Journal articles on the topic 'Live loads Bridges'
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1
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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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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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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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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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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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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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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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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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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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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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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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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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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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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Guo, Long, Ai Rong Chen, and Li Ping Xu. "Strait Crossing Cable Stayed Bridge Girder Evolution." Advanced Materials Research 250-253 (May 2011): 1407–17. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.1407.
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The design of bridges, in particular long spanned ones, is challenging in the sense that there are many complicated issues to be considered. Amidst the loads to be considered, like dead load, live load, wind load, and earthquake load, the wind load becomes the prime concern for the design of the bridges. The paper will introduce several newly evolved kinds of girder that were based on commonly known physic natural law by structural engineer. Further structural analysis and wind effect research should be done in the future to validate and decide the structural member dimensions. The main problem to be solved in strait crossing bridge is lateral wind load that will effect traffic safety as well as wind effect on structures (statically and dynamically) for long span bridge arrangement.
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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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Cheung, M. S., N. J. Gardner, and S. F. Ng. "Ultimate load distribution characteristics of a model slab-on-girder bridge." Canadian Journal of Civil Engineering 14, no. 6 (December 1, 1987): 739–52. http://dx.doi.org/10.1139/l87-112.
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The introduction of limit states design philosophy and the ever growing demand for higher permissible loads for overload vehicles or special permit vehicles necessitates a thorough investigation of the behaviour and live load distribution characteristics of bridges beyond the working stress range. Evaluation of the live load moment capacity at ultimate utilizing elastic load distribution factors is neither realistic nor logical, as the distribution factors should reflect the ultimate structural/load responses including nonlinear behaviour, load redistribution due to yielding, etc.The purpose of this paper is to study load distribution characteristics of a slab-on-girder bridge model at ultimate loads and to develop load distribution factors for the ultimate limit state which include load redistribution, nonlinear behaviour, and other effects. Key words: load distribution factor, ultimate limit state, load redistribution, nonlinear behaviour, slab-on-girder bridge, OHBD truck.
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Wang, Zi Jian, Li Ming Wu, and Huan Xiong. "Analysis of Mechanical Property of Taniguchi Bridges in Mountainous Areas Loaded by Fluctuating Wind." Applied Mechanics and Materials 71-78 (July 2011): 3543–47. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.3543.
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Besides live loads like cars,earthquakes and people,wind loads should not be neglected on small bridges in mountainous areas,especially by taniguchi and mountain pass.This text does an analogue computation taking a typical slant legged rigid frame bridge in a mountainous area of Chongqing. This bridge lies in the taniguchi of mountainous area where wind condition is complicated.Mathematical model conforming to the local wind load should be established according to the meteorological and hydrological conditions of the bridge site and hydrodynamics and energy conservation principle in order to truly reflect the actual condition of wind in bridge site. Comparing with the calculating result by ANSYS and model of static wind load for normal design, it shows that model of fluctuating wind load established almost accords with the model of static wind load which provides a new train of thoughts and method for further promoting the model of wind load to lead the wind-resist design of bridge construction of taniguchi in mountainous area to better approximate to the real facts.
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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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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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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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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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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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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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Belyi, Andrei, Eduard Karapetov, and Ekaterina Tsygankova. "Design norms and live load development by the example of saint petersburg depot of reinforced concrete automobile road bridges." Proceedings of Petersburg Transport University, no. 3 (June 20, 2018): 344–57. http://dx.doi.org/10.20295/1815-588x-2018-3-344-357.
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Objective: To analyze and cover the statistical data concerning the development and application of live load and relevant design standards by the example of Saint Petersburg bridge constructions. Methods: A comprehensive three-stage analysis of technical documentation on the operated reinforced concrete bridge constructions of the city was applied. Historical and technical review of norms and specifications of design, since the end of the 19th century was conducted. Systematization, statistical analysis and splitting into stages and groups were carried out. Results: The article presents the development of design standards and temporary loads of reinforced concrete highway bridges. The statistics is made on the basis of the depot of Saint Petersburg bridges. The latter is characterized by the increased esthetic, and difficult technical operation features. Classification of temporary loads on structures of Saint Petersburg since 1891 was carried out. The stages of occurrence and formation of circulating load norms were analyzed. A certain feature in regulation of requirements for urban bridges was singled out. Examples of the relevant objects were given. A number of conclusions concerning the evolution of design standards were made. Practical importance: Taking into account the specifi city of the large megalopolis, management of technical condition of bridge constructions in Saint Petersburg represents an extremely responsible and difficult task. Authentic, exact and relevant data on the history of design of facilities, circulating load (both design and current) is necessary for the solution of the task in question. Statistical analysis was carried out to apply operation of reinforced concrete bridge constructions in practice as the most mass transportation facilities of the city. From a practical point of view the data in question will make it possible to provide and support the set standard (design) levels of reliability, safety and durability of bridge constructions with a sufficient share of probability.
