Academic literature on the topic 'Railroad bridges Live loads'

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Journal articles on the topic "Railroad bridges Live loads"

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Doornink, J. D., T. J. Wipf, and F. W. Klaiber. "Use of Railroad Flatcars in Cost-Effective Low-Volume-Road Bridges." Transportation Research Record: Journal of the Transportation Research Board 1819, no. 1 (January 2003): 385–96. http://dx.doi.org/10.3141/1819b-49.

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The use of railroad flatcars (RRFCs) as the superstructure in lowvolume bridges has been investigated in a research project at Iowa State University. These alternative bridges should enable county engineers to replace old, inadequate county bridges for less money and in a shorter construction time than required for a conventional bridge. Capital saved can be used to improve other areas of secondary road transportation. A feasibility study completed in 1999 by the Bridge Engineering Center at Iowa State University determined that RRFC structures have adequate strength to support Iowa legal traffic loads. In a follow-up research project, two RRFC demonstration bridges with different substructures and RRFC lengths were designed, constructed, and tested to validate the conclusions of the feasibility study. Bridge behavior predicted by grillage models was supported by data from field load tests, and it was determined that the engineered RRFC bridges had live-load stresses significantly below the safe yield strength of the steel and deflections well below the AASHTO bridge design specification limits. Moreover, since analytical procedures were able to predict RRFC bridge behavior, it is possible to analyze each bridge to determine its adequacy for any state’s legal traffic loads or for roads with larger hauling loads, such as quarry or coal-hauling roads. From the results of this research, it has been determined that, through proper RRFC selection, connection, and engineering design, RRFC bridges can be a viable, economic alternative for low-volumeroad bridges.
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Hidayat, Irpan. "Analisis Perhitungan Jembatan Gelagar I pada Jembatan Jalan Raya dan Jembatan Kereta Api." ComTech: Computer, Mathematics and Engineering Applications 4, no. 1 (June 30, 2013): 517. http://dx.doi.org/10.21512/comtech.v4i1.2797.

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The bridge is a means of connecting roads which is disconnected by barriers of the river, valley, sea, road or railway. Classified by functionality, bridges can be divided into highway bridge and railroad bridge. This study discusses whether the use of I-girder with 210 m height can be used on highway bridges and railway bridges. A comparison is done on the analysis of bridge structure calculation of 50 m spans and loads used in both the function of the bridge. For highway bridge, loads are grouped into three, which are self weight girder, additional dead load and live load. The additional dead loads for highway bridge are plate, deck slab, asphalt, and the diaphragm, while for the live load is load D which consists of a Uniform Distributed Load (UDL) and Knife Edge Load (KEL) based on "Pembebanan Untuk Jembatan RSNI T-02-2005". The load grouping for railway bridge equals to highway bridge. The analysis on the railway bridges does not use asphalt, and is replaced with a load of ballast on the track and the additional dead load. Live load on the structure of the railway bridge is the load based on Rencana Muatan 1921 (RM.1921). From the calculation of the I-girder bridge spans 50 m and girder height 210 cm for railway bridge, the stress on the lower beam is over the limit stress allowed. These results identified that the I-girder height 210 cm at the railway bridge has not been able to resist the loads on the railway bridge.
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Unsworth, John F. "Heavy Axle Load Effects on Fatigue Life of Steel Bridges." Transportation Research Record: Journal of the Transportation Research Board 1825, no. 1 (January 2003): 38–47. http://dx.doi.org/10.3141/1825-06.

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Heavy axle railway loads (freight equipment with more than a 100-ton capacity and gross vehicle weights exceeding 263,000 lb) have been introduced extensively on North American Class I freight railroads in the past decade. An overview is presented of the effects of heavy axle loads on the fatigue life of steel bridges in the North American freight railroad infrastructure. Also outlined are life extension and rehabilitation techniques typically used to maintain the safety and reliability of existing steel railway bridges.
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Jacobs, David W., and Ramesh B. Malla. "On live load impact factors for railroad bridges." International Journal of Rail Transportation 7, no. 4 (April 27, 2019): 262–78. http://dx.doi.org/10.1080/23248378.2019.1604182.

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Bojović, A., A. Mora Muñoz, Z. Marković, and N. Novaković. "Network arches over the Danube – Railway Road Bridge in Novi Sad/Netzwerkbögen über die Donau – Eisenbahn-Straßenbrücke in Novi Sad." Bauingenieur 93, no. 03 (2018): 110–15. http://dx.doi.org/10.37544/0005-6650-2018-03-46.

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The Railway road bridge in Novi Sad (Serbia) is situated on the international railroad line No 2 (Belgrade-Budapest) and designed for two railway tracks (160 km/h), two road lanes and two footpaths. The bridge structure consists of four structures: two approach composite bridges at the banks and two steel tied network arch bridges over the river. The spans are 27,0 m + 177,0 m + 3,0 m + 219,0 m + 48,0 m, totally 474,0 m in length. The rises of arches are 34,0 m and 42,0 m respectively. The width of the bridge is 31,5 m. The arches and ties, as well as the girders of the approach spans, are steel box girders. The decks of all bridge structures are the composite reinforced concrete slabs with thickness of 300 mm, locally 400 mm. The launching itself was very complex and unique, in both analysis and construction. The arch bridges were fully assembled on the banks and launched by skids over the bank and by pontoons over the river, to the final position on piers. The bridge is, despite of heavy loads and structural complexity, very rational in steel volumes and construction costs as well.
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Flanigan, Katherine A., Jerome P. Lynch, and Mohammed Ettouney. "Probabilistic fatigue assessment of monitored railroad bridge components using long-term response data in a reliability framework." Structural Health Monitoring 19, no. 6 (June 7, 2020): 2122–42. http://dx.doi.org/10.1177/1475921720915712.

