An anchor bolt length determination method based on monitoring of a roof rock stratum horizontal extrusion force includes drilling a borehole in the middle of a roadway roof to determine a surrounding rock fracturing scope by a borehole television. The method includes selecting the number and locations of horizontal extrusion force measuring points according to the surrounding rock fracturing scope. The method includes monitoring and recording a change of the horizontal extrusion force over time in the borehole by a device for monitoring a roof rock stratum horizontal extrusion force. The method includes selecting a location with the largest horizontal extrusion force as a center of a anchoring segment of an anchor bolt to determine a distance between the anchoring center and the roof. The method includes calculating a total length of the anchor bolt.

The present invention provides a safety system (1) for protecting against a hazard of a drill rod failure in a drilled rock bore (B) above horizontal, and especially a hazard posed by a broken drill rod section (S) lodged within the bore (B). The safety system (1) comprises: a plug member (2) for insertion into a proximal end region (E) of the bore (B) adjacent a rock-face (F), the plug member (2) being configured to be fixed within the proximal end region (E) of the bore (B); and an impact reduction member (5) for reducing an impact of the broken drill rod section (S) striking the plug member (2) within the proximal end region (E) of the bore (B). The impact reduction member (5) is configured to be located within the proximal end region (E) of the bore (B) and to extend within the bore (B) above the plug member (2).

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.

A monitoring system includes a fastener. A sensor is coupled to the fastener. A circuit board is electrically coupled to the sensor. An antenna electrically coupled to the circuit board.

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.

The present invention provides a safety system (1) for protecting against a hazard of a drill rod failure in a drilled rock bore (B) above horizontal, and especially a hazard posed by a broken drill rod section (S) lodged within the bore (B). The safety system (1) comprises: a plug member (2) for insertion into a proximal end region (E) of the bore (B) adjacent a rock-face (F), the plug member (2) being configured to be fixed within the proximal end region (E) of the bore (B); and an impact reduction member (5) for reducing an impact of the broken drill rod section (S) striking the plug member (2) within the proximal end region (E) of the bore (B). The impact reduction member (5) is configured to be located within the proximal end region (E) of the bore (B) and to extend within the bore (B) above the plug member (2).

A monitoring system includes a fastener. A sensor is coupled to the fastener. A circuit board is electrically coupled to the sensor. An antenna electrically coupled to the circuit board.

Provided is a mounting method for an extensible reaming self-anchoring anchor rod, which is especially applicable to roadway construction in coal mines. A big helical structure is arranged on two rod sections of a sectional type anchor rod, a simple drill bit drills and reams a bore and cuts the coal mass in one operation, the outer diameter of the simple drill bit is smaller than the outer diameter of the big helical rod body, and the big helical structure accomplishes secondary reaming, self-drilling and self-anchoring in the drilling process; the big helical structure inhibits propagation and development of sheet cracks of the coal wall in the radial direction, and is embedded in the coal mass through a self-stabilization process of the rock mass.

Provided is a mounting method for an extensible reaming self-anchoring anchor rod, which is especially applicable to roadway construction in coal mines. A big helical structure is arranged on two rod sections of a sectional type anchor rod, a simple drill bit drills and reams a bore and cuts the coal mass in one operation, the outer diameter of the simple drill bit is smaller than the outer diameter of the big helical rod body, and the big helical structure accomplishes secondary reaming, self-drilling and self-anchoring in the drilling process; the big helical structure inhibits propagation and development of sheet cracks of the coal wall in the radial direction, and is embedded in the coal mass through a self-stabilization process of the rock mass.

A bung has a body which extends between a leading end and a trailing end and which includes an inner part of a rigid material which has a cylindrical aperture for receiving a rock bolt and an outer sealing part of a resiliently deformable material circumscribing the inner part. The inner part and the outer part engage at an interface which has a co-efficient of friction which allows the outer part to disengage from the inner part at the interface when a shear force above a predetermined level is applied to the outer part or the inner part.