Design Of Railway Bridges Research Articles

Comparison of the Behavior of PSC Bridges According to Design Train Load before and after Revision of Railway Bridge Design Standard

Comparison of the Behavior of PSC Bridges According to Design Train Load before and after Revision of Railway Bridge Design Standard

Development of design and construction of high-speed railway bridges in Germany

Bridges are vital components of high-speed rail (HSR) lines for crossing obstacles such as valleys, rivers, and existing highways or railway lines. The main goal of this paper is to provide a review of the development of HSR bridges in Germany. A short summary of the history of high-speed rail lines is given first. Subsequently, the development of HSR bridges, along with emerging design issues and the two relevant German design guidelines, is reviewed. Further, bridge structure types on German HSR lines, such as simply supported bridges, continuous bridges, arch bridges, integral and semi-integral bridges, composite truss bridges and rigid-frame bridges are discussed. The article concludes with a short discussion about the current situation and future trend of HSR bridges.

Model test study on seismic performance of new type column-plate hollow high pier

There are many disadvantages in the design of high pier in high intensity zone for traditional circular end-shaped hollow pier. The design concept of multi-column grid pier can improve the seismic performance of high-strength pier. The column-plate hollow high piers not only retain the good seismic performance of the lattice pier, but also improve the longitudinal and transverse stiffness of the hollow high piers, which lays a foundation for the application of the column plate bridge piers to the design of railway bridges. To understand the seismic performance of such piers systematically, a local model of plate pier is made on the basis of the column plate pier of the Zongmu Gou Bridge in this paper. The destructive mode and hysteresis characteristics of the pier are studied by means of pseudo-static test. It provides reference for the seismic design of the piers. The test results show that the column-plate structure as a whole has strong seismic performance. Under seismic loading, the inter-column plates can be completely sheared and destroyed, and the frame columns remain flexible. The energy consumption of the inter-column plate during the destruction process ensures the normal operation of the frame column.

Interaction between continuous welded rail and long-span steel truss arch bridge of a high-speed railway under seismic action

Track–bridge interaction under the seismic excitation is a dominant factor to the design and operation of railway bridges. A spatial model integrating rails, deck system, stringers, cross beams, suspenders, main trusses, piers and foundations was established in this paper, adopting non-linear springs to simulate the longitudinal resistance between the track and the bridge. The improved Penzien model was utilised to simulate the soil-pile interaction effect and a computer program was developed to generate artificial seismic waves. Comparison of natural vibration characteristics for the track–bridge system with and without considering the track constraint was made. Furthermore, the effects of sensitive parameters were investigated, including the ballast resistance, friction of movable bearings, location of rail expansion joint (REJ), etc. Present study results indicate that the track–bridge interaction enhances the structural integrity and induces relatively higher natural frequencies of the bridge. In general, the response obtained by the ballast resistance specified in the Chinese code is smaller than that by UIC code. Neglecting the friction of movable bearing will lead to over-estimated rail stresses and under-estimated internal forces of some piers in the system. Setting REJ at both beam ends is more efficient to release the seismic stress of the rail on the bridge.

06.01: Critical bridges in high‐speed railway lines: Systematic identification for specific trains

ABSTRACTFor the design of railway bridges in railway lines with a speed limit above 200 km/h the dynamic effects have to be considered. The present design codes such as Eurocode (EN 1991‐2) achieve this by assuming different high‐speed load models (for example HSLM‐A) for the dynamic calculations of all railway bridges in the network. If train manufacturers design a new high‐speed train which fulfills the limits of the load model HSLM‐A (geometric and weight parameters), then no additional verification of the dynamic effects are required as all the railway bridges already comply with the HSLM‐A. New challenges arise if a train manufacturer decides to differ from these limits, as they may be uneconomic (for example short length of single car). Furthermore, a railway operator may wish to expand the use of high‐speed trains on traditional lines, which were, up to now, not verified for dynamic loads. In both cases, each single railway bridge in the railway network has to be recalculated by considering the geometry and weight parameters of the new developed train, which seems to be a cumbersome task. Therefore this paper deals at first with the different train parameters and their limits, which need to be fulfilled in order to be in line with the load model HSLM‐A and shows which of them are more critical than the others. This is done by assuming 8 different fictitious trains which fulfill or slightly exceed these limits. The different structural hazard is determined by performing systematic dynamic analyses for a large parameter range of single‐span bridges and train speeds. The second part of this paper deals with a methodology, which makes it possible to determine the critical bridges in high‐speed railway lines (critical length and critical first natural frequency) for a given train load model in order to reduce the total number of bridges to be investigated. In addition, the train signature curve is analysed with respect to support the dynamic analysis.

