Journal articles: 'The rigidity of bridges'

1

Jaeger, Leslie G., and Baidar Bakht. "Semicontinuum analysis of shear-weak grillages." Canadian Journal of Civil Engineering 17, no. 3 (June 1, 1990): 294–301. http://dx.doi.org/10.1139/l90-036.

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Cellular bridges and voided slab bridges with large and frequently spaced circular voids undergo distortion of the cross section under nonuniform loads, which may have a significant effect on the load distribution characteristics of the bridge. For two-dimensional analysis of these bridges, it is usual to represent the transverse medium of the bridge as having finite shear rigidity. Up to the present time, the semicontinuum method of analysis did not have the capability of handling finite shear rigidity of the transverse medium. A modification is introduced in this paper through which it can now do so. It is shown that the proposed modifications consist of only minor changes to the set of equations of the earlier version of the method. By comparing the results of the proposed method with those obtained from grillage analysis, it is shown that the accuracy of the proposed method is equal to that of the grillage method, which has already been found by many researchers to be suitable for the analysis of shear-weak bridges. The paper also contains proposed modifications to the semicontinuum method so that it can handle finite shear rigidities of the longitudinal beams as well. Key words: analysis, bridges, load distribution, semicontinuum method, shear rigidity, shear-weak grillages, shear-weak plotes.

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Chen, Xu Yong. "Tests before and after Reinforcement of Tujiazui Bridge." Applied Mechanics and Materials 204-208 (October 2012): 2095–99. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.2095.

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This paper is aimed to verify the effects of reinforcement by tests before and after reinforcement of a two-way curved arch bridge with a clear span of 70m. Four 100kN and 180kN trucks are used for load tests of the bridge before and after reinforcement, and then the test values are compared with the calculated values. Tests before reinforcement has proved insufficient rigidity in some parts of the bridge, the design load grade is low, and the common fault in two-way curved arch bridges. The finite element numerical analysis tool ANSYS is used for finite element simulative analysis of the bridge, and the comparison of test values with calculated values shows the bridge can meet the existing design load grade after reinforcement. This paper has verified the feasibility and rationality of utilizing the physical unit of ANSYS for analysis of two-way curved arch bridges after reinforcement, and meanwhile, proved that the rigidity and design grade of bridges can be improved by reinforcement.

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Zhou, Zhi Hui, Guo Liu, Zhi Dong Qian, Ying Wen, and Qing Yuan Zeng. "Study on Critical Speed of Freight Train Derailment on Bridges." Advanced Materials Research 639-640 (January 2013): 456–59. http://dx.doi.org/10.4028/www.scientific.net/amr.639-640.456.

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The mechanism of train derailment was demonstrated to be the loss of lateral vibration stability of train-bridge (track) system. Based on the theory of energy increment analysis for system movement stability, the energy increment criterion for derailment evaluation and the method of analyzing critical speed of train derailment Vcr were presented. The critical speed of empty freight train on Laoluanhe bridge, Huanghe bridge and Youshui bridge were calculated as 65.2 km/h，64.8 km/h and 66.5 km/h respectively, which were close to actual derailment speed. It is manifested that the method of analyzing critical speed of train derailment is reasonable. According to the calculated results of the critical speed on bridges with different lateral rigidity, it is testified that the critical speed of train derailment rises with the bridge lateral rigidity strengthened. The measure to prevent derailment on bridge is to ensure enough bridge lateral rigidity to meet the running safety of train.

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Wang, Guang Hui, Lian Shen, and Cheng Long Wei. "Research on Strengthening Existing Bridges by Widening." Advanced Materials Research 639-640 (January 2013): 1092–95. http://dx.doi.org/10.4028/www.scientific.net/amr.639-640.1092.

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This paper aims to put forward a new method of strengthening the existing bridges with narrow decks and low bearing capacity to overcome the high cost and pollution problems in dismantling them. The method, strengthening bridges by built stringers and cross beams, is by widening some parts of a bridge. Based on the basic theory of finite element, we have set up an analysis model of strengthening the bridges by widening, which helps to demonstrate the rationality of this method. Meaningful conclusions have been drawn from the parameter analysis of the rigidity of the new widening stringers, the rigidity of the new cross beams and the relative settlement of the new and the old foundations. This method can be referenced by the reinforcement and maintenance of medium and small bridges.

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Huang, Xin Yi, Wei Dong Zhuo, and Shang Guan Ping. "Parameter Correlation Study of Impact Factors on Concrete Curved Box Girder Bridges." Advanced Materials Research 255-260 (May 2011): 926–30. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.926.

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The impact factors for vehicle load were ever characterized by varied parameters among different countries, and it is now commonly described by the fundamental frequency of the first bending mode for straightened bridges, but there are still no computation formulae proposed for concrete curved bridges. Massive vehicle-bridge interaction analysises are carried out on concrete curved box girder bridges with different span length, curvature radius, section type, span number and boundary conditon, using a validated numerical method. Based on the obtained results, the impact factors for varied effects are discussed, as well as their correlation with parameters of central radius, ratio of bending to torsional rigidity, integral impact coefficient and the fundamental frequency of vertical bending mode. It is indicated that, the impact factor of interal forces, deflection and reaction force are minus correlated with the discussed parameters except for ratio of bending rigidity to torsional rigidity. The impact factors are most closely correlated with the fundamental frequency of vertical bending mode, so it is best suited to characterize the change of impact factors.

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Wang, Jiawei, Guanhua Zhang, Jinliang Liu, and Yanmin Jia. "Research on destructive test of pretensioning prestressed concrete hollow slab in service." International Journal of Structural Integrity 9, no. 4 (August 13, 2018): 429–41. http://dx.doi.org/10.1108/ijsi-07-2017-0043.

