The largest challenge in performing remedial work on the S6 motorway between Gloggnitz and Maria Schutz was inserting 50-metre-long permanent strand anchors at heights of roughly 40 m. In the technique used to date – working from a platform with a drill rig using the right/right drilling technique – work proceeds very gradually, which would have made it impossible to meet the agreed deadline and would lead to contractual penalties. This, in turn, would have created huge additional costs for the employer, ASFINAG. The solution was a new equipment combination developed by PES in close collaboration with PORR Spezialtiefbau, comprising a cable excavator with the mount removed and a separate power pack, using the left/right drilling method. A custom platform was produced, the add-on device removed and the platform’s design tailored to the specific project requirements. This specialist structure was assembled on site by Liebherr in coordination with PES Himberg, Specialist Civil Engineering, where it was then assessed and signed off by a civil engineer.
It delivered impressive advantages over the conventional method:
- Approx. 25% higher drilling capacity where the soil permitted
- Desired depths achieved more efficiently in these geological conditions
- Reduced risk of drill string loss
- Deadline met and contractual penalties avoided
