Gunnstein Thomas Frøseth

Estimating Remaining Service Life of Steel Railway Bridges

The Norwegian railway was mainly built in the period between 1850 and 1964 and consists of over 2700 bridges. About 1000 of these bridges are steel structures and common for all these bridges are that they were not designed for the current axle loads and train speeds. In addition, the fatigue limit state was typically not considered in design of structures during this period. Although effort has been put in to meet the immediate demands and to ensure safe operation, questions regarding the current state and remaining service life of these bridges have risen. Being able to accurately predict the state of these bridges is essential to manage the railway infrastructure as efficient as possible in respect to economic, social and environmental requirements.

 

Field measurements are the most precise way of assessing the state of bridges, but due to the sheer amount of bridges it is not feasible to conduct these investigations on the bridge stock. Numerical simulations are efficient tools which can be utilized to predict structural response, but the precision is dependent on the model complexity and uncertainties of input parameters. Combining field measurements with numerical simulations provides the best of both worlds and are necessary to obtain precise and complete state estimation of the bridge stock.

 

Main Objectives

• Improve prediction of remaining service life of steel railway bridges
• Quantify model error in finite element analysis of railway bridges
• Determine current and historic load conditions in the norwegian railway network
• Apply and improve model updating techniques for railway bridge simulations by field measurements.

 

Research Group

Structural Dynamics

 

Supervisors

Professor Anders Rönnquist

Associate Professor Ole Øiseth