Статті в журналах: "Railroad bridges Live loads"

1

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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2

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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3

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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4

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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5

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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6

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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7

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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8

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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9

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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10

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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11

Wipf, Terry J., Michael A. Ritter, and Douglas L. Wood. "Evaluation and Field Load Testing of Timber Railroad Bridge." Transportation Research Record: Journal of the Transportation Research Board 1696, no. 1 (January 2000): 323–33. http://dx.doi.org/10.3141/1696-34.

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Several spans of a 60-year-old open-deck timber railroad bridge on the Southern Pacific Railroad Line (now the Union Pacific) in Southwest Texas were field tested. The tests were conducted with the sponsorship and cooperation of the Association of American Railroads to determine the vertical live load distribution characteristics of the superstructure. The bridge was originally constructed with Douglas-fir larch solid sawn stringers but was rehabilitated on several occasions to allow comparisons to be made with respect to different rehabilitation options, including the use of a helper stringer and the use of glued laminated timber (glulam) stringers. The test spans measured approximately 4.1 m (13.5 ft) center-to-center of supports and included two closely “packed” chords, each consisting of four timber stringers (one test span included an additional helper stringer added to one chord). One chord was made up of glulam timber and the other was made up of solid sawn timber. The bridge superstructure was generally in satisfactory condition, with some stringer horizontal splitting noted over the bents. The bents were in reasonably good condition, but chord bearing was uneven on bent caps. Static and dynamic deflection load test data were obtained using a special test train. The test results indicate that the glulam chord performed better than the older sawn stringer chord, even when a helper stringer was added. Individual stringers within a chord did not always share the load equally.

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12

Uppal, A. S., R. B. Pinkney, and S. H. Rizkalla. "An analytical approach for dynamic response of timber railroad bridges." Canadian Journal of Civil Engineering 17, no. 6 (December 1, 1990): 952–64. http://dx.doi.org/10.1139/l90-107.

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In the 1970s, it was reported that there were approximately 3700 track kilometers of timber railroad bridges in the United States and Canada. For short spans, they offer an attractive alternative to other types of bridges, as they are economical, faster to construct, and easy to maintain. Current design practices do not allow an independent consideration of the effects of the dynamic loads in sizing the bridge components, because very little information is available on the subject. Dynamic tests were carried out in 1986 on timber bridge spans at two test sites using test trains consisting of a locomotive unit, two loaded hopper cars, and a caboose. This paper gives a brief description of the analytical approach employed for determining the dynamic response of timber bridge spans under railway vehicles travelling at a constant speed. The model comprises a multi-degree-of-freedom system with each vehicle having bounce, pitch, and roll movements. Two parallel chords, each having its distributed mass lumped at discrete points, were used to idealize the bridge spans. A computer program developed on this basis was used to predict the loads at the wheel–rail interfaces and the vertical displacements at the discrete points on the spans. The predicted loads at wheel–rail interfaces and the maximum vertical displacements were found to be in agreement within about 20% and 16% respectively of the measured values. The program was utilized to study the effect of speed and other factors on the dynamic response of open-deck and ballast-deck bridges. Key words: analytical approach, timber railway bridge, railway locomotive and cars, constant speed, wheel–rail interface, loads, displacements, accelerations, dynamic response.

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13

Kuzmanovic, Bogdan O., and Manuel R. Sanchez. "Lateral Distribution of Live Loads on Highway Bridges." Journal of Structural Engineering 112, no. 8 (August 1986): 1847–62. http://dx.doi.org/10.1061/(asce)0733-9445(1986)112:8(1847).

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14

Uppal, A. S., S. H. Rizkalla, and R. B. Pinkney. "Response of timber bridges under train loading." Canadian Journal of Civil Engineering 17, no. 6 (December 1, 1990): 940–51. http://dx.doi.org/10.1139/l90-106.

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Timber bridges are still commonly used by several North American railroads. For short spans, they offer an attractive alternative to other types of bridges, as they are economical, faster to construct, and easy to maintain. Current design practices do not allow an independent consideration of the effects of the dynamic loads in sizing the bridge components, because very little information is available on the subject. Dynamic tests were carried out at two timber railroad bridge sites under the passage of trains at speeds varying from crawl, i.e., 1.6 km/h (1 mph), to 80.5 km/h (50 mph). The loads at wheel–rail interfaces, the vertical displacements, and the accelerations were measured at several locations on the bridge spans, the bridge approaches, and the normal track sections. The maximum values of the dynamic load factors obtained were 1.50, 1.65, and 1.85 for bridge, bridge approach, and normal track, respectively; and the corresponding maximum values of the dynamic displacement factors obtained were 1.30, 1.00, and 1.20. The main objective of this paper is to describe the experimental work and the influence on the measured values of the train speed and other factors. Key words: railroad, timber, bridge, wheel–rail interfaces, load, deflection, frequency, load factor, dynamic displacement, track modulus.

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15

Gasim M. Hussein, Ahmed, and Khalil Fawzi Ajabani. "Light Live load Bridges over the River Nile in Sudan." FES Journal of Engineering Sciences 9, no. 1 (February 22, 2021): 65–71. http://dx.doi.org/10.52981/fjes.v9i1.660.

