A rock bolt dolly for connecting a self-drilling rock bolt to a rock bolting apparatus includes a drive shaft having a central bore and defining a proximal end and a distal end defining an engagement means for engagement with a corresponding engagement means located on the proximal end of the rock bolt. A sleeve is mounted over the distal end of the drive shaft and arranged to slide along and over the drive shaft and defines a female engagement means at a distal end, for engaging with a nut threaded onto the proximal end of the rock bolt. The interior of the sleeve and exterior of the drive shaft are configured to rotate together about their central axis. A spring biases the distal end of the sleeve away from the distal end of the drive shaft. The dolly operates in two modes, one in which the nut and rod rotate together, and a second where the nut rotates on the rod.

A drilling assembly for simultaneously drilling a hole and inserting a friction bolt, the drilling assembly comprising a drill string, a drill bit and a friction bolt, wherein: (i) the drill string defines a leading end adapted to releasably operatively connect to the drill bit and a trailing end adapted to operatively engage with a means for imparting energy on said drill string; (ii) the drill bit is mounted on the leading end of said drill string; (iii) the friction bolt at least partially surrounds said drill string; and wherein (iv) the drilling assembly further comprises an elongate spacer that defines a leading end and a trailing end and is located between said friction bolt and said means for imparting energy on said drill string.

A tunnel constraint anchor cable and a method for improving stability of an initial support structure. The tunnel constraint anchor cable comprises steel strands (1) anchored in surrounding rock, first anchor plates (2) and first anchorage devices (3) which are installed on the surface of the surrounding rock, longitudinal connection members (5) installed between two adjacent steel ribs (4), and second anchor plates (6) and second anchorage devices (7) which are installed on the longitudinal connection members (5). With the support of the tunnel constraint anchor cable, the ability of the initial support structure to resist self instability and destruction is improved, overall settlement and convergence deformation of the initial support structure can also be suppressed. The method for improving stability of an initial support structure has the characteristics of simplicity, speed, reliability, and avoiding interference with subsequent construction processes of tunnels.

A rock bolt includes a tube having a leading end and a trailing end. An expander mechanism is disposed within the tube near the leading end. An elongate bar is disposed within the tube and is connected at a first end with the expander mechanism and at a second end with an anchor arrangement positioned at the trailing end of the tube. The elongate bar is arranged to actuate the expander mechanism and remain connected between the expander mechanism and the anchor arrangement while the expander mechanism is actuated. The tube has a displaceable wall section at the leading end, which has a hinge end proximal the leading end connecting the displaceable wall section to the tube. The expander mechanism can be actuated to displace the displaceable wall section to rotate about the hinge end to shift the anchor end outwardly from the tube.

A rock bolt dolly for connecting a self-drilling rock bolt to a rock bolting apparatus includes a drive shaft having a central bore and defining a proximal end and a distal end defining an engagement means for engagement with a corresponding engagement means located on the proximal end of the rock bolt. A sleeve is mounted over the distal end of the drive shaft and arranged to slide along and over the drive shaft and defines a female engagement means at a distal end, for engaging with a nut threaded onto the proximal end of the rock bolt. The interior of the sleeve and exterior of the drive shaft are configured to rotate together about their central axis. A spring biases the distal end of the sleeve away from the distal end of the drive shaft. The dolly operates in two modes, one in which the nut and rod rotate together, and a second where the nut rotates on the rod.

A mine bearing element for holding a mesh sheet in place against a rock formation is disclosed. The mine bearing element includes a body having (a) a rock bolt engagement portion, (b) a mesh engagement portion, and (c) a transition that connects together the mesh engagement portion and the rock bolt engagement portion in an as-manufactured form of the bearing element. The transition includes a stiffening rib.

A rock bolt dolly for connecting a self-drilling rock bolt to a rock bolting apparatus includes a drive shaft having a central bore and defining a proximal end and a distal end defining an engagement means for engagement with a corresponding engagement means located on the proximal end of the rock bolt. A sleeve is mounted over the distal end of the drive shaft and arranged to slide along and over the drive shaft and defines a female engagement means at a distal end, for engaging with a nut threaded onto the proximal end of the rock bolt. The interior of the sleeve and exterior of the drive shaft are configured to rotate together about their central axis. A spring biases the distal end of the sleeve away from the distal end of the drive shaft. The dolly operates in two modes, one in which the nut and rod rotate together, and a second where the nut rotates on the rod.

A rock bolt device with replaceable head is provided comprised of an enhanced rock bolt assembly for ground support in mining and tunneling, designed to address bolt head damage, mesh displacement, and repair complexities while ensuring continuous structural stability and safety. The assembly comprises a threaded bolt shaft, a bolt head, a face plate, a wire mesh, and a flange that secures the plate and mesh. The face plate distributes load evenly across the rock surface, stabilizing loose rock, while the mesh, positioned behind the plate, remains tensioned and securely clamped, preventing sagging or dislodgement even in case of bolt head failure. The flange, serving as a secondary anchoring point, incorporates a calibrated weak point designed to fail cleanly upon impact, enabling bolt head detachment without damaging the bolt shaft or plate. The bolt head can be replaced by re-engaging fasteners, simplifying repairs and reducing costs.

A rock bolt includes a tube having a leading end and a trailing end. An expander mechanism is disposed within the tube near the leading end. An elongate bar is disposed within the tube and is connected at a first end with the expander mechanism and at a second end with an anchor arrangement positioned at the trailing end of the tube. The elongate bar is arranged to actuate the expander mechanism and remain connected between the expander mechanism and the anchor arrangement while the expander mechanism is actuated. The tube has a displaceable wall section at the leading end, which has a hinge end proximal the leading end connecting the displaceable wall section to the tube. The expander mechanism can be actuated to displace the displaceable wall section to rotate about the hinge end to shift the anchor end outwardly from the tube.