Evolution of load conditions in the Norwegian railway network and imprecision of historic railway load data Gunnstein T. Frøseth and Anders Rönnquist Norwegian University of Science and Technology (NTNU). Department of Structural Engineering, Richard Birkelands vei 1A, 7491 Trondheim, Norway ARTICLE HISTORY Compiled July 6, 2018 ABSTRACT This paper describes historic load conditions in the Norwegian railway network to improve estimates of the remaining service life of bridges. Data on rolling stock, traffic and infrastructure throughout the history of the railway are presented. Axle loads, geometry, design, composition and operation of both passen- ger and freight trains have changed several times since the initial construction. The capacities of both rolling stock and infrastructure influence the load conditions in a railway network. Historic loads may have been more severe than modern loads for certain structural details. A probability distribution of load variables for a specific bridge cannot be obtained in the general case. Future research directions and suggestions for the use of non-probabilistic data in estimating the service life of bridges are discussed. KEYWORDS Bridge loads; service life; railway bridges; rolling stock; locomotives; imprecise data CONTACT Gunnstein T. Frøseth. Email:
[email protected] 1. Introduction Technological advances and population and trade growth have led to increasing axle loads and train speeds, placing higher demands on the ageing railway infrastructure. The existing infrastructure must be assessed under conditions of increased operational demands to ensure safe operation of the transportation system. To this end, numeri- cal models are essential due to the vast number of components requiring assessment. Numerical models are used to determine the appropriate actions and predict the con- dition of many parts of the infrastructure, e.g., bridges (Imam, Chryssanthopoulos, & Frangopol, 2012; Imam & Righiniotis, 2010; Imam, Righiniotis, & Chryssanthopoulos, 2007).