GB1573609A - Method of and means for repairing mine roofs - Google Patents

Description

(54) METHOD OF AND MEANS FOR REPAIRING MINE ROOFS (71) I, BRIAN HUBBARD, of Cleveland Cottage, Brass Castle Lane, Middlesborough, Cleveland, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a method of and means for repairing roofs which have collapsed in, for example, coal mines.

During, or subsequent to, tunnelling in mines such as coal mines, unsupported sections of the roof may collapse. Heretofore it has been common practice to repair such collapses by locating steel arches in the tunnel at the region of the fall, on top of which arches are positioned lengths of timber or steel planking to provide a support platform below the void to be filled. Rocks or timbers are then manually loaded into the void above the platform until the void is substantially filled.

Clearly such a procedure is both laborious and time-consuming and has the additional disadvantage that the void can never be completely filled because of the presence of the loaders themselves.

According to the present invention there is provided a method of repairing a collapsed roof within a mine below which collapse there is support means, the method comprising the steps of providing a bag of flexible material the extended shape of which can conform substantially with that of the void to be filled, positioning said bag in the void, feeding gas conveniently air, into the bag whereby said bag is extended substantially to fill the void above the support means, introducing, at the upper region of the bag, liquid filler material to fill said bag in such a manner that the gas is expelled therefrom without the pressure of said gas exceeding a predetermined maximum value, and allowing the filler material to set.

Apparatus for effecting the method of the invention comprises a bag of flexible material, conveniently substantially cylindrical or rectanguloid in shape when extended to conform substantially with the shape of the void to be filled, and inlet and outlet hoses communicating into the interior of the bag, the outlet hose incorporating therein a pressure regulating device adapted to prevent gas pressure within the bag exceeding a predetermined maximum value.

The bag may include at least one tubular portion which, with the bag in use in its extended state, extends through the bag to terminate within, adjacent the upper region of, the bag, said tubular portion communicating with the interior of the bag only through the upper end thereof - in such an arrangement, the inlet and outlet hoses extend through said tubular portion to communicate, through said upper end of said portion, into the interior of the bag.

By way of example only a method and apparatus according to the invention will now be described in greater detail with reference to the accompanying drawings of which: Fig. 1 shows, partly cut-away, a flexible bag and associated hoses of apparatus according to the invention; Fig. 2 shows apparatus according to the invention in position in a void to be filled, and Fig. 3 shows the apparatus of Fig. 2 in the extended state filling the void.

Referring to the drawings, when the roof 2 of a mine collapses it is necessary to fill the void 4 so formed in such a way as to support the walls defining said void from further collapse. Steel arches 6 are first of all positioned in the tunnel 8 below the fall, and lengths of timber or steel planking are located on top of said arches to provide support means in the form of a platform 10 forming a continuation of the existing roof and above which is the void 4 to be filled. Such a step is in common with established practice.

One or more small holes such as 12 are left in said platform for insertion therethrough of one or more bags adapted to fill substantially said void.

More particularly, a bag, indicated generally at 14, is of a flexible material and of such a shape as to conform substantially, when unfolded and expanded, with that of the void. The bag may be of generally cylindrical configuration in its extended state as seen in Fig. 1, or, alternatively, may be of substantially rectangular section. The bag 14 includes a tubular portion 16 extending from the centre of its base to terminate within the bag adjacent the upper region of the bag, the upper end of said tubular portion comprising an injection assembly 18. This injection assembly 18 contains three nozzles 20,22,24 communicating into the interior of the bag 14.

An air inlet hose 26, an air outlet hose 28 and a liquid-grout inlet hose 30 extend up the tubular portion 16 of the bag 14 to be connected to the nozzles 20, 22, 24 respectively and thereby communicate into the interior of the bag. A further hose 32 extends up through the tubular portion 16, through the inJection assembly 18 to terminate in the vicinity of the nozzles 20, 22. 24 but externally of the bag 14 for reasons to be detailed below.

