Rock bolts are typically used to provide support for rock formations and to hold the formation together. Rock bolts may fail due to a number of reasons. Failures in rock bolts may cause overload or loss of preload in the rock bolt. Aspects of the disclosure provide a sensing device for a rock bolt. The sensing device includes a spacer and at least one load sensor. Each said at least one load sensor includes a respective resilient compressible element that is adjacent a respective end of the spacer. The resilient compressible element compresses responsive to a respective load threshold. Each load sensor provides respective sensor output as a function of whether or not the respective resilient compressible element is compressed. The sensing device generates device output indicating a status of the rock bolt.

The present disclosure relates to a self-diagnosis type ground anchor and a construction method. The self-diagnosis type ground anchor includes: a bond length part located at a predetermined depth of a boring hole excavated from a target surface of the ground; a head part located near the target surface; and a tensile material provided by connecting the bond length part and the head part in a state of receiving a tensile force, so as to deliver an anchorage force of the bond length part to a structure. The self-diagnosis type ground anchor further includes a displacement measurement material of which one end is fixed at a predetermined position of the bond length part and the other end is placed in a free end form on the target surface, provided such that a relative displacement of the target surface for the bond length part can be detected.

The present disclosure relates to a self-diagnosis type ground anchor and a construction method. The self-diagnosis type ground anchor includes: a bond length part located at a predetermined depth of a boring hole excavated from a target surface of the ground; a head part located near the target surface; and a tensile material provided by connecting the bond length part and the head part in a state of receiving a tensile force, so as to deliver an anchorage force of the bond length part to a structure. The self-diagnosis type ground anchor further includes a displacement measurement material of which one end is fixed at a predetermined position of the bond length part and the other end is placed in a free end form on the target surface, provided such that a relative displacement of the target surface for the bond length part can be detected.

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 rock bolt assembly provides an indication of a coupling. The rock bolt assembly includes two shaft sections, namely inner and outer shaft sections. A coupler is configured to couple the two shaft sections together at proximate ends. An electrical conductor is insulated from the outer shaft section and extends from the dead end of the outer shaft section to the head at the live end of the outer shaft section. An electrical contact arrangement is provided at the dead end of the outer shaft section, configured to electrically interconnect the outer shaft section and the conductor when the inner and outer shaft sections are coupled. Electrical terminals are provided at the head and connected respectively to the outer shaft section and to the conductor, the electrical terminals being electrically interconnected or continuous when the outer shaft section and the conductor are electrically interconnected.

A rock bolt assembly provides an indication of a coupling. The rock bolt assembly includes two shaft sections, namely inner and outer shaft sections. A coupler is configured to couple the two shaft sections together at proximate ends. An electrical conductor is insulated from the outer shaft section and extends from the dead end of the outer shaft section to the head at the live end of the outer shaft section. An electrical contact arrangement is provided at the dead end of the outer shaft section, configured to electrically interconnect the outer shaft section and the conductor when the inner and outer shaft sections are coupled. Electrical terminals are provided at the head and connected respectively to the outer shaft section and to the conductor, the electrical terminals being electrically interconnected or continuous when the outer shaft section and the conductor are electrically interconnected.

A device for testing overall anchorage performance of a basalt fiber reinforced plastic (BFRP) anchor cable includes an anchor cable anchoring system and a data acquisition system. The anchor cable anchoring system includes a test bed, BFRP arranged over the test bed, and a distributed optical fiber bonded to a surface of the BFRP, the test bed being provided with an anchoring section at one end and an outer anchoring section at the other end, the anchoring section anchors one end of the BFRP, and the outer anchoring section anchors the other end of the BFRP. The data acquisition system includes a modem and a grating connected to two ends of the distributed optical fiber in series, and a center hole jack and a dynamometer arranged between the outer anchoring section and an end of the test bed, and the BFRP penetrates the center hole jack and the dynamometer.

A rock anchor assembly includes a rock anchor with a flexible element and first/second cylindrical connector elements engaged to proximal and distal ends of the element, a flexible tubular sleeve longitudinally extending between first and second ends, on the rock anchor so end parts of the rock anchor project from sleeve ends; a load bearing barrel centrally bored engaging the first connector element between the first end of the sleeve and a proximal end of the rock anchor, the barrel engaging the first end of the sleeve in sealing contact, the barrel having a grout conduit between the barrel exterior and the bore, the conduit defining part of a grout passage interconnecting the barrel exterior and sleeve interior, when the barrel engages the sleeve; a seal preventing grout outflow but accommodating grout inflow; a tensioner engaging the first tubular connector element, and a mechanical anchor engaging the second tubular connector.

A high-strength confined concrete support system for an underground tunnel. The support system includes multiple confined concrete arches, bolts and cables, and a prestressed steel strand backfilling system. The confined concrete arches all support the surrounding rock of the tunnel and are sequentially arranged along the tunnel. Every two adjacent confined concrete arches are connected by a longitudinal connection structure. The support system is provided with a plurality of layers of steel bar meshes on the surrounding rock side and the tunnel side, and shotcrete layers are sprayed on the support system and the steel bar meshes. The prestressed steel strand backfilling system comprises a prestressed steel strand system and a filling material. The filling material fills the space between each confined concrete arch and the surrounding rock to equalize a load on the confined concrete arch and generate prestress.