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Bridge structures are vital for majority of Sudanese due to the fact that they live besides rivers, valleys and inside islands. Bridge construction is faced by the fact that it is extremely expensive. Cost of such structures is affected by live load which accordingly dictates the required dead Loads from both superstructure and substructure. In this analytical study a light live bridge load is derived making use of AASHTO principles. This practical live load is derived from data collected from sedan cars, bicycles, motorcycles, motorcycles rickshaws, auto rickshaws and pedestrian. The derivation yielded a design light live load composed of design lane load and design vehicle; to be applied simultaneously to this type of light bridges. The live loads are to be controlled at the bridge entrance. The derived loads are applied to different superstructures' systems, namely steel truss and composite steel plate girder. A single pier over two piles substructure system is chosen for such light loads. A case study bridge is designed over the River Nile. The results obtained showed tremendous savings in material and cost. Relative to normal highway bridges over the Nile, the steel truss bridge option reduces the cost by almost 60%.

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16

CARVALHO NETO, J. A. DE, and L. A. C. M. VELOSO. "Weighing in motion and characterization of the railroad traffic with using the B-WIM technique." Revista IBRACON de Estruturas e Materiais 8, no. 4 (August 2015): 491–506. http://dx.doi.org/10.1590/s1983-41952015000400005.

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AbstractThe knowledge on the active moving load of a bridge is crucial for the achievement of the information on the behavior of the structure, and thus foresee maintenance, repairs and better definition of the logistics of its active vehicles. This paper presents the development of the algorithms for the application of the Bridge-Weigh In Motion (B-WIM) method created by Moses for the weighing of trains during motion and also for the characterization of the rail traffic, allowing the obtainment of information like passage's train velocity and number and spacing of axles, eliminating the dynamic effect. There were implemented algorithms for the determination of the data referring to the geometry of the train and its loads, which were evaluated using a theoretical example, in which it was simulated the passage of the train over a bridge and the loads of its axles were determined with one hundred percent of precision. In addition, it was made a numerical example in finite elements of a reinforced concrete viaduct from the Carajás' Railroad, in which the developed system reached great results on the characterization and weighing of the locomotive when the constitutive equation of the Brazilian Standards was substituted by the one proposed by Collins and Mitchell.

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17

Chen, Yue Ping, Yuan Qing Wang, Xin Yue Zhao, Yong Jiu Shi, Hui Zhou, and Yun Sheng Li. "The Fatigue Research of Straight Thread Sleeve Connection for Beijing South Railway Station." Applied Mechanics and Materials 94-96 (September 2011): 1003–7. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.1003.

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As for Beijing South Railway Station, railway track just lies on the roof slab of the basement, in railroad bridge or the railroad station orbit layer structure, the reinforcing bar designs general is used thick diameter reinforcing bar.However weld can’t assure the quality, and the reinforcing bar is dense, it is hard to site operation;But the mechanical connection has many advantages, such as have high quality, convenient construction,high productivity ,so now more and more project will choose it.Railroad station orbit layer has a total of 500 000 steel bar joints inside and directly bears the live load of moving trains,which need to do a fatigue search for assuring its satisfy use and specification request.Finally,through the test and application,the result is very good, gives reference for other construction projects of machinery connectivity on the live load.

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Shahid, I., A. K. Noman, S. H. Farooq, and Ali Arshad. "Investigation of the Adequacy of Bridge Design Loads in Pakistan." Indonesian Journal of Science and Technology 4, no. 2 (July 9, 2019): 171–87. http://dx.doi.org/10.17509/ijost.v4i2.18174.

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Weight, configuration, and volume of traffic vary from country to country. But, in developing countries like Pakistan, bridges are designed based on codes of developed countries. Hence, these bridges may not have desired safety level. In this study, safety levels of three sample bridges has been investigated in terms of structural reliability index. Live load effects (shear and moments) in girders were determined using weigh-in-motion data (WIM) and were extrapolated to 75 years using non-parametric fit. Two live load models and two strengths, required by 1967 Pakistan Code of Practice for Highway Bridges (PHB Design-Case) and that required by the 2012 AASHTO LRFD Bridge Design Specifications (AASHTO Design-Case) were used in reliability analysis. It is found that actual trucks produce moment and shear in girders 11 to 45 percent higher than live load models of PHB and AASHTO design cases. Values of structural reliability indices vary from 1.25 to 2.50 and from 2.45 to 3.15 for PHB and AASHTO design cases, respectively, and are less than the target reliability index value of 3.50 used in the design codes as benchmark. It is revealed after the research that bridges in Pakistan may not have desired safety level, and current live load models may not be the true representation of service-level truck traffic.

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Zhang, Chang Yong, Tie Yi Zhong, Ke Jian Chen, and Yun Kang Gong. "Study on the Effects of Train Live Loads on Isolated and Non-Isolated Simply Supported Railway Bridges." Applied Mechanics and Materials 50-51 (February 2011): 100–104. http://dx.doi.org/10.4028/www.scientific.net/amm.50-51.100.

