A rock bolt includes an elongate metallic body having a first end and an opposed second end, a threaded portion at the second end, for attaching thereto and locating thereon, a nut and a bearing plate, a mechanical anchor at, or at least partially located on, a first end portion of the body and a first resistive anchor, located between the threaded portion and the mechanical anchor.

The disclosure relates to a device for reinforcing a ground on which is disposed a loading structure. Threaded inclusions are disposed vertically within the ground and reinforce said ground. The core diameter of threaded inclusions is between 250 mm and 450 mm and the external diameter is between 350 mm and 600 mm. A load transmitting layer is interposed between the ground and the loading structure disposed thereon, so as to transmit and distribute the load from the loading structure to both the ground and the plurality of inclusions. A ratio between a distance between axes of two adjacent inclusions and the internal diameter of said adjacent inclusions is between 4 and 14, and the inclusions are made from a material having a specified 28-day compressive strength between 5 MPa and 35 MPa.

Disclosed is a rock bolt assembly including: an elongate bolt extending with distal and proximal ends; a tubular sleeve longitudinally extending between leading and trailing ends on the bolt so at least a proximal end portion projects from the trailing end of the sleeve; and a nozzle docking bush on the proximal end portion between the sleeve's trailing end and the bolt's proximal end. The bush has a cylindrical body between first and second ends, a central hole extending through the body, spaced-apart annular ridges on the cylindrical body, a grout distributing channel between the ridges, and an aperture in the channel connecting the channel and hole. The central hole includes a leading portion ending at the first end, sealingly receiving the trailing end. A trailing portion of the central hole ends at the second end and sealingly engages the bolt. Each annular ridge seals against a grout nozzle.

An end coupling for a rock bolt having a shaft having an external thread, the coupling having an axis and the coupling comprising a body having a leading end and a trailing end spaced apart along the axis, a first passage portion extending along the axis from the leading end; a second passage portion extending along the axis from the trailing end; the first passage portion including a first thread portion to threadingly engage the external thread on the shaft of the rock bolt; the second passage portion including a drive receiving portion arranged to be engaged with a drive inserted into the second passage portion via the trailing end to impart rotation to the coupling about the axis.

A constant-resistance and large deformation anchor cable and a constant-resistance device are provided. The constant-resistance and large deformation anchor cable comprises cables (7), an anchoring device (13), a loading plate (12) and clipping sheets (4). The upper end of cables (7) is fixed on the anchoring device (13) and the loading plate (12) by clipping sheets (4). The constant-resistance and large deformation anchor cable also comprises a constant-resistance device, and the constant-resistance device comprises a sleeve (8) and a constant-resistance body (5). The sleeve (8) is a straight tube. The constant-resistance body is conical, and the diameter of the lower end of the constant-resistance body is bigger than the diameter of the upper end of the constant-resistance body. The inner diameter of the sleeve (8) is smaller than the diameter of the lower end of the constant-resistance body. A cuneiform part is arranged on inner wall of the lower end of the sleeve (8), and the constant-resistance body (5) is arranged on the cuneiform part. The strength of constant-resistance body (5) is higher than the strength of the sleeve (8), thus the sleeve (8) generates plastic deforming and the shape of the constant-resistance body (5) is not changed, when the constant-resistance body (5) moves in the sleeve (8). The lower end of the cables (7) is fixed on the constant-resistance body (5). The constant-resistance and large deformation anchor cable and the constant-resistance device have the properties of constant-resistance and preventing fracture, and can detect and early warn the all process of the activity of the landslides and the causative fault.

The invention relates to the technology of rib spalling. In the present invention, adjacent support anchors are tightly connected with each other by anchor cables; each of the support anchors are at least connected with an anchor cable tightly extending from four different directions, so that each of the anchor cables constitutes a mesh structure, and a flexible gap corresponding to the thickness of the support anchor is formed between the inner flexible support net and the outer support net at the anchor cable, which not only allows the support anchor to tighten an anchor bolt, but also makes the anchor bolt in the entire region form a whole.

The present invention relates to a device, method and system for the installation of a fixative in a drill-hole, such as to secure rock bolts. The device comprises (a) a chamber adapted to hold the fixative, and (b) a thrust member, wherein the fixative is displaced from the chamber into the drill-hole following application of force to the thrust member.

An anti-seismic support method for a mine shaft includes: providing a circular support groove in a liquefaction-prone layer of the mine shaft; providing horizontal support holes in a groove wall, and fixing an outer support spring steel cylinder against the groove wall; drilling vertical support holes at a groove bottom, anchoring a vertical anchor rod group into the vertical support holes, and injecting an expansion anchoring slurry into the vertical anchor rod group; making a lower positioning support ring abut against an upper end of the vertical anchor rod group and an inner wall of the outer support spring steel cylinder; fixing an anti-seismic connecting rod group between lower and upper positioning support rings; making an outer wall of an inner support spring steel cylinder abut against the upper and lower positioning support rings; and providing an upper support cover seat atop the outer and inner support spring steel cylinders.

An anti-seismic support method for a mine shaft includes: providing a circular support groove in a liquefaction-prone layer of the mine shaft; providing horizontal support holes in a groove wall, and fixing an outer support spring steel cylinder against the groove wall; drilling vertical support holes at a groove bottom, anchoring a vertical anchor rod group into the vertical support holes, and injecting an expansion anchoring slurry into the vertical anchor rod group; making a lower positioning support ring abut against an upper end of the vertical anchor rod group and an inner wall of the outer support spring steel cylinder; fixing an anti-seismic connecting rod group between lower and upper positioning support rings; making an outer wall of an inner support spring steel cylinder abut against the upper and lower positioning support rings; and providing an upper support cover seat atop the outer and inner support spring steel cylinders.

A method for ensuring the quality of a multi-component mixture in a system for rock reinforcement is described herein. The system comprises a first and a second channel for a respective first and second component intended for injection in a rock hole. The respective channel comprises a pump and a container intended for the respective component. The method comprises the steps of pumping of the respective component from the respective container through the respective channel and continuously comparing the flow of the first component in the first channel with the flow of the second component in the second channel. The method further comprises the step of controlling the pumps individually, based on the comparison of the flows, in such a way that a deviation from a pre-defined volume ratio between the first component and the second component in the mixture is below a pre-defined first threshold.