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Fatigue is a primary concern for railroad bridge owners because railroad bridges typically have high live load to dead load ratios and high stress cycle frequencies. However, existing inspection and post-inspection analysis methods are unable to accurately consider the full influence of bridge behavior on the fatigue life of bridge components. Reliability-based fatigue analysis methods have emerged to account for uncertainties in analysis parameters such as environmental and mechanical properties. While existing literature proposes probabilistic fatigue assessment of bridge components, this body of work relies on train parameter estimates, finite element model simulations, or controlled loading tests to augment monitoring data. This article presents a probabilistic fatigue assessment of monitored railroad bridge components using only continuous, long-term response data in a purely data-driven reliability framework that is compatible with existing inspection methods. As an illustrative example, this work quantifies the safety profile of a fracture-critical assembly comprising of six parallel eyebars on the Harahan Bridge (Memphis, TN). The monitored eyebars are susceptible to accelerated fatigue damage because changes in the boundary conditions cause some eyebars to carry a greater proportion of the total assembly load than assumed during design and analysis; existing manual inspection practices aim to maintain an equal loading distribution across the eyebars. Consequently, the limit state function derived in this article accounts for the coupled behavior between fatigue and relative tautness of the parallel eyebars. The reliability index values for both the element (i.e. individual eyebars) and system (i.e. full eyebar assembly) reliability problems are assessed and indicate that under the conservative assumption that progressive failure is brittle, first failure within the parallel eyebar system is generally equivalent to system failure. The proposed method also serves as an intervention strategy that can quantify the influence of eyebar realignment on the future evolution of the reliability index.
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Purnomo, D. A., W. A. N. Aspar, W. Barasa, S. M. Harjono, P. Sukamdo, and T. Fiantika. "Initial Implementation of Structural Health Monitoring System of a Railway Bridge." IOP Conference Series: Materials Science and Engineering 1200, no. 1 (November 1, 2021): 012019. http://dx.doi.org/10.1088/1757-899x/1200/1/012019.

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Abstract In order to determine the actual condition of the railway bridge structure in the field, predictive monitoring is needed by installing a structural health monitoring system (SHMS). In the process of applying the SHMS, a bridge design review was applied to have railway bridge characteristics. The purpose of conducting this design review is to determine the allowable threshold for deflection and vibration of the bridge. This paper will present the analysis of the steel frame structure; with a span of 51.60 meters, 4.45 meters wide, of 5.00 meters high, respectively. According to the applicable standards, the loads used following the function of the bridge on the railroad tracks are calculated. The purpose of this paper is to (1) analyze the strength of the attached profile against the working forces, especially the live load of the rail line, (2) to know the deflection that occurs, (3) to know the natural frequency that occurs, and (4) to develop expert systems. The simulation results are used as the basis for placing sensors on the bridge and as the basis for determining the threshold for the railway bridge SHMS.
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Dahniel, Dahniel, and F. X. Supartono. "Analisis Deformasi dan Tegangan Pada Bascule Bridge Akibat Pengaruh Sudut Angkat Jembatan." JMTS: Jurnal Mitra Teknik Sipil 3, no. 4 (November 1, 2020): 1257. http://dx.doi.org/10.24912/jmts.v3i4.8369.

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Bumi sedang menghadapi masalah pemanasan global yang besar sehingga membuat es di kutub mencair dan menambah tinggi muka air, juga mengurangi luas daratan. Dalam mengatasi masalah tersebut dibutuhkan suatu akses yang menghubungkan transportasi darat dan juga transportasi laut, jembatan bergerak merupakan solusi untuk mengatasi masalah tersebut. Jembatan bergerak memiliki banyak jenis, salah satunya adalah jembatan bascule, jembatan bascule adalah jembatan bergerak yang bergerak arah vertikal dan horizontal untuk memberikan akses kendaraan laut dan darat. Jembatan bascule ini menggunakan rangka batang yang biasanya digunakan untuk jalur kereta api, tetapi jembatan kali ini untuk jalur kendaraan beroda. Model Jembatan bascule dibuat dengan menggunakan program Midas Civil menggunakan wizard rangka batang yang bergerak vertikal dengan sudut 0º, 30º, 45º, 60º. Hasil dari analisis menggunakan program Midas Civil menunjukkan bahwa untuk jalur kendaraan beroda, jembatan bascule tipe rangka batang bisa digunakan dengan ketentuan seperti dalam penelitian ini dengan menahan tegangan dan defleksi akibat beban mati dan beban hidup. Kata kunci: Jembatan Bascule, Rangka Batang, Tegangan, Defleksi, Midas Civil. The earth is facing a big problem of global warming that makes the polar ice melt and increase the water level, also reduce the land area. In overcoming this problem, we need an access that connects land transportation and also sea transportation, moving bridges are a solution to overcome these problems. Moving bridges have many types, one of which is the bascule bridge, the bascule bridge is a moving bridge that moves vertically and horizontallyto provide access to sea and land vehicles. This bascule bridge uses truss which is usually used for railroad lines, but this time the bridge is for wheeled vehicles. The bascule bridge model was created using the Midas Civil program using steel wand truss that moves vertically with angles of 0º, 30º, 45º, 60º. The results of the analysis using the Midas Civil program show that for wheeled vehicle lines, the truss type bascule bridge can be used with the provisions as in this study by holding stress and deflection due to dead load and live load. Keywords: Bascule Brdege, Truss, Stress, Deflection, Midas Civil.
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Arwani, M. Hamizan Najib, SUGENG RIYANTO, and SUNARTO Suryanto. "PERENCANAAN ULANG JEMBATAN TALANG DI JALAN JUPRI KELURAHAN PISANGCANDI MALANG DENGAN MENGGUNAKAN STRUKTUR RANGKA BAJA." Jurnal JOS-MRK 2, no. 1 (March 21, 2021): 173–78. http://dx.doi.org/10.55404/jos-mrk.2021.02.01.173-178.

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Bridge are structures that are made to cross ravines or obstacles, such as rivers, railroad tracks, or highways. Gutter bridges are included in the type of water crossing bridge or also known as aqaduct. In actual conditions this gutter bridge has a lot of damage caused by several factors. Based on this, research is needed to re-plan the entire construction of the gutter bridge. The data needed is data from measurements on existing conditions and Malang city HSPK in 2019. Planning is done using modeling using STAAD Pro V8i software. The loading analysis method uses SNI 1725-2016 and for stem and connection control uses RSNI T-03-2005. The profiles used in this plan are the single profile of Isolation Elbow 65.65.9 in the upper main girder, the single profile of Isolation Elbow 60.60.6 in the transverse girder and upper bracing, and the single profile of Elbow Feet 55.55.6 on other trunks with type of steel BJ 37. From the analysis results obtained and the conclusion that the self weight of the entire upper structure weighs 814,068 kg, the largest compressive force with a value of 11,517,418 kg or 112,985,871 N, the bending moment in the diaphragm girder that supports the live load and dead load additional rod 109 is 838,874 N-m or 838,874.00 N-mm, the largest tensile strength is 4,187,521 kg or 41,079.58 N, the connection uses high quality bolt joints A325 type with a diameter of 16 mm and uses a gusset plate with a thickness of 10 mm, and the calculation of the required Budget Plan is Rp 159.067.800,00.
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Michelle, Michelle, and FX Supartono. "ANALISIS JEMBATAN PRATEGANG BOX GIRDER DENGAN INCREMENTAL LAUNCHING METHOD." JMTS: Jurnal Mitra Teknik Sipil 3, no. 2 (May 17, 2020): 419. http://dx.doi.org/10.24912/jmts.v3i2.6933.

