The support 10 of the present invention resembles a conventional Acrow prop which may be used for temporarily supporting a load. In particular, the present invention is arranged to support a surface at a static position. For example, the surface may comprise a ceiling/beam/lintel within a structure wherein the usual permanent supports for the ceiling/beam/lintel are being replaced or deemed temporarily insufficient. However, the present invention can be used in numerous situations where a support 10 is required and for which the support 10 can be quickly and easily installed. The present invention provides (hydraulic) movement means to move the upper end relative to the lower end. In addition, the present invention provides retraction prevention means to prevent the upper end moving towards the lower end while supporting the load and prevents the inner core member 14 being forcibly retracted back into the outer sleeve member 12 due to the compressive force of the load. A hydraulic ram 22 has a maximum extension limit and the present invention uses an adjustable mounting/abutment mechanism which means that a relatively small hydraulic ram 22 can be installed in the outer sleeve member 12. This size of hydraulic ram 22 will then be suitable for all heights and the support is not limited to simply being moveable within a restricted range.

The present invention relates to a mining method including the step of forming one or more sets of gate roads. Each set of gate roads includes at least two headings typically for providing and retuning ventilation. Dead end plunge cuts extend from the sets of gate roads. Each plunge cut is formed with a continuous miner coupled to a flexible conveyor system. Each plunge cut is greater than 30 meters in length. Advantageously, narrow elongate pillars may be left between adjacent plunge cuts, thereby resulting in greater material removal per volume and improved operating costs when compared with bord and pillar mining.

The present invention relates to a mining method including the step of forming one or more sets of gate roads. Each set of gate roads includes at least two headings typically for providing and retuning ventilation. Dead end plunge cuts extend from the sets of gate roads. Each plunge cut is formed with a continuous miner coupled to a flexible conveyor system. Each plunge cut is greater than 30 meters in length. Advantageously, narrow elongate pillars may be left between adjacent plunge cuts, thereby resulting in greater material removal per volume and improved operating costs when compared with bord and pillar mining.

A fractured roof 110 mining method entry-side anti-collapsed structure, one working face of the 110 mining method corresponds to one roadway but without retaining any coal pillar, the roadway retains an entry after the previous working face implements mining top-cutting pressure release, and a roof of the roadway is arch-shape, directional cutting is conducted on one side of the roadway, and the cutting angle is between 15-20 degrees. One working face corresponds to one roadway but without retaining any coal pillar when underground mining is conducted, which can save resources and improve recovery rate of mining. And, the roof of the roadway of the retained entry is arch-shaped, which can improve safety and ensure safety of the coal mining working face. In addition, a cutting angle is 15-20 degrees, which can effectively determine a roof caving direction after top-cutting and reduce affect to the retained entry.

A fractured roof 110 mining method entry-side anti-collapsed structure, one working face of the 110 mining method corresponds to one roadway but without retaining any coal pillar, the roadway retains an entry after the previous working face implements mining top-cutting pressure release, and a roof of the roadway is arch-shape, directional cutting is conducted on one side of the roadway, and the cutting angle is between 15-20 degrees. One working face corresponds to one roadway but without retaining any coal pillar when underground mining is conducted, which can save resources and improve recovery rate of mining. And, the roof of the roadway of the retained entry is arch-shaped, which can improve safety and ensure safety of the coal mining working face. In addition, a cutting angle is 15-20 degrees, which can effectively determine a roof caving direction after top-cutting and reduce affect to the retained entry.

Disclosed are an anti-spalling blocking bar for a large cross-section coal gallery excavation work surface and a supporting method. The anti-spalling blocking bar comprises a blocking bar (1) and a support bar (7). Both a top portion of the blocking bar and an end of the support bar are provided with screw holes (2). A steel peg (5) is provided on an outer side of a bottom portion of the blocking bar. Locking teeth (6) is provided on an inner side of a mid-upper portion of the blocking bar, and a locking catch (8) is provided on one end of the support bar. The blocking bar and support bar are secured, using the screw hole and a screw bolt, to a temporary support device. After removing coal, a tool is used to hammer the blocking bar so as to wedge the steel peg thereof into a coalface (13). The locking catch of the support bar is held within the locking teeth to support a coal heading. After use, the blocking bar and support bar can be retrieved and suspended, using a hanging device, from the temporary support device. The anti-spalling blocking bar offers the advantages of easy installation, good support, reusability, convenient storage, and the like. The invention reduces the probability of personnel injury caused by coal loosening and falling from the heading, shortens the time for establishing coal heading support, and enhances a safety index and an excavation speed of a large cross-section coal gallery excavation work surface.

An equipment system for a self-retaining mining method mainly comprises a transition support, an end support, a following support, and a fast-retracting support. Working face gateroads do not need to advance in mining, and a coal mining machine may be used to cut a neat coal wall at the end of a district. The entry rib is automatically formed after roof caving, thus forming a gateroad in a re-mining process. The coal mining machine is under digital control when its end cuts the coal, automatically enabling the end to laterally cut the coal wall to form a vertical straight line, which is used as the entry rib of the gateroad. A scrapper conveyor works in coordination with an arc-shaped coal grabbing plate of the coal mining machine to clean up float coal at the end as much as possible.

A pumpable mine ventilation stopping wall structure comprised of a pumpable bag having spaced walls of generally parallel nonporous and flexible sheets with the sheets retained in spaced relationship with spaced flexible cross ties. The perimeter of the spaced walls may be closed off with a permeable mesh having a mesh size which will permit restricted flow of cementitious grout therethrough for sealing the wall structure to surrounding rough mine faces. The bag is provided with at least one grout fill port for filling the bag by pumping cementitious grout into the bag.

A longitudinally yieldable support for underground roof support includes first and second outer shell portions having a first wall thickness and a third outer shell portion having a second wall thickness that is greater than the first wall thickness. The support is filled with a solid compressible filler material. At least one air ventilation tube extends between opposite sides of the third outer shell portion to allow a flow of air through the support as the first and second outer shell portions and filler material therein yield under load.

A yielding mine roof support is provided which is made in the form of a hollow tube made from an epoxy, phenolic, or polyester fiberglass composite.