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Purpose During service period, the bridge structures will be affected by the environment and load, so the carrying capacity will decline. The purpose of this paper is to research on the bearing capacity of bridge structures with time. Design/methodology/approach Destructive test and non-linear finite element analysis are carried out by utilizing two pretensioning prestressed concrete hollow slabs in service for 20 years; using the structural test deflection value to simulate the stiffness degradation of the service bridge and the finite element calculation results verify the accuracy of the calculation. Findings The flexural rigidity of the main beam when the test beam is destructed is degraded to approximately 20 percent of that before the test, which agrees well with the result of finite element analysis and indicates that the method of deducing the flexural rigidity of the structure according to the measured deflection value can effectively simulate the rigidity degradation law of the bridge in service. The crack resistance property of the test beam degrades obviously and the ultimate bearing capacity of the bending resistance does not degrade obviously. Originality/value The research results truly reflect the destruction process, destructive form, bearing capacity and rigidity degradation law of the old beam of the concrete bridge in service for 20 years and can provide technical basis for optimization design of newly built bridges of the same type and maintenance and reinforcement design of existing old bridges.

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Wang, Jie, and Jian Xin Liu. "Calculation of Horizontal Rigidity of the Plate Type Elastomeric Pad Bearing for Highway Bridge." Applied Mechanics and Materials 204-208 (October 2012): 2244–47. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.2244.

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The plate type elastomeric pad bearing is the most commonly used in highway bridge bearings. In the seismic design of bridges, the horizontal rigidity of the bearing is an important calculation parameters. The specific values of each parameter in the formula are not clear, and it can not provide a clear computation measures, although the formula of horizontal rigidity is given in the specification. Against Series bearings in plate type elastomeric pad bearing for Highway Bridge (JT/T4-2004), the People's Republic of China Communications Industry Standard, the structural parameters of the bearing are systematically introduced, including the shape factor, the bearing thickness, the thickness of the single-layer rubber and the total thickness of rubber layer. The methodology and detailed steps of the bearing horizontal rigidity are then analyzed and summarized by the formulas above. At last several examples of the different type of bearings are given. Some reference are Provided for the calculation of the stiffness frequently of plate type elastomeric pad bearing which are frequently used for highway bridges.

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XIANG, J., and Q. Y. ZENG. "MECHANISM AND ENERGY RANDOM ANALYSIS OF TRAIN DERAILMENT ON RAILWAY BRIDGES." International Journal of Structural Stability and Dynamics 09, no. 04 (December 2009): 585–605. http://dx.doi.org/10.1142/s0219455409003193.

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In this paper, the mechanism of train derailment on bridge is developed by applying the system dynamics stability concepts. The theory of energy random analysis for train derailment on bridge is put forward. The contents of the theory are as follows: (1) establishing vibration equation set for the train–bridge system; (2) determining exciting source of transverse vibration of the system; (3) method of energy random analysis of transverse vibration of the system; (4) geometric rules of derailment; (5) calculation of the whole process of train derailment on bridge; (6) criteria of energy increment for judging train derailment on bridge. Finally, three cases concerning train derailment on bridges are treated that coincide with actual conditions. Some main conclusions obtained are: (1) insufficient transversal rigidity of bridge is the reason causing train derailment on bridge and (2) enhancing transversal rigidity of bridge is the main preventive measure against train derailment on bridge.

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9

Liang, Peng, Xiang Nan Wu, and Yue Xu. "Static and Dynamic Behaviours of Three-Tower Suspension Bridges and the Structure Selection of the Mid-Tower." Advanced Materials Research 163-167 (December 2010): 2343–49. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.2343.

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In order to discuss the mechanical behaviour differences between the two-tower and three-tower suspension bridges, based on the Taizhou Yangtze River Bridge, three dimensional space finite element models of two-tower, three-tower with concrete mid-tower and with steel mid-tower were constructed. Through the comprehensive analysis, main conclusions are got as follows: due to the mid-tower lack of effective restraint from side cable, compared with two-tower suspension bridges, three-tower suspension bridges have lower total stiffness and natural frequency, with larger deflection-to-span ratio of main girder. So, some factors such as anti-slipping safety factor between the main cable and saddle, deflection-to-span ratio of main girder and force in mid-tower, which are not important in two-tower design, become controlling ones in three-tower suspension bridges. These factors are related to anti-pushing rigidity of mid-tower, but in contradictory demanding for the rigidity of mid-tower. After comprehensive analysis, steel tower with shape of upside-down ‘Y’ meets all demands, and then, was selected as appropriate structure for the mid-tower.

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10

Kleinas, Vilius. "Rational cross-sectional design and behavioural analysis of the low-sag stressed ribbon pedestrian bridges/Rationale Querschnittsbemessung und Verhaltensanalyse der Fußgänger-Spannbandbrücken mit geringem Durchhang." Bauingenieur 96, no. 04 (2021): 121–31. http://dx.doi.org/10.37544/0005-6650-2021-04-57.

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Stress ribbon bridges represent one of the simplest and the most efficient modern bridge constructions used in modern lightweight pedestrian bridges. The article presents an analysis of the stress ribbon bridge behaviour by applying different values of constant loads, assessing the possibilities of using steels and composite materials. The article presents the methodology for the rational cross-section and shape design of the low-sag stressed ribbon structure, based on the rigidity conditions. The article discusses the structure‘s behaviour in asymmetric loads and provides recommendations for Design.

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11

Choi, Dong-Ho. "Effects of Flexural Rigidity of Center Tower in Four-Span Suspension Bridges." Journal of the Korean Society of Civil Engineers 34, no. 1 (2014): 49. http://dx.doi.org/10.12652/ksce.2014.34.1.0049.

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Svoboda, Adam, and Ladislav Klusáček. "Possibility of Increasing the Load Bearing Capacity of Parapet Bridge Structures." Solid State Phenomena 272 (February 2018): 319–24. http://dx.doi.org/10.4028/www.scientific.net/ssp.272.319.

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Post-tensioning is a suitable, reliable and durable method for strengthening existing reinforced concrete bridge structures. The high efficiency of post-tensioning can be seen on many implemented applications for bridge reconstructions worldwide. There are still several thousands of beam and slab bridges the load capacity of which no longer meets the demanding transport conditions. The oldest reinforced concrete beam bridges, from 1905-1915, are designed according to the Austrian Ministry of Railways Bridge Standard of 1904 when the largest load to be considered was the 18-tonne road steamroller. These bridges are not dimensioned for the currently valid traffic load values. The paper deals with the strengthening of the parapet beam bridges from the period of 1905-1930. These bridges have two main beams pulled over the bridge deck which is supported by cross beams. The cross beams connect the two main beams, forming a half-frame in the transverse direction which provides spatial rigidity of the structure. The spans of these bridges are usually in the range of 15 to 25 m.