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The purpose of this research is to gain a broader understanding in analysing bridges that are built in stages. With Incremental Launching Method, bridges are casted in segments behind one of the abutments and launched over piers. Therefore, this method has little effect on surroundings and much efficient for constructions of highways or railroad lines. This method uses 40 meter long nose made of steel and is connected to the front part of the bridge to reduce the cantilever moment that occurs. The structure of the bridge is modelled in Midas Civil. 31 centric pre-stressing tendons are used during launching, whereas 20 tendons are placed in the top flanges and 11 tendons are placed in the bottom flanges. 2 pre-stressing tendons are placed in each web, to be tensioned after the bridge has reached its final position. The results from analysis using Midas Civil stated that the tendons used are sufficient to withstand the stresses due to dead load and live load.AbstrakTujuan dari penelitian ini adalah untuk memperoleh pemahaman yang lebih luas dalam menganalisis jembatan yang dibangun secara bertahap. Dengan Incremental Launching Method (ILM), jembatan dicor per segmen di belakang salah satu abutmen dan diluncurkan diatas tiang setelah beton mencapai kekukatannya. Oleh karena itu, metode ini memiliki efek yang sedikit pada lingkungan dan sangat efisien untuk pembangunan jalan raya atau jalur kereta api. Metode ini menggunakan nose sepanjang 40 meter yang terbuat dari baja dan disambungkan pada bagian depan jembatan untuk mengurangi momen kantilever yang terjadi. Model struktur jembatan dibuat dalam program Midas Civil menggunakan wizard ILM. 31 tendon centric prestressing digunakan selama peluncuran, 20 ditempatkan di flens atas box girder dan 11 ditempatkan di bawah. 2 tendon ditempatkan di masing-masing web yang akan ditarik setelah jembatan berada di posisi akhir. Hasil dari analisis menggunakan Midas Civil menunjukan bahwa tendon yang digunakan cukup untuk menahan tegangan akibat beban mati dan beban hidup.
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Dissertations / Theses on the topic "Railroad bridges Live loads"

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Memory, Terry James. "On the dynamic behaviour of highway bridges : a thesis." Thesis, Queensland University of Technology, 1992. https://eprints.qut.edu.au/36245/1/36245_Memory_1992.pdf.

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Thomson (1910) first suggested that when designing a bridge the static stress should be increased to account for the dynamic nature of vehicle-bridge interaction. Since that time engineers have increased the static design loads on bridges by a factor usually referred to as the impact factor. Between 1925 and 1979 this impact factor was codified throughout the world as a function of maximum span length. In 1979 the Ontario Highway Bridge Design Code (OHBDC) renamed the impact factor as the "Dynamic Load Allowance" (DLA) and specified it as a function of the first flexural frequency of bridge superstructures. This code provision was subsequently adopted by the National Association of Australian State Road Authorities (NAASRA), now known as AUSTROADS. Neither the OHBDC nor the NAASRA bridge design specification suggest analysis methods for evaluating the first flexural frequency of bridge superstructures. Consequently, this thesis investigates, in detail, methods used to estimate the fundamental frequency of bridge superstructures and proposes a simple, accurate and quick method for simply supported bridges. As the correlation between field results and theoretical estimates was considered paramount, the significance of transverse and longitudinal support stiffness, dynamic modulus of elasticity and idealisation complexity were assessed. Subsequent to this, a relationship between support stiffness and the shift in fundamental frequency, relative to the frictionless case, was developed. A second major component of this thesis is the concept of Dynamic Load Allowance itself. To gain an appreciation of this phenomenon, full scale bridge testing was undertaken. Results obtained raised several questions about the significance of higher modes of bridge excitation and about the ability of a DLA-first flexural frequency code provision to embody vehiclebridge interaction. The results of the bridge testing led to the suggestion that the dynamic load allowance should be codified as a function of both the first flexural frequency and the length of a bridge.
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Ransom, Angela L. "Assessment of bridges by proof load testing." Thesis, Queensland University of Technology, 2000. https://eprints.qut.edu.au/36104/1/36104_Ransom_2000.pdf.

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Throughout the world, many countries are faced with the problem of ageing bridge infrastructure that is being called upon to carry increasing loads. With the difficulties associated with gaining funding to replace or rehabilitate these bridges, asset managers must ensure that the most efficient use is made of the existing infrastructure. It has been shown that theoretical assessment of bridges by analytical means often leads to conservative estimates of capacity. Many bridges therefore have been posted with load limits which do not accurately reflect the structural capacity of these bridges. Various methods of assessing bridge capacity are adopted by. road authorities throughout the world. These forms of assessment include analytical rating, calibration of analytical models by supplementary load testing and assessment by proof load testing. Proof load testing has consistently demonstrated that bridges often have reserves of strengths in excess of that indicated by theoretical analysis. The aim of proof load testing is to determine a realistic bridge load rating which accurately reflects the load capacity of the bridge. This thesis investigates the use of proof load testing in the assessment of bridges and its application to the Australian bridge infrastructure. The procedures used in proof load testing do not vary greatly between countries but the magnitude of the loads applied and the load factors used to calculate a load rating vary significantly. The procedures and practices adopted internationally were reviewed and adapted to suit Australian bridge infrastructure and conditions. The methodology was evaluated through a series of pilot proof load tests and subsequently potential improvements were identified. One of the challenges associated with proof load testing is the determination of the proof load that should be applied. In this thesis, structural reliability methods have been used to determine the proof load required to achieve a desired level of safety after testing. These methods were extended to incorporate the expected residual life of the structure and to investigate the resulting effect on the proof load required. Reliability theory has also been used to assess the risks involved, and the benefits gained by proof load testing. These risks and benefits are expressed in terms of a decreased probability of failure or an increased safety index after a successful proof load test. The methods developed have been applied to the results of the proof load test conducted on the South Pine River Bridge.
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程遠勝 and Yuansheng Cheng. "Vibration analysis of bridges under moving vehicles and trains." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B3124001X.

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Kabani, Matongo. "Reliability based live loads for structural assessment of bridges on heavy-haul railway lines." Doctoral thesis, Faculty of Engineering and the Built Environment, 2018. http://hdl.handle.net/11427/30126.