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Kennedy, D. J. Laurie, Darrel P. Gagnon, David E. Allen, and James G. MacGregor. "Canadian highway bridge evaluation: load and resistance factors." Canadian Journal of Civil Engineering 19, no. 6 (December 1, 1992): 992–1006. http://dx.doi.org/10.1139/l92-119.
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Consistent load and resistance factors are developed for a range of target values of the reliability index, β, following first-order second-moment analysis techniques for use in the evaluation of highway bridges. Dead load factors are established for steel girders, concrete girders, concrete bridge decks, and wearing surfaces, taking into account the statistical variations of weights and the range of load fractions as determined from field measurements. Live load factors are established for four categories of live loads: NP — non-permit traffic that are permitted by legislation; PM — permit, multiple trip, bulk haul, divisible loads; PS — permit, single trip, unsupervised, mixed with non-permit traffic; and PC — permit, controlled, supervised extremely heavy loads with escort. These live load factors are based on field surveys of truck weights, in Alberta and elsewhere. The event curves for NP, PS, and PM traffic have been used to determine the maximum annual truck, as the period of evaluation was chosen as 1 year based on a life-safety criterion-related to the consequences of failure. Because PC traffic is so rare, it was dealt with on an event basis. Impact data of others were analyzed to determine the appropriate bias coefficients and coefficients of variation. Uncertainties in the transverse distribution of both dead and live loads were also considered.Resistance factors are based on statistical data reported in the literature and take into account the variation in material properties, member size, and the resistance formulations. Key words: dead and live load factors, resistance factors, impact, maximum annual, traffic categories, transverse distribution, weight fractions.
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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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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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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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Abrishamkar, Mohammad Bagher, Reza Kholghi, and Shervin Maleki. "A New Proposal for Live Load Distribution Factors of Bridges with Transverse Beams." Journal of Civil Engineering and Construction 11, no. 3 (August 15, 2022): 166–76. http://dx.doi.org/10.32732/jcec.2022.11.3.166.
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Many bridge superstructures use transverse beams as load carrying components. In these systems, usually the transverse beams are connected to the main longitudinal girders or trusses on the two sides of the bridge. Such systems are commonly used in plate girder, box girder, cable-stayed and truss bridges. The live load distribution factor (LLDF) for bridge superstructures with transverse beams in AASHTO-LRFD bridge design specification has remained unchanged for decades and is prescribed as a function of the distance between the transverse beams. However, for slab-beam superstructures in which longitudinal beams at close spacing carry the loads to the substructure, the LLDFs have gone through many changes throughout the years and in their current forms depend on many parameters such as concrete slab thickness, beam span, longitudinal beam stiffness as well as the distance between the longitudinal beams. This study investigates the factors affecting the LLDF for transverse beams and intends to obtain new equations similar to AASHTO’s longitudinal beam equations. For this purpose, 3D finite element models of different sample bridges were developed and critical parameters affecting the LLDF were identified and varied. Accordingly, the LLDFs for moment and shear forces of transverse beams were obtained through regression analyses. The proposed equations have less than 3.1% of average error for the cases considered.
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Xia, Hai Bing. "Fatigue Properties Estimates of Orthotropic Deck on Steel Bridges." Applied Mechanics and Materials 71-78 (July 2011): 1528–31. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.1528.
