, even more preferably at least about 8000 pounds, and even more preferably at least about 16,000 pounds. Such sliding or telescoping movement does not inelastically deform the central beam


37


or the slide members


41


and does not alter their structural integrity. Because the engagement is frictional, should the mine walls move after installation of the brace


35


, the slides


41


will still be able to move in either an extension or contraction direction relative to the central beam


37


. This relative movement prevents excessive axial or longitudinal loading of the central beam


37


and the slide members


41


so that inelastic deformation of the compression chord


31


is inhibited.




As an example, a cup point set screw of .625 inches diameter has a longitudinal holding force of about 4000 pounds (


Mark's Handbook for Mechanical Engineers


, page 8-23, 8th edition, 1978). Thus, in the configuration of

FIG. 1

where two cup point set screws


49


engage each slide member


41


, the slide members will provide resistance without yielding or sliding under a longitudinal load of at least about 8000 pounds. Similarly, if the configuration is changed so that four set screws


49


engage each slide member


41


, the slide members will resist a longitudinal load of at least about 16,000 pounds. Thus, the compression chord


31


has substantial columnar strength for bearing a substantial columnar load (e.g., at least about 800 pounds, more preferably at least about 4000 pounds, even more preferably at least about 8000 pounds, and even more preferably at least about 16,000 pounds), but the slide member


41


will slide under a predetermined load such that the compression chord


31


is not damaged. As will be understood, the frictional resistance force may be accurately controlled by including any number, type or size of set screws.




The brace


35


has substantial bending strength for bearing a substantial transverse load applied to the beam generally transversely of the beam. Such load is typically applied by the air pressure differential acting against the mine stopping system


1


and transferred to the brace


35


. Preferably, the brace


35


is sized for an exemplary sized stopping system


1


having a width of 20 feet and a height of 15 feet so that it does not inelastically yield under a transverse load caused by a pressure differential of at least about 2 inches water gauge, more preferably at least about 5 inches water gauge, more preferably at least about 10 inches water gauge, and even more preferably at least about 20 inches water gauge. For another exemplary sized stopping system


1


having a width of 40 feet and a height of 30 feet, the brace


35


is sized so that it does not inelastically yield under a transverse load caused by a pressure differential of at least about 2 inches water gauge, more preferably at least about 5 inches water gauge, more preferably at least about 10 inches water gauge, and even more preferably at least about 20 inches water gauge. Note that the brace


35


and each panel


18


will be stressed due to the air pressure differential and will deflect a distance due to the air pressure differential (the transverse load). Preferably, the stiffness of the brace


35


and stiffness of the panels


18


are selected so that the brace and panels are similarly stressed when the stopping system


1


is placed under the transverse load. More specifically, the point of extreme fiber stress in the brace generally occurs midway across the passageway, and such extreme fiber stress is substantially similar to extreme fiber stress in the panels


18


that are positioned midway across the passageway. The point of extreme fiber stress in the panels


18


is likely to be adjacent the point of extreme fiber stress in the brace. Extreme fiber stress is local stress through a small area (a point or a line) furthest from the neutral axis or centroid on the brace or the panels


18


, and is typically measured in pounds per square inch (psi). More specifically, for panels


18


positioned generally midway across the passageway, extreme fiber stress in the panels is at least about 40 percent, more preferably about 60 percent, even more preferably about 80 percent, of the extreme fiber stress in the brace when the transverse load is applied to the stopping so that the beam and the panels are both effective to resist the transverse load. For example, if the brace


35


has an extreme fiber stress of 10,000 psi due to the transverse load, then the extreme fiber stress in the adjacent panels is at least about 4000 psi, more preferably at least about 6000 psi, and even more preferably at least about 8000 psi. Also note that the brace and panels will deflect similar distances under similar loads. By stressing the panels


18


and brace


35


similarly, overstressing one or the other beyond their respective yield points is inhibited. Moreover, material used in the panels


18


and brace


35


is not wasted as would be the case if only one of the panels and brace was significantly stressed by the transverse load. For example, if the brace


35


did not carry a significant portion of the transverse load, then the material therein would be wasted with respect to resisting the transverse load.