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13

Nikkhoo, Ali, Ardalan Bahrami Eskandari, Ali Farazandeh, and Iman Hajirasouliha. "Vibration control of bridges under simultaneous effects of earthquake and moving loads using steel pipe dampers." Journal of Vibration and Control 25, no. 19-20 (July 11, 2019): 2580–94. http://dx.doi.org/10.1177/1077546319861820.

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This study aims to develop a practical methodology based on the eigenfunction expansion method to assess the effects of simultaneous action of vertical earthquake excitation and moving vehicle loads in single-span and multi-span simply-supported bridges. While the effects of vertical earthquake ground motions are generally ignored in common design practice, it is shown that the influence of simultaneous vertical earthquake excitation and vehicle loads can considerably affect the structural response of the bridge, especially in near-field earthquakes with high amplitude vertical components. To address this issue, a novel vibration suppression system is proposed using steel pipe dampers and its reliability is investigated for a wide range of bridge flexural rigidity under seven different earthquake records. The results indicate that the proposed system can significantly (up to 75%) suppress the vertical vibrations generated in the bridge, especially for the systems with lower flexural rigidity. For the same maximum deflection limits, application of pipe dampers could reduce the required flexural rigidity of the bridge (up to 50%), and therefore, lead to more economic design solutions with lower structural weight.

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MACHACEK, Josef, and Martin CHARVAT. "STUDY ON SHEAR CONNECTION OF BRIDGE STEEL TRUSS AND CONCRETE SLAB DECK." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 23, no. 1 (May 23, 2016): 105–12. http://dx.doi.org/10.3846/13923730.2014.976258.

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Longitudinal shear flow in the connection of a bridge steel truss upper chord and a concrete bridge slab is studied both in elastic and plastic stages of loading up to the shear connection collapse. First the distribution of the shear flow with an increasing level of loading is shown as resulted from 3D MNA (materially nonlinear analysis) using ANSYS software package and a former experimental verification. Nevertheless, the flow peaks in elastic stages above truss nodes due to local transfer of forces are crucial for design of the shear connection in bridges. Therefore a simple approximate 2D elastic frame modelling was suggested for subsequent extensive parametric studies. The study covers various loadings including the design loading of bridges and demonstrates importance of rigidity of the shear connection, rigidity of an upper steel truss chord and rigidity of a concrete deck. Temperature effects and a creep of concrete are also studied. The substantial part of the study deals also with concentration of shear connectors in the area of steel truss nodes and influence of the connector densification on distribution of the longitudinal shear along an interface of the steel truss chord and the concrete deck. Eurocode 4 approach and quest to find an optimum design of the shear connection in composite bridge trusses are discussed. Finally the resulting recommendations for a practical design are presented.

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Cha, Taegweon, and Ilyoung Jang. "Analysis of Static Characteristics of Steel Box Girder Bridge being composited High Strength Concrete at the Lower Flange of the Support." Journal of the Korean Society of Hazard Mitigation 21, no. 1 (February 28, 2021): 219–24. http://dx.doi.org/10.9798/kosham.2021.21.1.219.

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The steel box girder bridge has excellent applicability to curved bridges owing to its large torsional rigidity. In addition, because the weight of the segments is smaller than that of concrete bridges, it also has many applications for medium-range bridges. However, when a bridge with a span greater than 70 m is constructed, the height of the steel box girder increases, which is disadvantageous for the manufacture and transportation of girders and for bridge construction. Therefore, improvements in the construction methods are required to facilitate construction. Therefore, a structural system of a double composite box girder bridge with an upper slab and composite high-strength concrete at the lower flange of the support of continuous span was proposed, and the structural performance was verified by finite element analysis and a static loading test of an actual specimen. It was confirmed that such a structure minimizes the height of the girder of continuous support by optimizing the sectional efficiency and also improves usability.

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Pushpangadan, Silpa, Arjun S. Menon, and A. Sofi. "Parametric Study of Stiffeners in Steel Composite Tub Girders." International Journal of Engineering & Technology 7, no. 3.6 (July 4, 2018): 64. http://dx.doi.org/10.14419/ijet.v7i3.6.14940.

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Closed structural sections (rectangular, circular, trapezoidal shape) possess high rotational rigidity compared to open sections like I girder. For highly curved bridges, closed sections with high torsional rigidity is an absolute choice. This paper suggests the use of steel – composite Tub girder instead of concrete I girder in rail bridges. Stiffeners were used to strengthen the girder. Deflection and stress study has been done for the entire girder on various thickness of stiffeners under different loading.

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Li, Chunwei, Quansheng Sun, and Yancheng Liu. "Study on static load test of simply supported hollow slab bridge flexural strengthened with polyurethane–cement composite." International Journal of Structural Integrity 13, no. 1 (October 25, 2021): 112–32. http://dx.doi.org/10.1108/ijsi-08-2020-0073.

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PurposeAs the service time of bridges increases, the degradation of bending capacity, the lack of safety reserves and the decrease in bridge reliability are common in early built bridges. Due to the defective lateral hinge joints, hollow slab bridges are prone to cracking of hinge joint between plates, transverse connection failure and stress of single plates under the action of long-term overload and repeated load. These phenomena seriously affect the bending capacity of the hollow slab bridge. This paper aims to describe a new method of simply supported hollow slab bridge reinforcement called polyurethane–cement (PUC) composite flexural reinforcement.Design/methodology/approachThis paper first studies the preparation and tensile and compressive properties of PUC composite materials. Then, relying on the actual bridge strengthening project, the 5 × 20 m prestressed concrete simply supported hollow slab was reinforced with PUC composites with a thickness of 3 cm within 18 m of the beam bottom. Finally, the load test was used to compare the performance of the bridge before and after the strengthening.FindingsResults showed that PUC has high compressive and tensile strengths of 72 and 46 MPa. The static test revealed that the measured values and verification coefficients of the measured points were reduced compared with those before strengthening, the deflection and strain were reduced by more than 15%, the measured section stiffness was improved by approximately 20%. After the strengthening, the lateral connection of the bridge, the strength and rigidity of the structure and the structural integrity and safety reserves were all significantly improved. The application of PUC to the flexural strengthening of the bridge structure has a significant effect.Originality/valueAs a new type of material, PUC composite is light, remarkable and has good performance. When used in the bending strengthening of bridge structures, this material can improve the strength, rigidity, safety reserve and bending capacity of bridges, thus demonstrating its good engineering application prospect.