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For estimating the fatigue properties of orthotropic deck bridges, a finite element analysis method was provided. In the method, the models of orthotropic decks steel bridge were established by using Midas and Ansys finite element software respectively, the Midas software has tracked two kinds of live load positions that corresponding to maximum and minimum stress of the fatigue checking points, and the most unfavorable loads were loaded to the Ansys model, then the stress ranges of fatigue checking points were obtained and the fatigue properties of the bridge were estimated. The results show that, it is feasible that using the new finite element method to checking the fatigue performance of orthotropic deck steel bridge.
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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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Chajes, Michael J., Harry W. Shenton, and Dennis O’Shea. "Bridge-Condition Assessment and Load Rating Using Nondestructive Evaluation Methods." Transportation Research Record: Journal of the Transportation Research Board 1696, no. 1 (January 2000): 83–91. http://dx.doi.org/10.3141/1696-48.
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In most cases, bridge-condition assessment is made according to visual inspections, and bridge-load ratings are determined with fairly simple analytical methods and without site-specific, live-load, bridge-response data. As a result, estimates of bridge load-carrying capacity are often quite conservative. The increased weight of today’s trucks compared with design loads that are used for older bridges, combined with the continued aging and deterioration of our nation’s bridges, has resulted in a significant number of them being classified as structurally deficient. Reliable condition assessments are essential to ensure the safety of the traveling public. Furthermore, because load-carrying capacity is often used to prioritize bridges for repair, rehabilitation, and replacement, and because funds for these actions are limited, it is more important than ever that these estimates be as accurate as possible. To achieve this goal, researchers at the University of Delaware have been working with engineers at the Delaware Department of Transportation to develop methods for improving the accuracy of bridge-capacity evaluation through use of nondestructive evaluation techniques. Among the methods currently used are diagnostic load testing and in-service monitoring. These methods are described, and a detailed case study that illustrates the applied methodologies is discussed.
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Ellobody, Ehab. "Finite element modelling and design of composite bridges with profiled steel sheeting." Advances in Structural Engineering 20, no. 9 (December 1, 2016): 1406–30. http://dx.doi.org/10.1177/1369433216678865.
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This article discusses the non-linear analysis and design of highway composite bridges with profiled steel sheeting. A three-dimensional finite element model has been developed for the composite bridges, which accounted for the bridge geometries, material non-linearities of the bridge components, bridge boundary conditions, shear connection, interactions among bridge components and bridge bracing systems. The simply supported composite bridge has a span of 48 m, a width of 13 m and a depth of 2.3 m. The bridge components were designed following the European code for steel–concrete composite bridges. The live load acting on the bridge was load model 1, which represents the static and dynamic effects of vertical loading due to normal road traffic as specified in the European code. The finite element model of the composite bridge was developed depending on additional finite element models, developed by the author, and validated against tests reported in the literature on full-scale composite bridges and composite bridge components. The tests had different geometries, different boundary conditions, different loading conditions and different failure modes. Failure loads, load–mid-span deflection relationships, load–end slip relationships, failure modes, stress contours of the composite bridge as well as of the modelled tests were predicted from the finite element analysis and compared well against test results. The comparison with test results has shown that the finite element models can be effectively used to provide more accurate analyses and better understanding for the behaviour and design of composite bridges with profiled steel sheeting. A parametric study was conducted on the composite bridge highlighting the effects of the change in structural steel strength and concrete strength on the behaviour and design of the composite bridge. This study has shown that the design rules specified in the European code are accurate and conservative for the design of highway steel–concrete composite bridges.
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Zhang, Fei Jin, Li Li Nie, and Hong You Cao. "Static Deformational Behaviors of Cable-Stayed Suspension Bridge and its Simplified Material Cost Model." Applied Mechanics and Materials 501-504 (January 2014): 1221–27. http://dx.doi.org/10.4028/www.scientific.net/amm.501-504.1221.
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Cable-stayed suspension bridge is an unconventional bridge type with a bridge typology based on the combination of both cable-stayed and suspension systems. In this paper, the static behaviors of cable-stayed suspension bridge were revealed from the viewpoint of the structural deformational characteristics under different kinds of live loads. To more clearly illustrate these characteristics, the simplified analytical method based on the simplified analytical solutions for cable-stayed bridges and suspension bridges were adopted in the derivations. Furthermore, the simplified material cost model based on allowable stress method for cable-stayed suspension bridge was also proposed for researchers and designers to adopt in preliminary design stage.
