DSI supplies DYNA Grip® Stay Cables for new Waschmuehltal Bridge
In conjunction with the six-lane extension of federal highway A6 between Mannheim and Saarbruecken, the Waschmuehltal Bridge, which is a listed monument, is being repaired and widened. For this purpose, a new bridge is being built on the north side parallel to the existing historical sandstone arch bridge. The structure was planned as a continuous post-tensioned beam with spans of 45.05m, 2 x 68.10m and 45.55m and is very thin due to the masts that are placed above the piers and the slim tendons.
The superstructure is built using the composite construction method, with the main girders consisting of welded steel hollow box girders. The masts are designed as steel structures tapering down from top to bottom. The stay cables consist of parallel strand bundles with adjustable anchorages in the superstructure and non-adjustable anchorages in the masts. The galvanized, waxed and PE coated strands (St 1570/1770) are hexagonally aligned using a guide deviator on both sides and are inserted in HDPE ducts.
The alignment of the 22 to 27m long stay cables resembles the shape of a harp in two exterior planes. Three stay cables are located on each side of each mast. For six masts, a total of 36 Type DYNA Grip® DG-P 55 Stay Cables with a maximum capacity of 55 strands are used. The actual number of strands per stay cable is 42. This makes it possible to add strands in reaction to higher loads caused by increasing traffic volumes in the future.
For stay cable installation, the strands are individually placed in the ducts using a hydraulic pushing device. The tensioning work was carried out using the patented ConTen Method with control unit in order to ensure a uniform allocation of strand forces.
The individual approval (ZiE) necessary for the DYNA Grip® Stay Cable Method was issued by the Landesbetrieb fuer Mobilitaet Rheinland-Pfalz. Prior to this, the DIBt (German Institute for Civil Engineering) had issued the necessary advisory opinion.