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In this paper, based on the finite element program ANSYS, the model of a simply supported railway bridge with and without isolation using lead rubber bearing is established. Seismic response time-history analyses of the bridge subjected to high-level earthquakes are carried out considering and not considering train live loads. Through the comparison and analyses of the results, the effects of train live loads on seismic calculation of non-isolated railway bridges and isolated railway bridges are obtained. The results of the research will support the further study on seismic design and isolation design of simply supported railway bridges.

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20

Gomez, Jose A., Ali I. Ozdagli, and Fernando Moreu. "Reference-free dynamic displacements of railroad bridges using low-cost sensors." Journal of Intelligent Material Systems and Structures 30, no. 9 (August 15, 2017): 1291–305. http://dx.doi.org/10.1177/1045389x17721375.

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Displacements of railroad bridges under service loads are important parameters in assessing bridge conditions and risk of train derailment, according to railroad bridge managers. Measuring bridge responses in the field is often expensive and challenging due to the high costs of sensing equipment. Consequently, railroad bridge managers typically rent or subcontract field measurements to others or choose not to collect dynamic data in the field and make visual inspections. This article studies the use of a low-cost data acquisition platform to measure reference-free dynamic displacements of railroad bridges by combining low-cost microcontrollers and accelerometers. Researchers used off-the-shelf systems to measure accelerations and reconstructed reference-free displacements from several railroad bridge crossing events by running trains with different levels of serviceability in the laboratory. The results obtained from the proposed low-cost sensors were compared with those of commercial sensing equipment. The results show that low-cost sensors and commercial sensing systems have comparable accuracy. The results of this study show that the proposed platform estimates reference-free displacements with a peak error between 20% and 30% and a root mean square error between 10% and 20%, which is similar to commercial structural health monitoring systems. The proposed low-cost system is approximately 300 times less expensive than the commercial sensing equipment. The ultimate goal of this research is to increase the intelligent assessment of bridges by training owners and inspectors to collect dynamic data of their interest with their own resources.

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Landers, Jay. "Shake Table Suggests Live Loads May Improve Bridges’ Seismic Performance." Civil Engineering Magazine Archive 82, no. 1 (January 2012): 38–39. http://dx.doi.org/10.1061/ciegag.0000636.

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22

Zhu, Jin Song, and Jian Song. "Study on Time-Variant Robustness Assessment Method of Complex Bridges." Advanced Materials Research 250-253 (May 2011): 1962–65. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.1962.

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In order to accurately assess the robustness of the complex bridge structure, a method of robustness assessment that takes structure degradation and accidental loads into consideration is proposed. Firstly, the degradation rates of member section properties and the increasing rate of live load are set as variables. The parametrical model of structure is established by the finite element software of ANSYS. Secondly, the structure robustness is based upon analysis from the robustness index, the reserve strength factor and the residual strength factor. The effects of three degradation rates of section properties, the established increasing rate of live loads and accidental loads on the robustness of bridges are considered. Finally, this method is used to analyze the time-variant robustness of Guotai Bridge located on the Haihe River of Tianjin. The results indicate that different degradation rates of member section properties have different effect on the robustness of Guotai Bridge, the effect of accidental loads has a close relationship with its acting position.

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23

Au, Alexander, Clifford Lam, Akhilesh C. Agarwal, and Bala Tharmabala. "Bridge evaluation by mean load method per the Canadian Highway Bridge Design Code." Canadian Journal of Civil Engineering 32, no. 4 (August 1, 2005): 678–86. http://dx.doi.org/10.1139/l05-015.

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The Canadian Highway Bridge Design Code (CHBDC) provides two alternative methods for evaluating the strength of existing bridges. The load and resistance factor method provides a general approach and covers the most extreme load situations that can occur in a general bridge population. The mean load method considers the uncertainties of loads acting on a specific bridge, the method of analysis, and resistance of the structure involved, and thus can provide a more accurate evaluation of individual bridges. Since traffic load represents a major portion of bridge loads, a better evaluation of specific bridges is obtained by using the statistical parameters of traffic loads observed on the structure. However, the overall accuracy depends heavily on capturing the most critical loading conditions during the survey periods. The mean load method is particularly valuable where actual traffic loads are expected to be significantly lower than those used in code calibration and when the potential economic benefits arising from a more realistic evaluation outweigh the extra costs of live load data collection and analysis. This paper demonstrates that the mean load method using site-specific traffic loading information can lead to a significantly higher live load-carrying capacity of a bridge.Key words: highway bridges, bridge evaluation, reliability, mean load method, bridge testing.

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24

Jacobs, David W., Suvash Dhakal, and Ramesh B. Malla. "Live-Load Response of Eyebars on a 110-Year-Old Steel Truss Railroad Bridge." Practice Periodical on Structural Design and Construction 26, no. 1 (February 2021): 04020045. http://dx.doi.org/10.1061/(asce)sc.1943-5576.0000523.

