Artykuły w czasopismach na temat „Girders”
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1
Shawky, Wael, i Ghaidaa Nabil. "Experimental and numerical study for the post buckling behaviour of plate girders subjected to bending and shear". MATEC Web of Conferences 162 (2018): 04027. http://dx.doi.org/10.1051/matecconf/201816204027.
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This research offers experimental and numerical study for the ultimate strength analysis and post buckling behaviour of plate girders subjected to shear and bending stresses. Two Plate girders of length 2.5m are designed consisting from three separate structural steel plates welded together to form I - section. The dimensions of the first girder section is 512 mm × 120 mm while the second girder section is 412mm × 120 mm. Mechanical properties for plate girders components were found by testing three samples of each plate. The ultimate shear strength was found by examining two plate girders in the laboratory under concentrated load applied at the middle span. A numerical study of the tested plate girders was carried out by using the software program (ANSYS) to study the behaviour of girders steel under the influence of loads application. The results showed that the ratio of the experimental ultimate load strength to the numerical ultimate load strength is 97% 94% for plate girders 1 and 2 , respectively. For the part of using theoretical study. The results obtained from the equations , it was observed that the ratio of the experimental ultimate load strength to the theoretical ultimate load strength is 83% for plate girders1 and 90% for the plate girder 2.Through comparison between experimental, numerical and theoretical results it was observed good andacceptable agreement. Thus confirming the accuracy of the modelling between this methods and obtain convergent results in all cases. Also it was found when an increase in the depth of the web has effect in increasing the ultimate shear strength for plate girder by about 19%.
2
Ezzeldin Yazeed Sayed-Ahmed. "Design aspects of steel I-girders with corrugated steel webs". Electronic Journal of Structural Engineering 7 (1.06.2007): 27–40. http://dx.doi.org/10.56748/ejse.772.
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Corrugated web girders represent a new structural system emerged in the past two decades. The girder’s flanges provide the flexural strength of the girder with no contribution from the corrugated web which provides the girder’s shear capacity. Failure of the web occurs by steel yielding, web buckling or interactively between them. Lateral torsion and local flange buckling of corrugated web girders represent another two possible failure criteria. Here, the work previously performed by the author on corrugated web girders was compiled and presented in a comprehensive format. The starting point is the shear behaviour of the corrugated webs which is investigated focusing on the failure modes affecting the web design. An interaction equation that considers web buckling and yielding is proposed. Numerical analyses are performed to investigate the buckling modes of the corrugated web, verify the validity of the proposed equation and explore the post-buckling strength of corrugated web girders. The numerical model is extended to determine the critical moment causing lateral instability for corrugated web girders. The applicability of the critical moment design equations, currently used for plane web girders, to corrugated web girders is examined. The numerical model is then used to scrutinize the local buckling behaviour of the compression flange. The applicability of the currently used limiting values for the flange outstand-to-thickness ratios to corrugated web girders is investigated.
3
Almoosi, Y., i N. Oukaili. "The Response of a Highly Skewed Steel I-Girder Bridge with Different Cross-Frame Connections". Engineering, Technology & Applied Science Research 11, nr 4 (21.08.2021): 7349–57. http://dx.doi.org/10.48084/etasr.4137.
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Braces in straight bridge systems improve the lateral-torsional buckling resistance of the girders by reducing the unbraced length, while in horizontally curved and skew bridges, the braces are primary structural elements for controlling deformations by engaging adjacent girders to act as a system to resist the potentially large forces and torques caused by the curved or skewed geometry of the bridge. The cross-frames are usually designed as torsional braces, which increase the overall strength and stiffness of the individual girders by creating a girder system that translates and rotates as a unit along the bracing lines. However, when they transmit the truck’s live load forces, they can produce fatigue cracks at their connections to the girders. This paper investigates the effect of using different details of cross-frames to girder connections and their impacts on girder stresses and twists. Field testing data of skewed steel girders bridge under various load passes of a weighed load vehicle incorporated with a validated 3D full-scale finite element model are presented in this study. Two types of connections are investigated, bent plate and pipe stiffener. The two connection responses are then compared to determine their impact on controlling the twist of girder cross-sections adjacent to cross-frames and also to mitigate the stresses induced due to live loads. The results show that the use of a pipe stiffener can reduce the twist of the girder’s cross-section adjacent to the cross-frames up to 22% in some locations. In terms of stress ranges, the pipe stiffener tends to reduce the stress range by 6% and 4% for the cross-frames located in the abutment and pier skew support regions respectively.
4
Zhao, Hang, i Bassem Andrawes. "Experimental Testing and Strut-and-Tie Modeling of Full-Scale Precast Concrete Girders with FRP Repaired End Regions". Applied Sciences 10, nr 17 (22.08.2020): 5822. http://dx.doi.org/10.3390/app10175822.
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Bridges located in cold regions are susceptible to extreme deterioration due to harsh climate conditions. Distressing of girder’s end regions is among the most common damage types in these bridges. This work focuses on addressing this type of damage through the use of a fiber reinforced polymer (FRP) repair scheme. Three-point-bending tests are conducted on the control, damaged, mortar repair and carbon fiber reinforced polymer (CFRP) repair cases of bridge girders that are taken out of service. Test results are analyzed to investigate the effectiveness of FRP to repair precast concrete (PC) girders with damaged end regions. Furthermore, since the damage is mainly localized at girder’s end region where beam theory is invalid, the behavior of FRP repaired end region (D-region) is studied using the strut-and-tie method. Based on the test results, a strut-and-tie model (STM) is proposed to estimate the shear capacity of the girder with the FRP repaired end region. The outcome of the experimental work shows that the FRP laminate repair system is effective in recovering and improving the shear behavior of the girder including both peak force and ductility. The proposed STM can be used to predict the shear capacity of the PC girder with a similar damage pattern to the one considered in this study.
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Nguyen, Hue Thi, Hiroshi Masuya, Tuan Minh Ha, Saiji Fukada, Daishin Hanaoka, Kazuhiro Kobayashi i Eiji Koida. "Long-term Application of Carbon Fiber Composite Cable Tendon in the Prestressed Concrete Bridge-Shinmiya Bridge in Japan". MATEC Web of Conferences 206 (2018): 02011. http://dx.doi.org/10.1051/matecconf/201820602011.
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Carbon fiber reinforced plastic (Carbon Fiber Composite Cable, CFCC) has the outstanding features in comparison with regular steel. In October 1988, CFCC was applied as the tensioning material in main girders of new Shinmiya Bridge in Ishikawa, Japan. This was the first bridge in Japan and in the world, which CFCC tendons were used in the prestressed concrete bridge to counter salt damage. To investigate the serviceability and durability of the main girders and CFCC, three full-scale test girders were fabricated in 1988. At the same time, a bending experiment was conducted on one girder to investigate the ultimate behavior, load carrying capacity of the PC girder, as well the strain behavior of the CFCC. Besides, two PC girders were placed next to the main girders of the bridge in the same conditions. One of them was used for a destructive test after six years of the construction time (1994). In this study, another test specimen that was exposed to the actual corrosive environment after nearly 30 years was subjected to a destructive test by bending load. The load carrying capacity of the girder was clarified, and the durability of the PC girders using CFCC tendon was confirmed.
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Alotaibi, Emran, Nadia Nassif, Mohamad Alhalabi, Humam Al Sebai i Samer Barakat. "Numerical investigation on redundancy of bridges with AASHTO I-girders". Bridge Structures 17, nr 1-2 (11.06.2021): 41–50. http://dx.doi.org/10.3233/brs-210187.
