An asymmetric coordinated support device for gob side entry is provided. The device includes an inner support board, an outer roadway side support assembly, an outer roof support assembly, and a flexible reinforcement layer, wherein the inner support board is supported to an innermost side closest to a rock layer to be supported in an extending direction of the roadway, and wherein a side of the inner support board remote from the rock layer is provided with the outer roadway side support assembly extending along the roadway direction and the outer roof support assembly located on a roof of the outer roadway side support assembly.

Disclosed is a grout anchored rock bolt which includes an elongate cylindrical body of a suitable material which has at least one integral anchor portion which includes of a plurality projection, each of which extends laterally from the body in at least one radial direction, wherein the projections are consecutively serially arranged along the length of the anchor portion and wherein each projection is radially offset relatively to the preceding formation at an angle that is not orthogonal.

An assembly which includes a first member with torque transmission elements, and a coupler which connects together, in a rotatably driving relationship, the first member and a second member. The coupler includes an intermediate section disposed between an axial forward end and an axial rearward end of the coupler, a forward section extending between the intermediate section and the axial forward end, and a rearward section extending between the intermediate section and the axial rearward end. The intermediate section includes torque transmission elements for engaging with the torque transmission elements of the first member, to facilitate transmission of torque from the first member to the coupler. The torque transmission elements of the coupler are automatically brought into a torque-transmitting relationship with the torque transmission elements of the first member when the coupler is engaged with the first member. Other variants and embodiments are broadly contemplated herein.

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.

A bolting and drilling system comprising a vehicle, a gantry mounted to the vehicle, a boom assembly having a first end mounted to the gantry and a second end having a first quick connector and a second quick connector. The system includes a bolter assembly connectable to the first quick connector, wherein the bolter assembly comprises a stinger, a drill and a bolter for stinging, drilling and bolting a roof of an underground mine. The system includes a drill feed assembly connectable to the second quick connector, wherein the drill feed assembly comprises a drill for drilling a rock face of a heading. The drill feed assembly is longer than the bolter assembly.

A friction bolt assembly to frictionally engage a bore formed in rock strata. The assembly includes an elongate tube and an expander mechanism acted on by an anchor mechanism via an elongate bar or cable. A retainer mechanism is mounted to act between the bar or cable and the tube to prevent ejection of the bar or cable from the assembly should the bar or cable break.

The present disclosure relates to a construction method for a deformable anchor cable capable of being prestressed. The anchor cable includes an outer sleeve, a shrinkage pipe, an inner sleeve, a steel strand, an anchor and a tray. When the anchor cable is in use, a hole is drilled first, then the anchor cable is mounted in the drilled hole, and finally a prestress is applied to the steel strand of the anchor cable. According to the construction method, the construction is convenient; the anchor cable has the characteristics of high strength and large deformation, and can be easily prestressed; and the large deformation is realized by squeezing the inner sleeve by means of the anchor, which completely overcomes the problem of breaking a cold-drawn rod during the large deformation process.

A cable bolt assembly is disclosed comprising a cable bolt having a shaft, an end fitting disposed on the shaft and including an end fitting body. Mechanical interlocking is provided between the body and the shaft to form a connection therebetween. The mechanical interlocking may be formed directly between the body and the shaft and/or by engagement formations disposed intermediate the body and shaft. The body further including an exterior profiling arranged to engage a further component of the end fitting to install and/or tension the cable bolt assembly in use. A method of forming the cable bolt assembly is also disclosed.

Disclosed is a resin bolt which includes an elongate shaft which extends between a leading end and a trailing end and a positioning head which is integral to the shaft at the leading end and which extends in the elongate axis of the shaft from a perimeter rim to a crown, with the head formed with a plurality of projections, with each projection extending laterally, beyond the radial dimension of the shaft and each projection having a leading surface which slopes, at least partially, from the crown to the perimeter rim, and a trailing surface from the perimeter rim to the shaft.

Disclosed is a resin bolt which includes an elongate shaft which extends between a leading end and a trailing end and a positioning head which is integral to the shaft at the leading end and which extends in the elongate axis of the shaft from a perimeter rim to a crown, with the head formed with a plurality of projections, with each projection extending laterally, beyond the radial dimension of the shaft and each projection having a leading surface which slopes, at least partially, from the crown to the perimeter rim, and a trailing surface from the perimeter rim to the shaft.