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25

Mohseni, Iman, Yong Cho, and Junsuk Kang. "Live Load Distribution Factors for Skew Stringer Bridges with High-Performance-Steel Girders under Truck Loads." Applied Sciences 8, no. 10 (September 21, 2018): 1717. http://dx.doi.org/10.3390/app8101717.

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Because the methods used to compute the live load distribution for moment and shear force in modern highway bridges subjected to vehicle loading are generally constrained by their range of applicability, refined analysis methods are necessary when this range is exceeded or new materials are used. This study developed a simplified method to calculate the live load distribution factors for skewed composite slab-on-girder bridges with high-performance-steel (HPS) girders whose parameters exceed the range of applicability defined by the American Association of State Highway and Transportation Officials (AASHTO)’s Load and Resistance Factor Design (LRFD) specifications. Bridge databases containing information on actual bridges and prototype bridges constructed from three different types of steel and structural parameters that exceeded the range of applicability were developed and the bridge modeling verified using results reported for field tests of actual bridges. The resulting simplified equations for the live load distribution factors of shear force and bending moment were based on a rigorous statistical analysis of the data. The proposed equations provided comparable results to those obtained using finite element analysis, giving bridge engineers greater flexibility when designing bridges with structural parameters that are outside the range of applicability defined by AASHTO in terms of span length, skewness, and bridge width.

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26

Nowak, Andrzej S., Junsik Eom, and Ahmet Sanli. "Control of Live Load on Bridges." Transportation Research Record: Journal of the Transportation Research Board 1696, no. 1 (January 2000): 136–43. http://dx.doi.org/10.3141/1696-55.

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Application of field testing for an efficient evaluation and control of live-load effects on bridges is described. A system is considered that involves monitoring of various parameters, including vehicle weight, dynamic load component, and load effects (moment, shear force, stress, strain) in bridge components, and verification of the minimum load-carrying capacity of the bridge. Therefore, an important part of the study is development of a procedure for measuring live-load spectra on bridges. Truck weight, including gross vehicle weight, axle loads, and spacing, is measured to determine the statistical parameters of the actual live load. Strain and stress are measured in various components of girder bridges to determine component-specific load. Minimum load-carrying capacity is verified by proof load tests. It has been confirmed that live-load effects are strongly site specific and component specific. The measured strains were relatively low and considerably lower than predicted by analysis. Dynamic load factor decreases with increasing static load effect. For fully loaded trucks, it is lower than the code-specified value. Girder distribution factors observed in the tests are also lower than the values specified by the design code. The proof load test results indicated that the structural response is linear with the absolute value of measured strain considerably lower than expected. Field tests confirmed that the tested bridges are adequate to carry normal truck traffic.

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27

Shokravi, Hoofar, Hooman Shokravi, Norhisham Bakhary, Mahshid Heidarrezaei, Seyed Saeid Rahimian Koloor, and Michal Petrů. "Vehicle-Assisted Techniques for Health Monitoring of Bridges." Sensors 20, no. 12 (June 19, 2020): 3460. http://dx.doi.org/10.3390/s20123460.

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Bridges are designed to withstand different types of loads, including dead, live, environmental, and occasional loads during their service period. Moving vehicles are the main source of the applied live load on bridges. The applied load to highway bridges depends on several traffic parameters such as weight of vehicles, axle load, configuration of axles, position of vehicles on the bridge, number of vehicles, direction, and vehicle’s speed. The estimation of traffic loadings on bridges are generally notional and, consequently, can be excessively conservative. Hence, accurate prediction of the in-service performance of a bridge structure is very desirable and great savings can be achieved through the accurate assessment of the applied traffic load in existing bridges. In this paper, a review is conducted on conventional vehicle-based health monitoring methods used for bridges. Vision-based, weigh in motion (WIM), bridge weigh in motion (BWIM), drive-by and vehicle bridge interaction (VBI)-based models are the methods that are generally used in the structural health monitoring (SHM) of bridges. The performance of vehicle-assisted methods is studied and suggestions for future work in this area are addressed, including alleviating the downsides of each approach to disentangle the complexities, and adopting intelligent and autonomous vehicle-assisted methods for health monitoring of bridges.

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28

Sinha, Ananta, Mi G. Chorzepa, Jidong J. Yang, S. Sonny Kim, and Stephan Durham. "Enhancing Reliability Analysis with Multisource Data: Mitigating Adverse Selection Problems in Bridge Monitoring and Management." Applied Sciences 12, no. 20 (October 14, 2022): 10359. http://dx.doi.org/10.3390/app122010359.

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Data collected using sensors plays an essential role in active bridge health monitoring. When analyzing a large number of bridges in the U.S., the National Bridge Inventory data as been widely used. Yet, the database does not provide information about live loads, one of the most indeterminate variables for monitoring bridges. Such asymmetric information can lead to an adverse selection problem in making maintenance, rehabilitation, and repair decisions. This study proposes a data-driven reliability analysis to assess probabilities of bridge failure by synthesizing NBI data and Weigh-In-Motion (WIM) data for a large number of bridges in Georgia. On the resistance side, tree ensemble methods are employed to support the hypothesis that the NBI operating load rating represents the distribution of bridge resistance capacities which change over time. On the loading side, the live load distribution is derived from field data collected using WIM sensors. Our results show that the proposed WIM data-enabled reliability analysis substantially enhances information symmetry and provides a reliability index that supports monitoring of bridge conditions, depending on live loads and load-carrying capacities.