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Bridge safety is one of the most critical concerns among civil engineering fields due to its high importance. The redundancy of bridges was heavily investigated in the literature; however, they were focused on twin girder redundancy cases. Additionally, literatures were scarce in studies that focused on the improvement that should be made to achieve redundancy systems in different AASHTO I-girder types. Thus, this study focused on assessing the additional required number of tendons for different AASHTO I-girder types and spacing between them to achieve the redundancy of I-girder bridges. The additional unbonded tendons are suggested to be added externally or internally. The parameters varied in this study are compressive strength of ultrahigh-performance concrete (UHPC), spacing between girders (i.e. number of girders) and type of girders. Leap Bridge Concrete software was used to simulate the required structural modes. After performing extensive numerical analyses following AASHTO LRFD guidelines, the results have shown that in case of the removal of external I-girder, the tendons in the nearest girder need to be nearly increased by 1.85 to 2.3 times compared to the original design, depending on spacing, compressive strength, and the number of girders. On the other hand, in the case of interior girder removal, the number of tendons in the nearest two girders need to be increased by 1.24 to 1.32 times the original design. The effect of compressive strength variation of the used UHPC was negligible compared to spacing and type of girder. It is worth mentioning that all simulations in this study were verified using CSI Bridge software.
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Hamood, Mohammed, Wael AbdulSahib i Ali Abdullah. "The effectiveness of CFRP strengthening of steel plate girders with web opening subjected to shear". MATEC Web of Conferences 162 (2018): 04012. http://dx.doi.org/10.1051/matecconf/201816204012.
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The present study is experimental by nature; it involves applying shear buckling test on seven steel-plated girders that are subjected to shear loading. Four of these girders represent the strengthened girders whereas the other three are reference girders. One of the latter type of girders has a square web opening; the second has a diamond web opening while the last one has no opening at all. The webs of the strengthened girders were adhesively attached to CFRP sheets of different patterns. This step was carried out to evaluate the most effective strengthening scheme by CFRP composite. The study aims at examining the effect of several parameters on the behavior of web girders. It further examines the percentage of increase in the ultimate shear capacity of the perforated girders that have a fixed location and size where the latter is equal to 40 percent of the web depth. Results have shown that, first, the ultimate shear load of the CFRP-strengthened girders with square web opening is higher than that of the reference girder with a square web opening; ranging from 8.7% to 15.7%. The obtained ranges depend on the orientation of the CFRP strips. Second, the ultimate shear load of the CFRP-strengthened girders with a diamond web opening is higher than the reference girder with a range of 9.8% to 21.5%. Again, the obtained ranges depend on the orientation of the CFRP strips. Analytically speaking, Von Mises stresses have been used to predict the ultimate shear load of girders with square and diamond web openings and without web opening.
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Mochizuki, Hidetsugu, Katsuhiko Hanada, Tomokazu Nakagawa, Youji Hanawa, Ichiro Yamagiwa, Katsunori Yasuda, Yozo Fujino i Masatsugu Nagai. "Design and Construction of a Cable-Trussed Girder Bridge". Transportation Research Record: Journal of the Transportation Research Board 1696, nr 1 (styczeń 2000): 293–98. http://dx.doi.org/10.3141/1696-30.
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Takehana No. 3 Bridge is a cable-trussed girder bridge constructed on a highway route in Shikoku Island, Japan. This is the first application of a cable-trussed girder bridge to a highway bridge in Japan. The cable-trussed bridge (or reversed cable-stayed girder bridge) consists of relatively slender steel plate I-girders, a spatial frame-type post arranged beneath the girders at the middle of the span, and external cables anchored at the ends of the girders. The structural details, static and dynamic characteristics, and design and construction of the bridge are presented. In addition, the efficiency of this type of bridge is emphasized.
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Naser, Mohannad, i Venkatesh Kodur. "Response of fire exposed composite girders under dominant flexural and shear loading". Journal of Structural Fire Engineering 9, nr 2 (11.06.2018): 108–25. http://dx.doi.org/10.1108/jsfe-01-2017-0022.
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Purpose This paper aims to present results from numerical studies on the response of fire exposed composite girders subjected to dominant flexural and shear loading. A finite element-based numerical model was developed to trace the thermal and structural response of composite girders subjected to simultaneous structural loading and fire exposure. This model accounts for various critical parameters including material and geometrical nonlinearities, property degradation at elevated temperatures, shear effects, composite interaction between concrete slab and steel girder, as well as temperature-induced local buckling. To generate test data for validation of the model, three composite girders, each comprising of hot-rolled (standard) steel girder underneath a concrete slab, were tested under simultaneous fire and gravity loading. Design/methodology/approach The validated model was then applied to investigate the effect of initial geometric imperfections, load level, thickness of slab and stiffness of shear stud on fire response of composite girders. Findings Results from experimental and numerical analysis indicate that the composite girder subjected to flexural loading experience failure through flexural yielding mode, while the girders under shear loading fail through in shear web buckling mode. Further, results from parametric studies clearly infer that shear limit state can govern the response of fire exposed composite girders under certain loading configuration and fire scenario. Originality/value This paper presents results from numerical studies on the response of fire exposed composite girders subjected to dominant flexural and shear loading.
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Sami Malik, Hawraa, i David A. M. Jawad. "Parametric Study of the Intermediate External Bracing System of Composite Steel Box Girder Bridges". Basrah journal of engineering science 21, nr 1 (1.02.2021): 56–60. http://dx.doi.org/10.33971/bjes.21.1.8.
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During the pouring of concrete deck, the installation of external bracing between the inner and outer girders may be necessary when the bridge has sharp curve in order to control the deflection and rotation of the girders. However, it is important to minimize the number of external bracing members, as they have expensive cost and they also have opposite effects for the fatigue features of the steel tub girders. The analysis of curved box girder bridges is carried out numerically by the use of finite element method through (ANSYS 19.2) software. The curved box girder with the intermediate external diaphragms was modeled and the analysis was carried out for many parameters like external bracing sections, girders with or without concrete deck, girders with end diaphragms or without them. The study concluded that ANSYS program has a good ability in evaluating the external bracing force comparing with code equations.
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Waldron, Peter. "The significance of warping torsion in the design of straight concrete box-girder bridges". Canadian Journal of Civil Engineering 15, nr 5 (1.10.1988): 879–89. http://dx.doi.org/10.1139/l88-113.
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Out-of-plane warping, resulting from torsional loading, is an important feature of box-girder bridges of thin-walled cross section. This may be of some consequence in girders where warping is restrained, since it may alter the level of stress both around the cross section and along the entire length of the beam. It is well known that some girders with very thin walls are not susceptible to warping, whereas others, with thicker walls, warp significantly when twisted. It is shown that the degree of warping is not governed by wall thickness alone; cross-sectional geometry, girder configuration, and loading must also be considered. The significance of these various factors in estimating the effects of warping restraint is assessed. In many cases this will permit the selection of box-girder cross sections at the conceptual design stage for which torsional warping effects are negligible. A simply supported concrete box girder is used as an example to demonstrate the importance of cross-sectional geometry, girder configuration, and loading in the assessment procedure. This is extended to the more general case of multi-span girders subjected to realistic patterns of loading. Key words: torsion, warping, box-girders, bridges, concrete, design.
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Hayatdavoodi, Aliakbar, i Nandivaram Elumalai Shanmugam. "Web Buckling and Ultimate Strength of Composite Plate Girders Subjected to Shear and Bending". International Journal of Structural Stability and Dynamics 15, nr 02 (3.02.2015): 1450047. http://dx.doi.org/10.1142/s0219455414500473.
