Balanced Lift Method
This new bridge construction method consists in building the bridge girders in a vertical position and in rotating the bridge girders into the final horizontal position. In some topographical situations it will be more efficient to produce bridge girders with this innovative method than with the traditional incremental launching method or the balanced cantilever method.
The span of the bridge girders is reduced by the compression struts which enables considerable savings in construction materials. The proposed method will be especially advantageous for bridges with high piers and span length between 50 m and 250 m.
Fig. 1: Bridges with high piers
The usage of a temporary pier enables the expedient application of the balanced lift method for bridges with piers of modest height (Fig. 2). The temporary pier can additionally be used for auxiliary cables during the subsequent construction phases, as is shown for the bridge over the Lafnitz river in the paper "Building bridges using the balanced lift method, opens a file in a new window".
Fig. 2: Bridges with low piers
The following patents have been granted for the balanced lift method:
Germany: DE 102006039551, 20.09.2007
USA: US 7 996 944, 16.08.2011
Russia: RU 2436890, 20.12.2011
Canada: CA 2661311, 20.11.2012
China: CN 101535571, 29.05.2013
Australia: AU 2007288151, 30.05.2013
Japan: JP 5302195, 28.06.2013
The European patent will be granted in April 2016. The patents in Norway and India are still pending.
Several field tests have been carried out to further investigate and improve structural details of this new bridge construction method in order to show the feasibility and the easy practical application (see Fig. 3).