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29

Cheung, M. S., R. Jategaonkar, and Leslie G. Jaeger. "Effects of intermediate diaphragms in distributing live loads in beam-and-slab bridges." Canadian Journal of Civil Engineering 13, no. 3 (June 1, 1986): 278–92. http://dx.doi.org/10.1139/l86-040.

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For small-span to medium-span bridges, the beam-and-slab type of construction is popular, mainly because of its ease of construction, and is preferred in practice even though this form of construction may sometimes exhibit rather poor transverse load distribution qualities. This deficiency is often reduced by the incorporation of one or more diaphragms in the deck construction. Although the use of diaphragms in beam-and-slab bridges is very extensive, their use is almost entirely empirical rather than based upon any logical method of analysis. Thus, the requirements for diaphragms that are found in codes of practice all over the world usually consist of simple and arbitrary statements. It is proposed here to carry out a thorough theoretical study of the structural behaviour of diaphragms in beam-and-slab bridges, with a view to establishing this behaviour on a well-reasoned footing. Key words: beam-and-slab bridge, diaphragm, cross frame, grillage analogy, finite element method, orthotropic plate theory.

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30

Arellano, Hiram, Roberto Gomez, and Dante Tolentino. "Parametric Analysis of Multi-Span Cable-Stayed Bridges Under Alternate Loads." Baltic Journal of Road and Bridge Engineering 14, no. 4 (December 27, 2019): 543–67. http://dx.doi.org/10.7250/bjrbe.2019-14.457.

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The influence of the stiffness of piers, pylons and deck in the behaviour of multi-span cable-stayed bridges under alternate live loads is analysed. The variation of these parameters is discussed considering both a harp cable system and a fan cable system. Different types of connections between pier-pylon and deck are also considered. Based on the behaviour of a three-span cable-stayed bridge, the variation of pier-pylon stiffness and deck stiffness was analysed. A similar state of stress and deflections was obtained for both a three-span and a multi-span cable-stayed bridge. The study shows that the harp type system presents advantages compared to fan type in terms of its behaviour under alternate live loads considering the same values of deck stiffness and pier-pylon stiffness. It is demonstrated that the resistant mechanism of multi-span cable- stayed bridges is provided by the pier-pylon element.

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31

Mohseni, Iman, A. R. Khalim, and Junsuk Kang. "Live Load Distribution Factor at the Piers of Skewed Continuous Multicell Box Girder Bridges Subjected to Moving Loads." Transportation Research Record: Journal of the Transportation Research Board 2522, no. 1 (January 2015): 59–69. http://dx.doi.org/10.3141/2522-06.

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The multicell box girder bridge is a popular choice of designers because of its large torsional stiffness. The skewness at the support line of bridges has a significant influence on distribution of live loads. The current American bridge design code, AASHTO load and resistance factor design (LRFD), defines several correction factor expressions to account for the skew effect in bridges. In addition, the effect of skewness on reactions of continuous multicell box girder bridges is obtained by using the skew correction factor of shear or by the shear distribution factor of straight bridges, despite a significant disparity between the shear and reaction that is observed in skewed bridges. This study investigated the effect of skewness on the reactions and shear distribution factors for three continuous multicell box girder bridges. There was a significant difference between reactions at the piers and the shear distribution factors of skewed bridges. Thus, a statistical analysis was used to propose new equations for the skew correction factors and the external girder correction factor of shear and reaction to improve the accuracy of the AASHTO LRFD specifications.

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32

Vasilyev, Alexander I. "Safety of live loads for the bridges in Russia, USA and Europe." IABSE Symposium Report 102, no. 36 (September 1, 2014): 522–26. http://dx.doi.org/10.2749/222137814814028124.

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33

Lee, Jeonghwa, Heesoo Kim, Keesei Lee, and Young-Jong Kang. "Effect of Load Combinations on Distortional Behaviors of Simple-Span Steel Box Girder Bridges." Metals 11, no. 8 (August 4, 2021): 1238. http://dx.doi.org/10.3390/met11081238.

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Анотація:

When eccentric live loads are applied on the deck overhang of steel-box girder bridges, torsional moments, comprising pure torsional and distortional moments are generated on the box sections. The torsional moment on the bridge girders distorts the box girder cross-sections, inducing additional normal stress components and causing instability of the box girder sections in severe cases. Hence, it is essential to install intermediate diaphragms in the box sections to minimize distortional behaviors. Although the applied live loads are critical parameters that influence intermediate diaphragm spacings, the effects of live load combinations have rarely been addressed in the design of intermediate diaphragm spacings. Thus, load combinations should be evaluated to design the intermediate diaphragm spacing of the box girder bridges more thoroughly. In this study, the load combination effects on the distortional behavior and adequate intermediate diaphragm spacing were evaluated through a finite element analysis (FEA). Composite rectangular box girder bridges with different cross-sectional aspect ratios (H/B) and spans (L) were analyzed in the parametric study. It was found that the truck load, which represents the concentrated load, significantly influences the distortional warping normal stress, normal stress ratio, and intermediate diaphragm spacing. In addition, the FEA results showed that the controlling load combinations could be varied with the span.

