Influence of track-bridge interaction in the comparison of load model HSLM-A vs. conventional and regular high-speed convoys derived from EN1991-2

This paper investigates the influence of track-bridge interaction (TBI) in the comparison of dynamic effects of actual (or envisaged) high-speed trains vs. load models prescribed by national or international standards.The focus is set on concentrated load models of high-speed vehicles travelling over simple bridges, following a general methodology previously presented by the authors (Museros, P., A. Andersson, V. Martí, and R. Karoumi.Dynamic behaviour of bridges under critical articulated trains: Signature and bogie factor applied to the review of some regulations included in en 1991-2.J. Rail and Rapid Transit, 1-21, 2020).For such comparison, two variables named exceedance (in amplitude) and required speed increase were used to analyse whether a real train is or is not duly covered by a model prescribed in a standard.Two particular cases are analysed here of one regular and one conventional train, both compliant with Annex E in EN1991-2, which are compared vs model HSLM-A in two slab-type bridges of spans 10.8 m and 25.2 m.Two different mathematical models are considered for each bridge, characterised by very different levels of refinement.The frequencies of the bridges are selected intentionally low, close to the limit of the frequency band defined in EN1991-2, section 6.4.4; therefore, it is of interest to note how the resonant speeds are also low, particularly for the second example.The main conclusions of this work are two.First,