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The highest live loads on railway lines are on dedicated freight corridors operated as heavy-haul lines. These lines carry high axle loads above 25 tonnes and total tonnage above 20 million tonnes per annum over distances greater than 150km. The South African iron ore line currently operates long trains of length 4.1km with 30 tonne per axle wagons on a narrow gage (1065mm) line over a distance of 861km. The operation of heavy haul lines require close monitoring and structural performance evaluation of existing bridges. This study covered both analytical studies and field measurements of bridge dynamic response and static vertical loads required to compute moments shear for beam-type bridges. The field study of dynamic amplification factors was based on strain measurements on the Olifants bridge located on the heavy-haul iron line in South Africa. The Olifants bridge is a 23 span box girder consisting of 2 continuous span segments of 11 spans at either end and a drop span in the middle. The collected strain data consisted 1174 loaded and 1372 empty train crossing events from June 2016 to March 2017. The probabilistic study was based on weigh-in-motion data of heavy-haul freight collected from January 2016 to August 2016. The study was limited to single span, 2 span and 4 span bridges with equal spans and did not consider fatigue. The dynamic response parameters of interest were frequency time evolution of bridge under heavy loads and dynamic amplification factors. An approximate formula derived using 2 dimensional beam model with moving masses is presented. The approximate formulae predicts the reduced frequency within 12% of the estimate from field vibration measurements of an 11 span continuous bridge with train to bridge linear mass ratio of 88%. The approximate formula underestimates the frequency as the stiffening contribution from train suspension system is ignored in a moving mass approximation. Dynamic amplification factors from strain measurements of a continuous 11 span bridge where considerably higher with maximum of 12% compared to 5% from a moving force analytical model for train speed below 60km/h. The amplification from measurements were considerably higher due to the additional local amplification of strains in upper flange of the box girder. A comparison of amplification factors for loaded and empty trains shows that increase in gross weight increases amplification factors. Furthermore, dynamic amplification factors are not dependent on changes in speed during train crossing. Different extrapolation techniques were used to obtain load effects from the same block maxima data. It was shown that the normal, GEV and Bayesian extrapolation methods give load effects within 1% of each other with the normal extrapolation being marginally on the lower end. This observation holds across beam types and span lengths from 5m to 50m. Although the GEV allows for all the three extreme type distributions, an analysis based on available weigh-in-motion data of axle weights show that the fitted distributions using Bayesian and Maximum Likelihood Estimate for all load effects for the span ranges are all Weibull type. On the other hand it is known that the domain of attraction for the normal distribution is Gumbel type. The study also found that extrapolated loads effects are less sensitive to increase in return period beyond 50 years. This aspect is significant as return period is a measure of safety target when determining design values for loads. The study investigated the impact of traffic volume increase and wagon axle load dependencies. The load effects on heavy-haul were shown to be more sensitive to the weak dependence than to traffic growth over the remaining service life of 50 years. The increase in return levels of load effects is less than 1% for traffic volume growth of 4% over a period of 50 years in contrast to the much higher values between 6% and 9% reported on highway bridges for 3% traffic volume growth over 40 year period. Assessment loads that account for some wagon axle dependence have lower return values of load effects than the assume that axle loads are independent which is consistent with theory.
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Erhan, Semih. "Effect Of Vehicular And Seismic Loads On The Performance Of Integral Bridges." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613739/index.pdf.

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Integral bridges (IBs) are defined as a class of rigid frame bridges with a single row of piles at the abutments cast monolithically with the superstructure. In the last decade, IBs have become very popular in North America and Europe as they provide many economical and functional advantages. However, standard design methods for IBs have not been established yet. Therefore, most bridge engineers depend on the knowledge acquired from performance of previously constructed IBs and the design codes developed for conventional jointed bridges to design these types of bridges. This include the live load distribution factors used to account for the effect of truck loads on bridge components in the design as well as issues related to the seismic design of such bridges. Accordingly in this study issues related to live load effects as well as seismic effects on IB components are addressed in two separate parts. In the first part of this study, live load distribution formulae for IB components are developed and verified. For this purpose, numerous there dimensional and corresponding two dimensional finite element models (FEMs) of IBs are built and analyzed under live load. The results from the analyses of two and three dimensional FEMs are then used to calculate the live load distribution factors (LLDFs) for the components of IBs (girders, abutments and piles) as a function of some substructure, superstructure and soil properties. Then, live load distribution formulae for the determination of LLDFs are developed to estimate to the live load moments and shears in the girders, abutments and piles of IBs. It is observed that the developed formulae yield a reasonably good estimate of live load effects in IB girders, abutments and piles. In the second part of this study, seismic performance of IBs in comparison to that of conventional bridges is studied. In addition, the effect of several structural and geotechnical parameters on the performance of IBs is assessed. For this purpose, three existing IBs and conventional bridges with similar properties are considered. FEMs of these IBs are built to perform nonlinear time history analyses of these bridges. The analyses results revealed that IBs have a better overall seismic performance compared to that of conventional bridges. Moreover, IBs with thick, stub abutments supported by steel H piles oriented to bend about their strong axis driven in loose to medium dense sand are observed to have better seismic performance. The level of backfill compaction is found to have no influence on the seismic performance of IBs.
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姜瑞娟 and Ruijuan Jiang. "Identification of dynamic load and vehicle parameters based on bridge dynamic responses." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B31244270.

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Barthelot, Shyamalie Lorraine. "Development of a probability based load criterion for the NAASRA Bridge Design Specification in LSD format." Thesis, Queensland University of Technology, 1989. https://eprints.qut.edu.au/36456/1/36456_Barthelot_1989.pdf.

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The objective of this research is to develop a rational approach to the safety analysis of highway bridge superstructures. The developed models have been demonstrated on examples of short and medium span, prestressed concrete deck unit and girder bridges. Probabilistic models for structural resistance and load effects have been constructed using measured data. The load components considered were dead load and traffic live load. The ultimate resistance was assumed to be lognormally distributed, while dead load was assumed to be normally distributed. The Gumbel distribution was selected to model traffic live load effects. Safety was measured Reliability indices in terms of a reliability index. were calculated for the ultimate strength limit state for bridge superstructures. Structural reliability is calculated using the advanced methods, allowing consideration of actual distributions of loads and resistance. Safety was evaluated for prestressed concrete designed to the existing NAASRA Bridge Specification and also in accordance with the Bridge Design Code in Limit States format. The members Design draft draft code has achieved a more uniform level of reliability for all structures.
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Issa, Camille Amine. "Nonlinear earthquake analysis of wall pier bridges." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/54297.