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34

Lou, Peng, Dongjian Gao, Hani Nassif, and Mula Reddy. "Reliability Assessment of Steel Bridges for Specialized Hauling Vehicles." Transportation Research Record: Journal of the Transportation Research Board 2673, no. 12 (July 16, 2019): 391–403. http://dx.doi.org/10.1177/0361198119835512.

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Specialized hauling vehicles (SHVs) are short heavy trucks within the legal weight limits but induce higher load effects than routine commercial loads. The Manual for Bridge Evaluation (MBE) adopted a series of single-unit trucks (SUs) to represent this type of vehicle. However, the SUs were introduced without rigorous reliability-based analysis due to the lack of data on SHVs. With the availability of vast amounts of data on weigh-in-motion (WIM) truck weights and configurations, the reliability of steel bridges under the SHVs should be evaluated in a more robust and quantitative manner. Through the utilization of WIM data, the authors quantified the SHVs in terms of percentages of SHVs among all truck traffic, daily average counts of SHVs, and number of axles. The gross vehicle weights (GVWs) and typical configurations of SHVs were investigated. In addition, their load effects were determined and normalized by the corresponding SUs. The maximum live loads corresponding to a return period of 5 years were also extrapolated using normal probability paper (NPP). To evaluate the effectiveness of current load-rating procedures for SHVs, the authors investigated the relationship between the load-rating factors and the corresponding reliability indices for existing bridges using the developed live load parameters based on the WIM data. Results indicated that the current live load factors were not able to provide a uniform and appropriate reliability index at different average daily truck traffic (ADTT) scenarios. This paper thus proposes new live load factors and weight adjustments of SU trucks to provide an adequate and uniform safety margin for the evaluation of steel bridges.

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35

Santos, C. A. N., A. A. El Damatty, M. S. Pfeil, and R. C. Battista. "Structural optimization of two-girder composite cable-stayed bridges under dead and live loads." Canadian Journal of Civil Engineering 47, no. 8 (August 2020): 939–53. http://dx.doi.org/10.1139/cjce-2019-0140.

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A large number of variables are involved in the optimization of cable-stayed bridges, which makes the optimization impractical when many load cases are considered. To reduce the number of variables to be optimized, a discrete phases approach for structural optimization is developed in this study. The approach couples the finite element method with the genetic algorithm optimization approach. The design variables are divided into two categories: (i) main variables: number of stay cables, I-girder inertia, concrete slab thickness, and tower dimensions; and (ii) secondary variables: I-girder dimensions, stay-cable areas, and pre-tensioning forces. Two design objectives are tested: (i) lightest deck mass; and (ii) lowest material cost. Three load cases are considered: (i) dead and truck plus lane live loads; (ii) dead and lane live loads; and (iii) dead load. The results show the importance of considering the truck loads in structural optimization and the efficacy of the phases approach for different objectives.

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36

Carlin, G. P., and M. S. Mirza. "Replacement of reinforced concrete deck of Champlain Bridge, Montreal, by orthotropic steel deck." Canadian Journal of Civil Engineering 23, no. 6 (December 1, 1996): 1341–49. http://dx.doi.org/10.1139/l96-942.

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The Champlain Bridge, Montreal, Quebec, has recently undergone replacement of its deteriorated reinforced concrete deck situated over the St. Lawrence Seaway with a new orthotropic steel deck. The new deck consists of 210 prefabricated steel panels which have been installed at the rate of one panel per night. The panels arrived on site with a base course of pavement to allow traffic flow over the new panels without disrupting the rush hour and daytime traffic. As a result of the new deck being 25% lighter in weight, the reserve strength capacity of the steel superstructure to accommodate live loads has increased sufficiently to bring the bridge within the governing live load requirements of the CAN/CSA Standard S6-1988 "Design of highway bridges." The governing design live loads on bridges have increased by about 50% since the original construction of the bridge over 30 years ago and reflect the larger vehicle weights permitted over Canadian roadways. Key words: alternative deck systems, cantilevered steel superstructure, closed rib stiffeners, counterweights, diaphragms, field erection, orthotropic plate deck, prefabrication, reinforced concrete, welding.

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37

Gergess, Antoine N., and Rajan Sen. "Design implications of increased live loads on continuous precast, prestressed concrete girder bridges." PCI Journal 58, no. 2 (March 1, 2013): 64–79. http://dx.doi.org/10.15554/pcij.03012013.64.79.

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38

George, Hany W. "Influence of Deck Material on Response of Cable-Stayed Bridges to Live Loads." Journal of Bridge Engineering 4, no. 2 (May 1999): 136–42. http://dx.doi.org/10.1061/(asce)1084-0702(1999)4:2(136).