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The paper is concerned with ultimate load behavior of steel–concrete composite plate girders subjected to combined action of shear and bending. An analytical method is presented to predict the interactive response of the girder. The method considers the tension field action in the plate girder web panel and shear failure of concrete slab. The method is approximate and can be applied to composite plate girders at the preliminary stages of design. Strength of composite plate girders is investigated by varying the moment/shear ratio. It is shown that ultimate load capacity of composite plate girder is influenced by moment/shear ratio. The predicted results are compared with the corresponding finite-element values.
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Jahjouh, Mahmoud, i Semih Erhan. "Design Optimization of PCI Girders: A Parametric Study". Bridge Structures 18, nr 3-4 (6.01.2023): 101–11. http://dx.doi.org/10.3233/brs-220203.
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This study investigates the effect of superstructure configuration on the optimum design of slab on Precast I (PCI) girder bridges. For this purpose, more than 20,000 bridge cases of varying superstructure configurations are considered to investigate the effects of various superstructure parameters such as girder spacing, span length, slab thickness and girder types on the optimum design of slab on PCI girder bridges. PCI girders are designed conforming to the AASHTO LRFD for flexure using stress limits at the service limit state, then checked at ultimate for flexure and shear using factored loads at the strength limit state. A modified harmony search optimization algorithm is used to obtain optimum bridge design parameters using standard AASHTO PCI girders according to these AASHTO LRFD requirements. Those girders are designed taking into consideration geometrical constraints, stress constraints and constraints related to the conformity of the design with the AASHTO LRFD code. Various sensitivity analysis are performed to investigate the effect of different geometrical factors on the design of the girders, and easy-to-use design aids were developed. The outcomes of this study may facilitate the bridge engineers to choose optimum design parameters such as girder types and spacing as well as number strands for a certain span length before the design of slab on PCI girder bridges.
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Borzovič, Viktor, Ján Laco, Miroslav Pecník i Peter Pažma. "The Crack Development Mechanism of Prestressed Girder Influenced by Different Bond between Prestressed Tendons and Concrete". Key Engineering Materials 691 (maj 2016): 309–20. http://dx.doi.org/10.4028/www.scientific.net/kem.691.309.
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The paper deals with formation and development of cracks up to the failure of two span post-tensioned concrete girder. It is focused on influence of different bond between prestressing units and surrounding grout. Monitored and analysed phenomena affected by different bond are as follows: crack initiation, crack spacing and crack width of the prestressed girder. Sources of analysis are results from experimental program focused on influence of oil based corrosion protection agents on bond of prestressing units. Two span post-tensioned girders were subjected to the loading in laboratory till the bending failure has occurred. Girders were in two cases prestressed with bonded tendons. Other two girders were post-tensioned with unbonded tendons and two girders with tendons with decreased bond, due to corrosion protection coatings. Girders have demonstrated different behaviour by loading regarding to the bond level of prestressing units. Experimental results are faced with the results of the theoretical calculation of crack width according to European standards.
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Rashid, Muhammad U., Liaqat A. Qureshi i Muhammad F. Tahir. "Investigating Flexural Behaviour of Prestressed Concrete Girders Cast by Fibre-Reinforced Concrete". Advances in Civil Engineering 2019 (1.04.2019): 1–11. http://dx.doi.org/10.1155/2019/1459314.
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The main objective of this research was to investigate the effect of adding polypropylene and steel fibres on flexural behaviour of prestressed concrete girders. Although the construction industry is frequently using prestressed concrete to increase the load-carrying capacity of structures, it can be further enhanced by using fibres. In this paper, experimental work was carried out to encourage the construction industry in utilizing fibres in prestressed concrete members to improve the mechanical properties of these members. As past investigations on fibre-reinforced prestressed beams were limited, the present work was done on small-scale fibre-reinforced I-shaped prestressed concrete girders. Six small-scale prestressed concrete girders were cast comprising a control girder, a hybrid girder, two girders with varying percentages of steel fibres, and two girders with varying percentages of polypropylene fibres. These girders were tested by centre point loading up to failure. It was concluded that, by the addition of small volume fraction of fibres, not only the ductility but also the tensile strength and flexural strength of FRC girders could be improved. It also altered the failure pattern positively by enhancing large strains in concrete and steel. Steel fibre-reinforced concrete showed higher energy absorption and deflection at ultimate loads in comparison to other specimens.
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Liu, Jie, Xiangyu Huang, Juanjuan Chen i Qiaoyun Wu. "Effect of Shear Deformation at Segmental Joints on the Short-Term Deflection of Large-Span Cantilever Cast Prestressed Concrete Box Girders". Buildings 13, nr 1 (12.01.2023): 219. http://dx.doi.org/10.3390/buildings13010219.
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The excessive deflection of large-span cantilever cast prestressed concrete (LCCPC) box girders has always been a complex problem to be solved in bridge engineering. To analyze the effect of shear deformation at segmental joints on the deflection of LCCPC box girders, comparison tests were carried out on three prestressed concrete (PC) I-girders with joints and a PC I-girder without joints, and a finite element simulation method of segmental joints was proposed based on the tests. Subsequently, finite element analysis was conducted on a test girder and the Assistant Shipping Channel Bridge of Humen Bridge (a PC continuous rigid frame bridge with a main span of 270 m) using this method. The experimental and theoretical analysis results showed that the effect of the shear deformation at joints compared to the deformation at midspan of the girder specimens was negligible. Deformation at midspan of the specimens would not significantly increase, even if shear rigidity at the joints was significantly reduced or there were more joints in the girder specimen. The effect of shear deformation at segmental joints on the deflection of LCCPC box girders was quite small and thus insignificant.
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Sali, Jefeena, i Regi P. Mohan. "Parametric Study of Single Cell Box Girder Bridge under Different Radii of Curvature". Applied Mechanics and Materials 857 (listopad 2016): 165–70. http://dx.doi.org/10.4028/www.scientific.net/amm.857.165.
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Box girders are now prominently used in freeway and bridge systems because of its structural efficiency, better stability, serviceability, economy of construction and pleasing aesthetics. Due to its high torsional rigidity box girders are most suited for curved bridges. In the present investigation, a comparative study of straight and curved box girder bridges with trapezoidal cross section has been carried out. The analysis is carried under the dead load, super imposed dead load, live load of IRC Class A tracked vehicle and prestressed load .This paper focus on the parametric study of box girders with different radius of curvature by keeping the span, cross sectional shape and material properties constant. The parametric investigations performed on curved box girders helps to evaluate the effects of change in radius of curvature on the behaviour of the box girders. This study would help the bridge engineers to better understand the behaviour of straight and curved box girder bridges. The results obtained from this study will be a valuable guidance to the bridge designers.
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Li, Li, Yu Lu i Miaojuan Peng. "Deterioration Model for Reinforced Concrete Bridge Girders Based on Survival Analysis". Mathematics 10, nr 23 (24.11.2022): 4436. http://dx.doi.org/10.3390/math10234436.
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The prediction of bridge service performance is essential for bridge maintenance, operation, and decision making. As a key component of the superstructure, the performance of the main girders is critical to the structural safety of the bridge. This study makes full use of the inspection records from the Bridge Management System (BMS) in Shanghai and performs pre-processing work on a large amount of data. Recent advances in survival analysis were utilized to investigate the inspection records of over 40,000 reinforced concrete bridge main girders over a 14-year period. Survival analysis methods based on the Weibull distribution were used to predict the service performance of the main girders, and, in addition, a COX proportional hazards model was used to analyze the effect of different covariates on the survival of the main girders. The results show that the deterioration rate of main girders increases with age, with an average life of 87 years for main girders in Shanghai. The grade of the road on which the bridge is located and the position of the main girder in the bridge superstructure have a significant impact on the probability of survival of the main girder. It can be concluded that more attention should be paid to the inspection and maintenance of side girders on branch roads to reduce the pressure on bridge management in the future. Furthermore, the analysis in this study found that the deterioration rate of the main girders is faster than the deterioration rate of the whole bridge and superstructure, and, therefore, more attention and necessary preventive maintenance measures should be taken in the maintenance and management of the main girders.