The air inlet hose 26 communicates, through nozzle 20. into a series of flexible ducts 34 sewn to the inside face of the bag 14, as at 36, some of said ducts themselves communicating into the interior of the bag through outlets 38 initally closed with Velcro (Registered Trade Mark), while the other ends of the ducts are sealed as at 40.

In order to fill a void such as 4, the folded bag 14 is first of all positioned on the platform 10 with the hoses 26,28, 30, 32 extending from the bag down through the hole 12 in the support platform, the longitudinal axis of the bag being aligned with the centreline of the tunnel 8 as seen in Fig. 2 Compressed air is fed through hose 26, said air feeding throughthe ducts 34 initally to unfold the bag in a controlled and predictable manner and then breaking the Velcro (Registered Trade Mark) seals to enter the interior of the bag through the outlets 38.

While the air continues to inflate the bag 14, the injection assembly is raised to the upper region of the void 4, the bag being extended sufficiently to fill the void 4 as seen in Fig. 3 A pressure regulating device 42 is contained within the outlet hose 28 and is set to ensure that the air pressure within the bag 14 does not exceed a predetermined maximum value. This value is chosen such that the bag, when extended, provides initial temporary support to the walls of the void to control further collapse but does not exert sufficient pressure on the support platform 10 to cause buckling of said platform.

A suitable pump (not shown) is then attached to the grout inlet hose 30 and liquid grout 44 is fed into the upper region of the bag through said hose and nozzle 24. The air pressure within the bag thus tries to increase, but the regulating device 42 in the outlet hose 28 enables said air to be displaced in a controlled manner from the bag through said outlet hose.

The liquid grout 44 fed into the bag falls to, and settles on, the bottom of said bag and is designed to solidify soon after insertion.

Feed of the liquid grout continues until said grout is seen to be coming out of the outlet hose 28.

The hose 32 enables further, secondary liquid grout 46 to be injected therethrough to the exterior of the filled bag 14, whereby any remaining void above said bag, or fissures connecting with said void can be completely filled, as seen in Fig. 3. Once this stage is reached, the extents of the hoses below the platform 10 are cut off and the repair is complete.

A collapse may be such as to require the location in the void so formed of more than one bag to enable complete filling of said void.

The bags will be provided in a number of different shapes and sizes to suit varying roadway widths. Rectangular-section bags are particularly suitable when filling of the void is to be achieved by locating a bag laterally across the roadway, as opposed to the longitudinal arrangement detailed above.

Plastics materials, which may or may not be elastic in nature, may be used for the bags, which materials will be such that there is no build up of static electricity therein.

The setting time of the liquid grout 44, 46 can be chosen to suit particular requirements and may vary from a few minutes to hours.

In an alternative method according to the invention, the rubble that has fallen from the roof into the tunnel is used as the support means for one or more flexible bags substantially as heretofore described. In such a method, a bag (or bags) is located on the rubble in the void, the bag preferably being of substantially rectangular section and positioned to extend laterally of the roadway. The bag is extended and filled with grout, in a manner substantially as detailed above, to fill the void.

The roadway is then re-formed by digging away the rubble and the lower part of the solidified grout, arches being located in position as required to support the roof of the roadway, said roof being formed by the remainder of the solidified grout.

It may not prove possible to gain access to a tubular portion such as 16 located substantially at the centre of a bag when said bag is located on rubble, in which case tubular por tions equivalent to that shown at 16 in Fig. 1 may be provided extending from one or both ends of the bag to enable pumping in of air and grout at one or both ends of the bag.

WHAT I CLAIM IS: 1. A method of repairing a collapsed roof within a mine below which collapse there is support means, the method comprising the steps of providing a bag of flexible material the extended shape of which can conform substantially with that of the void to be filled, positioning said bag in the void, feeding gas into the bag whereby said bag is extended substantially to fill the void above the support means, introducing, at the upper region of the bag, liquid filler material to fill said bag in such a manner that the gas is expelled therefrom without the pressure of said gas exceeding a predetermined maximum value, and allowing the filler material to set.