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Accurately predicting the response of complex bridge structures to strong earthquake ground motion requires the use of sophisticated nonlinear dynamic analysis computer programs not generally available to the bridge design engineer. The analytical tools that have been developed are generally applicable to bridges whose substructures can be idealized as beam-columns. Bridges with wall piers do not belong to this category The major objective of this study is to develop an analysis tool capable of simulating the effects of earthquakes on monolithic concrete wall pier bridges. Thus, after surveying the literature, a mathematical model is developed for the geometrically nonlinear earthquake analysis of wall pier bridges. Mixed plate elements are used to model the wall pier. The plate element has eight nodes and the degrees of freedom per node are three displacements and three moments. Beam elements are used to model the bridge deck. The beam element accounts for shear deformation and it has two nodes with three displacements and three rotations as degrees of freedom per node. A transitional element is used to join the beam elements to the plate elements. The equation of dynamic equilibrium is solved using the Newmark method with modified Newton-Raphson type iteration at each time step. The mixed plate element is used to model two plate structures and the results are compared with analytical and other finite element solutions. A two span wall pier bridge is modeled using the structural elements developed in this study. The digitized time history for the N-S component of the El Centro Earthquake of May 18, 1940, is used to seismically excite the bridge model.
Ph. D.
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Senthilvasan, Jeevanandam. "Dynamic response of curved box girder bridges." Thesis, Queensland University of Technology, 1997.

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Malan, Andreas Dawid. "Critical normal traffic loading for flexure of bridges according to TMH7." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80013.

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Thesis (MScEng)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: Different types of live loading due to traffic may act on bridges. The focus of this study is on normal traffic loading according to the South African specification of TMH7. Heavy vehicles are not included in normal traffic loading. TMH7 represents the code of practice for the design of highway bridges and culverts in South Africa. The aim of the study is to provide an insight into the flexural analysis of skew bridges, under the effects of normal traffic loading. The need for the study arose since the specification of TMH7 does not explicitly specify application patterns for normal traffic loading. Only the intensity of normal traffic loading is specified and it should be applied to yield the most adverse effects. For these reasons, a set of so-called standard application patterns are investigated and developed through the course of this study. The envelope of the values from the standard application patterns are compared to the most adverse application pattern for flexural effects in certain design regions of the bridge deck. Flexure, as in the context of this study, translates into the bending and twisting of the bridge deck under loads. A number of numerical experiments are performed for typical single span and multi-span continuous carriageways, where the standard application patterns are compared to the most adverse application patterns. The results from the numerical experiments are documented and compared as the angle of skew of the bridge deck increases in plan-view. For this purpose, the development of effective and specialized software was necessary. It was found that the set of standard application patterns can be used as a preliminary approximation for the most adverse effects of normal traffic loading, for specific flexural resultants in certain design regions of a bridge deck. However, for a large number of secondary flexural effects, the set of standard application patterns did not represent a good approximation for the most adverse values.
AFRIKAANSE OPSOMMING: Verskillende tipes lewendige belasting, as gevolg van verkeer, kan op brûe inwerk. Die fokus van die studie is op normale verkeers-belasting volgens die Suid-Afrikaanse spesifikasie van TMH7. Swaar-voertuie word nie ingesluit by normale verkeers-belasting nie. TMH7 verteenwoordig die kode vir die ontwerp van padbrûe en duikers in Suid-Afrika. Die doel van die studie is om insig te verskaf in die buig-analise van skewe brûe, as gevolg van die werking van normale verkeers-belasting. Die rede vir hierdie studie ontstaan aangesien die spesifikasie van TMH7 nie eksplisiet aanwendingspatrone vir normale verkeers-belasting voorskryf nie. Slegs die intensiteit van normale verkeersbelasting word voorgeskryf en dit moet aangewend word om die negatiefste effekte te verkry. Vir hierdie redes word 'n versameling van sogenaamde standaard aanwendings-patrone deur die loop van die studie ondersoek en ontwikkel. Die omhullings-kurwe van die waardes wat deur die standaard patrone gelewer word, word vergelyk met die waarde van die aanwendings-patroon wat die negatiefste buig-effek in sekere ontwerp-areas van die brugdek veroorsaak. Buig-effekte, soos van toepassing op hierdie studie, verwys na buig en wring van die brugdek as gevolg van belastings. 'n Aantal numeriese eksperimente, vir enkel-span sowel as multi-span deurlopende brugdekke, word uitgevoer en die standaard aanwendings-patrone word vergelyk met die aanwendings-patrone wat die negatiefste waardes lewer. Die resultate van die numeriese eksperimente word gedokumenteer en vergelyk soos die hoek van skeefheid van die brugdek in plan-aansig toeneem. Vir hierdie doel is die ontwikkeling van effektiewe en gespesialiseerde sagteware dus nodig. Daar is gevind dat die standaard aanwendings-patrone, vir spesifieke buig-resultante in sekere ontwerp-areas van die brugdek, as 'n voorlopige benadering vir die negatiefste effekte van normale verkeers-belasting gebruik kan word. Dit was egter verder gevind dat vir 'n groot aantal sekondêre buig-effkte, die versameling standaard aanwendings-patrone nie as 'n goeie benadering vir die negatiefste waardes dien nie.
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Books on the topic "Railroad bridges Live loads"

1

Raimundo, Delgado, ed. Dynamics of high-speed railway bridges. London, UK: Taylor & Francis, 2008.

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Rui, Calçada, ed. Track-bridge interaction on high-speed railways. London, UK: Taylor & Francis, 2008.

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Gamble, W. L. Static response of three precast pretensioned concrete railroad bridges. Chicago, Ill: AAR Technical Center, 1995.

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Vehicle-bridge interaction dynamics: With applications to high-speed railways. Singapore: World Scientific, 2005.

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Issa, Mohsen A. Construction loads and vibrations. [Edwardsville, IL]: Illinois Transportation Research Center, Illinois Dept. of Transportation, 1998.

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Moses, Fred. Load capacity evaluation of existing bridges. Washington, D.C: Transportation Research Board, National Research Council, 1987.

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O'Connor, Colin. Bridge Loads. London: Taylor & Francis Group Plc, 2003.

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Georgia. Department of Transportation. Evaluation of bridge load-bearing capacity estimation technology. [Georgia: Dept. of Transportation, 2008.

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Dorton, Roger A. Methods for increasing live load capacity of existing highway bridges. Washington, D.C: National Academy Press, 1997.