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Stojkovski, Valentino, Viktor Iliev i Filip Stojkovski. "Nаdоgrаdnjа sistеmа zа hlаđеnjе vоdоm sа mоgućnоstimа ispirаnjа". Energija, ekonomija, ekologija 23, nr 2 (2021): 48–56. http://dx.doi.org/10.46793/eee21-2.48s.
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This paper presents an analysis of the operating parameters of a water cooling system of the structural part of a furnace for rolling mills preparation. The structural solution of the cooling system is performed as flow, with a constant inflow of fresh water and drainage from the system. Four longitudinal pipes are installed, which are supported by vertical girders. Vertical girders should provide thermal stability to ensure pipe- plate horizontality. The vertical girders are regularly connected to the cooling system by placing pipes direct into the vertical girder, which engages the part of the water supply that cools the vertical girder, and the same water is returned to the cooling system and continuously transferred to the next girder. During operation, due to the quality of cooling water that is not chemically treated, calcium carbonate is formed; the presented impurities clog the flow channels of the cooling system in the vertical girders. The application of CFD analysis reveals the conditions of water flow in the cooling system of vertical girders. From the analysis of the obtained results, it is proposed to upgrade the existing system by installing a flushing system, which will ensure a directed and controlled inflow in the zones of the cooling system. The conceptual solution for the flushing system and the effects of its operation are given in this paper.
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Song, Chaojie, Gang Zhang, Wei Hou i Shuanhai He. "Performance of prestressed concrete box bridge girders under hydrocarbon fire exposure". Advances in Structural Engineering 23, nr 8 (3.01.2020): 1521–33. http://dx.doi.org/10.1177/1369433219898102.
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This article presents an approach for investigating performance of prestressed concrete box bridge girders under hydrocarbon fire exposure. A three-dimensional nonlinear finite element model, developed in computer program ANSYS, is utilized to analyze the response of prestressed concrete box bridge girders under combined effects of fire exposure duration and simultaneous structural loading. The model validation is performed using a scaled prestressed concrete box girder exposed to ISO834 fire in furnace. Subsequently, the validated model is used to investigate fire performance of prestressed concrete box bridge girders through taking into consideration some variables, namely concrete cover thickness to prestressing strands, prestress degree, load level, fire exposure length, and position. Through a case study, results from numerical analysis show that concrete cover thickness to prestressing strands and load level has significant effect on fire resistance of prestressed concrete box bridge girders. Increasing prestress degree in prestressing strands can speed up the progression of deflection (sudden collapse) in prestressed concrete box bridge girder toward the final fire exposure stage. Reducing fire exposure length or preventing fire exposure on mid-span zone can highly enhance the fire resistance of simply supported prestressed concrete box bridge girders. Failure of prestressed concrete box bridge girder, under hydrocarbon fire exposure conditions, is governed by rate of deflection failure criterion in particular cases.
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Tepic, Jovan, Rade Doroslovacki i Mirko Djelosevic. "Unconventional Bearing Capacity Analysis and Optimization of Multicell Box Girders". Scientific World Journal 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/496398.
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This study deals with unconventional bearing capacity analysis and the procedure of optimizing a two-cell box girder. The generalized model which enables the local stress-strain analysis of multicell girders was developed based on the principle of cross-sectional decomposition. The applied methodology is verified using the experimental data (Djelosevic et al., 2012) for traditionally formed box girders. The qualitative and quantitative evaluation of results obtained for the two-cell box girder is realized based on comparative analysis using the finite element method (FEM) and the ANSYS v12 software. The deflection function obtained by analytical and numerical methods was found consistent provided that the maximum deviation does not exceed 4%. Multicell box girders are rationally designed support structures characterized by much lower susceptibility of their cross-sectional elements to buckling and higher specific capacity than traditionally formed box girders. The developed local stress model is applied for optimizing the cross section of a two-cell box carrier. The author points to the advantages of implementing the model of local stresses in the optimization process and concludes that the technological reserve of bearing capacity amounts to 20% at the same girder weight and constant load conditions.
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Qiao, Peng, Jin Di i Feng-jiang Qin. "Warping Torsional and Distortional Stress of Composited Box Girder with Corrugated Steel Webs". Mathematical Problems in Engineering 2018 (2018): 1–13. http://dx.doi.org/10.1155/2018/7613231.
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The torsional behaviors of composite box girders with corrugated steel webs are more obvious than traditional concrete girders due to the lower torsional rigidity. In this paper, the torsion and distortion of this kind of composite girder are studied. The formulas for warping normal stress and shear stress were put forward according to the second theory of Umanskii, considering the accordion effect of corrugated steel webs. Then, the influences of different dimensional parameters on the torsional and distortional stress are investigated. Results show that the effect of parameters on stress is different and implicit in composite box girders with corrugated steel webs. Under eccentric loads, the warping torsional and distortional stress in this kind of girder should not be neglected. Compared with girders under corresponding symmetric loads, the total warping stress may be as big as flexural normal stress, and the total shear stress usually reaches 30 to 50 percentage of flexural shear stress. So the warping stress and additional shear stress due to warping torsion and distortion are suggested to be calculated by the proposed equations in structural analysis, which are usually not taken into account in conventional concrete box girders.
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Wang, Zhiqiang, Tiantian Li, Hongya Qu, Hongyi Wei i Yang Zhang. "Seismic performance comparison of precast segmental bridge girders with different cross sections and boundary conditions under vertical quasi-static cyclic testing: An experimental investigation". Advances in Structural Engineering 21, nr 12 (28.02.2018): 1936–48. http://dx.doi.org/10.1177/1369433218759780.
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In this study, five 1/5-scale bridge girder specimens are tested with vertical quasi-static cyclic loading, in order to understand their performance in high seismic zones. The study is focused on the superstructures at two critical regions: (1) close to mid-span where high moments and low shears are present (2) and close to the supports where high negative moments and high shears are induced. The first case includes one precast segmental bridge box-girder, one precast segmental bridge I-girder, and one reference cast-in-place I-girder, while the second case consists of one precast segmental bridge I-girder and one cast-in-place I-girder. The ratios of the internal and external tendons are 1:1 for case 1 and 3:5 for case 2, respectively. Test results show that cast-in-place girders have better energy dissipation capacity and higher ultimate strength, but the precast segmental girders retain larger displacement capacity and self-centering capability. Internal post-tensioning tendons are subjected to more significant stress concentration at the joint locations of the precast segmental girders, while stress of external tendons is distributed more evenly. In terms of vertical loading, box-girder and I-girder possess similar hysteretic behaviors, as long as the effective widths are the same.
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Ashiquzzaman, Md, Li Hui, Ahmed Ibrahim, Will Lindquist, Nader Panahshahi i Riyadh Hindi. "Exterior girder rotation of skew and non-skew bridges during construction". Advances in Structural Engineering 24, nr 1 (30.07.2020): 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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Chen, Jing Xi, Guang Zhang, Hong Fei Li i Fa Min Chen. "Experimental Study on Mechanical Behaviors of the Prestressed Concrete Girder". Key Engineering Materials 348-349 (wrzesień 2007): 361–64. http://dx.doi.org/10.4028/www.scientific.net/kem.348-349.361.
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The prestressed concrete girder is a new type of bridge structure. Compared with the traditional concrete girders, its crack resistance has been greatly improved. This type of new girders was used in a certain viaduct in China. In order to probe working characteristics of this type of new girders, some site tests, such as tension-camber test, concentrated load test, uniform load test and mixed load test, were carried out. The results of the tests are analyzed and summed up in this paper.
