Ballasted track interaction effects in railway bridges with simply-supported spans composed by adjacent twin single-track decks

This paper presents a non-stationary random vibration analysis of railway bridges under moving heavy-haul trains by the pseudo-excitation method (PEM) considering the train-track-bridge coupling dynamics. The train and the ballasted track-bridge are modeled by the multibody dynamics and finite element (FE) method, respectively. Based on the linearized wheel-rail interaction model, the equations of motion of the train-ballasted track-bridge coupling system are then derived. Meanwhile, the excitations between the rails and wheels caused by the random track irregularity are transformed into a series of deterministic pseudo-harmonic excitation vectors by the PEM. Then, the random vibration responses of the coupling system are obtained using a step-by-step integration method and the maximum responses are estimated using the 3[Formula: see text] rule for the Gaussian stochastic process. The proposed method is validated by the field measurement data collected from a simply-supported girder bridge (SSB) for heavy-haul trains in China. Finally, the effects of train speed, grade of track irregularity, and train type on the random dynamic behavior of six girder bridges for heavy-haul railways are investigated. The results show that the vertical acceleration and dynamic amplification factor (DAF) of the midspan of the SSB girders are influenced significantly by the train speed and track irregularity. With the increase in the vehicle axle-load, the vertical deflection-to-span ratio ([Formula: see text]) of the girders increases approximately linearly, but the DAF and vertical acceleration fail to show clear trend.

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Simply supported prestressed concrete deck for high speed railway bridges

IABSE Symposium Report ◽

10.2749/222137803796329042 ◽

2003 ◽

Vol 87 (11) ◽

pp. 57-63

Author(s):

Maja Della Vedova ◽

Luigi Evangelista ◽

Francesco Sacchi

Keyword(s):

Prestressed Concrete ◽

High Speed ◽

High Speed Railway ◽

Railway Bridges ◽

Simply Supported ◽

Concrete Deck

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The Influence of the Track Axis Curvature at Railway Filler-Beam Deck Bridges

Mathematical Modelling in Civil Engineering ◽

10.1515/mmce-2016-0008 ◽

2016 ◽

Vol 12 (2) ◽

pp. 27-37

Author(s):

Marian Stănescu Răzvan

Keyword(s):

Fem Analysis ◽

Steel Beams ◽

Design Codes ◽

Structural Stiffness ◽

Railway Bridges ◽

Cracked Concrete ◽

Simply Supported ◽

Simplified Method ◽

Curve Radius ◽

As Effects

Abstract The article presents a comparative study between the simplified method calculation proposed by the prescriptions of design codes and the analysis with the FEM program LUSAS [1], regarding the influence of the curvature of the track axis at railway bridges with steel beams embedded in concrete. The study was made on three simply supported bridges with the openings chosen so as to cover the openings used for this constructive solution, namely 10m ≤L≤30m. For each analysed opening the curve radius of the track axis was varied, in the domain in which are representative as effects, namely 100m ≤R≤1500m. In the case of Lusas FEM analysis, a physically nonlinear analysis it was previously carried out, after which the cracked concrete was removed, as its participation in the structural stiffness is practically non-existent. Studying the outcomes revealed by the two calculations presented, it can be concluded that the simplified method proposed by the design codes leads to a overvaluation of the track axis curvature influence at the railway filler-beam deck bridges.

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Vehicle‐Bridge‐Interaction in the Dynamic Calculation of Railway Bridges: Case Study and Dynamic Analysis for 75 Existing Simply Supported Bridge Structures of the Austrian Railway Network

ce/papers ◽

10.1002/cepa.1035 ◽

2019 ◽

Vol 3 (3-4) ◽

pp. 109-114

Author(s):

Bernhard Glatz ◽

Josef Fink

Keyword(s):

Dynamic Analysis ◽

Dynamic Calculation ◽

Railway Network ◽

Railway Bridges ◽

Simply Supported ◽

Bridge Structures

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Dynamic behaviour of bridges under critical articulated trains: Signature and bogie factor applied to the review of some regulations included in EN 1991-2

Proceedings of the Institution of Mechanical Engineers Part F Journal of Rail and Rapid Transit ◽

10.1177/0954409720956476 ◽

2020 ◽

pp. 095440972095647

Author(s):

Pedro Museros ◽

Andreas Andersson ◽

Victor Martí ◽

Raid Karoumi

Keyword(s):

High Speed ◽

Computational Cost ◽

Detailed Knowledge ◽

Railway Bridges ◽

Simply Supported ◽

Load Models ◽

Theoretical Approaches ◽

Accurate Definition ◽

Essential Components ◽

Definition Of

The information contained in this paper will be of interest not only to bridge engineers, but also to train manufacturers. The article provides practical insight into the degree of coverage of real articulated trains (ATs) that Eurocode EN1991-2 guarantees. In both the design of new railway bridges, as well as in the assessment of existing ones, the importance of a detailed knowledge of the limits of validity of load models cannot be overemphasised. Being essential components of the rail transportation system, the capacity of bridges to withstand future traffic demands will be determined precisely by the load models. Therefore, accurate definition of the limits of validity of such models reveals crucial when increased speeds and/or increased axle loads are required by transportation pressing priorities. The most relevant load model for a significant portion of the bridges in high-speed railway lines is the so-called HSLM-A model, defined in EN1991-2. Their limits of validity are described in Annex E of such code. For its singular importance, the effects of vibrations induced by HSLM-A are analysed in this paper with attention to the response of simply supported bridges. This analysis is carried out in a view to determine whether the limits of validity given in Annex E of EN1991-2 cover the largest part of cases of interest. Specifically, the vibration effects of HSLM-A are compared with those of the ATs described in such Annex E, and the response is analysed in depth for simply supported bridges, which are structures especially sensitive to passing trains at high speeds. New theoretical approaches have been developed in order to undertake this investigation, including a novel, simplified expression of the train signature for ATs that is convenient for its low computational cost. The mathematical proofs are included in the first part of the paper and two separate appendices.

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On the Assessment of Fatigue Damage in Railway Bridges

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.569-570.406 ◽

2013 ◽

Vol 569-570 ◽

pp. 406-413

Author(s):

Dermot W. O'Dwyer

Keyword(s):

Service Life ◽

Monitoring Systems ◽

Assessment Methodology ◽

Railway Bridge ◽

Loading History ◽

Single Track ◽

Fatigue Assessment ◽

Railway Bridges ◽

Strain Measurements ◽

Level Of Knowledge

This paper discusses the benefits to using direct strain measurements when undertaking a fatigue assessment of a railway bridge. The paper gives a brief overview of the assessment methodology for assessing fatigue in a bridge carrying a single track before outlining a method suitable for assessing multi-track bridges. The accuracy of a fatigue assessment depends on the level of knowledge of many different parameters including: an accurate loading history comprising axle loads and train frequencies over its service life; details of changes to the track form, including changes in the depth of ballast; and changes to the structure including damage or repairs. Many of these parameters are not known with certainty. However, using monitoring systems to measure the strain cycles in a bridge helps to address some of these uncertainties and hence improves the accuracy of the assessment.

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