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Moses, Fred. Calibration of load factors for LRFR bridge evaluation. Washington, D.C: National Academy Press, 2001.

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Book chapters on the topic "Railroad bridges Live loads"

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Gómez, Roberto, Raul Sánchez-García, J. A. Escobar, and Luis M. Arenas-García. "Analysis of the Response Under Live Loads of Two New Cable Stayed Bridges Built in Mexico." In Springer Tracts on Transportation and Traffic, 17–26. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-19785-2_2.

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Stagnitto, Giuseppe, Roberto Siccardi, and Massimiliano Ghioni. "The Somigliana’s Double Dislocation Method for the Calculation of the Live Loads Collapse Multiplier of Masonry Arch Bridges." In Lecture Notes in Civil Engineering, 304–12. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-91877-4_36.

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Yang, Y., and D. Magistro. "Railroad bascule bridge load rating." In Bridge Maintenance, Safety, Management and Life Extension, 1337–44. CRC Press, 2014. http://dx.doi.org/10.1201/b17063-202.

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"Distressing - Loading - Modelling of Vehicles." In Bridges’ Dynamics, edited by George T. Michaltsos and Ioannis G. Raftoyiannis, 15–47. BENTHAM SCIENCE PUBLISHERS, 2012. http://dx.doi.org/10.2174/978160805220211201010015.

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This chapter deals with all load types imposed to bridge structures. Typical permanent and live loads such as self-weight, traffic loads, snow and wind loads and thermal loads are presented with reference to international codes for structural loadings. Special loads such as seismic loads, accidental loads, blast loads, support settlement, centrifugal forces etc. are also given. The designer must take into account all loads specified by the codes as well as special load cases due to structural type of the bridge.
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Kamiński, T., J. Bień, M. Kużawa, and J. Zwolski. "Live loads in condition assessment of old bridges." In Maintenance, Monitoring, Safety, Risk and Resilience of Bridges and Bridge Networks, 315–16. CRC Press, 2016. http://dx.doi.org/10.1201/9781315207681-154.

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Dai, B. R., Q. Li, and D. J. Wu. "Multiple presence factor for live loads on road-rail bridges." In Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations, 2188–96. CRC Press, 2021. http://dx.doi.org/10.1201/9780429279119-297.

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Kabani, Matongo, and Pilate Moyo. "Live loads for assessment of bridges on heavy haul rail freight lines." In Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations, 462–68. CRC Press, 2021. http://dx.doi.org/10.1201/9780429279119-59.

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"Trucks were used later in various positions and strains were measured due to these truck loads. Stresses were calculated from measured strains and compared with analytical stresses calculated based on the design assumptions which are according to AASHTO Standard Specifications. Reasonable agreement between the analytical and experimental results was obtained for dead loads where the steel girders were acting alone without the concrete composite action. Furthermore the diaphragms connecting girder 5 (the instrumented girder) to girder 4 were only loosely connected under the dead loading. Differences in magnitude and distribution pattern, however, were observed for the live loading. These differences are basically due to the conservatism in AASHTO load distribution method as well as the inability of the two dimensional composite beam approach in depicting the actual three dimensional behavior of the bridge system The testing of the bridge was sponsored by Maine Department Of Transportantion, James Chandler is the Bridge Design Engineer. The analytical results presented in this paper were calculated by Steve Abbott of MODT. The interest and support of Jim and Steve as well as Karel Jacobs, also of MDOT, Is greatly appreciated. American Association of State Highway Transportation Officials, Standard Specification for Highway Bridges 2. Newmark, N., "Design of I-Beam Bridges", Transactions ASCE, Vol. 74, No. 3, Part I, March, 1948. 3. Heins, C.P. and Kuo, J.T.C., "Live Load Distribution on Simple Span Steel I-Beam Composite Highway Bridges At Ultimate Load", CE Report No. 53, University of Maryland, College Park, MD., April, 1973. 4. Heins, C.P. and Kuo, J.T.C., "Ultimate Live Load Distribution Factor For Bridges", Journal Of The Structural Division, ASCE, Vol. 101, No. ST7, Proc. Paper 11443, July 1975." In Composite Steel Structures, 52. CRC Press, 1987. http://dx.doi.org/10.1201/9781482286359-12.

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Conference papers on the topic "Railroad bridges Live loads"

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Jacobs, David W., and Ramesh B. Malla. "Review of Live Load Impact Factor for Existing Truss Railroad Bridges in the United States." In 2013 Joint Rail Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/jrc2013-2567.

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The current American Railway Engineering and Maintenance-of-Way Association (AREMA) Manual provides live load impact formulas for the design of steel railroad bridges. The only variable in those formulas is span length and do not include other parameters that bridge engineers know affects live load impact factor. Years of use in practice and research have shown that these formulas are reliable, safe and simple to apply, though often very conservative. In order to make the nation’s transportation more efficient and energy efficient, a significant effort is underway in the U.S. to enhance its railroad infrastructures. Bridges built before the 1950s, many of which are still in service, were designed to sustain the effects of steam engine hammer blow, and consequently slow speed. Yet, most of these bridges may not be replaced and may be required to carry high speed passenger equipment. This raises the question of what effects higher speed trains will have on old, long span truss steel bridges. This paper presents finding from the detail literature review on the current live load impact factor on truss railroad bridges and its implication to the future.
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Gomez, Jose A., Ali I. Ozdagli, and Fernando Moreu. "Application of Low-Cost Sensors for Estimation of Reference-Free Displacements Under Dynamic Loading for Railroad Bridges Safety." In ASME 2016 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/smasis2016-9294.

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The concept of SHM is that a sensing system on the structure monitors the system responses and notifies the owner about the condition of the structure. The aim of this paper is to propose an inexpensive SHM method employing low-cost sensors to monitor the railroad bridges. Traditional monitoring systems can have limitations regarding the deployment of wired sensors due to their high cost. In this paper, the utilization of low-cost sensors for live load monitoring of railroad bridges is explored. In this study an Arduino microcontroller along with an inexpensive accelerometer manufactured by Analog Devices were used as test platform. In order to determine the ability of the low-cost accelerometer to assess the condition of a vibrating structure, the sensor system was attached to an actuator simulating bridge vibrations and different types of frequencies and amplitudes were tested. The values obtained with the Arduino microcontroller are very similar to the commercial accelerometer while being 60 times cheaper, which shows the potential of investing on low-cost instrumentation for inexpensive monitoring of railroad bridges. The findings of this research indicate that low-cost sensors can be effectively utilized for structural health monitoring of railroad bridges.
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Lei, Jun-Qing, Xian-Qing Zhang, Shu-Lun Guo, Zu-Wei Huang, and Wu-Qin Wang. "Mechanics analysis of long span railroad cable-stayed bridge under effect of vertical loads." In IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2021. http://dx.doi.org/10.2749/christchurch.2021.0554.

