Permissible configurations: 2, 3, 4, 6, 8 anchors
ETAG 001, Annex C and TR 029 permit single anchors and fastenings with two, three, four, six and eight anchors (any load direction, tension and/or shear loads) provided that the edge distance in all directions is c ≥ 10 ∙ hef and c ≥ 60 ∙ d (the greater of both values governs, hef = anchorage depth of the post-installed fastener, d = diameter of the anchor bolt or thread diameter, for anchors with internal thread d = outer diameter of the anchor).
If no shear loads and/or torsion moments act on the fastening the configurations mentioned above are also permitted with small edge distances, although the minimum distances given in the European approval must be observed. If shear loads and/or torsion moments act on the fastening and the conditions c ≥ 10 ∙ hef and c ≥ 60 ∙ d are not met then only single anchors or groups with two or four post-installed anchors are permitted.
The actual CEN/TS 1992-4 (TS = Technical Specification) permits the use of single anchors and groups with two, three, four, six and eight anchors even with small edge distances for any load directions if the annular gap between anchor and fixture is filled with mortar of sufficient strength or eliminated by other suitable means such as snap rings (CEN/TS 1992-4: Design of Fastenings for Use in Concrete). This rule corresponds to the actual state-of-the-art and is also used in DesignFiX.