Characterization of track geometric imperfections leading to maximal dynamic amplification of internal forces in railway bridges

ABSTRACT This paper resorts to a simplified dynamic analysis methodology for the study of vibrations in railway bridges produced by the passage of a typical passenger train, or EUT (Electric Unit Train). It starts from a model with fifteen degrees-of-freedom, namely vertical (bounce) and horizontal displacements (sway) and rotations about the longitudinal (roll), transverse (pitch) and vertical (yaw) axes. In this methodology, dynamic models of the train and the bridge are assumed to be initially uncoupled, yet being bound by the interaction train-bridge forces. Thus, the loads are evaluated for the train running on a rigid and fixed deck, considering geometric irregularities, different for each rail line, in both the vertical and horizontal track planes, as well as in the wheels. The contact forces are statically condensed at the vehicle’s centre of gravity and applied on a simplified 3D beam model. To represent the train passage over the bridge, functions are used to describe the interaction forces at each node of the beam model, as time evolves. Thus, it is possible to identify the dynamic response caused by the geometric irregularities and also evaluate the dynamic amplification obtained for any internal force, which is compared to the impact coefficient proposed by the Brazilian standards for the design of railway bridges (NBR 7187), used in quasi-static analysis. For the sake of an illustration, a thirty-six-metre-span concrete bridge with box girder section was considered. A study was carried out to find out the parameters of the irregularity functions that could potentially lead to maximal amplification of internal forces in the bridge.

Puentes mixtos continuos de ferrocarril en zona sísmica en el norte de Argelia

The design of continuous railway bridges in an active seismic zone is complex, due to rail-structure interaction criteria that require very rigid structural systems in the longitudinal direction. This generates large seismic forces at the fixed points and usually results in an uneconomical substructure design. The use of a composite deck (in order to reduce the mass), together with seismic isolation (using steel devices with elastic-plastic properties) has permitted the construction of 3 railway viaducts in Northern Algeria, adapting them to the requirements imposed by the Algerian railway administration.

Interaction of buckling modes in railway plate girder steel bridges

This paper investigates, for the first time, the behaviour and design of railway double track open timber floor plate girder deck steel bridges under combined buckling modes including web distortional buckling. A 3-D finite element model has been developed for the railway bridges, which accounted for the bridge geometries, initial geometric imperfections, material nonlinearities of the bridge components, bridge boundary conditions, interactions among bridge components and bridge bracing systems. Most of the aforementioned parameters are not incorporated in current design codes of railway bridges, which are credited to this study. The simply supported bridges investigated had a span of 30m, a width of 7.2m and a depth of 3.12m. The bridge components comprising main plate girders, stringers, cross girders, connections, bracing members, stiffeners, bearings, and field splices were designed following the design rules specified in the European Code for steel bridges. The live load acting on the bridge was Load Model 71, which represents the static effect of vertical loading due to normal rail traffic as specified in the European Code. The finite element model of the double track bridge was developed depending on additional finite element models, developed by the author, for small and full-scale plate girder steel bridge tests previously reported in the literature. Ultimate loads, load-mid-span deflection relationships, failure modes, stress contours of the double track bridge as well as of the small and full-scale tests were predicted from the finite element analysis and compared well against test results. Parametric studies were performed on the railway bridges highlighting the effects on the structural behaviour and ultimate loads carried by the bridges owing to the change in the bridge geometries, slenderness and steel strength. The paper presents a complete piece of work regarding the finite element analysis and design of railway steel bridges, which can be used for further parametric studies, finite element analyses and investigations of the bridges under different loading and boundary conditions. The parametric study has shown that the presence of web distortional buckling causes a considerable decrease in the ultimate load of the steel bridges. It is also shown that the use of high strength steel offers a considerable increase in the ultimate loads of less slender steel bridges. The study has also shown that the design rules, loading and recommendations specified in the European Code provide accurate and conservative estimations for the design of railway steel bridges, except for the bridges failing mainly by web distortional buckling.

Temperature Effects on Strain Influence Lines and Dynamic Load Factors in a Steel-Truss Arch Railway Bridge Using Adaptive FIR Filtering

AbstractThe dynamic strain response due to the passing trains is one of the most important indexes in the design and maintenance of long-span steel-truss arch railway bridges. The strain influence ...

