| 摘要 |
In mining, the rock pressures are only held temporarily, e.g. for the support of roadways, in the course of which the rock continues to deform. On the one hand, these deformations must be permitted so that a new state of equilibrium can set in; on the other hand, the extent of the deformations exceeds the extensibility of the steel anchor bars. According to the invention, the anchoring element (5) for a steel bar (1) provided with force-transmission ribs is elastically deformable in at least one radial direction. It undergoes an expansion as a result of the ring tensile force occurring when a certain longitudinal tensile force, caused by the sloping flanks of the force-transmission ribs (2), is exceeded. The force-transmission ribs (2) are thereby disengaged from the recesses of the anchoring element (5), which is displaced be a certain distance along the steel bar in a sliding manner via the force-transmission ribs. As a result of accompanying reduction in the longitudinal force, the force-transmission ribs come into engagement again at an another point with the recesses of the anchoring element. With regard to a larger rock pressure area, a uniformly continuous relief of the surface under the rock pressure is thereby obtained when there are several anchors of this type. <IMAGE>
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