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Nadeem, Mohd. "Finite Element Analysis of I-Girder Bridge." International Journal for Research in Applied Science and Engineering Technology 9, no. 8 (August 31, 2021): 2084–97. http://dx.doi.org/10.22214/ijraset.2021.37747.
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Abstract: In India railway bridge structures are widely designed with the method suggested by IRS – Concrete bridge code 1997.This Code of Practice applies to the use of plain, reinforced and prestressed concrete in railway bridge construction. It covers both in-situ construction and manufacture of precast units. The Code gives detailed specifications for materials and workmanship for concrete, reinforcement and prestressing tendons used in the construction of railway bridges. After defining the loads, forces and their combinations and requirements for the limit state design, particular recommendations are given for plain concrete, reinforced concrete and prestressed concrete bridge construction. The design of I-Girder bridge superstructure (deck slab and PSC I-beam) are done by calculating bending moments, shear forces, bending resistance in transverse direction, bending resistance in longitudinal direction, checking flexural cracking. The Design of PSC I-Girders is done for Bending moments and Shear forces by Dead Load, Super Imposed Dead Load (SIDL) and Live Loads (LL). The Shrinkage strain, Creep Strain and effect of Temperature rise and fall are also determined. The design is complete for Pre-stressing cables, un-tensioned reinforcements, End cross girder, Shear connectors. I-girder superstructures are the most commonly used superstructures at cross-over location in metro bridges in india, as it has the wide deck slab and it easily permits metro’s to change tracks. I-Girder superstructure construction is component wise construction unlike U-Girders. I-Girders are constructed in casting yard and its deck slab is cast in situ, parapets are also installed on later stage. Keywords: SIDL effects, Live Load effects, Derailment effect, with or without 15% future PT margin
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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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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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PORTELA, E. L., R. M. TEIXEIRA, T. N. BITTENCOURT, and H. NASSIF. "Single and multiple presence statistics for bridge live load based on weigh-in-motion data." Revista IBRACON de Estruturas e Materiais 10, no. 6 (November 2017): 1163–73. http://dx.doi.org/10.1590/s1983-41952017000600002.
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Abstract Modeling the traffic loads on bridges has been the subject of numerous studies. Defining a live load model to be used for bridge design is not an easy task. It demands among many other things a reliable dataset, a well-defined procedure for filtering data and also the determination of statistics for single and multiple presence occurrences. This study examines and characterizes the live load statistics for Brazilian concrete bridges. Single and multiple truck presence are evaluated for different bridge spans and truck daily volume. The sample is comprised of the thirteen months of data from a High Speed Weigh-In-Motion station (HS-WIM) in a resolution of one hundredth of a second currently operating on the Fernão Dias highway, also known as BR-381. The system provides eleven thousand records on a daily basis. After the filtering process three thousand trucks remain. The station takes measures in an same-direction two-lane highway, which allows the evaluation and characterization of both single and multiple presence statistics. Three case of multiple presence are considered: following, side-by-side and staggered cases. The consideration of truck multiple presence on concrete bridges is mandatory to understand and characterize live load models. The results show that with the exception of the side-by-side case, the frequency of multiple truck presence is significantly affected by span length. It also shows that the daily truck volume considerably affects the multiple presence statistics for all load patterns. The results show that the general tendency of the occurrence of all multiple presence events is to increase as the truck volume increases.
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Juozapaitis, Algirdas, Giedrė Sandovič, Ronaldas Jakubovskis, and Viktor Gribniak. "Effects of Flexural Stiffness on Deformation Behaviour of Steel and FRP Stress-Ribbon Bridges." Applied Sciences 11, no. 6 (March 14, 2021): 2585. http://dx.doi.org/10.3390/app11062585.