In the illustrated embodiment, the brace


35


is in the form of a king post truss. As shown in

FIG. 2

, the web


33


includes a compression member such as a king post


52


, having opposite ends


53


and


54


. The king post


52


is mounted generally centrally of the central beam


37


. It has one end


53


adjacent to and suitably secured to the central beam


37


adjacent the center thereof such as by welding. The king post


52


, as shown, has a generally rectangular transverse cross section and can be tubular. The other end


54


is positioned a distance from the central beam


37


. The king post


52


can be generally perpendicular to the central beam




The tension chord


32


is a tension or brace member that has opposite end portions


58


,


59


and a center portion


57


. The end portions


58


,


59


are positioned adjacent opposite ends of the central beam


37


and are suitably secured thereto, as by welding. The end


54


of the king post


52


engages the center portion


57


and is preferably suitably secured thereto, as by welding. The tension chord


32


can be made from a flat metal strap and, when the truss


35


is in use, normal loading thereof will put the tension chord


32


in tension allowing for the use of a simple transverse cross section. When the brace


35


is loaded due to the pressure differential across the stopping, the loading force is directed from the front side


67


of the central beam


37


toward the end


54


placing the tension chord


32


in tension and the king post


52


in compression. If the pressure differential is reversed so that the force is directed from the opposite side of the central beam


37


, the tension chord may be reconfigured to resist compression loading (i.e., so that the tension chord is instead a compression chord).




The brace


35


is provided with suitable securement means that is affixed to the central beam


37


for attaching or securing the brace


35


to the stopping panels


18


. In one embodiment (FIG.


4


), the securement means includes a plurality of uprights


61


(formed from metal plate, for example) suitably secured to the central beam


37


and spaced apart along the length thereof. An elongate panel securement member such as rib member


62


, is suitably secured to the uprights


61


with the open side facing away from the brace


35


and toward the stopping panels


18


. The rib member


62


is preferably a metal angle. Twist wires, clamps or other suitable means


30


can be used to secure the rib member


62


and hence the brace


35


to the stopping panels


18


(

FIGS. 1

,


8


).




A modified form of brace


35


and stopping system is illustrated in FIG.


8


. The modified brace is designated generally as


65


. It is the same as the brace


35


except that it uses two securement members which are shown as upper and lower sets of uprights


61


and rib members


62


. The rib members


62


and sets of uprights


61


are positioned on opposite sides of the central beam


37


whereby the two rib members


62


are spaced apart in positions above and below the central beam


37


. In this embodiment, the brace


65


can be used at a joint between two sets of stopping panels


18


to secure them in end-to-end abutting relation allowing the use of shorter stopping panels


18


. For example, two ten (10) foot sets of stopping panels


18


can be used instead of one twenty (20) foot set of stopping panels


18


. The joint


66


between the two sets of stopping panels


18


is located between the two rib members


62


. The brace


65


is secured to the stopping panels


18


as described above for the brace


35


with clamps or twist wires


30


. If desired, one or more braces


35


can be used along with the brace


65


on a stopping system


1


for additional reinforcement.




As seen in

FIG. 1

, the stopping system can utilize one or more braces


35


secured thereto in a generally horizontal orientation. The braces


35


are secured to the stopping panels


18


on the normally low pressure side of the stopping system to reduce bending or deformation of the stopping system. Such mounting and loading places the tension chord


32


in tension. The generally V-shape of the brace


35


results in a smaller quantity of material being needed to provide the required strength. Also, the general V-shape of the brace


35


results in the brace having a higher or larger moment of inertia at the center of the brace


35


than at its opposite ends. Further, in the V-shape form of brace


35


, the moment of inertia continuously increases from adjacent each end of the brace toward the central area of the brace


35


where it is at a maximum.




A modified form of the invention is shown in

FIGS. 5

,


6


,


7


and


9


. In this form, a stopping system


71


is provided with a selectively openable door


70


that will allow passage of personnel or equipment thru the stopping system and/or the controlled passage of air therethrough.




The stopping system


71


includes a door frame means


72


comprising spaced apart generally vertical columns


73


and a header or lintel


74


spaced from the floor


16


and roof


12


and secured to upper ends


75


of the columns


73


. The columns


73


can have feet


76


that are adapted to be suitably secured to the floor


16


by fasteners


77


to prevent movement of the columns on the floor


16


and along the mine passageway


3


. The columns


73


preferably have a height less than the height of the roof. The columns


73


can have any suitable transverse cross section and preferably are tubular with a generally rectangular transverse cross section.




