CS232515B1 - Head of anchor for anchorage - Google Patents

Abstract

The invention addresses the anchor head for anchoring to rocks consisting of a conical ring and a spherical washer. A spherical shank is inserted into the ring on which the negative spherical bearing surface is formed, the center of which lies outside the taper axis. The spherical washer is provided with a positive ball bearing surface of the same radius as the negative spherical bearing surface of the conical ring. A support surface is formed on the spherical washer. The anchor head according to the invention is intended for anchoring rock in the underground, but it can also be used for anchoring retaining walls, foundation joints, slopes and the like.

Description

(54) Anchor head for rock anchoring

The invention provides an anchor head for rock anchoring consisting of a conical ring and a spherical washer. The shank of the spherical washer is inserted into the ring on which the negative spherical bearing surface is formed, whose center lies outside the axis of the cone. The spherical washer is provided with a positive spherical bearing surface of the same radius as the negative spherical bearing surface of the conical ring. A support surface is formed on the spherical support. The anchor head according to the invention is intended for anchoring rock underground, but it can also be used for anchoring retaining walls, foundation joints, slopes and the like.

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The invention provides an anchor bolt for rock anchoring consisting of a conical ring and a spherical washer.

Until now, the bolt and anchor heads were supported on flat or convex washers. A major disadvantage of the flat washers is that when the borehole is not perpendicular to the excavation wall, which happens very often, the washers cause a bending moment in the rod, which adversely affects the stress conditions in the rod at high preloads.

A certain improvement in the tension conditions in the tie rod has been achieved by the use of convex washers, which, however, at a higher anchorage of the anchor causes a small bearing surface to deform the washer.

In order to use flat or convex washers to support the anchor head at higher preloads, it was necessary to adjust the surface of the bearing surface so that it was perpendicular to the bore axis.

This operation is time-consuming and difficult to perform, especially in the profile head.

It also increases the costs of rock anchoring.

These deficiencies are largely overcome by the rock anchor head consisting of a conical ring and a spherical washer according to the invention. It is based on the fact that a shaft of a spherical washer is inserted in a conical ring on which a negative spherical bearing surface is formed whose center lies outside the axis of the cone. The spherical washer has a positive spherical bearing surface of the same radius as the negative spherical bearing surface of the conical ring. A support surface is formed on the positive spherical bearing surface of the spherical washer.

The new design of the anchor head in the vast majority of cases leads to the elimination of these deficiencies. In particular, the occurrence of bending moment in the tie rod is excluded. The anchor is able to transmit substantially higher stresses as evidenced by measurements where no signs of damage to the anchor head have yet been detected at a load of 45 t.

Another advantage is that the time required to install the anchor is shortened and that there is no need to adjust the bearing surface in cases where the borehole is not perpendicular to the excavation wall, without the labor and the anchoring costs of the rock. As a simple casting requiring no further machining, it is very cheap to manufacture compared to pressed washers. The design of the same shape can be freely increased for the transmission of higher voltages. The anchor head according to the invention can be used not only for rod anchors, but also for cable anchors.

The accompanying drawings show schematically an exemplary embodiment of the anchor heads according to the invention. FIG. 1 is a cross-sectional view of a conical ring. Giant. 2 is a partial front view of the spherical washer, and FIG. 3 is a plan view of the spherical washer.

The anchor head according to the invention consists of a conical ring 10 and a spherical washer 20.

A negative spherical bearing surface 11 of radius R is formed on the conical ring 10, the center of which does not lie in the axis of the cone. The ring 10 is provided a cavity 1 2. d ^e inserted the shank 21 of a spherical substrate 20. Positive spherical surface 22 of the substrate 20 has the same radius R, as negative spherical surface 11 of the ring on the 10th

A support abutment surface 23 is provided on the spherical washer 20, on which either a rod anchor rod or a cable anchor head, which passes through an axial bore 24 provided in the spherical washer 20, bears over a flat washer.

The anchor head according to the invention is intended for anchoring rock underground, but it can also be used for anchoring retaining walls, foundation joints, slopes and the like.

SUBJECT OF THE INVENTION

Claims (1)

Anchor head for rock anchoring consisting of a conical ring and a spherical washer, characterized in that a shank (21) is inserted into the ring (10) on which the negative spherical bearing surface (11) is centered outside the cone axis. a spherical washer (20) having a positive spherical bearing surface (22) having the same radius as the negative spherical bearing surface (11) and having a support surface (23). 3 drawings 232