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Ma, Jun, and Yan Li. "Dynamic Response Analysis of Half-through CFST Arch Bridges Affected by Crossbeams Setting." Advanced Engineering Forum 5 (July 2012): 201–6. http://dx.doi.org/10.4028/www.scientific.net/aef.5.201.

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As one of the most important components of CFST arch bridges, the cross beams should affect the bridges’ dynamic performance and response magnificently by means of affecting these three factors mentioned above. Based on the Maocaojie Bridge, its FEM models of half-through CFST arch bridges with different settings of cross beams are built. The different seismic responses of six operating conditions are calculated with three dimensional earthquake waves input. The internal force and displacement envelope diagrams of arch ribs are extracted and analyzed in situations of in-plane moment, out-plane moment, vertical displacement and transverse displacement. It can conclude that the joint section between arch rib and bridge deck should be designed carefully because of its large displacement and internal force, and the cross beams should be optimized to safety the arch bridge dynamic response considering lateral rigidity. The conclusions may be useful to the seismic design and strengthening treatment of CFST arch bridges. To strengthen the joint section between arch rib and bridge deck or optimize the setting of cross beams will increase the ductility of half-through CFST arch bridge and decrease the damages caused by large earthquake.

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Khitruk, S. A., V. T. Chemodurov, and O. A. Kuzmenko. "DESIGNING THE SPAN OF A HANGING BRIDGE BY METHODS OF SYSTEM ANALYSIS." Construction and industrial safety, no. 19 (71) (2020): 65–70. http://dx.doi.org/10.37279/2413-1873-2020-19-65-70.

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As you know, suspension bridges are much lighter in their total weight than bridges of other structures. This is their undoubted positive quality. It is no accident that this type of bridge is widely used in practice. However, along with the undeniable advantages, this type of bridge is quite sensitive to wind loads, which are a generator of bending and torsional vibrations of spans at certain speeds of transverse air flow. If the drag of the bridge with a transverse air flow can be easily reduced by designing streamlined surfaces, then ensuring the stability of the bridge span surface for bending and torsion can only be ensured by properly selecting the profile of its cross-section, which provides the necessary moment of inertia, as necessary components of its rigidity.

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Grigorjeva, Tatjana, Algirdas Juozapaitis, and Zenonas Kamaitis. "STATIC ANALYSIS AND SIMPLIFIED DESIGN OF SUSPENSION BRIDGES HAVING VARIOUS RIGIDITY OF CABLES." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 16, no. 3 (September 30, 2010): 363–71. http://dx.doi.org/10.3846/jcem.2010.41.

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Increased deformability can be considered as the basic disadvantage of suspension bridges. One of the ways to increase the rigidity of a suspension bridge is to transfer a part of stiffening girder rigidity to a suspension main cable. To give the suspension bridge more stable appearance, the authors propose to use the cables of varying bending stiffness. The main cables can be made of standard section shapes or have a composite section. The object of this work was to study a method for analyzing and determining the internal forces in the main cables and stiffening girder under static loading to provide recommendations for designing suspension bridges with stiffened cables. Simple formulas are presented for determining displacements, internal forces and stresses in the main cable and stiffening girder. Finite element modeling was performed. The final part of the paper discusses design procedures for such suspension systems. An example of a pedestrian suspension bridge is appended. Santrauka Esminis kabamuju tiltu trūkumas ‐ didelis ju deformatyvumas. Deformatyvumui sumažinti autoriai siūlo dali standumo sijos lenkiamojo standžio perduoti kabamajam lynui. Baigtinio lenkiamojo standumo lynai gali būti daromi iš standartiniu valcuotuju profiliuočiu arba sudetinio skerspjūvio. Šio darbo tikslas ‐ pateikti supaprastinta metodika kabamojo tilto standaus lyno ir standumo sijos elgsenos analizei atlikti bei rekomendacijas tokiems statiškai apkrautiems tiltams projektuoti. Pateiktos paprastos formules lyno ir sijos poslinkiams, iražoms ir itempiams apskaičiuoti. Atliktas kabamosios tilto siste‐mos modeliavimas baigtiniais elementais. Aptartos tokiu kabamuju tiltu projektavimo procedūros. Pateiktas pesčiuju via‐duko kabamuju konstrukciju projektavimo pavyzdys.

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Koo, Ki-Young, and Jin-Hak Yi. "Substructural Identification of Flexural Rigidity for Beam-Like Structures." Shock and Vibration 2015 (2015): 1–15. http://dx.doi.org/10.1155/2015/726410.

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This study proposes a novel substructural identification method based on the Bernoulli-Euler beam theory with a single variable optimization scheme to estimate the flexural rigidity of a beam-like structure such as a bridge deck, which is one of the major structural integrity indices of a structure. In ordinary bridges, the boundary condition of a superstructure can be significantly altered by aging and environmental variations, and the actual boundary conditions are generally unknown or difficult to be estimated correctly. To efficiently bypass the problems related to boundary conditions, a substructural identification method is proposed to evaluate the flexural rigidity regardless of the actual boundary conditions by isolating an identification region within the internal substructure. The proposed method is very simple and effective as it utilizes the single variable optimization based on the transfer function formulated utilizing Bernoulli Euler beam theory for the inverse analysis to obtain the flexural rigidity. This novel method is also rigorously investigated by applying it for estimating the flexural rigidity of a simply supported beam model with different boundary conditions, a concrete plate-girder bridge model with different length of an internal substructure, a cantilever-type wind turbine tower structure with different type of excitation, and a steel box-girder bridge model with internal structural damages.

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Chen, Xia-Chun, Zhen-Hu Li, Francis T. K. Au, and Rui-Juan Jiang. "Flexural Vibration of Prestressed Concrete Bridges with Corrugated Steel Webs." International Journal of Structural Stability and Dynamics 17, no. 02 (March 2017): 1750023. http://dx.doi.org/10.1142/s0219455417500237.