The lintel


74


is suitably secured to the columns


73


adjacent their upper ends


75


. As shown in

FIG. 7

, the lintel has brackets


79


secured to opposite ends of the lintel


74


, e.g., by welding. The brackets


79


are in turn suitably secured to sleeves


80


such as by welding. The sleeves


80


are tubular and are sized to slide over the columns


73


and to be adjustably secured in selected vertical position on the columns, e.g., by set screws


81


. This mounting arrangement allows for adjustability of the components during installation. The lintel


74


can have any suitable transverse cross section and can be tubular with a generally rectangular transverse cross section. The lintel


74


has an upper disposed surface


84


with an upwardly opening channel member


85


secured (e.g., welded) thereto and extending along the length of the lintel


74


. The channel member


85


is preferably generally U-shaped with two upstanding legs


86


defining an upwardly opening channel


87


(see FIG.


6


).




The stopping system


71


includes stopping panels


18


positioned between the columns


73


and the side walls


14


,


15


and secured in place as described above. Shorter stopping panels


18


are positioned above the lintel


74


, extending upwardly therefrom. The shorter stopping panels


18


are positioned between the lintel


74


and the roof


12


and are suitably secured together using bars


28


and twist wires


30


. The lower disposed ends


88


of the stopping panels


18


above the lintel


74


are positioned in the channel


87


between the legs


86


to secure them against movement as described below. A brace


35


is also mounted or secured in the channel member


85


to reinforce the stopping system


71


in an area adjacent the lintel. The brace


35


reduces the amount of deflection or movement of the columns


73


and the lintel


74


during loading and thus eliminates the need for floor to roof columns. The central beam


37


of the brace


35


is placed in the channel


87


between the lower end portions


88


of the stopping panels and a leg


86


of the channel. The brace


35


and the stopping panels


18


above the lintel


74


are supported vertically by the lintel


74


. The channel member


85


functions as a securement means associated with the brace


35


and the stopping panels


18


above the lintel


74


for tying the lintel to the central beam


37


and upper stopping panels


18


at a position adjacent to the lower ends


88


of the selected stopping panels. When the stopping system


71


deflects under load, the brace


35


is urged into frictional engagement with one leg


86


by the stopping panels


18


in the channel member


85


. The channel member


85


thus secures or retains the selected stopping panels


18


above the lintel


74


and the brace


35


substantially immoveable relative to one another. As shown in

FIG. 5

, one or more additional braces


35


can be used on the stopping system


71


.




The use of a lintel


74


and columns


73


changes the load distribution on the brace


35


relative to the form of the invention shown in FIG.


1


and should also help reduce deflection of the stopping system.




The door


70


can include one or more door panels or leaves


90


suitably moveably mounted on the columns


73


as for example by hinges


91


. The leaves


90


can be retained closed by a suitable latch (not shown). One of the leaves


90


can have a man door


94


movably mounted thereon.




As seen in

FIGS. 1 and 5

, a pair of vertical anchor channels


98


can be mounted on the side walls


14


,


15


, as with anchor bolts (not shown), and be positioned between the plates


45


and the respective side wall


14


,


15


. These channels provide smoother surfaces than the walls


14


,


15


and thus a better side fit for the stopping panels


18


. Seal material


17


can be used between the stopping system


1


or


71


and the roof


12


, side walls


14


,


15


and the floor


16


of the mine passageway


3


.




In a preferred embodiment, the stopping systems are constructed of metal, e.g., steel.




In an embodiment shown in

FIG. 10

, a brace


135


(generally, elongate beam) is used to support the side walls


14


,


15


of the passageway


3


. The brace


135


(similar to compression chord


31


) has opposite first and second ends


142


,


143


and a longitudinal axis L. The brace comprises a central beam


137


, slide members


141


having anchor means (generally, bearing members) in the form of plates


145


on one end, and retaining means in the form of T-handled set screws


149


. The central beam


137


, slide members


141


, anchor means and retaining means are substantially identical to those described above. However, the brace


135


of this embodiment does not include a compression chord or tension chord. Moreover, the stopping is not shown in

FIG. 10

to illustrate that the brace


135


, and the braces


35


,


65


described above, may be used with or without the stopping to support the side walls


14


,


15


.




A method of supporting the side walls


14


,


15


will be described with respect to brace


135


, but the method is applicable to the braces


35


,


65


. In other words, the method applies to the embodiment of

FIG. 10

, to the embodiments described above, and to variations of these embodiments.




