The predecessor structures in the glacier sand of Grindelwald, which had been destroyed by floods, were replaced by Switzerland’s first timber-UHFB composite bridge. The structure is 40 m long and, as part of a main hiking trail, runs in an elegant arch across the Schwarze Lütschine.
The wooden substructure consists of three 25 m long GL 24c glulam beams of 25 m length, each with two slip-on beams. The substructure transfers the loads as a wooden arch over the pile-founded, disintegrated concrete abutments into the ground. The slips rest in concrete niches directly on the concrete abutments. The force transmission of the wooden arched beams is effected via a corresponding steel joint to the concrete abutments.
The shear connection interlocks the glulam (BSH) with the UHFB so that both building materials interact statically. The bond is ensured by steel threaded rods which are glued into the glued laminated timber with epoxy resin: GSA® technology from the company neue Holzbau AG.
Here the article from the magazine Brückenbau. (german)