Background and activities

Force identification in bridges using measured dynamic response

In order to ensure sufficient structural safety of novel structures such as very slender suspension brides or long floating bridges, it is important to have auccurate knowledge about the load exposure. By measuring dynamic response at existing bridges, full-scale external forces can be estimated with the use of newly developed system inversion methods. Measurement campaigns are therefore carried out at the Bergsøysund Bridge and the Hardanger Bridge, both engineering feats representing advancements in bridge technology. Force identification at full-scale bridges has never been tried before. Results obtained from the measurement data provides valuable information on the in-situ dynamic force behaviour, which cannot practically be obtained otherwise. The results also helps better understand the load-response relationship.  The estimated forces can be used to validate the existing load models, thereby reducing the load uncertainies and increasing the structural reliability.



  • Identify hydrodynamic forces on floating bridges
  • Identify wind forces on suspension bridges
  • Compare the estimated forces with state of the art load models and try to explain any discrepancies
  • Estimate the structural response and compare with the measured response
  • Quantify the uncertainties related to force identification and response estimation

Research Group

Structural Dynamics


Associate Professor Ole Øiseth

Assistant Professor Eliz-Mari Lourens (TU Delft)

Animation of second vertical mode (f=0.16 Hz). Model and animation by NTNU/Øyvind Wiig Petersen and Knut Andreas Kvåle.

Animation of mode on Hardanger bridge. Animation by NTNU/Øyvind Wiig Petersen.