A drilling assembly is disclosed for drilling a borehole in a rock body and inserting a rock bolt within the borehole in a single pass. The drilling assembly includes an elongated drill string having a downhole end. A drill bit is detachably joined to the downhole end of the drill string, with the drill bit having an external screw thread extending in an axial direction of the drill string. The drill string is surrounded by a rock bolt sleeve that has a thread engaging formation at or near its downhole end and that is arranged to cooperate with the external screw thread of the drill bit so that the drill bit is able to be screwed into the rock bolt sleeve.

A friction bolt assembly to frictionally engage a bore formed in rock strata includes an elongate tube and an expander mechanism acted on by an anchor mechanism via an elongate bar or cable. A retainer mechanism is mounted to act between the bar or cable and the tube to prevent ejection of the bar or cable from the assembly should the bar or cable break.

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 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.

Facility for transferring data over a network between two network endpoints by transferring hash signatures over the network instead the actual data. The hash signatures are pre-generated from local static data and stored in a hash database before any data is transferred between source and destination. The hash signatures are created on both sides of a network at the point where data is local, and the hash database consists of hash signatures of blocks of data that are stored locally. The hash signatures are created using different traversal patterns across local data so that the hash database can represent a larger dataset then the actual physical storage of the local data. If no local data is present, then arbitrary data is generated and then remains static.

A friction bolt assembly includes: an expansible sleeve having a tubular body between leading and trailing ends, which body has a longitudinally extending formation about which the body resiliently deforms and which formation extends along at least part of the body, ending at the body leading end; a rod extending through the sleeve body and between first and second ends and on which a projecting part is defined between the trailing end of the sleeve body and the second end; an expansion element on the rod at the first end; a first load bearing formation on the projecting rod part, moveable along the projecting part to abut the sleeve trailing end; a load applicator on the projecting part of the rod; and a second load bearing formation mounted over the projecting part of the rod between the first load bearing formation and the load applicator unit.

The present invention relates to a tunneling method, and particularly, to a tunneling method by installing an internal pre-support member and a corresponding post support member in an alternate manner or by installing an external pre-support member and a corresponding post support member in an alternate manner, and an apparatus, respectively, therefor. The tunneling method includes: excavating a pilot tunnel in a main tunnel to be constructed; radially forming a drilled hole from an excavation surface of the pilot tunnel to a tip end of the pre-support member of the main tunnel at a plurality of locations in the pilot tunnel to install the pre-support member; inserting the pre-support member into the drilled hole, and conducting grouting and performing curing to fix the pre-support member; excavating the tunnel in stages in a longitudinal direction along an excavation line of the main tunnel and primarily spraying shotcrete to an excavation surface of the main tunnel in the main tunnel; installing a post-support member between a plurality of the pre-support members on the main tunnel surface to which the shotcrete is primarily sprayed; and connecting the pre-support member and the post-support member with a plate type support member.

A drilling and bolting tool includes a drill feed for driving a bit to form a hole in a rock surface, a cable feed system, and a resin system. The drill feed includes a frame and a drill head supported on the frame. The cable feed system is coupled to the drill feed, and the cable feed system includes a cable drive for driving a cable into the hole. The resin system includes a hose in fluid communication with a resin supply. The resin system further including a hose drive system for selectively extending the hose into the hole and retracting the hose from the hole.

An anchor bolt for fastening an object in a drilled borehole in a rock mass formation, which is to absorb violent impact loads such as those occurring during earthquakes in an energy dissipating manner. The anchor bolt comprises a split sleeve and a bolt component inserted in the split sleeve that, when pulled outwardly, expends the split sleeve until a key protruding from the surface of the bolt component abuts a ring, thereby informing the operator that appropriate anchoring and pre-tensioning of the anchor bolt in the borehole is reached. Another ring, interfacing with the split sleeve about the entry of the borehole, is designed to force expansion of the split sleeve, preventing a breaking anchor bolt to become a high-speed projectile.

A carbon fiber rock bolt including: an outer carbon fiber rope including a series of tow fibers; and an inner core material. As the tension on the rock bolt increases beyond a predetermined limit, the inner core material undergoes a spatial compression, whilst the angle of twist in the carbon fiber rope strands decreases, resulting in extension of the carbon fiber rock bolt, replicating the ductility seen in steel rock bolts.