In one embodiment of this invention, first and second locations


150


,


151


, on the side walls


14


,


15


(first and second walls), respectively, are selected to provide suitable areas for supporting the side walls. Suitable areas of the side walls


14


,


15


preferably have little or no cracking and spalling and are not adjacent to areas of the walls that have sloughed off. The brace


135


is positioned by raising it from the floor and supporting it generally at the same elevation as the first and second locations and in an orientation generally transverse to the passageway


3


. Lighter braces may be raised and supported by one or more persons, but heavier braces can be raised and supported using a fork lift, end loader, cribbing or other suitable means. The length of the brace


135


is adjusted to correspond to the distance between the side walls


14


,


15


by sliding the slide members


141


relative to the central beam


137


to bring the plate


145


at the first end


142


of the brace into position at the first location


150


and the plate at the second end


143


into position at the second location


151


. Optionally, the plates may be forced against the side walls


14


,


15


, as by a jack shown in U.S. Pat. No. 4,483,642, to pre-tension the brace. The plates


145


are then secured to the respective side walls


14


,


15


using anchor bolts


147


. Note that other suitable fasteners may be used, such as any of the fasteners described above. When using anchor bolts


147


, holes are drilled in the side walls


14


,


15


, and the bolts are inserted into the apertures


146


and into the holes. Each slide member


141


is locked relative to the central beam


137


by tightening the set screws


149


. Note that the brace


135


is selected to have the strength and yielding characteristics described above with respect to brace


35


. Briefly, each slide member


141


is locked relative to the central beam


137


such that the slide member will resist a longitudinal load of preferably at least about 800 pounds, more preferably at least about 4000 pounds, more preferably at least about 8000 pounds and even more preferably at least about 16,000 pounds.




After the brace is secured, a stopping may optionally be erected between the side walls


14


,


15


. As described above, the stopping is erected by placing the stopping panels


18


side-by-side and extending the panels so that the lower panel section


20


engages the floor and the upper panel section


19


engages the mine roof


12


, as described in U.S. Pat. No. 4,483,642 which is incorporated herein by reference. Preferably, each panel


18


of the stopping is secured to a rib member


162


of the brace


135


.




It is contemplated that the braces


35


,


65


and


135


may be non-extensible, i.e., the slide members may be omitted and the brace sized to fit a passageway of a known width. Even if the braces are non-extensible, the braces preferably do not inelastically yield under longitudinal load of at least about 800 pounds, preferably at least about 4000 pounds and more preferably about 8000 pounds.




The braces


35


,


65


and


135


may be used to reinforce an existing stopping, i.e., the stopping panels are already in position when the brace is installed. Preferably though, the braces


35


,


65


,


135


are installed in the passageway prior to installing the panels


18


, and the angle bars


28


are not used. Because the braces


35


,


65


,


135


are much more readily sized to fit the passageway, installation of the reinforced stopping system


1


is generally quicker and easier than the prior art method of erecting a stopping.




The braces


35


,


65


and


135


, and the described methods of installation, may also be used in combination with a pre-assembled stopping or pre-assembled stopping sections, as shown in our co-assigned U.S. patent application Ser. No. 09/903,429 filed Jul. 11, 2001, which is incorporated herein by reference.




The embodiments of the invention disclosed above are illustrative. Many variations of the mine stopping


1


and braces


35


,


65


,


135


are possible without departing from the scope of the invention. For instance, the brace


35


may have shapes other than the general V-shape shown in FIG.


10


. For example, the brace may be generally rectangular. The cross sectional shapes of the components of the brace can also be different. For example, the tension chord


32


could be an angle member and the compression chord


31


and slide members


41


could be round or have an I-beam shape. Also, the slide members


41


need not telescope relative to the central beam


37


.




The braces


35


,


65


,


135


will accommodate convergence and divergence of the mine and still be effective in supporting the stopping panels


18


against deflection from a pressure differential, and in supporting the mine walls


14


,


15


. The structure of the braces


35


,


65


,


135


allows them to self adjust to accommodate mine convergence and divergence while continuously supporting the walls to inhibit cracking and sloughing off. Such support reduces maintenance and operation costs. By having variable length, the braces can be used in mine passages of various widths increasing the versatility of application and thereby decreasing the number of different braces needed in inventory. The brace


65


further provides a simple means of joining together two tiers of stopping panels


18


stacked end on end, while also providing resistance to deflection of the stopping system


1


due to different pressures on opposite sides of the system.




When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.




As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.