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Du, Jin Sheng, i Hai Bin Liu. "Effect of Pier Vertical Deformations on Deflections of Main Girders for High Pier and Long-Span Continuous Rigid-Frame Bridges". Advanced Materials Research 163-167 (grudzień 2010): 1436–39. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.1436.
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In some long-span prestressed concrete box girder bridges, excessive deflections of main girders are often observed. These unacceptable deflections have detrimental influence on the serviceability and safety of the structures. To better understand and estimate short term and long term deflections for prestressed concrete box girder bridges, pier vertical deformation and its effect on deflections of main girders of Jinghe Bridg is investigated in this paper. Piers in Jinghe Bridge are tall and the difference in height between piers up to 22 m. Analysis indicates that although the short term deformations of piers are small, the long term deformations of piers can be 3 times as large as that of short-term ones. The maximum short-term downward deflection of Jinghe Bridge caused by pier deformation for main girders is 7.7 mm and the maximum long-term downward deflection is 33.3 mm. These values are relatively small compared with the span length of the bridge. But when the deflection of the main girder itself is also included, the final total deflection of the main girder may exceed the design code limit.
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Kazemi, M. T., i S. Erfani. "Analytical study of special girder moment frames using a mixed shear–flexural link element". Canadian Journal of Civil Engineering 34, nr 9 (1.09.2007): 1119–30. http://dx.doi.org/10.1139/l07-037.
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The present paper introduces a mixed shear–flexural (VM) link element that is capable of modelling shear yielding, flexural yielding, and their interaction under monotonic and cyclic loadings. The inelastic deformations are modelled using the multisurfaces approach with dissimilar yield surfaces and a stiffness matrix with nonzero off-diagonal components in shear–flexural space. A new kinematic hardening and new non-associated flow rules are employed. A special girder, which has an open web in the middle, is introduced and modelled using the developed VM link element. It is shown that the results of analyses using the VM link element are in good agreement with those from a finite element analysis. Nonlinear dynamic analyses are performed on a benchmark ordinary moment frame (OMF) and its improved versions with special girders. The special girder moment frame (SGMF), which consists of special girders at the lower storeys and ordinary girders at the roof level, has better seismic performance.Key words: mixed shear–flexural (VM) link element, inelastic zone, shear–flexural interaction, cyclic loading, multisurface, special girder, special girder moment frame (SGMF), ordinary moment frame (OMF).
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Lee, Jung Woo, Chang Joh, E. S. Choi, I. J. Kwak i Byung Suk Kim. "Estimation of Shear Behavior of Ultra High Performance Concrete I Girder without Shear Stirrups". Key Engineering Materials 525-526 (listopad 2012): 557–60. http://dx.doi.org/10.4028/www.scientific.net/kem.525-526.557.
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Thinner and lighter members can be designed by utilizing the high stiffness and toughness, and high compressive strength of Ultra High Performance Concrete (UHPC), which reaches up to 180MPa. This high strength and ductile tensile behavior of UHPC makes it possible to design the web of the UHPC I Girder without conventional shear stirrups, which makes the UHPC I girder slender, light and economical. However, establishing shear design procedure for UHPC I girders without stirrups requires additional theoretical and experimental studies. This paper investigated shear behavior of UHPC I girder without shear stirrups. The test results show, in spite of no shear stirrups, test specimens have high ductility due to the bridging action of steel fibers against crack opening. UHPC I girders without shear stirrups tested show gradual increase of strength after initial cracking instead of brittle loss of strength as expected from the ordinary reinforced concrete I girders without stirrups. The decrease of the shear span-depth ratio increase the shear strength of the UHPC I girder without stirrups.
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Zhou, Yongjun, Yu Zhao, Hengying Yao i Yuan Jing. "Full-Scale Experimental Investigation of the Static and Dynamic Stiffness of Prestressed Concrete Girders". Shock and Vibration 2019 (4.12.2019): 1–13. http://dx.doi.org/10.1155/2019/7646094.
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Cracking damage influences the stiffness of the girders. Many articles in the literatures have studied the development of stiffness of the scale-down model; however, full-scale model testing cannot be completely replaced by scale-down testing because of material component characteristics and boundary effects. This paper deals with the effects of cracking damage on the structural static and dynamic stiffness based on three prestressed concrete (PC) girders which were removed from an old bridge. First, the equivalent flexural rigidity of cracked prestressed concrete girder was assessed using the measured load-deflection response under cycles of loading and unloading. Then, after unloading, the frequencies were measured on the PC girders supported by the elastomeric bearings. Next, the development of frequency under different damage was studied, and finally, the dynamic stiffness of PC girders with cracks was assessed. The results indicate that the first frequency is more sensitive to the cracking of concrete compared with the second frequency and that the mode shapes are not sensitive to girder damage. The test girders cannot be simplified as an ideal simply supported beam for the purpose of identifying frequencies. In addition, the “final” (the end of the ultimate load case) equivalent flexural rigidity of the girders is 30% of the “initial” (the beginning of the first load case) equivalent flexural rigidity, compared with 50% in the scale-down test; and the final dynamic stiffness is approximately 84% of the initial dynamic stiffness, whereas the scale-down test is 72%.
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Liu, Sumei, Hanshan Ding, Luc Taerwe i Wouter De Corte. "Shear Strength of Trapezoidal Corrugated Steel Webs for Horizontally Curved Girder Bridges". Applied Sciences 9, nr 9 (12.05.2019): 1942. http://dx.doi.org/10.3390/app9091942.
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Curved composite girder bridges with corrugated steel webs (CSWs) have already been constructed around the world. However, limited work has been done on their shear behavior. In this paper, the corrugated steel web (CSW) in horizontally curved girders (HCGs) is treated as an orthotropic cylindrical shallow shell, and the analytical formula for the elastic global shear buckling stress is deduced by the Galerkin method. Calculation tables for the global shear buckling coefficient for a four-edge simple support, for a four-edge fixed support, and for the two edges constrained by flanges fixed and the other two edges simply supported are given. Then, a parametric study based on a linear buckling analysis is performed to analyze the effect of the curvature radius and girder span on the shear buckling stress. Analytical and numerical results show that the difference of shear buckling stress of CSWs between curved girders and straight girders is small, so the shear design formulas for straight girders can be applied for curved girders. Finally, a series of tests were performed on three curved box girders with CSWs. Similar to CSWs in straight girders, the shear strain distributions of CSWs in HCGs are almost uniform along the direction of the web height and the principal strain direction angles are close to 45°. For the three specimens, CSWs carry about 76% of the shear force. In the destructive test, shear buckling after yielding occurred in all specimens which is in good agreement with the theoretical prediction, which means that the analytical formulas provide good predictions for the shear buckling stress of CSWs in HCGs and can be recommended for design purposes.
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Li, Yong, Zijie Yu, Qifan Wu, Yongqian Liu i Shang Wang. "Experimental-Numerical Study on the Flexural Ultimate Capacity of Prestressed Concrete Box Girders Subjected to Collision". Materials 15, nr 11 (1.06.2022): 3949. http://dx.doi.org/10.3390/ma15113949.
