Dyckerhoff & Widmann Aktiengesellschaft

Rochling Haren Kg

Lorenz Schnitzler

Thomas Herbst

Dieter Jungwirth

Oswald Nutzel

Johann Wlodkowski

Alto Mannhart

Anton Lugering

Hartmut Von Grolman

Berthold Bolmer

A method of mounting and tensioning a freely tensioned tension member, particularly a stay cable for a cable-stayed bridge, and a device for carrying out the method, wherein the polyethylene casing of each individual strand is removed during the tensioning process over the length of the extension distance occurring during tensioning at the tensioning end. The peeling tool of the device for carrying out the method is composed of a sleeve having at one end thereof at least one cutting edge, wherein the sleeve surrounds the respective strand over at least an essential portion of the circumference thereof. The sleeve can be positioned in a stationary manner between the anchoring disk and the tensioning press, wherein the strand is pulled through the sleeve during the tensioning process.

Method of mounting and tensioning a freely tensioned tension member and

An anchoring arrangement for use in underground mining or foundation work or as a reinforcing element for concrete includes a rod-shaped tension member of composite fiber material which has, over at least an anchoring portion thereof, a helically extending external thread with ribs formed by impressing valleys in the tension member. An anchoring member having a corresponding internal thread can be screwed onto the tension member. For obtaining a radial pressure on the tension member as a result of a wedge effect, the angle of inclination of the sides of the thread relative to the longitudinal axis of the tension member is smaller than 45.degree.. The thread preferably is a fiat trapezoidal thread. In an anchoring member which is stiff relative to circumferential tensile forces, the flat angle of inclination of the sides of the thread increases the radial pressure acting on the tension member, which leads to an increased effect into the depth and a higher resistance to shearing. The anchoring member may have a changing circumferential tensile stiffness over the length of the threaded engagement with the tension member, so that the anchoring member can expand at the point of highest stress concentration, with the result that a change in length of the tension member may occur.

Arrangement for anchoring a rod-shaped tension member of composite fiber

An anchoring device for a tension member of an earth- or rock anchor, where a support element transmitting the tensile force is arranged between an anchoring element undisplaceably connected with the tension member and an anchor plate abuttable against a support base, the support element includes a cylindrical hollow body surrounding the anchoring element, whose inner wall has in its lower region projections protruding inward beyond its inner contour, against which the anchoring element abuts in a force-transmitting manner with partial regions of its cross-sectional area. If a predetermined tensile force is exceeded, the support element and/or the anchoring element can plastically deform in the region of their inter-engaging surfaces, so that a relative displacement occurs in axial direction. Distance or spacer pins are provided in a head plate placed upon the tension member for visual indication of the relative displacement, which after contact with the surface of the hollow body exit upwards from the head plate.

Anchoring device for the rod-shaped tension member of an anchor,

An anchoring device, such as a rock anchor, includes an anchor rod with force transmission ribs projecting outwardly from its outside surface. An anchor nut is in threaded engagement with the rod and has at least an axially extending portion formed of a material having lesser strength than the material of the rod. The anchor nut has at least two axially extending portions spaced apart by cuts through the nut, which cuts extend transversely of the nuts central axis. The portions follow one another in the central axis direction with at least the portion closer to the body into which the anchor rod extends having the lesser strength. The nut portions are dimensioned so that the portion closer to the body loses its force locking engagement with the ribs on the rod and its threads shear off when a predetermined load is exceeded. The nut portions are interconnected by narrow webs remaining after the cuts are made in the nut separating the portions. The webs cannot transmit the anchor force when the predetermined load is exceeded, and, therefore, they act as breaking points with the two portions moving toward one another and closing off the cuts. The closure of the cuts is visible and signals that the predetermined load has been exceeded, accordingly, steps can be taken to secure the stability of the body into which the anchoring device is inserted.

Anchoring device, such as a rock anchor

To form a radially outwardly extending bulge in a steel wire strand made up of a plurality of individual wires, the strand is compressed along an axial length so that the individual wires deform radially outwardly and in spaced relation to one another. Compressive force is applied to one end of the strand and the strand is anchored at an axially spaced location from the end. A tubular member with a cylindrically shaped inside surface forms a limiting boundary for the outward movement of the individual wires. The tubular member is located between the end of the strand and the location where it is anchored. The end of the strand and the tubular member are rotatably supported. Each individual wire extends along an angular path about the axis of the strand between the end of the strand and the anchor location.

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Pocking, Germany

Lorenz Schnitzler