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Prestressed concrete bridges with corrugated steel webs have emerged as a new form of steel-concrete composite bridges with remarkable advantages compared with the traditional ones. However, the assumption that plane sections remain plane may no longer be valid for such bridges due to the different behavior of the constituents. The sandwich beam theory is extended to predict the flexural vibration behavior of this type of bridges considering the presence of diaphragms, external prestressing tendons and interaction between the web shear deformation and flange local bending. To this end, a [Formula: see text] beam finite element is formulated. The proposed theory and finite element model are verified both numerically and experimentally. A comparison between the analyses based on the sandwich beam model and on the classical Euler–Bernoulli and Timoshenko models reveals the following findings. First of all, the extended sandwich beam model is applicable to the flexural vibration analysis of the bridges considered. By letting [Formula: see text] denote the square root of the ratio of equivalent shear rigidity to the flange local flexural rigidity, and L the span length, the combined parameter [Formula: see text] appears to be more suitable for considering the diaphragm effect and the interaction between the shear deformation and flange local bending. The diaphragms have significant effect on the flexural natural frequencies and mode shapes only when the [Formula: see text] value of the bridge falls below a certain limit. For a bridge with an [Formula: see text] value over a certain limit, the flexural natural frequencies and mode shapes obtained from the sandwich beam model and the classical Euler–Bernoulli and Timoshenko models tend to be the same. In such cases, either of the classical beam theories may be used.

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Luo, Ru Deng, Mei Xin Ye, and Ye Zhi Zhang. "Study on Influences of Thickness of Flange of U Rib on Mechanical Behaviors of Orthotropic Monolithic Steel Bridge Deck System." Advanced Materials Research 163-167 (December 2010): 122–26. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.122.

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Orthotropic monolithic steel bridge deck system stiffened by U rib is very fit for high-speed railway steel bridges because of its excellent mechanical behaviors. Thickness of flange is a very important parameter of U rib and has influence on mechanical behaviors of orthotropic monolithic steel bridge deck system. Based on the engineering practice of Anqing Yangtze River Railway Grand Bridge, the kind and the extents of influences of thickness of flange of U rib on mechanical behaviors of orthotropic monolithic steel bridge deck system are studied with finite element analysis. The results show that thickness of flange of U rib has relative large positive influences on rigidity, strength and stability of orthotropic monolithic steel bridge deck system. 14~18mm is the appropriate range of thickness of flange of U rib for high-speed railway steel bridges.

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Hoang, Nam. "Design Formulas for Cable Tension in Cable-stayed Bridges Considering Sag and Bending Rigidity." Science and Technology Development Journal 18, no. 1 (March 31, 2015): 95–101. http://dx.doi.org/10.32508/stdj.v18i1.945.

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Estimating cable tension in cable-stayed bridges or in external tendons is essential for regular inspection and assessment of those structures. Vibration measurements provide a solution, however, may not be accurate in cases parameters such as amount of sag and bending rigidity of cable are significant. In this study, the characteristic equation for vibration of the most general case of a cable, where both the sag and flexure in the cable are taken into account, is analytically derived. After that by considering proper simplifying assumptions of small flexural rigidity parameter, asymptotic forms of that equation are obtained. It renders a practically applicable procedure to estimate cable tension using measured natural frequencies. The developed procedure is verified by realistic data of a cable stayed bridge in Vietnam.

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Xu, Li Ge, Yi Li Wang, and Chang Jie Xu. "Jacking Technology for a Simply Supported Girder Bridge." Applied Mechanics and Materials 477-478 (December 2013): 675–80. http://dx.doi.org/10.4028/www.scientific.net/amm.477-478.675.

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Numerous bridges have to be lifted to meet increased navigation capacity. However, no relevant technical standard for the jack-up technique is yet available. This paper presents a study on the integral lifting of simply supported girder bridge which implements the finite element method. Finite element analysis provides a reliable basis in controlling construction. Research shows that stress concentration is evident near support points in the lifting process. Thus, stress monitoring is necessary. These points should be near to the bridge web. Moreover, beam span and section rigidity should also be considered when jacking up a bridge. The value of allowable error in the jacking-up process decreases with increasing beam span or decreasing section stiffness. Therefore, jacking up a bridge will be safer when section rigidity is large enough and beam span is not extremely long. This paper offers tremendous reference value with regard to engineering projects.

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Pu, Guang Ning. "Experimental Study of the Influence of Beam-Reduction and Rib-Addition Strengthening Method on Bridge Natural Vibration Properties." Applied Mechanics and Materials 178-181 (May 2012): 2158–63. http://dx.doi.org/10.4028/www.scientific.net/amm.178-181.2158.

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In order to study the influence of beam-reduction and rib-addition strengthening method on the natural vibration properties of hollow slab bridges, based on bridge natural vibration frequency and the vibration mode in the first three orders as main comparison parameters, according to the comparison between the theoretical values as well as experimental values of the natural vibration properties before and after strengthening, the practical effect of this strengthening method is studied. The test data show that the beam-reduction and rib-addition strengthening method results in an obvious enhancement of the natural vibration frequency of simply supported hollow slab bridges, which proves that the strengthening method has remarkable improvement effect on the rigidity of bridges. It can be seen from the comparison of the changes of the vibration mode in the first three orders before and after strengthening that the transverse connection of bridge is strengthened and the integrity is prominently enhanced after strengthening. The study result is that the beam-reduction and rib-addition strengthening method can greatly enhance the structural behavior of hollow slab bridges.

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Ma, Shi Yan, Wei Yun Yu, and Ke Lun Wei. "Dynamic Characteristic Analysis of Lian-Huo Highway Bridges." Advanced Materials Research 912-914 (April 2014): 1245–48. http://dx.doi.org/10.4028/www.scientific.net/amr.912-914.1245.