Considering dynamic soil-structure interaction in design of high-speed railway bridges

This article presents preliminary theoretical results on the influence of dynamic soil-structure interaction (SSI) of slab foundations. Impedance functions, representing the dynamic SSI, were obtained from FE-models depicting the soil for a few cases of different geotechnical preconditions. The obtained impedance functions were attached to single-span bridges and HSLM-A analyses were performed. The effect of the impedance functions on the bridge response was studied and compared to the ultimate case of a bridge on rigid supports. The influence of SSI seems to have a significant effect on railway bridges. This study shows that by including this effect in bridge design, the damping ratio of the system is largely increased, giving lower acceleration amplitudes in the bridge, while the natural frequencies are less affected.

교량 상 자갈궤도의 종저항력 측정을 위한 실험 연구

Abstract When a ballast track of a high-speed train is constructed on a bridge, the displacement of the bridge deckscan occur because they are not fixed to the rails. Moreover, relative displacements occur between the bridge and railscaused by temperature changes and external loads. The current longitudinal resistance criteria (UIC Code 774-3, KRC-08080) on ballast tracks with continuous welded rails (CWRs) do not take into account the longitudinal movement of the bridge and the frictional force between the ballast and slabs. In addition, the magnitude of the longitudinalresistance, k, is calculated somewhat conservatively and, (therefore?) it acts as an unfavorable element in the design of long span and continuous railway bridges. Thus, in order to replicate the actual behavior more effectively, the longitudinal resistance of CWRs should take into account the additional rigidity between the slab and track. In this study, the longitudinal resistances of the ballasted track on the bridge were analyzed by carrying out an experimentalstudy with a test setup designed to simulate the deck and bed track. In the test results, the maximum longitudinalresistances of the tests were similar to the resistances of the current codes, however, the measured longitudinal stiffness designed to limit the displacement of the tests were much smaller in comparison with the longitudinal stiffness on the codes.

Evaluation of Dynamic Load Factors for a High-Speed Railway Truss Arch Bridge

Studies on dynamic impact of high-speed trains on long-span bridges are important for the design and evaluation of high-speed railway bridges. The use of the dynamic load factor (DLF) to account for the impact effect has been widely accepted in bridge engineering. Although the field monitoring studies are the most dependable way to study the actual DLF of the bridge, according to previous studies there are few field monitoring data on high-speed railway truss arch bridges. This paper presents an evaluation of DLF based on field monitoring and finite element simulation of Nanjing DaShengGuan Bridge, which is a high-speed railway truss arch bridge with the longest span throughout the world. The DLFs in different members of steel truss arch are measured using monitoring data and simulated using finite element model, respectively. The effects of lane position, number of train carriages, and speed of trains on DLF are further investigated. By using the accumulative probability function of the Generalized Extreme Value Distribution, the probability distribution model of DLF is proposed, based on which the standard value of DLF within 50-year return period is evaluated and compared with different bridge design codes.

Monitoring‐based performance assessment of rail‐bridge interaction based on structural reliability

AbstractFor today's railways, the continuous welded rail, which enhances driving dynamics and comfort for passengers, is often the construction method of choice. However, bridges and viaducts, which can be seen as singularities in the railway substructure, still pose a few unsolved problems; the bridge structure deforms under the impacts of thermal variation, creep, shrinkage, train passage and braking. The track‐bridge interaction is an important parameter in railway bridge design. Measurement campaigns and research projects have been performed to investigate the interaction process and learn how to predict longitudinal forces in the rail and the concrete slab track. For the construction of long bridges on high‐speed railway lines, new computational tools, monitoring systems and enhanced verification methods for tolerable rail stresses on bridges had to be developed. In order to take the modified stiffness conditions and recent findings on rail resistance into account, the verification schemes and safety concepts based on monitoring data have to be revised and performance‐based methods need to be developed. The target of this article is to present monitoring‐ and reliability‐based assessment methods for the concrete structure‐rail interaction using monitoring and non‐linear analysis techniques.

