CA2325177A1 - Cable line stopping - Google Patents

Abstract

A stopping for sealing off a mine area utilises bolts fixed in the floor, ribs and roof of the mine roadway (Figure 7) to create an array of intersecting cables (Figure 4) across the site to be sealed. The cables are tightened by tensioners (Figure 6).
A layer of mesh (Figure 6) about the size of shade cloth is secured to one face of the cable array with clips (Figure 6) and overlaps the periphery to allow contact with the rock face. A water-based latex is applied to one or both faces of the mesh in order to make the mesh impervious to air. The stopping remains flexible and withstands vehicle impacts and pressure peaks caused by blasting. Resealable apertures al low the passage of personnel and service conduits (Figure 11 ) are provided.

Description

CABLE LINE STOPPING
This invention relates to an improved method of constructing a stopping, particularly for use in underground mining.
Stopping is the process of sealing, sealing off, quarantining, closing or restricting access to or from an area.
Stoppings have a number of purposes. They are used for sealing roadways.
They are used for the segmentation of belt roads. They are used for the sealing of mine areas. They are used for the control of ventilation air. They are used for overcasts.
There have been many forms of stoppings used, however, the manufacture of those conventional stoppings has involved traditional means where the stopping is generally constructed using traditional building methods and traditional building materials. In this specification, those stoppings will be referred to as "traditional stoppings".
The conventional method of constructing a traditional stopping is to prepare the site of the stopping by removing and level I ing or straightening the area in which the stopping is to be placed, placing a foundation or other support and constructing a stopping from concrete, bricks, metal or other material.
The traditional manufacturing processes used in the construction of existing stoppings are labour intensive and expensive.
There are a number of problems and drawbacks with conventional stoppings. They include:-The materials used are expensive. The materials generally used in conventional stoppings comprise concrete, bricks, steel and wood. The invention uses mining anchor bolts, wire rope, fittings to attach the wire rope to the anchor bolts, mesh and a flexible membrane material.
The traditional methods requires building expertise to quite a high standard.
The area to be stopped must be accurately measured and the foundations accurately laid and the material used in the stopping measured and cut to a high degree of accuracy. The invention does not require particular accuracy in its construction.

The anchor bolts do not have to be accurately placed. The wire rope length is not critical as it can be adjusted by wire rope clamps and by turn buckles.
Traditional stoppings do not allow for the easy removal of the stopping.
Once the traditional stopping is in place, the complete structure normally has to be demolished to allow the passage of vehicles or any amendment. With the invention, movement through the stopping is much easier and cheaper and quicker by virtue of the fact that the stopping can be easily, partially or fully removed by undoing the anchor nuts on the bolts, moving the stopping and replacing it when requ i red.
The traditional stopping is generally inflexible. This a particular problem in high roof heave or floor heave areas where there is significant movement of the surfaces intended to be stopped. When traditional stoppings are used in these areas, the integrity and strength of the stopping is damaged by the movement or, alternatively, the sealing qualities in the event of a heave, which increases the area to be stopped, damages the sealing qualities of the stopping.
Traditional stoppings, particularly those used in high floor heave areas lose strength once the construction has been damaged. The invented stopping has a high rate of flexibility and so is not as sensitive to movement as the traditional stopping.
The inherent flexibility of the invention combined with its strength allows it to withstand forces without sustaining damage much more so than the conventional stopping. A conventional brick wall stopping, if struck by a vehicle, can collapse or be severely damaged. The invented stopping has a much higher ability to absorb such impacts than conventional stopping.
The invented stopping is able to withstand sudden changes in air pressure or explosions more so than conventional stoppings.
Traditional stoppings utilise bulky and heavy materials. There is a considerable cost component involved in conveying the mortar, bricks, timber and other equipment required to construct the conventional stopping. The materials required for the construction of the invention are much easier to transport.
The wire rope used normal ly comes on spools. The mesh or weave can be taken to the site in a rolled up form. The membrane coating is prior to application, a liquid which is transported in a container.
The short comings listed in the previous paragraph and the short comings generally evident in traditional stoppings, are overcome by the present invention which utilises commonly used and proprietary available materials constructed in such a manner that the resulting structure has the necessary rigidity in all dimensions required, has the sealing qualities required of a stopping, is robust enough to comply with mining use and is much more flexible, particularly when subjected to vertical movements of the area intended to be stopped in high floor and roof heave areas.
Figure 1 shows an area of mine working that requires a stopping. In this case, the area 2 required to be stopped requires a vertical stopping.
Figure 2 shows that a number of anchor bolts 4 are placed in the plane required to be sealed off. Normal fully encapsulated chemical anchor bolts are utilised in Figure 2. Seven have been placed in the floor 6, seven have been placed in the roof 8, three have been placed in the left vertical rib or side 10 and four have been placed in the right vertical rib or side 14. The placement, the dimensions and the specifications for the rock bolts would depend on the area to be stopped.
Figure 3 also shows the detail of a typical attachment to locate wire rope 16 of an appropriate dimension to that portion of the rock bolt which is visible so as to locate the wire rope near the surface which is required to be stopped. The form of the attachment is not critical. Proprietary manufactured attachments which are also detailed could be utilised.
Figure 4 shows wire rope threaded through the attachments 4. The configuration of the wire rope depends on the area to be stopped. In Figure 4, the illustration shown, a number of different lengths of wire rope have been utilised.
The number of different lengths of wire rope vary with the construction. In some instances, one length of wire rope could be utilised, much in the way that one length of material is used for stringing a tennis racquet. In the case of Figure 4, multiple pieces of wire rope have been used which have been attached to proprietary turn buckles 18 by conventional means.

