More than twenty years after the completion, the motorway A2 from Vienna to Graz still has to be monitored due to possible landslides in a mountainous area. Existing anchors were overloaded and the required additional anchor force could hardly be transferred to the non homogeneous rock within a drilling length of 100 m. The limited space between existing anchors determined very sharp criteria regarding borehole deviation. Works had to be executed on a very steep slope considering the existing concrete beams. Single bore multiple anchors allowed to reduce the number of anchors and their length. They could be tested successfully up to a single anchor load of 5.700 kN!