고속철도교의 지진 시 이동하중 해석을 통한 열차 운행규정 검토

최근 철도구조물의 내진에 대한 검토가 다양하게 이루어지고 있다. 하지만 열차의 탈선을 방지하기 위한 국내 고속철도 운행규정에 대한 연구는 미비한 실정이다. 국내 고속철도 운행규정은 지반가속도를 측정하여 사용하는 프랑스 규정을 기초로 설정되었지만, 지반가속도를 측정하여 사용하지 않고 교량 상부에 설치된 지진감시센서에서 측정된 가속도를 사용하여 지진 시 운행경보를 발령한다. 따라서 구조물에 의해 증폭되는 가속도로 열차운행을 제한함으로써 규모가 작은 지진에서도 열차가 운행할 수 없는 경보가 발령되어 열차운행에 경제적인 손실이 발생될 가능성이 크다. 본 논문에서는 PSC(Prestressed Concrete) 박스 철도교량을 대상으로 이동하중 해석, 지진하중 해석 및 지진 시 이동하중 해석을 수행하여 철도설계기준에서 제시하는 동적안정성 평가기준과 철도운행에 관한 안전지침에서 규정하는 지진 시 열차 운행규정을 비교하여 고속철도 운행규정의 적절성을 분석하였다. A large number of researches have been conducted on seismic resistant design of railway bridges. However, research on the running regulation of high-speed train during earthquake is limited. The current running regulation of high-speed train during earthquake was based on the French regulation. Accelerations were measured from the deck rather than ground acceleration, which results in reaching the limit value of the running regulation frequently due to amplified acceleration. This study investigates the dynamic behavior of high-speed railway bridges under earthquake. Analysis results are then compared against dynamic safety criterion in Korean railway design standard and train operation limits of safety instructions on the train operation. It is observed that both dynamic safety and derailment criterion are satisfied when the high-speed train runs over the bridge with the critical speed and under the earthquake level of serviceability limit state.

Estimation of the vibration serviceability deflection limit of a high-speed railway bridge considering the bridge-train interaction and travel speed

The static and dynamic displacements of high-speed railway bridges, which are determined by the load conditions, travel speed, and span, may cause passenger discomfort when they are excessive. In the Korea Railway Bridge Design Specifications, the allowable deflection is based on the train travel speed. It is, however, not sufficient for considering the vibration serviceability. The Eurocodes has also been quoted in the design guidelines of the Korean Honam High-speed Railway (KRNA, 2007). For the determination of the vibration serviceability of a passenger train, the Eurocodes proposes a deflection limit based on the vibration serviceability obtained from the ratio of the deflection to the span and considers the bridge–train interaction. However, the maximum speed and maximum span in the Eurocodes are 350 km/h and 120 m, respectively. Moreover, it does not provide a detailed process for determining the deflection limit based on vibration serviceability. It is therefore difficult to use the deflection limit as the design limit in increasing the span and travel speed. Hence, to ensure passenger comfort and enable changes in railway techniques, it is necessary to develop a vibration serviceability-based deflection limit that flexibly responds to changes in the railway environment regarding bridge span and travel speed. This study was conducted to determine the deflection limits of Korean railway bridges based on their vibration serviceability and considering the bridge–train interaction and increase in travel speed. In this paper, the bridge–train transfer function is developed using a simplified bridge–train model comprising a single mass–spring system. It is then verified by dynamic analysis of the bridge–train interaction. A parametric study and bridge–train dynamic interaction analysis are used to determine the correlation between the vertical acceleration of a car body and the bridge displacement with increasing travel speed. In addition, the vertical acceleration of the car body is shown to increase with increasing travel speed, and an amplification coefficient of the vertical acceleration of the car body is suggested. Further, a vibration serviceability deflection limit for high-speed railway bridges is developed in this paper using the transfer function and the amplification coefficient. Here, the deflection and vibration of the bridge are assumed to be respectively sinusoidal and harmonic. The suggested vibration serviceability deflection limit is also compared with those in the Eurocodes and the Shinkansen.

Design and construction deficiencies of timber railway bridges

British and Irish railways once featured several thousand timber bridges and viaducts. Modern and contemporary sources suggest that these structures were replaced due to problems with decay. Consequently, this decay presents a significant challenge to proponents of modern timber bridges, with their critics arguing that timber structures would fail to satisfy the service life requirements. In reality, what actually had a greater influence on their performance and longevity; timber's inherent liability to decay, or deficiencies in their design and construction? This paper presents the findings of the first major study on nineteenth-century timber bridges in the UK, aimed at documenting the design and construction methods used, and their subsequent performance. Despite problems with decay, many nineteenth-century railway bridges lasted beyond their expected design life. Moreover, most problems affecting their life span were the result of erroneous design practices coupled with poor construction and maintenance, rather than inherent material deficiency. Crucially, they could be either obviated or limited through better detailing, modern preservatives and a more judicious consideration of structural forces. These nineteenth-century structures provide crucial lessons in timber bridge design for modern engineers as the profession looks to provide more sustainable infrastructure both now and in the future.

