Inspection of PZ Anchors in Bischofshofen
For decades, DSI has been a recognized partner and leading system supplier of geotechnical products and systems both for private and for public clients. Highly qualified engineers, technicians and business people support clients with specific know-how, commitment and the willingness to perform.
This commitment to service was demonstrated by DSI Austria’s response to a special request received from the road and bridge construction department Strassen- und Brueckenmeisterei Hallein, Austria.
In the summer of 2011, blasting work was carried out near federal road B311 between Bischofshofen and Zell am See, near Klamm. A tied back anchor wall, built in 1986 to protect the federal road, is located in this area.
The anchors in the wall were supplied by the company Polensky und Zöllner. The Strassen- und Brueckenmeisterei Hallein asked DSI experts to measure the tensioning force of several of the permanent anchors that are also known as PZ anchors.
DSI engineers studied the problem and determined the exact geometry of the existing anchorage devices. During this process, they concluded that the use of standard tensioning jacks was impossible due to the special anchor type. A stressing chair had to be individually modified so that a DYWIDAG tensioning jack could be accurately assembled on it.
The inspections included random lift-off tests of several permanent anchors. Load cells with over 1,000kN were later installed on two of the PZ anchors. For this purpose, DSI engineers lengthened the existing anchor bolt using a special M56 tensioning spindle. With this accomplished, the anchors could be destressed, inspected and re-tensioned to 1,000kN.
The inspection was carried out in close co-operation with and to the full satisfaction of the Strassen- und Brueckenmeisterei Hallein.