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<p>This paper aims to explore the challenge of the design of over one-kilometer-long span road-rail cable-stayed bridge. Because of the large live load and the weight of the structure itself, it has important theoretical significance and engineering application value to study the design parameters of the long Road-Rail cable-stayed bridge with a main span of over 1000 m. The main content of this paper is to study the Steel Road-Rail Cable-stayed Bridge with a main span of 1200 m. The finite element model is established by large-scale analysis software to calculate the response of the structure under load. Based on the calculation results, the rationality of long-span cable-stayed bridge are preliminarily researched. Wind and seismic loads are not considered.</p>
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Nicks, Jennifer E., and Jean-Louis Briaud. "Preliminary Evaluation of the Bump at the End of the Railway Bridge." In ASME/IEEE 2007 Joint Rail Conference and Internal Combustion Engine Division Spring Technical Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/jrc/ice2007-40122.

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Bumps often develop at the interface between the bridge deck and the approach embankment of a railway bridge. The differential track movement at this transition zone creates higher impact loads, reduced bridge and embankment life, possible safety hazards, and higher maintenance costs. This study investigates the extent of the problem, typical maintenance expense, reasons behind the bump, and possible solutions. Based on a survey conducted to evaluate current practice, the bump problem affects about 50% of all railroad bridges and costs each railroad company an estimated $2,550,000 on maintenance. The typical slope for current bumps is equal to approximately 1:150. Using LS-DYNA, a 3-D, non-linear finite element program, a simple, rigid system was simulated to find the range of impact forces resulting from different bump slopes. A parametric study will be conducted in the future to examine the components involved and to optimize various solutions, such as approach slabs. The results from the entire study will help to minimize the bump at the end of the railway bridge.
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Hota, GangaRao V. S., P. V. Vijay, and Reza S. Abhari. "Rehabilitation of Railroad Bridges Using GFRP Composites." In 2010 Joint Rail Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/jrc2010-36053.

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The use of glass fiber reinforced polymer (GFRP) composite materials to rehabilitate timber Railroad Bridge is investigated in this research. Two different rehabilitation methods were developed and implemented to strengthen timber stringers using GFRP. These methods are referred to as GFRP spray lay-up and vacuum bagging of GFRP wraps around timber members. Tests were conducted on four full scale (8″×16″×12″) timber stringers in the WVU-CFC laboratory under four point bending loads. These creosote treated timber stringers were loaded up to 20% of their ultimate loads to verify their properties. The stringers were then repaired using the above two rehabilitation methods and retested to failure. Strengthening the stringers with GFRP composites increased the shear moduli of the two stringers by 41% and 267%. Rehabilitation and load testing were carried out on an open-deck-timber railroad bridge built during early 1900’s on the South Branch Valley Railroad (SBVR) owned by the WVDOT in Moorefield, WV. Specifically, field rehabilitation involved repairing piles using GFRP composite wraps and phenolic formaldehyde adhesives. Using a 80-ton locomotive, static and dynamic tests were performed to determine the dynamic response of the substructure. Rehabilitated SBVR Bridge showed a 43% and 46% strain reduction in the piles and pile cap, respectively.
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Li, Dingqing, and Luis Maal. "Heavy Axle Load Revenue Service Bridge Approach Problems and Remedies." In 2015 Joint Rail Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/jrc2015-5700.

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Two different remedies to reduce track stiffness and increase track damping for the track on the bridges were implemented for two separate ballast deck bridges with standard concrete ties located on a high tonnage heavy haul revenue service route. One remedy used concrete ties fitted with rubber pads on the bottom surface and the other used ballast mats between the ballast layer and bridge deck. The ballast sections were increased to a minimum depth of 12 inches below the bottom of the ties, and drainage improvement was made to ensure that water would not accumulate on the bridges or in the approaches. The two bridge locations were selected in September 2007 and June 2009, for remediation and long-term monitoring of performance as part of the heavy axle load revenue service mega site testing program conducted by Transportation Technology Center, Inc. and Union Pacific Railroad. Before remediation, these two locations experienced excessive track geometry degradation, mud pumping, and track component failure that required localized maintenance work on a quarterly basis (approximately 63 MGT). After remediation, no localized maintenance (except yearly surfacing operations for the entire line) has been required for more than 1,000 MGT. The main root causes of these problems were determined to be high track stiffness and low track damping for the track on the bridges, which adversely affected dynamic vehicle-track interaction when differential track settlement started to occur at the bridge approaches. Some of these ballast deck bridges with concrete ties had track modulus measured at 12,000 lb/in/in, which is considered too high to accommodate dynamic vehicle-track interaction. Long-term performance of these remedies has been excellent, resulting in significant benefits from reduction of slow orders, train delays, and major track maintenance activities.
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Liu, Bideng, Ali I. Ozdagli, and Fernando Moreu. "Cost-Effective Monitoring of Railroad Bridge Performance." In ASME 2017 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/smasis2017-3981.

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Railroads carry 40% of the U.S.’ freight tonnage. Railroad bridges are the most critical component of this network. Measuring transverse displacement of railroad bridges under train-crossing load is essential for the safe and cost-effective operation of railroad network. However, bridge displacement is difficult to collect in the field with traditional sensors due to the lack of fixed reference frame. Although reference-free sensors provide flexibility overcoming the aforementioned challenge, they often fail to capture pseudo-static components observed in timber bridges. This study proposes a novel reference-free sensing system to measure the total displacements of railroad bridges under train-crossing loads. A novel passive-servo electro-magnetic-induction (PSEMI) sensing technology provides accurate direct reference-free dynamic displacement measurement. Furthermore, researchers utilize two reference-free accelerometers to record inclination measurement and transform to pseudo-static displacement. Total bridge displacement is obtained by adding dynamic and pseudo-static responses together. Shake table experiments employing a bridge pier model excited by bridge displacements measured in the field has validated the effectiveness and accuracy of the novel sensing system.
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Anderson, Justin S., and Jerry G. Rose. "In-Situ Test Measurement Techniques Within Railway Track Structures." In IEEE/ASME/ASCE 2008 Joint Rail Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/jrc2008-63047.