The bolts are placed so that the wire rope follows the contour of the surface to be sealed inso much as is possible by tightening the nuts 20 on the rock bolts.
The wire ropes are tensioned by tightening the turn buckles. Figure 4 shows the wire ropes in a tensioned position.
Other means of tensioning the wire rope could be utilised including adjustable eye bolts, the tensioning of the wire ropes by deflection towards each other, the use of a mechanical tensioning device in conjunction with wire rope clamps 22 and other similar methods.
In areas of extreme floor or roof heave, the ability of the stopping to take up the altered area is obtained by loosely tensioning the vertical wire ropes as is shown in Figure 5.
After thewire ropes are tensioned, surface material 24 is attached to the wire ropes to form a surface to which a flexible membrane will adhere. In underground mining situations, "brattice", which is a non-static proprietary weave, could be used. Other mesh such as "tecrete" mesh or shade cloth or similar material could be used. In this specification whether mesh or weave or other material is used, it will be referred to as "mesh".
The mesh is affixed to the wire ropes by normal mechanical means such as zip ties 26, tie wire, U bolts or other similar fastenings depending on the type of mesh used.
The mesh is trimmed to size to fit the opening required to be stopped. To reduce the area required to be sealed and to strengthen the mesh, smal ler fasteners can be used to directly attach the mesh to the wall of the area required to be sealed.
Once the mesh is cut to size, an elastic membrane coating is applied to the mesh. The proprietary compound "master seal" °800A or similar membrane would be applied to either one or both sides of the mesh.
The elastic membrane coating would be applied by spraying or by manual application with brush, roller or trowel.
Figures 6 shows a side elevation of the stopping showing detai I of the anchor bolts and nuts, the wire rope, the wire rope to anchor bolt attachments, the wire rope tensioning device, the mesh, the attachments of the mesh to the wire rope and the elastic coating 28 after having been applied.
It will be realised that the stopping is not restricted to use in vertical situations as shown in Figure 1 nor in relation to the cross section of the area as 5 shown in those diagrams. The stopping can be used in any plane and to stop any shaped hole. Figure 7, for example, shows a stopping inserted so that the elastic membrane is horizontal. It could be used in a situation to protect workers from suffering injury from falling rocks or debris 30. The elastic membrane would restrain the smaller debris while the wire rope would restrain the larger objects and the invention would still have the elasticity that a conventional barrier would not have. The construction of the stopping in this horizontal situation shown would be very much easier than a conventional stopping.
Figure 8 shows a stopping constructed in a situation where the area to be covered would place an unacceptable force on the rock bolts without the assistance of a strengthening construction. In the figure shown, a steel I section girder 32 of appropriate dimensions has been placed and secured in a vertical plane in the concrete. The wire rope on the rib line has been attached to the girder as shown.
By utilising this means the invention can be utilised in almost unlimited lengths.
Figure 9 shows a stopping constructed in a situation where an angle is required in the stopping viewed from a plan view. In this case, the two separate angles of the stopping are attached to the section of I girder shown in the plan.
Figure 10 demonstrates the invention used in a typical long wall panel development.
Assume the long wall extraction sequence has extracted 110 metres of the block 36 before the first major fall occurs and the first only major consequent displacement of air. Stoppings 38 and 40 will take the major air displacement.
The retreating long wall face is 2.45 metres in width. It has a hard sandstone roof with 120-130 psi rating. Stoppings 38 and 40 remain as seal stoppings to force the intake air over the extracted long wall block (shown hatched in the drawing).
A
softer fragile roof (70-50 psi) will not leave the exposed roof suspended for an appreciable distance and no major air displacement will occur. The length of the long wall block 42 from the installation roadway 44 to the takeoff roadway 46 is 3000 metres. The height of the seam to be extracted is 3000 mm.
All cable line stoppings for panel development in long wall extraction are for air control in the intake and return roadway headings. The stoppings are not panel seals or long wall seals and their prime function is to ensure the efficient ventilation of the panel developments and the long wall extractions. I have found the advantages of the exemplified stoppings to be:
1. Labour efficiency in installation;
2. Portability; and 3. Minimal maintenance.
Figure 11 shows the invention used in a situation allowing water pipes 48 and air pipes 50 and electricity,wire ropes and similar utilities. Figure 12 shows the membrane 28 partially removed which is required in situations to alter the ventilation of an area or to al low personnel or vehicles to pass through the stopping.

Claims (6)

1. A stopping comprising anchor bolts capable of attachment to the periphery of the area which receives the stopping, wire ties and means to connect the ties to the anchor bolts, tie tensioning means, a mesh supported by the ties and a flexible membrane capable of excluding air passage applied to the mesh.

2. A stopping as claimed in Claim 1 wherein the membrane is elastic.

3. A stopping as claimed in Claim 1 or 2 wherein at least a portion of the stopping is detachable to allow for the resealable passage of vehicles, personnel or vehicles.

4. A stopping as claimed in any one of Claims 1 to 3 which permits the passage of service conduits.

5. A stopping as claimed in any one of Claims 1 to 4 wherein the stopping shape is adjustable by interaction of the ties and tensioning means in order to cope with ground heave.

6. A stopping substantially as herein described with reference to and is illustrated in Figures 4, 5, and 6 or as modified by Figures 7, 8, 9, 11 or 12.