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Stress-ribbon systems develop the most flexible and slender bridges. A structural system of such elegant bridges consists of cables or ribbons and deck slabs placed to these strips to distribute the live load. Although this structural system is simple, the design of such structures is a challenging issue. Design limitations of the bridge deck slope induce considerable forces in the ribbons, which transfer the tension to massive foundations. The deformation increase under concentrated and asymmetrical loads causes another problem of stress-ribbon bridges—the kinematic component, the design object of such structures, exceeds the dead load-induced vertical displacement several times. This paper introduces a new concept of such a structural system, comprising ribbons made of flexural-stiff profiles. The proposed approach to reduce kinematic displacements is illustrated experimentally by testing two pedestrian bridge prototypes with different flexural stiffness of the steel ribbons. Numerical models calibrated using the test results are used for the parametric analysis of the flexural stiffness effect on the deformation behaviour of the bridge system with steel and fibre-reinforced polymer (FRP) ribbons. A practical approach to the choice of the efficient flexural stiffness of the ribbon-profiles is also proposed.
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Mohseni, Iman, Amin Ashin, Won Choi, and Junsuk Kang. "Development of Dynamic Impact Factor Expressions for Skewed Composite Concrete-Steel Slab-On-Girder Bridges." Advances in Materials Science and Engineering 2018 (July 10, 2018): 1–9. http://dx.doi.org/10.1155/2018/4313671.
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In order to take into account the dynamic effects of moving vehicles, bridges are designed to carry static loads that are increased by dynamic impact (IFs) factors (or dynamic amplification factors) that are a function of either the span or the first flexural natural frequency of the bridge. However, this approach tends to produce very conservative designs as the IFs are calculated based on a relatively few general parameters, ignoring many significant bridge and truck dynamic characteristics. This paper presents a method for determining more realistic dynamic impact factors for skewed composite slab-on-girder bridges under AASHTO LRFD truck loading. An extensive parametric study of over 125 bridge prototypes examined key parameters, namely, the number of girders, number of lanes, skew angle, and span length. Based on the data generated by this analysis, appropriate expressions for dynamic impact factors for the longitudinal moment and deflection are proposed. In order to reduce the complexity of proposed expressions, the effects of road surface roughness on dynamic responses of bridge-vehicle interaction are considered in bridge modeling. The findings of this study are expected to help bridge engineers to design composite slab-on-girder bridges more reliably and economically and can also be used to reassess the safe live-load capacity of existing structures, potentially preventing the unnecessary posting or closing of busy highway bridges.
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Algohi, B., B. Bakht, H. Khalid, A. Mufti, and J. Regehr. "Some observations on BWIM data collected in Manitoba." Canadian Journal of Civil Engineering 47, no. 1 (January 2020): 88–95. http://dx.doi.org/10.1139/cjce-2018-0389.
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Three highway bridges in the Canadian province of Manitoba are being monitored continuously not only for their long-term performance but also for bridge weighing-in-motion (BWIM). Data collected for the BWIM study has led to some observations that have far-reaching consequences about the design and evaluation loads for highway bridges. This paper presents the well-known concept of equivalent base length, Bm, as a useful tool for comparing trucks with different axle weight and spacing configurations as they influence load effects in all bridges. It is discussed that the statistics of gross vehicle weights (GVWs), W, collected over a one-month period is not significantly different from that for the GVW data collected over a longer period. A rational method concludes that the value of W for the CL-W Truck, the design live load specified by the Canadian Highway Bridge Design Code, is 555 kN for Manitoba. The observed truck data in Manitoba presented on the W–Bm space is found to be similar to that collected in the Canadian province of Ontario more than four decades ago. It was also found that the multi-presence factors, accounting for the presence of side-by-side trucks in two-lane bridges, specified in North American bridge design and evaluation codes are somewhat conservative.
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Cai, Chun Sheng, Wei Zhang, Lu Deng, and Miao Xia. "Performance Evaluation of Existing Bridges under Vehicle Dynamic Effects." Advanced Materials Research 639-640 (January 2013): 42–53. http://dx.doi.org/10.4028/www.scientific.net/amr.639-640.42.
