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 metres 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 metres 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.

An internally injected replacement support room-type coal pillar recovery method is provided. During the recovery, the room-type coal pillars with an aspect ratio greater than 0.6 are divided into two parts: reserved coal pillars and pre-mined coal pillars. After the mining of the pre-mined coal pillars, a cemented filling material is injected into a goaf surrounded by the reserved coal pillars, and is stabilized to replace the coal pillars for support, and the reserved coal pillars are recovered. A mechanical model of the reserved coal pillars in a support overburden stage is established based on the Winkler beam theory, to obtain displacement and stress conditions of a roof of the reserved coal pillar in a support stage. A theoretical reserve-width of the reserved coal pillars is obtained according to a first strength theory of the roof and a criterion of ultimate strength of the reserved coal pillars.

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.

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 hydraulic support monitoring a support pose in real time based on an inertia measurement unit (IMU) and a detection method thereof. In the hydraulic support, IMU sensors are separately mounted on a roof beam, a rear linkage, and a base, and an auxiliary support pose monitoring system is disposed. Each IMU sensor measures movement states of the roof beam, the rear linkage, and the base of the support in real time, and the support pose monitoring system processes the movement states to monitor a support pose of the hydraulic support in real time. Especially, it can be technically determined whether the hydraulic support is adequately lowered, moved or raised, thereby effectively reducing the labor intensity of workers and improving the working efficiency of the hydraulic support.

A system or method for a structural mine roof support includes a roof support apparatus that includes a cylindrical cladding defining a hollow interior, a plurality of bamboo sections disposed in the hollow interior and coaxial with an axis of the cylinder. Also, a roof support apparatus with a cylindrical cladding defining a hollow interior, a plurality of bamboo sections disposed in the hollow interior and coaxial with an axis of the cylinder, and voids between adjacent bamboo sections, the voids being injected with a filler material, e.g., polyurethane foam, to maintain axial positioning of the bamboo sections when under load. The support apparatus configured to load and to yield in a predetermined fashion to control a mine roof from sudden failure.

An internally injected replacement support room-type coal pillar recovery method is provided. During the recovery the room-type coal pillars with an aspect ratio greater than 0.6 are divided into two parts: reserved coal pillars and pre-mined coal pillars. After the mining of the pre-mined coal pillars, a cemented filling material is injected into a goaf surrounded by the reserved coal pillars, and is stabilized to replace the coal pillars for support, and the reserved coal pillars are recovered. A mechanical model of the reserved coal pillars in a support overburden stage is established based on the Winkler beam theory, to obtain displacement and stress conditions of a roof of the reserved coal pillar in a support stage. A theoretical reserve-width of the reserved coal pillars is obtained according to a first strength theory of the roof and a criterion of ultimate strength of the reserved coal pillars.

A method of recovering a room-and-pillar coal pillar by using external replacement supports. In the recovery of a room-and-pillar coal pillar, a cement material wall is formed by performing pouring around a coal pillar having a width to height ratio of less than 0.6, by means of a single-pillar sack arrangement technique, such that a coal pillar resource may be mined while a wall made from a cement filling material supports an overlying stratum. After mining is complete, a coal pillar goaf region is filled with the cement filling material, and after the cement filling material solidifies and is stable, the single pillar can be recovered.

A load bearing support includes a cylindrical drum. A top portion, a bottom portion, a tapered cylindrical sidewall extends between the top and bottom portions. A core member extends between the top and bottom portions, and a load-bearing material is disposed between the sidewall and the core member. An opening extends through the top portion of the drum to receive load-bearing material. Each of the top portion and the bottom portions has a reinforcing chime. The core member includes a lateral transfer zone defined at one or more points along a vertical axis of the core member. The lateral transfer zone distributes an axial load on the drum to the cylindrical sidewall. The cylindrical sidewall provides a radial expansion area for compression of the core member and the load-bearing material.