An NPR rock bolt according to the present disclosure comprises a bolt body (1), a tray (2) and a lock (3). The bolt body (1) is an NPR spiral steel bar, an outer surface of the NPR spiral steel bar is provided with a number of convex spiral ribs, and the spiral ribs have a spiral structure. The tray (2) and the lock (3) are directly sleeved on a tail of the NPR spiral steel bar. The NPR bolt according to the present disclosure can effectively solve the problem in the prior art that conventional rock bolts have a low elongation and cannot meet the requirement of large deformation of the surrounding rock.

An NPR rock bolt according to the present disclosure comprises a bolt body (1), a tray (2) and a lock (3). The bolt body (1) is an NPR spiral steel bar, an outer surface of the NPR spiral steel bar is provided with a number of convex spiral ribs, and the spiral ribs have a spiral structure. The tray (2) and the lock (3) are directly sleeved on a tail of the NPR spiral steel bar. The NPR bolt according to the present disclosure can effectively solve the problem in the prior art that conventional rock bolts have a low elongation and cannot meet the requirement of large deformation of the surrounding rock.

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 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.

Embodiments of the present invention relate to a rock anchor with condition monitoring for determining tensions or deformations in form of a conductor trace which is applied on an anchor body, whose electrical resistance changes proportionally with respect to the tension/deformation. The conductor trace may consist of an electrically conductive ink which is directly applied on the anchor body by a printing method.

Embodiments of the present invention relate to a rock anchor with condition monitoring for determining tensions or deformations in form of a conductor trace which is applied on an anchor body, whose electrical resistance changes proportionally with respect to the tension/deformation. The conductor trace may consist of an electrically conductive ink which is directly applied on the anchor body by a printing method.

A collaborative erosion-control method of releasing-splitting-supporting based on coal mass pressure relief and roof pre-splitting provided by the disclosure includes the following steps: step 1, driving into a coal seam to release pressure; step 2, low roof pre-splitting during driving process; step 3, supporting of roadway surrounding rock and support reinforcement; step 4, floor destressing of the roadway; step 5, high roof pre-splitting before mining; step 6, distress sing and supporting of the advanced roadway surrounding rock during the mining process of the working face. The collaborative erosion-control method of releasing-splitting-supporting based on coal mass pressure relief and roof pre-splitting, and to carry out local pressure relief, roof pre-splitting and reinforcement support construction in the whole cycle of the coal working face in a progressive manner, so as to achieve the prevention and control of rock burst in the working face.

A collaborative erosion-control method of releasing-splitting-supporting based on coal mass pressure relief and roof pre-splitting provided by the disclosure includes the following steps: step 1, driving into a coal seam to release pressure; step 2, low roof pre-splitting during driving process; step 3, supporting of roadway surrounding rock and support reinforcement; step 4, floor destressing of the roadway; step 5, high roof pre-splitting before mining; step 6, distress sing and supporting of the advanced roadway surrounding rock during the mining process of the working face. The collaborative erosion-control method of releasing-splitting-supporting based on coal mass pressure relief and roof pre-splitting, and to carry out local pressure relief, roof pre-splitting and reinforcement support construction in the whole cycle of the coal working face in a progressive manner, so as to achieve the prevention and control of rock burst in the working face.

A component and method for evaluating load at a mine roof. An embossed bearing plate and a reinforcing washer are combined to thereby form a bearing system, wherein the bearing plate is a grade 2 plate (“x−1”), the bearing plate including a back surface which is adapted to contact a mine roof, an opposite surface and an aperture through which a shaft portion of a bolt can extend, the reinforcing washer including a rigid member having a first surface shaped to contact and complement the opposite surface of the bearing plate, a second opposing surface and a washer hole for alignment with the aperture through which the shaft can extend; driving a bolt with the shaft through the bearing system into a location of the mine roof, and, inspecting a curl of the grade 2 plate, wherein the curl and uniformity thereof is indicative of a load of around 20,000 pounds at the location.

A component and method for evaluating load at a mine roof. An embossed bearing plate and a reinforcing washer are combined to thereby form a bearing system, wherein the bearing plate is a grade 2 plate (“x−1”), the bearing plate including a back surface which is adapted to contact a mine roof, an opposite surface and an aperture through which a shaft portion of a bolt can extend, the reinforcing washer including a rigid member having a first surface shaped to contact and complement the opposite surface of the bearing plate, a second opposing surface and a washer hole for alignment with the aperture through which the shaft can extend; driving a bolt with the shaft through the bearing system into a location of the mine roof, and, inspecting a curl of the grade 2 plate, wherein the curl and uniformity thereof is indicative of a load of around 20,000 pounds at the location.