교량-궤도 작용력에 대한 교량 단부에서의 레일지지점간격의 영향

This paper, as a study for the serviceability design of railway bridges with concrete track, presents the effects of design parameters of tracks and bridges on the forces acting on the rail supports of the track. To calculate the forces acting on the track, an unequal spacing discrete supported model with different spacing of rail supports was induced. Design parameters are the rail support spacing of expansion joints above abutments or piers of bridges, the distance from the support of a girder to the last rail support on the end of the girder, and the number of additional rail supports. The causes of the displacement of track are axial force, unit vertical displacement, and unit rotation. From the analysis, the maximum compressive force and the maximum uplifting force acting on the rail supports were determined and the effects of the rail support spacing on the forces acting on the track were presented.

철도교량형식의 경간에 따른 효율성 비교연구

일반철도 및 고속철도를 포함한 철도교량의 상부구조로 현재 우리나라에서 주로 사용되고 있는 교량형식은 크게 박스 거더교와 I형 거더교로 구분된다. 박스 거더교는 동적 거동에 대한 안전성이 우수하기 때문에 주로 고속철도 교량으로 많이 사용된다. I형 거더교는 일반철도 교량으로 주로 사용되며, 일반 PSC 거더교 형태와 철골철근콘크리트로 합성화된 구조인 프리플렉스 거더교의 형태로 크게 구분되고 또한 새로운 형식도 지속적으로 개발되고 있는 추세에 있다. 본 연구에서는 현행 철도교설계기준에 의거하여 각 형식별로 경간장에 따라 거더 설계를 실시하여 적절한 형고를 분석하여 경간장에 따른 구조적 및 경제적 효율성을 비교분석하였다. 비교분석을 수행한 결과, 구조적 효율성의 측면에서는 프리플렉스 거더교 형태의 교량이 경간장에 따른 형고가 가장 낮은 것으로 나타났으며, 경제적 효율성의 측면에서는 일반 PSC 거더교 형태의 교량이 가장 효과적인 것으로 평가되었다. The superstructure type of the railway bridge in our country, is mainly classified into the box girder and the I-type girder. The box girder is widely used in the high speed railway bridge because of the safety due to dynamic behavior. The I-type girder is used in the conventional railway bridge, and is also divided into the general type and the composite type, and the newly modified types have been developed. According to the current railway bridge design code, the girder design by the span length in various railway bridge types are performed in this study. The suitable girder height by the span length are analyzed, and the comparative analysis of the structural efficiency and the economical efficiency is carried out. From this study, the composite type girder is appeared the good result in respect of the structural efficiency. However, in the economical aspect, the general I-type girder is required less cost than the other types.

The Response Analysis of the Train-Bridge System under Seismic Action

This article based on bridge structural dynamics, vehicle dynamics and soil dynamics theory, set up the practical space mode, with an example of a dual-line 32 m single box section beam on Beijing-Shanghai Railway Line. According to the typical soft soil sites of Shanghai, the dynamic response of the bridge was analyzed by the large finite element software ANSYS under seismic action. Moreover the impact about the dynamic interaction of pile-soil-structure affecting on the design of high-speed railway bridges was got which will provide reference and basis for the construction and design similar project.

Design of railway bridges considering life-cycle assessment

The world is currently confronted with the challenge of preventing environmental degradation and resource depletion. To compare the environmental performance of two railway bridge designs, an Excel-based model was developed with implementing a simplified quantitative life-cycle assessment. The model covers the entire life cycle of the bridge, from raw material extraction to construction materials recycling and disposal. Various assumptions are made for selecting the relevant emissions and environmental impacts. A streamlined approach is applied to compare the environmental burden throughout the life cycle of the Banafjäl Railway Bridge. The bridge is a simply supported composite structure carrying one railway track. Two track alternatives are investigated: ballasted track and fixed track. The results show that the environmental impacts of the fixed track alternative are lower than those of the ballasted track alternative. From a sustainable development perspective, it appears that fixed track has a significant advantage as the overall environmental impact is reduced by up to 77%. The raw material phase is found to be decisive in the life cycle of both alternatives. The frequency of track replacement is identified as a key environmental parameter, because the extra environmental burden of traffic delay during bridge closure nearly overwhelmed the other life-cycle stages.