Abstract: A ground anchor or rock anchor is provided that includes an anchor tension member composed of one or more individual elements, such as steel bars, steel wires, or steel wire strands. While the anchor tension member is intended to be introduced into a drilled hole and anchored there, the anchoring of the anchor tension member at the exposed end of the drilled hole is achieved with the aid of anchor head. To this end, the anchor head comprises a support element to bear directly or indirectly against the underlying rock or substratum, and an anchoring component for tensioning the individual elements, which can be brought into a frictional connection with the individual elements while bearing against the support element. In addition, a cap, which extends around the anchoring component and the ends of the individual elements, protects the exposed end of the anchor head.

Abstract: A ground anchor or rock anchor is provided that includes an anchor tension member composed of one or more individual elements, such as steel bars, steel wires, or steel wire strands. While the anchor tension member is intended to be introduced into a drilled hole and anchored there, the anchoring of the anchor tension member at the exposed end of the drilled hole is achieved with the aid of anchor head. To this end, the anchor head comprises a support element to bear directly or indirectly against the underlying rock or substratum, and an anchoring component for tensioning the individual elements, which can be brought into a frictional connection with the individual elements while bearing against the support element. In addition, a cap, which extends around the anchoring component and the ends of the individual elements, protects the exposed end of the anchor head.

Abstract: A method and apparatus for tensioning a staggered anchorage comprised of a plurality of tension members, which are anchored in a bore hole at various depths, thus having different free steel lengths. For each staggered anchorage, each tension member is tensioned up to a predetermined maximal load and is then subsequently adjusted to the working load. To achieve a consistent elongation reserve of the individual tension member and thus to increase the security of a staggered anchorage, the staggered anchorage is adjusted to the working load, all tension members are adjusted to a reduced elongation (?Iw) by a uniform elongation difference (?Imax??Iw) relative to the respective elongation (?Imax) of the predetermined maximal load. An arrangement for performing the method has a single tensioning plane, which is force interconnected with defined locking elements that are arranged on tension members in clamping planes.

Abstract: An apparatus (100) for post-grouting a rock bolt (1) has an elongate sleeve (101) adapted to receive a rock bolt (1) with a first end (1a) thereof extending beyond the sleeve first end (101a) and a second end (1b) thereof extending beyond the sleeve second end (101b). An end fitting (102) is attached to the sleeve second end (101b) and has a central aperture (106, 107) for receiving the rock bolt (1). Grout passages (112) communicate the exterior of the end fitting (102) with the interior of the sleeve (101). A seal means (117) is displaceable between open and closed positions so as to seal the grout passages (112). The seal means (117) is biased towards the closed position at which the grout passages (112) are substantially sealed. Injection of grout into the end fitting (102) via the passages (112) deflects the seal means (117) to the open position enabling flow of grout through the passages (112) and into the sleeve (101).

Abstract: A method and apparatus for tensioning a staggered anchorage comprised of a plurality of tension members, which are anchored in a bore hole at various depths, thus having different free steel lengths. For each staggered anchorage, each tension member is tensioned up to a predetermined maximal load and is then subsequently adjusted to the working load. To achieve a consistent elongation reserve of the individual tension member and thus to increase the security of a staggered anchorage, the staggered anchorage is adjusted to the working load, all tension members are adjusted to a reduced elongation (?Iw) by a uniform elongation difference (?Imax??Iw) relative to the respective elongation (?Imax) of the predetermined maximal load. An arrangement for performing the method has a single tensioning plane, which is force interconnected with defined locking elements that are arranged on tension members in clamping planes.

Abstract: A method of manufacturing an anchor element for a soil anchor or rock anchor, rock bolt or the like, from a strand of twisted steel wire. The anchor element includes a central wire and outer wires arranged radially relative to the central wire. The anchor element has at least one expanded section obtained by spreading the individual wires. Spacer members are provided for fixing the individual wires in the spread-apart position. The central wire is laterally deflected when the individual wires of the strand are being spread and, by inserting a rod-shaped spacer element, the central wire is fixed in an out of center position together with at least one outer wire.

Abstract: A tie member includes at least one tension element, such as a steel wire or strand, enclosed within a tubular sheathing. An anchoring unit is located at each end of the tie member for transmitting the tension force to a part of a structure. Each anchoring unit includes an anchor plate with at least one conically shaped bore so that a tension element can be secured in the borehole by a multi-part annular wedge. To provide additional corrosion protection and improve fatigue strength in the anchorage, the tension element is enclosed within a coating of a synthetic resin for its entire length. The inside surface of the wedge is shaped between the ends with a series of coarse or rough teeth with the tips rounded off.

Abstract: For their protection against corrosion, cables of high-strength steel wires, principally for use as tension members for post-stressable earth anchors or rock anchors, are treated with a corrosion protection material and furnished with a tubular sheathing member. In order to be able to surround completely all wires (3, 4) of the cable (2) with corrosion protection material, according to the invention the interior open spaces between the individual wires of the cable are in a first work operation filled with corrosion protection material, and in a second work operation immediately thereafter, when the strand is inserted into the tubular sheathing member, the annular interior open space between the cable and the tubular sheathing member is filled with corrosion protection material.

Abstract: An anchor head for a corrosion-protected prestressable injected anchor secures the end of a bundle of steel members, such as rods, wires or strands. The anchor head includes an abutment member and an anchor plate supported on the abutment member. The anchor plate has bores for receiving and anchoring the ends of the individual steel members. The bundle of steel members extends through a borehole and between the borehole and the abutment member the steel members are fanned or spread out before entering the anchor plate. Each of the steel members is covered with a corrosion protective sheathing. A closure plate is arranged at the abutment member and has a number of openings corresponding to the number of steel members. The steel members pass through the closure plate in a sealed manner.