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This paper summarizes the recent work by the first author’s research group related to the performance evaluation of existing bridges under vehicle dynamic effects. Based on the data from short-term monitoring of existing bridges, a framework to estimate the extreme structure responses from the live load in a mean recurrence interval is developed in the first part. The Gumbel distribution of the extreme values was derived from an extreme value theory and Monte Carlo Simulation. In the second part, a framework of fatigue damage and reliability assessment for existing bridges is presented to include the effects of the progressively deteriorated road conditions and random dynamic vehicle loads in bridge’s life cycle. The random effects of vehicle speed and type, road profiles, and stress ranges are included. Studies have shown that the vehicle-induced dynamic allowance IM value prescribed by the AASHTO LRFD code may be underestimated under poor road surface conditions (RSCs) of some existing bridges. In addition, multiple dynamic stress ranges induced by vehicles cannot be included in the maximum displacement-based dynamic allowance IM values. In the third part of this paper, the reliability indices of a selected group of prestressed concrete girder bridges are calculated by modeling the IM explicitly as a random variable for different RSCs. Nevertheless, a reliability based dynamic amplification factor on stress ranges (DAFS) for fatigue design is proposed to include the fatigue damages from multiple stress range cycles due to each vehicle passage at varied vehicle speeds under various road conditions in the bridge’s life cycle.
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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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Xiang, Sheng, Bin Cheng, Feng-yu Zhang, and Miao Tang. "An Improved Time Domain Approach for Analysis of Floating Bridges Based on Dynamic Finite Element Method and State-Space Model." China Ocean Engineering 36, no. 5 (October 2022): 682–96. http://dx.doi.org/10.1007/s13344-022-0061-4.
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AbstractThe floating bridge bears the dead weight and live load with buoyancy, and has wide application prospect in deep-water transportation infrastructure. The structural analysis of floating bridge is challenging due to the complicated fluid-solid coupling effects of wind and wave. In this research, a novel time domain approach combining dynamic finite element method and state-space model (SSM) is established for the refined analysis of floating bridges. The dynamic coupled effects induced by wave excitation load, radiation load and buffeting load are carefully simulated. High-precision fitted SSMs for pontoons are established to enhance the calculation efficiency of hydrodynamic radiation forces in time domain. The dispersion relation is also introduced in the analysis model to appropriately consider the phase differences of wave loads on pontoons. The proposed approach is then employed to simulate the dynamic responses of a scaled floating bridge model which has been tested under real wind and wave loads in laboratory. The numerical results are found to agree well with the test data regarding the structural responses of floating bridge under the considered environmental conditions. The proposed time domain approach is considered to be accurate and effective in simulating the structural behaviors of floating bridge under typical environmental conditions.
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Ng, S. F., M. S. Cheung, and H. M. Hachem. "Study of a curved continuous composite box girder bridge." Canadian Journal of Civil Engineering 20, no. 1 (February 1, 1993): 107–19. http://dx.doi.org/10.1139/l93-012.
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To better understand the behaviour of curved box girder bridges in resisting eccentric design truck loads, and the influence of plan curvature on the structural response, a model study was conducted at the University of Ottawa. In this study, the elastic response of a curved composite box girder bridge model was evaluated experimentally and confirmed analytically using the finite element method. Analytical predictions of both vertical displacements and normal stresses at critical sections compared fairly well with those evaluated experimentally. The isoparametric thin shell element employed in the analysis proved to be versatile and provided an accurate representation of the various structural components of a curved box girder bridge. Despite the eccentric nature of the applied OHBDC design truck loads and the bridge plan curvature, it was evident that in resisting the applied live loads, the girders at critical sections share equal proportions of the applied bending moments. Key words: bridge, curved, cellular, composite, eccentric loads, static, linear, experimental, finite element.
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Suparp, Suniti, and Panuwat Joyklad. "Appraisal of Strengthening Cost for Increasing Flexural Strength of Reinforced Concrete Slab Bridges in Thailand." Advanced Materials Research 931-932 (May 2014): 490–95. http://dx.doi.org/10.4028/www.scientific.net/amr.931-932.490.
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The highway live loadings, HS20-44, stipulated by Association of State Highway and Transportation Officials (AASHTO) are different from Thai truck weights according to government gazettes issued by Department of Highways. This article aimed to study the strengthening costs of the bridges due to Thai trucks. The reinforced concrete solid slab bridges with the span length ranging from 5 to 10 meters were selected to study. It was found that the bridge responses due to Thai trucks were greater than those from AASHTO loads. The average strengthening costs were approximately 6,958 Baht/sq.m and highest at 7 m-span length. The results of this study would be a reference data to create an alternative plan for bridge strengthening in Thailand in order to sustain the bridge safety level recommended by AASHTO.
