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 drilling and bolting rig includes a carousel rotatable about a carousel axis and including a plurality of stations configured to support a plurality of consumables, one or more actuators, and a position sensor coupled to the carousel. The one or more actuators are configured to rotate the carousel about the carousel axis. The drilling and bolting rig further includes an electronic processor coupled to the one or more actuators and the position sensor. The electronic processor is configured to detect, using the position sensor, a rotational position of the carousel, and rotate, using the one or more actuators, the carousel based on the rotational position of the carousel.

Amorphous calcium carbonate is included in a fire-resistant inorganic mortar system for a fire-resistant chemical fastening of anchors and post-installed reinforcing bars in mineral substrates. The system includes a curable aluminous cement component A and an initiator component B for initiating the curing process. The component A includes at least one blocking agent selected from the group of phosphoric acid, metaphosphoric acid, phosphorous acid and phosphoric acids, at least one plasticizer and water. The component B includes an initiator, at least one retarder, at least one mineral filler and water. Moreover, amorphous calcium carbonate in a fire-resistant inorganic mortar increases load values. Also, a method is used for a fire-resistant chemical fastening of anchors and post-installed reinforcing bars in mineral substrates, such as structures made of brickwork, concrete, pervious concrete or natural stone.

The present invention discloses a type of energy-absorbing rock bolt device with umbrella-shaped structure, which consists of a body of bolt, and one end of the said body of bolt is equipped with a preloaded system, as well as the other end of the said body of bolt is equipped with the first support system, in addition, the said body of bolt is equipped with several second support systems, and the said second support system is located between the said preloaded system and the said first support system; meanwhile, the said second support system consists of the first umbrella-shaped support system and the second umbrella support system.

The disclosure relates to a hollow rod shear connector for stabilizing rock layers in mining, tunnel construction, civil engineering and rock construction, at least having a connector base with one or more outlet channels and a hollow rod which can be fastened to the connector base and comprises a static mixing apparatus adjoining the connector base, a cartridge, divided by a partition into two compartments, for receiving chemical fastening means, and a two-part plunger corresponding to the compartment division, wherein the static mixing apparatus consists of a plurality of mixing elements one behind the other, wherein the flow direction of the chemical fastening means is changed by greater than or equal to 150° and less than or equal to 210° at least twice along the static mixing apparatus. The present disclosure also relates to a method for setting a hollow rod shear connector in a rock layer.

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, e.g., 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 to engage an abutment or shoulder on the outer or external periphery of the anchor rod to prevent its 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.

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.

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.