The present invention relates to a method and an apparatus for non-destructive testing of an effective anchorage depth of a fully grouted anchor bolt, which are applicable in geotechnical engineering. The method provided by the invention is for non-destructive testing of an effective anchorage depth of a fully grouted anchor bolt; the method is convenient to operate, non-destructive to an anchor bolt, and capable of testing an anchorage length of the anchor bolt. The present invention further provides an apparatus for non-destructive testing of an effective anchorage depth of a fully grouted anchor bolt. The apparatus has a simple structure, is convenient to install, and is capable of measuring an anchorage length of an anchor bolt without damaging the anchor bolt.

A device for measuring strain in an elongated metallic bar, the device comprising a housing arranged to be secured to the metallic bar, at least one optical sensor, at least one light source arranged to emit light across an interior space of the housing, and a thread arranged freely movable within a sheath and having a proximal end extending to a distal end of the housing and a distal free end arranged to be attached to the metallic bar at a distance from the housing such that longitudinal deformation of the metallic bar causes displacement of the proximal end of the thread in relation to the housing, and wherein the at least one optical sensor is configured to measure the displacement of the proximal end of the thread by measuring light emitted from the at least one light source.

A method for monitoring large deformation of a surrounding rock of a tunnel based on an automatic targeting and ranging system includes: acquiring, by a camera module, a target monitoring image; identifying a center image position in the target monitoring image; performing, by a laser ranging module, an automatic targeting and ranging task according to the center image position; and calculating a deformation offset of each target of left wall targets, right wall targets and a vault target based on an automatic targeting and ranging result corresponding to the target. The method solves the problem that a laser ranging device fails to measure a target at a fixed angle and obtains a real and accurate deformation offset thereby greatly improving the reliability of the large deformation monitoring result of the surrounding rock of the tunnel.

The present invention relates to a method and an apparatus for non-destructive testing of an effective anchorage depth of a fully grouted anchor bolt, which are applicable in geotechnical engineering. The method provided by the invention is for non-destructive testing of an effective anchorage depth of a fully grouted anchor bolt; the method is convenient to operate, non-destructive to an anchor bolt, and capable of testing an anchorage length of the anchor bolt. The present invention further provides an apparatus for non-destructive testing of an effective anchorage depth of a fully grouted anchor bolt. The apparatus has a simple structure, is convenient to install, and is capable of measuring an anchorage length of an anchor bolt without damaging the anchor 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 invention relates to a method and an apparatus for non-destructive testing of an effective anchorage depth of a fully grouted anchor bolt, which are applicable in geotechnical engineering. The method provided by the invention is for non-destructive testing of an effective anchorage depth of a fully grouted anchor bolt; the method is convenient to operate, non-destructive to an anchor bolt, and capable of testing an anchorage length of the anchor bolt. The present invention further provides an apparatus for non-destructive testing of an effective anchorage depth of a fully grouted anchor bolt. The apparatus has a simple structure, is convenient to install, and is capable of measuring an anchorage length of an anchor bolt without damaging the anchor 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 invention relates to a measuring sleeve for measuring a force in an anchor pile which has at least two anchor rods, wherein the measuring sleeve comprises a sleeve-shaped base body with a receiving hole, wherein a first internal thread extends from one side and a second internal thread extends from a second side into the base body, the internal threads are each designed for screwing in a threaded section of an anchor rod, between the first internal thread and the second internal thread an annular central section is designed which is free from a thread, and on the central section at least one force measuring element is arranged which is axially spaced apart from the internal threads.

A method for monitoring large deformation of a surrounding rock of a tunnel based on an automatic targeting and ranging system includes: acquiring, by a camera module, a target monitoring image; identifying a center image position in the target monitoring image; performing, by a laser ranging module, an automatic targeting and ranging task according to the center image position; and calculating a deformation offset of each target of left wall targets, right wall targets and a vault target based on an automatic targeting and ranging result corresponding to the target. The method solves the problem that a laser ranging device fails to measure a target at a fixed angle and obtains a real and accurate deformation offset thereby greatly improving the reliability of the large deformation monitoring result of the surrounding rock of the tunnel.