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Precise evaluation for flexural ultimate capacity of bridges which are subjected to the collision of over-height trucks is essential for making decisions on corresponding maintenance, strengthening or replacement. When the span of a cross-line continuous bridge with a double-box girder was hit by an overly high vehicle, the concrete floor of one girder was severely damaged, and part of the prestressed strands and reinforcements in the girder were broken. After the double-box girder was removed and separated into two single box girders, the ultimate flexural capacity of both box girders was studied by destructive tests, and a comparison was made between the damaged and undamaged girders. Moreover, finite element analysis was conducted to simulate the failure process. The results show that the flexural bearing capacity of the damaged box girder decreased by 33%, but it was still 1.07 times greater than the design bearing capacity, which basically meets the design requirements. Also, the damaged box girder showed a desirable serviceable limit state for three-axle vehicles and five-axle vehicles, but showed an undesirable serviceable limit state for six-axle vehicles. This study shows that repairing or strengthening the damaged span may be better than demolishing and rebuilding the whole superstructure bridge.
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Zhu, Lanying, Yuanzhang Yang, Zhijun Wang i Mengli Song. "Stability Analyses of the Upper Chord Tubes of Light Gauge Steel–Oriented Strand Board Composite Truss Girders". International Journal of Structural Stability and Dynamics 16, nr 01 (styczeń 2016): 1640012. http://dx.doi.org/10.1142/s0219455416400125.
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Light Gauge Steel (LGS) square tube truss girders with Oriented Strand Board (OSB) have larger bending stiffness and flexural capacities than the LGS square tube girders without OSB. In this paper, one LGS square tube truss girder without OSB and five composite LGS truss girders with OSB were tested under monotonic static loading to study the effects of OSB arrangements and screw distributions on the failure mode and flexural capacities of composite girders. Test results show that the failure mode of LGS–OSB composite truss girders tends to be local buckling of the upper chord tubes, and the ultimate bearing capacities of the composite girders are controlled by the stability of the upper chord tubes. LGS–OSB composite truss girders have higher bearing capacities than the truss girders without OSB. The thicker the OSB is, the larger the bearing capacity is. With the same OSB thickness, the number of layers and the orientation of OSB have little influence on the bearing capacities of LGS–OSB composite truss girders. Considering material, geometry and contact nonlinearities, the experimental tests were simulated using ABAQUS, and the simulation results agree well with the test observations. Finally, in order to obtain the ultimate bearing capacities of LGS–OSB composite truss girders, the modified methods for determining the effective areas and inertia moments (or sectional moduli) of the upper chord tube are proposed according to AISI S100-2007 and GB50018-2002.
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Li, Xue Min, Er Yu Zhu, Yong Zheng Zhou i Yue Hong Qin. "Research on the Key Technology in Steam Curing for 32m Simple-Supported Box Girder of High-Speed Railway". Applied Mechanics and Materials 90-93 (wrzesień 2011): 958–63. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.958.
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In the process of steam curing to high-speed railway’s simply-supported box girder, there are some problems must be faced such as the difficulty to determine steam curing system and to achieve automatic temperature control. With the construction site conditions of simple-supported box girder in Longwang beam field which is located on Shijiazhuang-Wuhan (Shi-Wu) section of Beijing-Guangzhou high-speed railway, the paper proposes the appropriate steam system for simply-supported box girders, determines the appropriate equipments, explores the temperature control system in the process of steam curing to the simply-supported box girder's concrete, and takes the temperature test of steam curing in the field. Results show that, the steam curing technology in this paper can increase the production efficiency of beam in production site, and effectively guarantee the prefabricated quality of simply-supported box girder.
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Mańkowski, Jarosław, i Rafał Szymański. "Evaluation of the Influence of the Diameter and Shape of Lightening Holes on Effort of Webs and Values of Critical Forces of Thin-Walled Girders". Advanced Materials Research 1036 (październik 2014): 637–41. http://dx.doi.org/10.4028/www.scientific.net/amr.1036.637.
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This article is dedicated to analysis of the impact of lightening holes (performed in the webs of girders, ribs, etc. elements of thin-walled structures) on the value of the critical forces and local effort of the material webs girders. Paper presents the results of typical analysis of two flanges thin-walled girders. Calculations was performed for one of the three most common ways of making lightening holes which differ in the way the edge of the hole shaping. Analysis includes the most common case of work of this construction type - that is the case in which the load acts in the plane of web girder. The article presents a comparison of the results of girders with holes with the results for the full girders (without holes). Particular attention was paid to the significant increase the stress concentration caused by the occurrence of holes.
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Turnic, Dragana, Srdjan Zivkovic, Marija Spasojevic-Surdilovic, Marko Milosevic i Aleksandra Igic. "Influence of geometrical and structural imperfections on the behavior of steel plate girders". Facta universitatis - series: Architecture and Civil Engineering 19, nr 2 (2021): 171–82. http://dx.doi.org/10.2298/fuace211130013t.
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The girders or parts of the girders are not ideally flat in terms of their geometry. The deviations that occur are defined as geometric imperfections. Also, in the material from which the girder is made, a certain deviation may occur during factory production or for some other reason, which is known as structural imperfection. This paper presents the analysis of the behavior of plate girders (welded steel I girders), with and without material stiffening and loaded with patch loading. The results were obtained by numerical simulation in the ANSYS for models with included geometric imperfections. The model was performed in accordance with the recommendations for different behavior curves of materials from Eurocode 3. The limit load obtained by numerical simulation corresponded to the experimental results from the literature. Stress values for girders with and without geometric imperfections for the same load value were compared.
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Huynh, Thanh-Canh, Young-Hwan Park, Jae-Hyung Park, Dong-Soo Hong i Jeong-Tae Kim. "Effect of Temperature Variation on Vibration Monitoring of Prestressed Concrete Girders". Shock and Vibration 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/741618.
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The effect of temperature variation on vibration monitoring of prestressed concrete (PSC) girders is experimentally analyzed. Firstly, vibration features such as autoregressive (AR) coefficient, correlation coefficient of power spectral density (CC of PSD), natural frequency, and mode shape are selected to estimate the effect of temperature variation on vibration characteristics of PSC girders. Secondly, vibration experiments on a lab-scale PSC girder are performed under the condition of temperature variation. Finally, the vibration features with respect to the temperature variation are analyzed to estimate the effect of temperature in vibration characteristics of the PSC girder.
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Ji, Wei, Kui Luo i Jingwei Zhang. "Computation of Deflections for PC Box Girder Bridges with Corrugated Steel Webs considering the Effects of Shear Lag and Shear Deformation". Mathematical Problems in Engineering 2020 (18.07.2020): 1–12. http://dx.doi.org/10.1155/2020/4282398.
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Prestressed concrete (PC) girders with corrugated steel webs (CSWs) have received considerable attention in the past two decades due to their light self-weight and high prestressing efficiency. Most previous studies were focused on the static behavior of CSWs and simple beams with CSWs. The calculation of deflection is an important part in the static analysis of structures. However, very few studies have been conducted to investigate the deflection of full PC girders or bridges with CSWs and no simple formulas are available for estimating their deflection under static loads. In addition, experimental work on full-scale bridges or scale bridge models with CSWs is very limited. In this paper, a formula for calculating the deflection of PC box girders with CSWs is derived. The longitudinal displacement function of PC box girders with CSWs, which can consider the shear lag effect and shear deformation of CSWs, is first derived. Based on the longitudinal displacement function, the formula for predicting the deflection of PC box girders with CSWs is derived using the variational principle method. The accuracy of the derived formula is verified against experimental results from a scaled bridge model and the finite element analysis results. Parametric studies are also performed, and the influences of shear lag and shear deformation on the deflection of the box girder with CSWs are investigated by considering different width-to-span ratios and different girder heights. The present study provides an effective and efficient tool for determining the deflection of PC box girders with CSWs.
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Yatim, M. Y. M., M. R. Azmi i M. Mukhlisin. "Performance of Steel Plate Girders with Inclined Stiffeners". Jurnal Kejuruteraan 32, nr 3 (30.08.2020): 485–92. http://dx.doi.org/10.17576/jkukm-2020-32(3)-13.
