Equivalent nosing force for a steel railway bridge based on in situ measurements

Abstract

<p>The weight and design speed of the railway vehicles increases in time. As a result, the values of design loads grow up. In old Bulgarian standard [1] the equivalent nosing force is prescribed as 60kN. In the present EN1991-2 [2] this value is 100kN. Meanwhile, a significant part of the very old bridges is not designed for nosing forces. In cases of long span between cross girders of the “open type” deck and lack of nosing braces, the load bearing capacity of longitudinal girders, concerning out of plane bending moments due to nosing forces, is insufficient. To investigate the value of equivalent nosing force are provided “in situ” measurements on the longitudinal girders of “open type” deck of a steel riveted railway bridge in exploitation in the Republic of Bulgaria. The strains and horizontal linear deformations are measured in the midspan of the longitudinal beams for real trains. The equivalent nosing force is calculated using developed procedures.</p>

Estimation of nosing load in existing railway transom top bridges based on field testing and finite element modelling

“…Overall, previous research performed on the assessment of nosing load applied to bridges is very limited and needs to be more focused by engineers or researchers as it can significantly impact bridge maintenance costs in railway organizations. Georgiev et al (Georgiev et al 2021) investigated the nosing load applied by some trains to a steel transom top bridge in Bulgaria and compared the stresses obtained from the field testing with the stresses obtained from a simple grillage model. They did not validate their grillage model but only used that model as a baseline to estimate the design stresses.…”