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Zhang, Zhenhao, Hesheng Li, Jun Xiong, Fuming Wang, Leijun Wei, and Lu Ke. "Determination of the Target Reliability Index of the Concrete Main Girder of Long-Span Structures Based on Structural Design Service Life." Buildings 12, no. 12 (December 16, 2022): 2249. http://dx.doi.org/10.3390/buildings12122249.
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This article studies the quantitative relationship between the target reliability index and the design service life for concrete main girders of cable-stayed bridges. A resistance degradation model of the concrete components is established by quantifying the effects of concrete carbonation and steel corrosion. It is assumed that the dead load and the live load are time-invariant with the distributions of normal and extreme type I, respectively, while the resistance is considered as time-variant with the distribution of lognormal. The standard values of the most unfavorable moment under dead and live loads are calculated by ANSYS, its mean value and standard deviation are further obtained using the statistical parameters suggested by the Unified Standard for Structural Reliability Design of Highway Engineering. The mean and standard deviation of resistance are obtained using the target reliability index value provided in the code above. The resistance value and reliability index at different times in a certain design service life can be obtained through the resistance degradation model. The result shows the reliability index decreases exponentially during the service life of the structure. For different design service years, different initial resistance values and initial reliability indexes can be deduced. Based on this, the target reliability index values considering the design service life are suggested. In the example analysis, the target reliability index of the concrete main girder of a cable-stayed bridge with a design service life of 100 years is suggested as 6.24. This research provides references for the design of concrete main girders of cable-stayed bridges.
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Labib, Shady N., and Ehab F. El-Salakawy. "Finite-Element Analysis of Adjacent Concrete Box Girders Transversely Post-Tensioned at the Top Flanges Only." CivilEng 3, no. 2 (March 22, 2022): 165–83. http://dx.doi.org/10.3390/civileng3020011.
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A three-dimensional non-linear finite-element model (FEM) was constructed using a commercial software (ATENA-Studio) to investigate the transverse load distribution behavior of adjacent precast prestressed concrete box-girder bridges. An innovative connection between box girders was used, where transverse post-tensioning was applied at the top flanges only eliminating the need for intermediate transverse diaphragms. The FEM was validated in terms of deflections, strains, cracking and ultimate loads against experimental results previously reported by the authors. The validated FEM was then used to perform a parametric study investigating the influence of adding concrete topping, load location, and bridge width on the transverse load distribution behavior of the newly developed connection. The results of the FEM demonstrated the efficiency of concrete topping in limiting mid-span deflections up to 25%. Additionally, the maximum live load moment distribution factors (LLMDFs) for different load locations and bridge widths were evaluated.
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Purnomo, Dwi Agus, Djoko Prijo Utomo, Agung Barokah Waseso, and Mira Marindaa. "COMPARISON ANALYSIS OF RAILWAY BRIDGE MODUL FOR “I†GIRDER TYPE AND “WARREN†TRUSS TYPE." Majalah Ilmiah Pengkajian Industri 14, no. 1 (April 30, 2020): 47–58. http://dx.doi.org/10.29122/mipi.v14i1.3833.
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The railway bridge in Indonesia, with a width of 1067 mm, was built in 1878, so that maintenance modules are needed to repair or to replace of construction modul at regular intervals. Implementation of maintenance and repairs refers to the Minister of Transportation Regulation No. 60 of 2012. Problems were encountered in the field at the BH182 Daop 2 railway bridge in Bandung due to lowering structural strength. Therefore, it was necessary to repair the bridge module with a new bridge design. The purpose of this study is to analyse and to calculate strength of the structure and to determine effectiveness of the use of construction materials on 2 alternative bridge construction selection with the type of “I" girder and the type of “Warren" Truss. Design implementation method used is to utilize Midas Civil Structure software. The loading used for railway bridges is grouped into three load groups, namely the girder's self-weight, additional dead load, and live load. Additional dead load analysed is line load including bearings, while for live load is trainset load based on loading requirements. From the results of calculations between the steel bridge “I" girder type height of 300 cm and the type of “Warren" Truss height of 600 cm, each span of 30 m showed that those were a function of the railway bridge. It would be more effective to use the type of “Warren†Truss structure that is quite able to withstand train traffic loads in accordance with applicable standards.
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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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