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39

Agarwal, Akhilesh C., and Moe S. Cheung. "Development of loading-truck model and live-load factor for the Canadian Standards Association CSA-S6 code." Canadian Journal of Civil Engineering 14, no. 1 (February 1, 1987): 58–67. http://dx.doi.org/10.1139/l87-008.

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Studies have shown that the MS-200 loading model in the Canadian Standards Association standard CAN3-S6-M78 for design of highway bridges no longer represents modern-day heavy trucks in Canada. For the new edition of the CSA-S6 code, based on the limit states philosophy, a new loading-truck model was developed based on the Council of Ministers' loading, which is the legal load limit for interprovincial transportation in Canada. The loading model, designated as the "CS-W loading truck," provides the flexibility to adopt a multiple-level loading system appropriate to various jurisdictions.The live-load factor was determined from a statistical approach using data from a truck survey conducted across Canada in seven provinces. Responses in simple-span bridges were determined by running one or more trucks from the survey across the bridge. Based on this study, a live-load factor of 1.60 was determined and CS-600, with a gross weight of 600 kN, was selected as the standard load level. As well, the validity of the truck model and the live-load factors were checked for continuous-span bridges. Key words: highway bridges, design loads, codes and standards, live-load models, load factors, load surveys, vehicle weight regulations.

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40

Nobile, Lucio, Veronica Bartolomeo, and Mario Bonagura. "Structural Analysis of Historic Masonry Arch Bridges: Case Study of Clemente Bridge on Savio River." Key Engineering Materials 488-489 (September 2011): 674–77. http://dx.doi.org/10.4028/www.scientific.net/kem.488-489.674.

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The Clemente Bridge is a multi-span masonry arch bridge built during the 18th century on Savio River in Cesena. The aim of this paper is to assess its static capacity under live loads prescribed by Italian Standards in force. The analysis is performed employing RING 3.0, a computational tool based on Limit State Analysis. This method allows to individuate the minimum adequacy factor, that is the multiplier on vehicle loads required to cause collapse. In this way, a first assessment on the bridge safety can be obtained.

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41

Mourad, Shehab, and Sami W. Tabsh. "Pile Forces in Integral Abutment Bridges Subjected to Truck Loads." Transportation Research Record: Journal of the Transportation Research Board 1633, no. 1 (January 1998): 77–83. http://dx.doi.org/10.3141/1633-10.

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Interest in the use of integral bridges has increased in recent years because of their economy, reliability, and strength. However, most of the published research on integral bridges has been concerned with determination of the thermal effect, creep analysis, and seismic behavior. Few studies on live load analysis of integral abutment bridges have been carried out. The pile load behavior of integral abutments supporting composite steel superstructures subjected to gravity loads is investigated. The applied loading is composed of one or more side-by-side HS20-44 trucks. The finite element method is used to analyze the three-dimensional bridge system and determine forces in the piles. A parametric study is performed to obtain the effects of the number of trucks and their location, superstructure geometry, pile spacing and stiffness, pile connection type, and wingwall length on the pile loads. A simple, approximate procedure for computing pile loads is developed on the basis of the findings of the finite element analysis. The results indicate that the abutment-wingwall system does not behave as a rigid block as in the conventional case of a footing on flexible piles. Also, the generated bending moment in the piles caused by gravity load is significant and cannot be neglected in design.

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42

Ashiquzzaman, Md, Li Hui, Ahmed Ibrahim, Will Lindquist, Nader Panahshahi, and Riyadh Hindi. "Exterior girder rotation of skew and non-skew bridges during construction." Advances in Structural Engineering 24, no. 1 (July 30, 2020): 134–46. http://dx.doi.org/10.1177/1369433220945061.

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In bridge design, bridge decks regularly overhang past the exterior girders in arrange to extend the width of the deck whereas constraining the specified number of girders. The overhanging part of the deck comes about in uneven eccentric loads to the exterior girders which are by and large most prominent. These eccentric loads are primarily a result of bridge construction operations as well as the weight of new concrete and other construction live loads. These unbalanced loads can lead to a differential edge deflection of overhang deck and a rotation of the exterior girders. The girder rotation or differential deck deflection can also affect local and global stability of the entire bridge. The objective of this study is to enhance the knowledge and understanding of external girder behavior due to unbalanced eccentric construction loads and to identify the critical factors affecting their rotation. In this article, field data obtained during the construction of two skewed (one with a small skew (3.8°) and the second with a severe skew (24°)) and one non-skewed steel girder bridges are described, and a detailed comparison is presented. The three bridges experienced maximum outward exterior girder rotation during construction which subsequently decreased following construction operations. The field results were used to validate and calibrate the finite element models. The numerical and field-monitored data showed good agreement and can be used to assist bridge designers and construction engineers to design appropriate systems to limit girder rotation during construction.

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43

Wang, Cao, and Quanwang Li. "Simplified Method for Time-Dependent Reliability Analysis of Aging Bridges Subjected to Nonstationary Loads." International Journal of Reliability, Quality and Safety Engineering 23, no. 01 (February 2016): 1650003. http://dx.doi.org/10.1142/s0218539316500030.