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Slender webs in steel plate girders are prone to local and shear buckling at relatively low shear and thus, need be stiffened to increase the strength and stability of the girders. The conventional way is to provide vertical stiffeners at specified intervals, but this practice serves only to prevent the buckling of web. Provision of inclined stiffeners, in addition to improving buckling resistance, forms a truss-like girder which allows those stiffeners to carry some percentages of forces exerted in the girder. This paper, therefore, presents the ultimate performance of thin-webbed plate girders containing inclined stiffeners. Five simply supported plate girders of practical size were tested to failure under concentrated load applied at the mid-span. This study focuses on the effects of different inclination angles of intermediate stiffeners, 𝜃 on the load carrying capacity and post-buckling behaviour. Five different inclination angles, viz., 90°, 75°, 60°, 45° and 30°, measured from the bottom flange, were accounted for in the test series. Considerable variations of strength, failure characteristic and load-deflection response can be observed due to effects of such inclinations. Test results have shown significant increases in the ultimate strength from 11% to the extent of 50% as the angle of inclined stiffeners reduced. All the girders exhibited shear-dominated behaviour in the web panels at failure.
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Domalik, Daniel E., Jason F. Shura i Daniel G. Linzell. "Design and Field Monitoring of Horizontally Curved Steel Plate Girder Bridge". Transportation Research Record: Journal of the Transportation Research Board 1928, nr 1 (styczeń 2005): 83–91. http://dx.doi.org/10.1177/0361198105192800109.
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Bridge 207 is a two-span horizontally curved steel plate girder bridge near Port Matilda, Pennsylvania. Although the curvature is not severe, the curvature combined with the unequal span balance caused an unusual distribution of force effects in the girders. A global twisting of the superstructure was caused by the unequal vertical deflections in the two spans. The computer program BSDI-3D was used to analyze the curved superstructure. To account for the out-of-plumb condition of the girders in their final condition, additional lateral flange bending moments were calculated. The magnitude of the additional lateral moments was a function of the vertical bending moments and the degree of twist in the girder. Field monitoring of the structure is focusing on the effects of curvature during construction. This is being accomplished by developing a detailed time line of superstructure erection and deck placement and through monitoring of the bridge by using vibrating wire strain gauges and tiltmeters positioned at critical locations on the girders and cross-frames. Field data were recorded before and after critical construction events, such as girder erection, cross-frame and formwork placement, and the deck pour. This information is being used to determine the effects of curvature on the cross-frames during construction by using axial stresses and strains and on the girders by using warping stresses and strains.
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M. P., Geetha, i Dr Girija K. "Critical Aspects in Design and Construction of Open Type Shallow Highway Girders Across Railways". International Journal of Engineering and Advanced Technology 10, nr 2 (30.12.2020): 236–40. http://dx.doi.org/10.35940/ijeat.b2100.1210220.
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A highway bridge across railways in-lieu of the level crossing will surely be smoothening the road traffic and the rail traffic. Hence, it is essential to bridge across the railways at all the level crossing locations in a developing country. Due to the introduction of a bridge across a busy railway track, the necessity to negotiate the level difference happens. This level difference is more with the usage of the conventional type of girders. By this, the delay of the project due to land acquisition is considerable. The most suitable superstructure for such highway bridge is the deck with shallow open type pre-stressed girders. When multiple shallow, open-type girders are placed adjacently and integrated with a deck slab above these, the load distribution and sharing between girders are to be refined based on experimental studies and authors discussed the same within this paper. An experimental study on two Double-T cross-section pre-stressed model girders and deck assembly revealed the structural behaviour between girders. The results from the two-point load testing helped in developing various design methodologies in this study. An escalation of 17% in the design forces need to be considered on the results obtaining from the grillage analysis, to cater the unbalanced forces on the individual web of the open-type girder, during the eccentric loading condition. The Authors elaborated the design of shear friction reinforcement. The self-managing capacity of the spreading tendency of the webs of this type of girders is due to the counteracting of radial pressure generated from the pre-stressing force. The critical aspects of construction also dealt with in this paper without which the usage of open-type girders with ends closed cannot be encouraged. The authors developed conceptual designs for the removable internal shutter, launching scheme and demolishing of the bridge superstructure, in this study. The dismantling of the bridge is a rare requirement arises only when the number of track increases. The reuse of girder-deck assembly is also found possible and suggested in this paper.
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Manjula, R., i A. Amrutha. "Parametric Analysis of Single-Cell Box Girder Bridge". IOP Conference Series: Materials Science and Engineering 1197, nr 1 (1.11.2021): 012047. http://dx.doi.org/10.1088/1757-899x/1197/1/012047.
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Abstract Bridges based on box girders concept are extensively utilized for their cost saving solution for different passages & viaducts that are seen in the present day highway systems. The behavior of box girder bridges is analyzed for stresses in longitudinal and transverse directions. In this paper, analysis of three different box girders has been carried out using SAP2000 as per Indian Road Congress(IRC) provisions for rectangular and trapezoidal sections. The behaviors of box girders with uniform depth and varying widths have been analyzed. A parametric study is conducted for various parameters like bending moments, axial force & shear force using SAP2000.
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Gazis, Nikolaos, Michail Anastasopoulos, Germana Riddone, Alexandre Samochkine i Helene Mainaud-Durand. "Study and Application of Micrometric Alignment on the Prototype Girders of the CLIC Two-Beam Module". Key Engineering Materials 495 (listopad 2011): 96–99. http://dx.doi.org/10.4028/www.scientific.net/kem.495.96.
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The Compact LInear Collider (CLIC), currently under study at CERN, aims at the development of a Multi-TeV e+ e- collider. The micro-precision CLIC RF-structures will have an accelerating gradient of 100 MV/m and will be mounted and aligned on specially developed supporting girders. The girder fabrication constraints are dictated by stringent physics requirements. The micrometric pre-alignment over several kilometers of girders, allow for the CLIC structures to fulfill their acceleration and collision functionality. Study of such girders and their sophisticated alignment method, is a challenging case involving dedicated mechanical design as well as prototype production and experimental testing.
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Wangbao, Zhou, Jiang Lizhong, Kang Juntao i Bao Minxi. "Distortional Buckling Analysis of Steel-Concrete Composite Girders in Negative Moment Area". Mathematical Problems in Engineering 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/635617.
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Distortional buckling is one of the most important buckling modes of the steel-concrete composite girder under negative moment. In this study, the equivalent lateral and torsional restraints of the bottom flange of a steel-concrete composite girder under negative moments due to variable axial forces are thoroughly investigated. The results show that there is a coupling effect between the applied forces and the lateral and torsional restraint of the bottom flange. Based on the calculation formula of lateral and torsional restraints, the critical buckling stress of I-steel-concrete composite girders and steel-concrete composite box girders under variable axial force is obtained. The critical bending moment of the steel-concrete composite girders can be further calculated. Compared to the traditional calculation methods of elastic foundation beam, the paper introduces an improved method, which considers coupling effect of the external loads and the foundation spring constraints of the bottom flange. Fifteen examples of the steel-concrete composite girders in different conditions are calculated. The calculation results show a good match between the hand calculation and the ANSYS finite element method, which validated that the analytic calculation method proposed in this paper is practical.
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Zhang, Tao, i Hai Feng Bai. "Design Thermal Gradients for Straddle Track Girders". Advanced Materials Research 163-167 (grudzień 2010): 1870–73. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.1870.