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Dynamiccharacteristic analysis of bridge structure is the foundation of the seismicresponse analysis and seismic design, includes the calculation and analysis ofnatural vibration frequency and main vibration mode.The natural vibrationfrequency not only is the index of bridge structure rigidity,but also is the basisof identifying whether the bridge structure resonance occur. In this paper thehealth condition evaluation of highway bridges was carried out based on anambient test and finite element analysis, using finite element analysissoftware ANSYS calculates and analyzes the dynamic characteristic of bridgestructure, then gets the natural vibration frequency and main vibration mode ofbridge structure, finally compares with results of ambient tests. The resultsshowe that, structural dynamic stiffness of Rencungou Viaduct and YingyugouViaduct can meet design requirements; but structural dynamic stiffness ofLiaoyugou Viaduct is lower

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Constantinou, M. C., Allaoua Kartoum, A. M. Reinhorn, and Paul Bradford. "Sliding Isolation System for Bridges: Experimental Study." Earthquake Spectra 8, no. 3 (August 1992): 321–44. http://dx.doi.org/10.1193/1.1585684.

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A seismic isolation system for bridges has been tested on a shake table. The system consisted of Teflon disc bridge bearings and displacement control devices. These devices provided restoring force for re-centering the bridge during earthquake excitation, additional energy dissipation capacity and rigidity for service loading. The tests were carried out with a 51-kip model which was subjected to strong recorded earthquake motions with a wide range of frequency content and to simulated motions compatible with CalTrans 0.6g design spectra. In all tests the isolated deck responded with peak acceleration less than the peak table acceleration and peak bearing displacement less than the peak table displacement. Results from an analytical model show very good agreement with experimental results.

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Takamura, Yoshiyuki, Kiyoshi Sakiya, and Yukio Adachi. "New Low-Rigidity Design for Widening of Elevated Bridges." IABSE Symposium Report 97, no. 7 (January 1, 2010): 24–31. http://dx.doi.org/10.2749/222137810796063670.

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Sali, Jefeena, and Regi P. Mohan. "Parametric Study of Single Cell Box Girder Bridge under Different Radii of Curvature." Applied Mechanics and Materials 857 (November 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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Lin, Guan Dong, Shu Jun Fang, Hua Wang, Zhi Wei Qi, and Chan Zi Chang. "Experimental Study on Forced Vibration of Prestressed Concrete Simply Supported Beam under Speed-Increase State." Advanced Materials Research 243-249 (May 2011): 1716–21. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.1716.

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Through dynamic performance test on prestressed concrete simply supported beam of Xiaotang-river Bridge on the Suhuang railway under different speed and different train formation, the dynamic characteristics of the bridge and its response under speed-increase trains are studied. Results indicate that the lateral forcing vibration frequency of train is close to the lateral natural vibration characteristics of the bridge when trains running at 70 and 75 km·h-1, and the resonance occurs. Consequently, vibration restraining measure for PCT beam should give priority to increasing the lateral rigidity of beam. When train speed exceeds 60 km·h-1, the maximum lateral amplitude of PCT beam exceeds the safety 1imit with no exception. The values of the lateral and vertical vibration acceleration of PCT beam are under the safety limits regulated by Code for Rating Existing Railway Bridges. The lateral vibration frequency of PCT beam in mid-span is obviously on the low level and is only 40-50 percentage of the reference value. The vertical natural vibration frequency of bridge in mid-span is enough and the ratio of vertical deflection and span is lower than the ordinary value stipulated in Code for Rating Existing Railway Bridges. It shows that the vertical rigidity of the beam is enough. Different formations of passing trains have a great influence on the 1ateral amplitude. When train formation is C64, the lateral amplitude is the maximum. while train formation is C64K, the lateral amplitude of the beam is smaller.

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Gasim, Ahmed, and Haitham A.A.Elboushi. "Fundamental Parameters Affecting Non Linearity of Suspension Bridges." FES Journal of Engineering Sciences 2, no. 1 (November 6, 2006): 29. http://dx.doi.org/10.52981/fjes.v2i1.92.

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In this research factors affecting the non-linearity of suspension bridges were studied. The fundamental parameters studied are the main and side span lengths, cable sag, tower height, cable x-section and the flexural rigidity of the stiffening girder .The effect of variation of each parameter on the cable tension and the girder moments is studied. A non-linear 2-dimensional mathematical model of a 3 span, continuous suspension bridge is considered . The solution is based on the second order deflection theory given in a computerized form. It has been found that the degree of effect of these parameters on the results of analysis in a descending order is: the main span length, side span length, cable sag, cable section and the stiffness of the bridge girder.

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Park, Jongchan, Namhyoung Lim, and Chinok Lee. "Stiffness and Distance of Lateral Support Member Considering Buckling Strength of Sliding Track Panel." Journal of the Korean Society of Hazard Mitigation 20, no. 3 (June 30, 2020): 197–201. http://dx.doi.org/10.9798/kosham.2020.20.3.197.

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Recently, the concept of a Sliding Track Panel (STP) system, which allows the bridge to slide in the longitudinal direction, has been proposed for continuous welded rail method laid on long span non-ballast bridges, such as truss railway bridges. The performance of the STP system is determined based on the ability to prevent the lateral buckling of STP. This study attempts to derive the optimum interval distance and required stiffness of the lateral support member to be installed in the STP system through buckling analysis. According to the analysis, the interval distance of lateral support member, which satisfies the strength of STP, is less than 2.8 m and the rigidity is more than 800 N/mm.

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Shim, Chang-Su, and Gi-Tae Roh. "Data-Driven Modeling Algorithms for Cable-Stayed Bridges Considering Mechanical Behavior." Applied Sciences 11, no. 5 (March 4, 2021): 2266. http://dx.doi.org/10.3390/app11052266.

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Digital transformation of bridge engineering utilizes distinct modeling techniques to combine domain knowledge with digital information modeling. In particular, a long-span bridge is a key link in a transportation network, with more than 100 years of service life. BIM (building information modeling) is an effort towards improving the current data delivery in the construction industry. However, it is limited by the rigidity that geometry affords; this is particularly problematic when the structure to be modelled is a deformable body. The quality and value of information for the bridges can be enhanced by establishing a data-driven digital information delivery through the entire life-cycle of the bridges. In this study, a data-driven modeling algorithm for cable-stayed bridges is proposed, considering the geometry change determining the mechanical behavior. Data delivery is accomplished by a combination of datasets and algorithms based on the different purposes. The master information model considers alignment of the bridge and essential constraints for the main members, such as stiffening girders, pylons, and cables, between the digital models. Geometry control of the stiffening girders and tension forces of cables are supported by the modeling algorithm of the interoperable target configuration under dead load analysis. The suggested modeling algorithm is verified by comparison with previous analytical studies on cable-stayed bridges.