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The performance of existing bridges may deteriorate in time due to aggressive environmental or operating conditions in service, which may eventually cause changes in structural resistance and reliability beyond the baseline assumed for new ones. In addition, the increasing trend of live loads applied to the bridges, which has been reported in many researches, also contributes to the reduction of structural reliability. In order to perform time-dependent reliability assessment for aging bridges subjected to nonstationary loading process with improved efficiency, a simplified method is proposed in this paper, where lower dimensional integral is involved in the calculation of reliability. With the proposed method, time-dependent reliability of a real aging RC bridge is conducted, and the effect of nonstationarity in load intensity on structural reliability is investigated. It is found that structural reliability is sensitive to the increase of load intensity, and is less sensitive to the varying mechanism of load intensity.

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44

Syed, Ali M. "A Comparative Study of Live Loads for the Design of Highway Bridges in Pakistan." IOSR Journal of Engineering 02, no. 10 (October 2012): 96–102. http://dx.doi.org/10.9790/3021-0210196102.

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45

George, Hany W., and Kamal Hassan. "Effect of material of deck on response of cable-stayed bridges to live loads." Journal of Constructional Steel Research 46, no. 1-3 (April 1998): 50–51. http://dx.doi.org/10.1016/s0143-974x(98)00088-1.

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46

Chen, Y. "Prediction of lateral distribution of vehicular live loads on bridges with unequally spaced girders." Computers & Structures 54, no. 4 (February 1995): 609–20. http://dx.doi.org/10.1016/0045-7949(94)00379-h.

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47

Shin, Sang-Uk, Myung-Rag Jung, Jaegyun Park, and Moon-Young Kim. "A deflection theory and its validation of earth-anchored suspension bridges under live loads." KSCE Journal of Civil Engineering 19, no. 1 (July 28, 2014): 200–212. http://dx.doi.org/10.1007/s12205-014-0641-9.

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48

Cheng, Jin, and Ying Li. "Simplified method for predicting the deflections of cable-stayed suspension bridges considering live loads." KSCE Journal of Civil Engineering 19, no. 5 (December 1, 2014): 1413–19. http://dx.doi.org/10.1007/s12205-014-1036-7.

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49

Lawson, William D., Hoyoung Seo, James G. Surles, and Stephen M. Morse. "Impact of Specialized Hauling Vehicles on Load Rating Older, Bridge-Class, Reinforced Concrete Box Culverts." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 41 (June 11, 2018): 87–100. http://dx.doi.org/10.1177/0361198118781148.

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This paper describes the comparison of load ratings associated with application of three live load models recognized by AASHTO—AASHTO legal loads, the notional rating load including single-unit specialized hauling vehicles (SHVs), and the HL-93 design tandem live load—versus load ratings associated with application of the typical HS-20 standard truck. The test bed for this study was a statistically representative sample of Texas’ older bridge-class reinforced concrete box culvert structures. Rating factors were determined using the load factor rating method with demands calculated from a production-simplified, calibrated, two-dimensional soil–structure interaction model using linear elastic constitutive models for both concrete and soil. The study was motivated in part by research which showed that SHVs create force effects significantly greater than those from the HS-20 truck (for bridges proper), and recent federal policy mandating that states load rate their bridges for SHVs. Findings from this study indicate the standard HS-20 truck, and not SHVs or other legal or design loads, is the critical model for most culvert load rating applications. In particular, operating rating factors calculated from both the AASHTO legal loads and SHV models tend to be higher than corresponding rating factors calculated using the HS-20 standard truck, most of the time. The response is explained primarily by considering the relatively short span length of culvert structures and the load-attenuating benefit of cover soil above the culvert top slab. More detailed exploration of rating variables suggests interactions between culvert geometry, cover soil thickness, and the various types of applied vehicle loads.

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50

Taghizadeh, Mohammad Hossein, and Alaeddin Behravesh. "Application of Spatial Structures in Bridges Deck." Civil Engineering Journal 1, no. 1 (November 1, 2015): 1–8. http://dx.doi.org/10.28991/cej-2015-00000001.

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Анотація:

Spatial structure is a truss-like, lightweight and rigid structure with a regular geometric form. Usually from these structures is used in covering of long-span roofs. But these structures due to the lightness, ease and expedite of implementation are a suitable replacement for bridge deck. However steel and concrete is commonly used to build bridge deck, but heavy weight of steel and concrete decks and impossibility of making them as long-span bridge deck is caused engineers to thinks about new material that besides lightness and ease of implementation, provide an acceptable resistance against applied loads including both dead load and dynamic load caused by the passage of motor vehicles. Therefore, the purpose of this paper is design and analysis bridge deck that’s made of double-layer spatial frames compared with steel and concrete deck. Then allowable deflections due to dead and live loads, weight of bridge in any model and also economic and environmental aspects of this idea is checked. As a result, it can be said that the use of spatial structures in bridge deck is lead to build bridge with long spans, reducing the material and consequently reducing the structural weight and economic savings. For geometric shape of the spatial structure bridge is used of Formian 2.0 software and for analysis of bridges is used of SAP2000 with finite element method (FEM).

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