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Thermal stresses and deformation in straddle track girders can be significant in comparison to dead or live load responses. In present paper, a comparison of current design-code provisions is present. The temperature distributions are obtained by a numerical technique for the solution of the Fourier heat-transfer equation and its boundary conditions. This technique is based on the finite-element method and takes into account the geometry of cross section of the track girder, thermal properties of concrete, and the climatic conditions. A field test is conducted on a track girder to verify the analytical models. The results of a temperature gradient study developed to evaluate design thermal vertical differences for the straddle type track girder are presented. The analysis suggests that straddle track girders are designed for larger temperature gradients than the codes suggested.
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Ying, Bai, i Ming Hai Yuan. "Stability Analysis of the Center Arch Girder for Special Astronomical Dome". Advanced Materials Research 485 (luty 2012): 540–43. http://dx.doi.org/10.4028/www.scientific.net/amr.485.540.
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The special astronomical dome is an important instrument in the multi-object space detecting system. With the background of the special astronomical dome, the potential energy equations of center arch girder with displacement and angle as unknown fundamental quantities were established according to energy principle. The critical loading in buckling of the hinged center arch girder under erect orientation and radial orientation loading was calculated in this paper. The results are very valuable for designing the center arch girders of the special dome and solving the mechanical problems of the statically indeterminate arch girders with the similar structure.
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Cakiroglu, Celal, Gebrail Bekdaş, Sanghun Kim i Zong Geem. "Optimisation of Shear and Lateral–Torsional Buckling of Steel Plate Girders Using Meta-Heuristic Algorithms". Applied Sciences 10, nr 10 (25.05.2020): 3639. http://dx.doi.org/10.3390/app10103639.
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The shear buckling of web plates and lateral–torsional buckling are among the major failure modes of plate girders. The importance of the lateral–torsional buckling capacity of plate girders was further evidenced when several plate girders of a bridge in Edmonton, Alberta, Canada failed in 2015, because insufficient bracing led to the lateral buckling of the plate girders. In this study, we focus on the optimisation of the cross-sections of plate girders using a well-known and extremely efficient meta-heuristic optimisation algorithm called the harmony search algorithm. The objective of this optimisation is to design the cross-sections of the plate girders with the minimum area that satisfies requirements, such as the lateral–torsional buckling load and ultimate shear stress. The base geometry, material properties, applied load and boundary conditions were taken from an experimental study and optimised. It was revealed that the same amount of load-carrying capacity demonstrated by this model can be achieved with a cross-sectional area 16% smaller than that of the original specimen. Furthermore, the slenderness of the web plate was found to have a decisive effect on the cost-efficiency of the plate girder design.
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Motak, Jan, i Josef Machacek. "EXPERIMENTAL BEHAVIOUR OF COMPOSITE GIRDERS WITH STEEL UNDULATING WEB AND THIN‐WALLED SHEAR CONNECTORS HILTI STRIPCON". JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 10, nr 1 (31.03.2004): 45–49. http://dx.doi.org/10.3846/13923730.2004.9636285.
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Two tests of real‐size composite steel and concrete girders are described. The girders had spans 7,5 m, thin‐walled undulating webs (WT girders) and concrete deck 120/1500 mm concreted into profile steel sheeting TR 60/235/0,75. Thin‐walled shear connectors Hilti Stripcon were used and fastened via powder actuated fasteners. Setup of the tests, relevant instrumentation and measuring procedure are presented. The girder tests supplemented large series of push tests of connectors Stripcon performed at CTU in Prague. One of the composite girders was designed with full‐shear connection while the second one with extremely low partial shear connection (44 %). Simple preliminary linear calculations proved that experimental strength capacities of the girders are in good agreement with the calculated values, however, the deflection are due to flexibility of the connectors higher. Buckling shear capacity of the undulating webs in both tests was higher than shear at collapse of the girders. Another test dealing with interaction of web buckling in shear and Stripcon shear connection is under progress. Comparison of theoretical and experimental results is performed and recommendations for practical design are presented.
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Liu, Mu Yu, i Feng Wang. "Geometrically Nonlinear Analysis of Long Span Composite Girder Cable-Stayed Bridge with Three Towers under Live Load". Applied Mechanics and Materials 34-35 (październik 2010): 371–75. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.371.
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A comparison on geometrically nonlinear analysis of composite girder cable-stayed bridge is presented. The spatial nonlinear analysis model named double-girder is established, the geometrically nonlinear behavior of whole bridge is analyzed under dead load plus live load in normal service stage, the nonlinear analysis involves cable sag, large displacement and beam-column, the three nonlinear factors effect on internal force and deformation of side tower, main girder are investigated. The results show that the effect of geometric nonlinearity is small on bending moment and deformation of side tower, and also small on vertical deflection of main girders, but nonlinear effect is large on bending moment of main girders. Results obtained in this research and conclusions made provide valuable insight and guidelines for the design of composite girder cable-stayed bridge with three towers.
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Deniaud, Christophe, i JJ Roger Cheng. "Shear rehabilitation of G-girder bridges in Alberta using fibre reinforced polymer sheets". Canadian Journal of Civil Engineering 27, nr 5 (1.10.2000): 960–71. http://dx.doi.org/10.1139/l00-032.
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Many bridges were built in Alberta after World War II with type G-girder precast concrete elements. Today, there are approximately 1500 G-girder bridges still in service all over the province. These bridges are typical short span (approximately 6 m long), simply supported, and without shear keys between girders. Structural deficiency of the G-girders, especially in shear, plus the economic constraints of the government demand that an economical and efficient method for rehabilitation of these bridges be developed. A research program at the University of Alberta, in collaboration with Alberta Transportation and Utilities and ISIS Canada, has been established to study the feasibility of using fibre reinforced polymers (FRP) to rehabilitate concrete bridge girders deficient in shear. This paper will address the structural deficiency of the G-girders and present eight full-scale test results from four G-girders removed from existing bridges. Carbon and glass FRP sheets and two repair schemes were used in the rehabilitation. Three commonly used shear strength evaluation methods, strut-and-tie model, modified compression field theory, and grid analysis, are investigated. The loads predicted by these three methods are in good agreement with the experimental results. The shear contribution of the FRP sheets at any angle can be accurately accounted for in the analysis. All three methods are found to be consistent.Key words: analysis, beams, bridges, composite materials, design, fibre reinforced polymers, rehabilitation, reinforced concrete, shear strengthening.
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Li, Huan, Xuhui He, Liang Hu i Guoji Xu. "Quantification of aerodynamic forces for truss bridge-girders based on wind tunnel test and kriging surrogate model". Advances in Structural Engineering 24, nr 10 (11.02.2021): 2161–75. http://dx.doi.org/10.1177/1369433221992497.
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This study presents an investigation to quantify the aerodynamics of truss bridge-girders via wind tunnel test and kriging surrogate model. Currently, the conventional methods documented in design specifications only take into consideration the mean drag force at null attack angle. To gain an in-depth understanding on the aerodynamics of truss bridge-girders, experiments on simplified bridge-girder models with various geometric parameters were carried out in uniform flow. A total of 15 truss bridge-girder models with aspect ratio (the ratio of width to height) B/D = 1.0, 1.3, 1.6, 1.9, and 2.2, solidity ratio (the ratio of projected to envelope areas) Φ = 0.20, 0.25, 0.30, 0.35, and 0.40, and two typical truss topologies (Warren and Pratt trusses) were examined in the most concerned range of wind angle of attack α = [–6°, 6°]. These truss bridge-girder models cover most of the high-speed railway bridges widely used in China. Experimental results show that the truss topology has limited effects on the aerodynamics of truss bridge-girders, whereas the effects of α, B/D, and Φ are significant. Based on these wind tunnel results, the ordinary kriging surrogate model was utilized to approximate the aerodynamics of truss bridge-girders. In using this model, aerodynamic force values for test cases can be interpolated with zero variance and uncertainties in unsampled design zones where geometric parameters can be quantified with Gaussian variance.