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Recent changes in national transportation needs have placed increased burden on railroad infrastructure. To meet the increased demand for efficient freight transport, the railroad industry has increased traffic volume and maximized axle loadings. Increased axle loads have forced railroads to reevaluate existing infrastructure to ensure their ability to accommodate the additional traffic loads. It is imperative to design and maintain tracks such that they can withstand high volume and increasing axle loads over an extended service life, considering the track structure is the most significant capital expense for railroad companies. It has been desirable for years to develop non-intrusive procedures to directly measure pressures and stresses at various levels and interfaces in the railroad track structure in order to optimize track designs and improve subsequent track performance. Methods for measuring both pressures and deflections have been presented in recent research focusing on assessing the performance of trackbeds with increased track modulus, primarily through the addition of asphalt underlayment. These studies involve instrumenting HMA trackbeds with earth pressure cells and displacement transducers to measure pressure levels and distributions within the track structure and rail deflections under moving trains. Additional test methodologies have been developed to include pressure readings at interfaces like the rail/tieplate interface and the tieplate/tie interface using very thin pressure sensitive Tekscan sensors. The Tekscan Measurement System uses a piezoelectric film sensor composed of a matrix-based array of force sensitive cells, similar to mini strain gauges, to obtain accurate pressure distributions between two surfaces in the track. The procedure appears applicable for a wide variety of specific track related measurements to include: 1) analyzing pressure distribution patterns at the rail base/tie plate/tie interfaces to minimize wear and eliminate pressure points, 2) validating and optimizing horizontal curve geometric design criteria relative to superelevation, 3) assessing crossing diamond, other special trackwork, and bridge approach impact pressures, and 4) evaluating the advantages/disadvantages of various types of tie plates, fastenings, and tie compositions with the objective of equalizing pressure distributions over the interface areas. Results of testing are presented in detail for test installations on CSX Transportation heavy tonnage mainlines and at the Transportation Technology Center (Pueblo) low track modulus heavy tonnage test track.
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Benham, N., C. Mundell, and C. R. Hendy. "Parametric Studies of Bridge Specific Assessment Live Loads and Implications for Assessment." In IABSE Conference, Copenhagen 2018: Engineering the Past, to Meet the Needs of the Future. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2018. http://dx.doi.org/10.2749/copenhagen.2018.154.

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A number of UK long span suspension bridges now require routine inspection, assessment and maintenance to ensure their continued durability. The UK Design Manual for Roads and Bridges (DMRB) has explicit guidance on the traffic loading for assessment lengths up to 50m, however beyond this the assumptions become conservative. In these instances, the assessment of these structures requires a Bridge Specific Assessment Live Load (BSALL) to be derived. Although a number of methodologies exist to derive BSALLs, there are several parameters that may significantly affect their results and there is little published guidance on the subject. <p> Through recent work covering the calculation of suspension bridges, Atkins have completed many parametric studies, considering different distribution methods and the relative importance of the various parameters involved. This paper discusses the above themes and outlines the advancements made by Atkins in this field, highlighting the critical parameters to consider, the advantages and limitations of the various approaches, and a recommended approach based on our findings to date.
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Gergel, John T., Vishali M. Vasudevan, and Matthew H. Hebdon. "Railroad Tie Lateral Resistance on Open-Deck Plate Girder Bridges." In 2020 Joint Rail Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/jrc2020-8053.

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Abstract On open-deck railroad bridges, the crossties (sleepers) are directly supported by the bridge superstructure and anchored with deck tie fasteners such as hook bolts. These fasteners provide lateral resistance for the bridge ties, and in railroad bridge design, their spacing is controlled by the required lateral resistance of the ties. Currently there are no provisions to assist in the calculation of lateral resistance provided by railroad ties on open-deck bridges, and as a result there are no specific requirements for the spacing of deck tie fasteners. This has led to different design practices specific to each railroad, and inconsistent fastener spacing in existing railroad bridges. A research plan was conducted to experimentally quantify the lateral resistance of timber crossties on open-deck plate girder bridges using different wood species and types of fasteners. Experimental tests were conducted on four different species of timber crossties (Beech, Sycamore, Southern Pine, and Oak) with three different types of fasteners (square body hook bolt, forged hook bolt, and Quick-Set Anchors). A structural test setup simulated one half of an open-deck bridge with a smooth-top steel plate girder, and hydraulic actuators to apply both vertical and horizontal load to a railroad tie specimen. The three main contributions to lateral resistance on open-deck bridges were identified as friction resistance between tie and girder due to vertical load from a truck axle, resistance from the fastener, and resistance from dapped ties bearing against the girder flange. Initial testing conducted at Virginia Tech isolated each component of lateral resistance to determine the friction coefficient between tie and girder as well as resistance from just the fastener itself. Results indicate that friction resistance varies based on the magnitude of vertical truck axle load, species of wood, and quantity of creosote preservative on the tie, while fastener resistance varies based on type of fastener and displacement of the tie. With the experimental results, a preliminary equation for calculating the overall resistance of open-deck timber crossties is developed, which allows for a recommendation of fastener spacing based on the type of fastener, wood species, and anticipated lateral loads on the structure.
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Reports on the topic "Railroad bridges Live loads"

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Han, Fei, Monica Prezzi, Rodrigo Salgado, Mehdi Marashi, Timothy Wells, and Mir Zaheer. Verification of Bridge Foundation Design Assumptions and Calculations. Purdue University, 2020. http://dx.doi.org/10.5703/1288284317084.

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The Sagamore Parkway Bridge consists of twin parallel bridges over the Wabash River in Lafayette, IN. The old steel-truss eastbound bridge was demolished in November 2016 and replaced by a new seven-span concrete bridge. The new bridge consists of two end-bents (bent 1 and bent 8) and six interior piers (pier 2 to pier 7) that are founded on closed-ended and open-ended driven pipe piles, respectively. During bridge construction, one of the bridge piers (pier 7) and its foundation elements were selected for instrumentation for monitoring the long-term response of the bridge to dead and live loads. The main goals of the project were (1) to compare the design bridge loads (dead and live loads) with the actual measured loads and (2) to study the transfer of the superstructure loads to the foundation and the load distribution among the piles in the group. This report presents in detail the site investigation data, the instrumentation schemes used for load and settlement measurements, and the response of the bridge pier and its foundation to dead and live loads at different stages during and after bridge construction. The measurement results include the load-settlement curves of the bridge pier and the piles supporting it, the load transferred from the bridge pier to its foundation, the bearing capacity of the pile cap, the load eccentricity, and the distribution of loads within the pier’s cross section and among the individual piles in the group. The measured dead and live loads are compared with those estimated in bridge design.
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