The present invention discloses a self-anchored opposite-pulling anti-impact anchor cable for sectional coal pillars and a using method thereof. The anchor cable includes a steel strand (100), with an energy-absorbing and yielding terminal (200) and a stressed expansion-cracking terminal (300) respectively fixed to two ends of the steel strand, a bushing (400) sleeved outside the steel strand, a first lock (610) provided at one end of the steel strand and a second lock (620) provided at the other end of the steel strand; the stressed expansion-cracking terminal includes a self-anchored bushing (420) with a plurality of pre-splitting lines (440) arranged in the wall of the self-anchored bushing. Under stress, the wall of the self-anchored bushing cracks along the pre-splitting lines and bends and expands, so that it abuts against and is self-anchored to the edge of a sectional coal pillar at the outer side.

A friction rock bolt assembly is arranged to frictionally engage an internal surface of the bore formed in rock strata. The rock bolt includes a loading mechanism provided at a rearward end of the rock bolt having a load absorber to absorb an initial predetermined loading force followed by transfer of the force to a main load element.

Disclosed is a method of adapting a metal bar, for use as a rock bolt, to ensure that the bar will break in a predictable manner, the method including the step of removing material from the bar in a circumferential band to reduce a diameter of the bar within the band to a minor diameter thereby to provide a failure zone within which the bar will break if subjected to enough tensile load.

The invention provides an umbrella-shaped anchor for rapid reinforcement of rock mass. The umbrella-shaped anchor for rapid reinforcement of the rock mass comprises an umbrella-shaped anchor head and a connecting rod. The umbrella-shaped head comprises the sliding mechanism, bearing block, guide block and main rod of anchor head. The main rod of anchor head is connected with the sliding mechanism after passing through the through-hole located in the middle of the guide block The sliding mechanism is connected with the connecting rod through the main rod of the anchor head. The multiple upper parts of bearing blocks are respectively inserted into the groove of the guide block, and they are fully fitted with the side guide rail of the sliding mechanism During installation, after the umbrella anchor head and connecting rod in the retracted state are extended into the anchor hole, the connecting rod is tensioned to drive the sliding mechanism to extrude the bearing block to open outwards and squeeze with the hole surface. The invention converts the tensile force of the anchor rod into the extrusion pressure on the rock mass, and obtains the larger anchoring force by using the higher compressive strength of the rock mass. The invention has the advantages of large applicable depth, fast construction speed, high efficiency, no grouting, large structural resistance and good stability.

A self-drilling rock anchor assembly includes: a friction fit tubular sleeve extending longitudinally between leading and trailing ends; a rod extending through the sleeve between first and second ends, and projecting from each sleeve end; a drill bit member engaged with the rod's first end having an exterior surface part of which tapers towards a back end of the member; a backstop element engaged with the rod's second end having a first drive surface; a load bearing element on the rod between the sleeve's trailing end and the backstop that has a second drive surface. The rod moves relative to the sleeve between a drill position, wherein the drill bit is spaced from the sleeve's leading end, and an insertion position, wherein the sleeve's leading end abuts the bit. The drill and insertion positions are achieved by applying a force to the first and second drive surfaces, respectively.

A self-drilling rock anchor assembly includes: a friction fit tubular sleeve extending longitudinally between leading and trailing ends; a rod extending through the sleeve between first and second ends, and projecting from each sleeve end; a drill bit member engaged with the rod's first end having an exterior surface part of which tapers towards a back end of the member; a backstop element engaged with the rod's second end having a first drive surface; a load bearing element on the rod between the sleeve's trailing end and the backstop that has a second drive surface. The rod moves relative to the sleeve between a drill position, wherein the drill bit is spaced from the sleeve's leading end, and an insertion position, wherein the sleeve's leading end abuts the bit. The drill and insertion positions are achieved by applying a force to the first and second drive surfaces, respectively.

The present invention provides a retainer device 1 for retaining or holding an anchor rod 11 of a rock anchor, especially a self-drilling anchor, in a hole H drilled above horizontal. The retainer device 1 comprises: a body portion 2 configured to be mounted on the anchor rod 11, and especially on an outer or external periphery of the anchor rod, and at least one locking arm or tab 6, 7 that projects from the body portion 2 in a direction transverse to a longitudinal extent of the anchor rod 11. The body portion 2 is configured for movement relative to the anchor rod 11 in use, and the at least one arm or tab 6, 7 is configured to deform so as to engage and bear against an inner wall W of the hole H when the retainer device 1 mounted on the anchor rod 11 is driven into the hole H. The invention also relates to a rock anchor system 10, comprising: at least one elongate anchor rod 11; a drill bit 12 configured for attachment to one end region 13 of the elongate anchor rod 11 for drilling the anchor rod 11 into rock strata R; and at least one retainer device 1 according to the invention described above for retaining or holding the anchor rod 11 in a hole H drilled in the rock strata R above horizontal. The invention also provides a method for installing a rock anchor.

It discloses a grouting bolt-cable composite beam and supporting method for advanced support of fractured surrounding rock in deep coal mines. The quadrate plates are fixed at both ends of the steel beam, the anchor cable holes are arranged in the center of the steel beam and the quadrate plates, and the diameter of anchor bolt holes should be larger than that of the grouting cables. There are four anchor bolt holes on each quadrate plate, and each anchor bolt hole corresponds to a anchor plate, the horizontal surface of the anchor plate is close to the quadrate plate, and the arc parts of the four anchor plates are all facing the center of the quadrate plate.

An anchor rod includes a sleeve open at one end and having a blocking plate at the other end; a pressure relief pipe fixedly arranged on an inner wall of the sleeve; and a rod body. A guide hole is formed in a center of the blocking plate. A part of the rod body penetrates through the guide hole and extends into the sleeve. A gap is formed between the pressure relief pipe and the blocking plate. An overflow valve is connected to the pressure relief pipe. A piston in sliding seal fit with the sleeve and the pressure relief pipe is arranged at the rod body. A sealing ring in sliding seal fit with the rod body is arranged at the inner wall of the guide hole; and a sealing cavity between the blocking plate and the piston in the sleeve is filled with emulsion.

A rock bolt and meshing assembly is arranged for installation of a meshing sheet against a surface of rock strata. The rock bolt includes an adapter having a first portion connectable to a trailing end of an elongate shaft of the rock bolt and means configured to receive and mount a meshing clamp to overlay a second section of meshing sheet against an already laid first section of meshing sheet.