Claims
  • 1. A method of supporting opposite first and second walls of a mine passageway, said method comprising the steps of:providing an elongate beam having opposite first and second ends and a longitudinal axis, said beam being configured to have columnar strength for bearing a longitudinal load applied to the beam generally longitudinally of the beam and bending strength for bearing a transverse load applied to the beam generally transversely of the beam, the beam including a central beam and a slide member slidable longitudinally relative to the central beam, selecting first and second locations on the first and second walls, respectively, providing suitable areas for supporting the first and second walls, positioning the first end of the beam at said first location and the second end of the beam at said second location by sliding the slide member relative to the central beam to adjust the length of the beam to correspond to the distance between the first and second walls so that the beam extends between the first and second walls of the mine passageway, securing the first end of the beam to the first wall at said first location and the second end of the beam to the second wall at said second location so that the beam is positioned for supporting the first and second walls, and locking the slide member relative to the central beam so that the slide member will slide longitudinally relative to the central beam under a longitudinal load greater than about 800 pounds.
  • 2. A method as set forth in claim 1 wherein at least one end of the beam has a bearing member thereon for bearing against a respective wall, said bearing member having a bearing surface area greater than the cross-sectional area of the beam, said securing step comprising securing the bearing member to a respective wall at said respective location.
  • 3. A method as set forth in claim 1 wherein said securing step comprises fastening the respective ends of the beam to the respective walls using one or more fasteners.
  • 4. A method as set forth in claim 3 wherein at least one end of the beam has a bearing member thereon for bearing against a respective wall, said bearing member having a surface area greater than the cross-sectional area of the beam, said fastening step comprising inserting at least one fastener of a respective set of fasteners through a hole in the respective wall, and then tightening the fastener so that the bearing member is in contact with the respective wall.
  • 5. A method as set forth in claim 1 wherein the central beam and the slide member do not inelastically yield under a longitudinal load of at least about 800 pounds.
  • 6. A method as set forth in claim 1 wherein the central beam and the slide member do not inelastically yield under a longitudinal load of at least about 4000 pounds.
  • 7. A method as set forth in claim 1 wherein the slide member is locked relative to the central beam after the ends of the beam are secured to respective walls.
  • 8. A method as set forth in claim 1 wherein the slide member is locked relative to the central beam such that the slide member will slide relative to the central beam under a longitudinal load greater than about 4000 pounds.
  • 9. A method as set forth in claim 1 wherein the slide member is locked relative to the central beam such that the slide member will slide relative to the central beam under a longitudinal load greater than about 8000 pounds.
  • 10. A method as set forth in claim 1 further comprising the step of erecting a stopping extending between said first and second walls after said beam has been secured to the walls.
  • 11. A method as set forth in claim 10 wherein said erecting step includes securing the stopping to the beam.
  • 12. A method as set forth in claim 11 wherein the beam does not inelastically yield under a transverse load caused by an air pressure of at least about two inches water gauge acting on said stopping.
  • 13. A method as set forth in claim 11 wherein the beam does not inelastically yield under a transverse load caused by an air pressure of at least about five inches water gauge acting on said stopping.
  • 14. A method as set forth in claim 11 wherein said stopping comprises a plurality of vertically extensible panels positioned side-by-side across the passageway, said erecting step comprising extending each of said panels to bring it into engagement with a floor and roof of the passageway, and then securing the panel in its extended position to said beam.
  • 15. A method as set forth in claim 1 wherein said securing step comprises drilling holes in the first and second walls at said first and second locations, and using fasteners inserted in said holes to fasten the first and second ends of the beam to respective walls.
  • 16. A method of supporting opposite first and second walls of a mine passageway, said method comprising the steps of:providing an elongate beam having opposite first and second ends and a longitudinal axis, each end of the beam having a bearing member thereon for bearing against a respective wall, the bearing member having a bearing surface area greater than the cross-sectional area of the beam, said beam being configured to have columnar strength for bearing a longitudinal load of at least 800 pounds applied to the beam generally longitudinally of the beam and bending strength for bearing a transverse load caused by an air pressure of at least two inches water gauge and applied to the beam generally transversely of the beam, the beam including a central beam and a slide member slidable longitudinally relative to the central beam, selecting first and second locations on the first and second walls, respectively, providing suitable areas for supporting the first and second walls, positioning the first end of the beam at said first location and the second end of the beam at said second location by sliding the slide member relative to the central beam to adjust the length of the beam to correspond to the distance between the first and second walls so that the beam extends between the first and second walls of the mine passageway, securing the bearing member of the first end of the beam to the first wall at said first location and the bearing member at the second end of the beam to the second wall at said second location so that the beam is positioned for supporting the first and second walls, and locking the slide member relative to the central beam after the ends of the beam are secured to respective walls so that the slide member will slide longitudinally relative to the central beam under a longitudinal load greater than about 800 pounds.
