However, the main reason for this routing is the hydraulic engineering and design. The longitudinal slope of the bridge girder is 6%, thus wheelchair users are able to cross the bridge without difficulty. Despite the slight slope, the bridge, including freeboard, lies high above the highwater level.
Bridge Structure
With a length of exactly 204.46 ft, the bridge passes over the 131-foot-wide river bed. The longitudinal girder is guyed by two steel pylons.
The main beam, with a depth of 21.2 inches and a width of 63 inches, is made of block‑glued laminated spruce timber. It consists of five elements that are joined in the secondary beam zones. The individual elements are connected to each other by means of dowels and slotted sheets which are welded to the cross beams.
The bridge has a total width of 6.5 ft and is stayed with ties of d=1.6 inches connected to 42.6-foot-high pylons. The horizontal forces caused by the cables are transferred as compressive forces into the main beam. Thus, only vertical forces are introduced into the foundations below the main girder.
The longitudinal girder is covered with natural stone slabs in order to protect the bridge against weathering. Furthermore, its sides are coated with larch wood. All structural steel parts are hot-dip galvanized and color coated.
The handrail of the guard railing is made of Accoya glued-laminated timber. Accoya wood is subjected to compression and heat and is treated with acetic anhydride, so it absorbs significantly less water.
The pylon bridge in Lohmar is arguably one of the most beautiful river bridges built in the Cologne/Bonn region in Germany.
Structural Engineering | Design, Structural Analysis, and Construction Planning Schaffitzel+Miebach Faszination Brücken GmbH, Lohmar, Germany |
Construction | Construction of Superstructure Schaffitzel Holzindustrie GmbH + Co. KG, Schwäbisch Hall, Germany www.schaffitzel.de |
Investor | City of Lohmar, Germany www.lohmar.de |