2. Apparatus for effecting the method of claim 1 comprising a bag of a flexible material the extended shape of which can conform substantially with that of the void to be filled, and inlet and outlet hoses communicating into the interior of said bag, the outlet hose incorporating therein a pressure regulating device adapted to prevent gas pressure within the bag exceeding a predetermined maximum value.

3. Apparatus as claimed in claim 2 in which the bag includes at least one tubular portion which, with the bag in use in its extended state, extends through the bag to terminate within. adjacent the upper region of, the bag, said tubular portion communicating with the interior of the bag only through the upper end thereof, the inlet and outlet hoses extending through said tubular portion to communicate, through said upper end of said portion, into the interior of the bag.

4. Apparatus as claimed in claim 3 in which each hose communicates into the upper region of the bag through an associated injection nozzle in the upper end of said tubular portion.

5. Apparatus as claimed in any one of claims 2 to 4 and comprising a gas inlet hose, a gas outlet hose and a primary liquid filler material inlet hose all communicating into the interior of the bag.

6. Apparatus as claimed in claim 5 and further comprising a secondary liquid filler material hose extending through, to terminate externally of, the bag.

7. Apparatus as claim in any one of claims 2 to 6 in which the bag is substantially cylindrical or rectanguloid in shape when extended.

8. A method of repairing a collapsed roof within a mine, the method being substantially as described herein with reference to the accompanying drawings.

9. Apparatus for effecting the method of claim 8, the apparatus being substantially as described with reference to and as illustrated by the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. tions equivalent to that shown at 16 in Fig. 1 may be provided extending from one or both ends of the bag to enable pumping in of air and grout at one or both ends of the bag. WHAT I CLAIM IS:

1. A method of repairing a collapsed roof within a mine below which collapse there is support means, the method comprising the steps of providing a bag of flexible material the extended shape of which can conform substantially with that of the void to be filled, positioning said bag in the void, feeding gas into the bag whereby said bag is extended substantially to fill the void above the support means, introducing, at the upper region of the bag, liquid filler material to fill said bag in such a manner that the gas is expelled therefrom without the pressure of said gas exceeding a predetermined maximum value, and allowing the filler material to set.

2. Apparatus for effecting the method of claim 1 comprising a bag of a flexible material the extended shape of which can conform substantially with that of the void to be filled, and inlet and outlet hoses communicating into the interior of said bag, the outlet hose incorporating therein a pressure regulating device adapted to prevent gas pressure within the bag exceeding a predetermined maximum value.

3. Apparatus as claimed in claim 2 in which the bag includes at least one tubular portion which, with the bag in use in its extended state, extends through the bag to terminate within. adjacent the upper region of, the bag, said tubular portion communicating with the interior of the bag only through the upper end thereof, the inlet and outlet hoses extending through said tubular portion to communicate, through said upper end of said portion, into the interior of the bag.

4. Apparatus as claimed in claim 3 in which each hose communicates into the upper region of the bag through an associated injection nozzle in the upper end of said tubular portion.

5. Apparatus as claimed in any one of claims 2 to 4 and comprising a gas inlet hose, a gas outlet hose and a primary liquid filler material inlet hose all communicating into the interior of the bag.

6. Apparatus as claimed in claim 5 and further comprising a secondary liquid filler material hose extending through, to terminate externally of, the bag.

7. Apparatus as claim in any one of claims 2 to 6 in which the bag is substantially cylindrical or rectanguloid in shape when extended.

8. A method of repairing a collapsed roof within a mine, the method being substantially as described herein with reference to the accompanying drawings.

9. Apparatus for effecting the method of claim 8, the apparatus being substantially as described with reference to and as illustrated by the accompanying drawings.