  • 17. A method as set forth in claim 16 wherein the slide member is locked relative to the central beam after the ends of the beam are secured to respective walls.
  • 18. A method as set forth in claim 16 wherein the slide member is locked relative to the central beam such that the slide member will slide relative to the central beam under a longitudinal load greater than about 8000 pounds.
  • 19. A method as set forth in claim 16 wherein the slide member is locked relative to the central beam such that the slide member will slide relative to the central beam under a longitudinal load greater than about 16000 pounds.
  • 20. A method of installing a mine stopping between the first and second walls of a mine passageway, said method comprising the steps of:providing an elongate beam having opposite first and second ends and a longitudinal axis, said beam being configured to have columnar strength for bearing a longitudinal load applied to the beam generally longitudinally of the beam and bending strength for bearing a transverse load applied to the beam generally transversely of the beam, positioning the first end of the beam at a first location on the first wall and the second end of the beam at a second location on the second wall so that the beam extends between the first and second walls of the mine passageway, securing the first end of the beam to the first wall at said first location and the second end of the beam to the second wall at said second location so that said beam is positioned to take a longitudinal load, and erecting a stopping extending between said first and second walls after said beam has been secured to the walls, said erecting step including securing the stopping to the beam so that a load applied to the stopping due to an air pressure differential across the stopping is transferred to said beam as a transverse load.
  • 21. A method as set forth in claim 20 wherein said stopping comprises a plurality of vertically extensible panels positioned side-by-side across the passageway, said erecting step comprising extending each of said panels to bring it into pressure engagement with a floor and roof of the passageway, and then securing the panel in its extended position to said beam.
  • 22. A method as set forth in claim 21 wherein stiffness of the beam and stiffness of said panels are selected such that the beam and at least some of said panels are similarly stressed under the transverse load applied to the stopping so that overstressing of the beam and said panels is inhibited.
  • 23. A method as set forth in claim 21 wherein stiffness of the beam and stiffness of said panels are selected such that for selected panels positioned generally midway across the passageway, extreme fiber stress in the selected panels is at least about 40 percent of the extreme fiber stress in the brace when the transverse load is applied to the stopping so that the beam and said panels are effective to resist the transverse load.
  • 24. A method as set forth in claim 21 wherein stiffness of the beam and stiffness of said panels are selected such that for selected panels positioned generally midway across the passageway, extreme fiber stress in the selected panels is at least about 60 percent of the extreme fiber stress in the brace when the transverse load is applied to the stopping so that the beam and said panels are effective to resist the transverse load.
  • 25. A method as set forth in claim 21 wherein stiffness of the beam and stiffness of said panels are selected such that for selected panels positioned generally midway across the passageway, extreme fiber stress in the selected panels is at least about 80 percent of the extreme fiber stress in the brace when the transverse load is applied to the stopping so that the beam and said panels are effective to resist the transverse load.
  • 26. A method as set forth in claim 20 wherein said securing step comprises drilling holes in the first and second walls at said first and second locations, and using fasteners inserted in said holes to fasten the first and second ends of the beam to respective walls.
  • 27. A method as set forth in claim 20 wherein the central beam and the slide member do not inelastically yield under a longitudinal load of at least about 800 pounds.
  • 28. A method as set forth in claim 27 wherein the beam does not inelastically yield under a transverse load caused by an air pressure of at least about two inches water gauge.
  • 29. A method as set forth in claim 20 wherein the central beam and the slide member do not inelastically yield under a longitudinal load of at least about 4000 pounds.
  • 30. A method as set forth in claim 29 wherein the beam not inelastically yield under a transverse load caused by an air pressure of at least about five inches water gauge.
CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of U.S. patent application Ser. No. 09/464,808 filed Dec. 17, 1999, now U.S. Pat. No. 6,379,084 which is incorporated herein by reference.

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617163 Jacobs Jan 1899 A
891897 Astrom Jun 1908 A
1478303 Snyder Dec 1923 A
1594921 Barnett Aug 1926 A
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Foreign Referenced Citations (2)
Number Date Country
2328552 Jun 2001 CA
2610986 Aug 1988 FR
Non-Patent Literature Citations (2)
Entry
Kennedy Interlocking Overcasts brochure, Jack Kennedy Metal Products & Buildings, Inc., Nov. 6, 2000.
Kennedy Steel Stoppings brochure, Jack Kennedy Metal Products & Buildings, Inc., Aug. 9, 2002.
Continuation in Parts (1)
Number Date Country
Parent 09/464808 Dec 1999 US
Child 10/061146 US