Dynamic performance of existing double track railway bridges at resonance with the increase of the operational line speed

Abstract

This article addresses the dynamic behaviour of double track simply supported bridges of short to medium span lengths (10 m < L < 25 m) belonging to conventional railway lines. These structures are susceptible to experience inadmissible levels of vertical vibrations when traversed by trains at high speeds, and in certain cases their dynamic performance may require to be re-evaluated in case of an increase of the traffic velocity above 200 km/h. In engineering consultancies, these structures have been traditionally analysed under the passage of trains at different speeds using planar models, neglecting the contribution of transverse vibration modes and also the flexibility of the elastomeric bearings. The study presented herein endeavours to evaluate the influence of these two aspects in the verification of the Serviceability Limit State of vertical accelerations, which is of great interest in order to guarantee a conservative prediction of the dynamic behaviour. In the present study, the dynamic response of representative slab and girder bridges has been evaluated using an orthotropic plate finite element model, leading to practical conclusions regarding the circumstances under which the above mentioned factors should be considered in order to adequately evaluate the transverse vibration levels of the deck.

Maximum resonance and cancellation phenomena in orthotropic plates traversed by moving loads: Application to railway bridges

“…More recently some authors have investigated the resonance phenomena caused by the circulation of periodic forces or masses following either a semi-analytical [21,22] or a numerical approach [23,24,7]. Neverthe-less, in the authors' opinion, regardless of the approach adopted, resonance phenomena caused by a series of periodic loads and the conditions for its maximization or cancellation depending on the free vibration amplitudes left by each single load have not been analysed in the case of orthotropic plates, especially when these separate from ideal well-known conditions i.e.…”

“…Definition of a bridge catalogueA representative ensemble of double-track, simply-supported pre-stressed concrete girder decks has been designed with the purpose of covering the mechanical properties of most existing bridges belonging to conventional and high-speed railway lines of this typology. Among the different bridge typologies that can be found in short-to-medium span lengths, precast decks composed by double-T girders have been selected due to their low intrinsic torsional stiffness which makes their dynamic behaviour significantly differ from that of a beam-type structure, exhibiting a noticeable contribution of the first torsion and first transverse bending modes to the vertical acceleration response under railway excitation[24]. Even though in new…”

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

“…The same strategy can be applied to any type of structure, and can be exploited with special success if the total response is largely governed by the contribution of one single mode. Because this is especially the case when the peak vibration is due to resonance of one particular mode, the single mode approach can be useful in practical applications and has been used by many researchers: the DER and LIR methods rely on the contribution of the fundamental mode of simple beams, 8 a similar approach was also adopted by Yang et al ., 16 some extensive parametric studies have confirmed its suitability under different conditions, 17,18 and recently the approach has been extended to include the soil-structure interaction effect. 19…”

Stress analysis of rigid hanger of railway arch bridge based on vehicle-bridge coupling vibration

“…In addition, due to dynamic action of the vehicle, the vibration of bridges may lead to the fatigue of structure components [6][7][8]. As railway transportation has the characteristics of heavy loads and obvious vehicle-induced vibration, the large structural stiffness and high durability of both overall structure and components are often required [9][10][11]. Flexible hanger, commonly used in highway arch bridges, are limited in the application to railway arch bridges, for the disadvantages of small stiffness, easy corrosion and needing to be replaced.…”