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Svoboda, Adam, Ladislav Klusáček, and Martin Olšák. "Strengthening and Rehabilitation of U-Shaped RC Bridges Using Substitute Cable Ducts." Advances in Materials Science and Engineering 2019 (November 30, 2019): 1–21. http://dx.doi.org/10.1155/2019/8920718.

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The presented paper deals with strengthening and rehabilitation of U-shaped reinforced concrete bridges from the period of 1905–1930 using post-tensioning, which is a suitable, reliable, and durable method. These bridges have two main beams pulled over the bridge deck, which is supported by cross girders. The cross girders connect the two main beams forming a half-frame in the transverse direction, which provides spatial rigidity to the structure. The spans of these bridges are usually between 15 and 25 m. The high efficiency of post-tensioning can be seen on many implemented applications for bridge reconstructions worldwide. However, in this paper, the post-tensioning method is extended by a unique structural system of substitute cable ducts that allows for significantly expanding applicability of this method on existing concrete bridges. This method is highly recommended due to minimization of interventions into the constructions, unseen method of cable arrangement, and hence the absence of impact on appearance, which is appreciated not only in case of valuable historical structures but in general as well. In conclusion, the post-tensioning by monostrands in substitute cable ducts is a highly efficient method for strengthening of existing bridges in order to increase their load-bearing capacities in terms of current traffic load and to extend their service life. This method was also verified by monitoring the behavior of rehabilitated bridges before and after strengthening.

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Huang, Hai Yun, Xiang Rong Yuan, and Ka Hong Cai. "Dynamic Performance Analysis for a Butterfly-Shaped Arch Bridge." Advanced Materials Research 163-167 (December 2010): 74–78. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.74.

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The dynamic characteristics are not only the important indexes for evaluating the bridge structural rigidity, but also the principal parameters for structural dynamic analysis and earthquake resistant analysis. In this paper, a three dimensional solid finite element model for a butterfly-shape arch bridge in Zhongshan city was established to analyze the dynamic characteristics. By comparison the numerical calculation results with measured results of the dynamic loading test, an analysis and evaluation of the dynamic performance of this new type spatial arch bridge was made, and can serve as reference to the dynamic analysis and seismic design of similar bridges.

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37

Kilpatrick, N. M., and R. W. Wassell. "The use of cantilevered, adhesively retained bridges with enhanced rigidity." British Dental Journal 176, no. 1 (January 1994): 13–16. http://dx.doi.org/10.1038/sj.bdj.4808349.

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38

Bagheri, Abdollah, Mohamad Alipour, Osman E. Ozbulut, and Devin K. Harris. "Identification of Flexural Rigidity in Bridges with Limited Structural Information." Journal of Structural Engineering 144, no. 8 (August 2018): 04018126. http://dx.doi.org/10.1061/(asce)st.1943-541x.0002131.

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39

Liu, Ai-Rong, Chun-Hui Liu, Ji-Yang Fu, Yong-Lin Pi, Yong-Hui Huang, and Jun-Ping Zhang. "A Method of Reinforcement and Vibration Reduction of Girder Bridges Using Shape Memory Alloy Cables." International Journal of Structural Stability and Dynamics 17, no. 07 (September 2017): 1750076. http://dx.doi.org/10.1142/s0219455417500766.

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Bending and torsional vibrations caused by moving vehicle loads are likely to affect the traffic safety and comfort for girder bridges with limited torsional rigidity. This paper studies the use of cables made of shape memory alloy (SMA) as the devices of reinforcement and vibration reduction for girder bridges. The SMA cables are featured by their small volume, expedient installation. To investigate their effect on the vibration of girder bridges, theoretical analysis, numerical simulation and experimental study were conducted in this paper. For bending vibration, the governing equations of the girder with and without SMA cables subjected to moving vehicle loads were derived, while for torsional vibration, the finite element (FE) simulations were used instead. The results of bending and torsional vibrations obtained by the analytical approach and FE simulations, respectively, were compared with the experimental ones from model testing. It was confirmed that the SMA cables can restrain the vibration of the girder bridge effectively.

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Constantinou, M. C., A. M. Reinhorn, A. Mokha, and R. Watson. "Displacement Control Device for Base-Isolated Bridges." Earthquake Spectra 7, no. 2 (May 1991): 179–200. http://dx.doi.org/10.1193/1.1585625.

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An isolation system consisting of sliding Teflon bearings and displacement control devices is described for the seismic protection of bridges. The system utilizes multidirectional Teflon bearings for accommodating thermal movements and for providing the isolation mechanism and displacement control devices which exhibit bilinear behavior with controlled stiffness and characteristic strength. The devices provide rigidity for service loads below their characteristic strength and restoring force and energy dissipation for strong earthquake forces.

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41

Shermuxamedov, Ulugbek, Said Shaumarov, and Aleksandr Uzdin. "Use of seismic insulation for seismic protection of railway bridges." E3S Web of Conferences 264 (2021): 02001. http://dx.doi.org/10.1051/e3sconf/202126402001.

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The problem of seismic protection of the bridge for the conditions of Uzbekistan is considered. The bridge is located in an area with estimated seismicity of 9 points. It has massive high supports on a natural foundation and relatively small and light spans. When selecting seismic isolation, this made it possible to use the span structures as a dynamic damper for the support vibrations in the direction along the bridge. Due to the damping effect, it was possible to achieve that the seismic forces in the support in the presence of the superstructure were less than in the free support without the superstructure. At the same time, the rigidity of fastening the superstructure to the support increased in comparison with the rigidity of classical seismic isolation, which facilitated the design of the supporting elements.

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42

Liu, Peng Hui, Yi Qian Yang, Jing Chuan Yao, Wei Wang, and Zhen Sheng Dong. "Experimental Study on Dynamic Behaviors of Concrete Bridge in China Existing Railway Speed Increase to 200~250km/h." Applied Mechanics and Materials 193-194 (August 2012): 1123–28. http://dx.doi.org/10.4028/www.scientific.net/amm.193-194.1123.

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On April fifteenth, 2007, the 4 vertical and 2 horizontal railway lines were increased the sixth time by the Chinese Ministry of Railways. The electrical multiple unit (EMU) was running at speed of 200km/h in these sections. In some sections, the EMU maximum speed has reached 250km/h. Dynamic behaviors of bridges and piers under the loads of the train were analyzed with different spans and types in existing speed-raising trunk lines. The critical parameters, such as lateral and vertical natural frequency, dynamic factor, lateral amplitude, lateral natural frequency and lateral amplitude of pier and so on, which play important roles in dynamic behaviors of bridge, are analyzed by experimental data. The lateral rigidity and dynamic behaviors of bridge including beams and piers are the most obvious problems in existing speed-raising lines. Based on years of research, especially lots of dynamic behavior tests of concrete bridge in recent year, the dynamic behaviors of bridges are analyzed comprehensively considering the vibration of bridge and train characteristics. Many results are got and used in the relevant codes.

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Bakht, Baidar, and Akhilesh C. Agarwal. "Deck slabs of skew girder bridges." Canadian Journal of Civil Engineering 22, no. 3 (June 1, 1995): 514–23. http://dx.doi.org/10.1139/l95-060.

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Canadian codes allow the design of concrete deck slabs of slab-on-girder bridges by taking account of the internal arching action that develops in these slabs under concentrated wheel loads in particular. Provided that certain prescribed conditions are met, a deck slab is deemed to have met the design criteria if it is provided with a top and a bottom layer of steel reinforcement with each layer consisting of an orthogonal mesh of steel bars in which the area of cross section of the bars in each direction is at least 0.3% of the effective area of cross section of the deck slab. For deck slabs of bridges having skew angles greater than 20°, the codes require the minimum amount of reinforcement to be doubled in the end zones near the skew supports. Model testing has shown that need for such an increase can be eliminated by providing composite end diaphragms with high flexural rigidity in the horizontal plane. The proposed concept is tested on a model of fibre-reinforced concrete deck without steel reinforcement in which deficiencies in the confinement of the deck slab readily manifest themselves in form of a bending, rather than punching shear, failure. Key words: highway bridges, bridge decks, deck slabs, skew deck, skew bridges, fibre-reinforced concrete decks.

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44

Zhang, Yu Min, and Xing Xu Qin. "Research on Bridge Damage-Reduction Seismic Performance with Variable Parameter Cable-Unseating Prevention Devices." Applied Mechanics and Materials 638-640 (September 2014): 977–82. http://dx.doi.org/10.4028/www.scientific.net/amm.638-640.977.

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The anti-seismic measures is effective in reducing the seismic damage of bridge, unseating prevention device is an effective structural measure to prevent collapse under unexpected earthquake, and its parameter will affect the function of unseating prevention devices. Based on relational design standards, the damage-reduction seismic performance of unseating prevention devices with variational design parameter have been analysis. The research results show that the unseating prevention devices with rational parameters can prevent collapse of the structure; the damage-reduction seismic performance of bridge was influenced by the cable rigidity and primary clearances. The unseating prevention devices will improve the seismic performance and integrality of bridge, but higher requirements have been proposed for the substructure of bridges.

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Sandovic, G., A. Juozapaitis, and V. Gribniak. "Experimental and Analytical Investigation of Deformations and Stress Distribution in Steel Bands of a Two-Span Stress-Ribbon Pedestrian Bridge." Mathematical Problems in Engineering 2017 (2017): 1–11. http://dx.doi.org/10.1155/2017/9324520.

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The article is dedicated to the analysis of problems related to design of pedestrian bridges with flexible ribbon bands made of steel. The study is based on test results of a bridge model that has two spans (each with a length of five meters). A simplified analytical technique has been proposed for predicting vertical deformations of the bridge structure subjected to symmetrical or asymmetrical loading patterns. The technique also allows assessing the tension forces in the ribbons, which are very important for design of such structures. The analysis reveals the importance of the flexural rigidity of the ribbons that might cause significant redistribution of stresses within the steel bands.

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Sun, Qingwen, Qiushi Yan, Liqu Liu, and Haowei Wang. "Experimental Study on Reasonable Horizontal Load Value on the Top of Railings of Glass Bridges or Gallery Roads in Scenic Area." Advances in Materials Science and Engineering 2021 (August 6, 2021): 1–10. http://dx.doi.org/10.1155/2021/6678261.

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With the increase of glass bridges or glass walkways in the scenic area, the safety protection provided by railings cannot be neglected. However, there is a difference between the demands for a horizontal load on the top of railings in the present design specifications. Especially, it does not give specific advice on the horizontal load on the top of railings of glass bridges or glass roads in the scenic area. In this study, experimental research is conducted on railing columns based on the investigation of common railings of glass bridges or glass roads in the scenic area. The type of railing columns includes finished products and field production. The number of railing columns is 12. The displacement and strain results of the railing columns under different loads are obtained. The rigidity and strength are analyzed by numerical simulation combined with test results. A reasonable horizontal load on the top of the railings of a glass bridge or glass road is advised. These results provide a reference for the design, inspection, and evaluation of railings of glass bridges or gallery roads in the scenic area.

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47

Yan, Banfu, Wenbing Chen, You Dong, and Xiaomo Jiang. "Tension Force Estimation of Cables with Two Intermediate Supports." International Journal of Structural Stability and Dynamics 20, no. 03 (February 19, 2020): 2050032. http://dx.doi.org/10.1142/s0219455420500327.

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The presence of intermediate supports usually imposes difficulties in identifying the tension force of stayed cables in cable-stayed bridges or hanger cables in arch bridges. This paper establishes the partial differential equations of motion of the cable and derives two numerical models with (Model 1) and without (Model 2) considering the flexural rigidity. The effects of two intermediate supports on the identification accuracy of the cable tension force are further studied analytically and experimentally. The effects of several non-dimensional parameters (e.g. damper location, support stiffness, flexural rigidity, and mode order of the cable) on the identification accuracy of the models are also investigated. It is theoretically concluded that the simplified Model 2 provides acceptable accuracy on tension force identification when the non-dimensional parameter [Formula: see text] is greater than 90 (slender cables), whereas the accurate Model 1 can be applied for tension force identification at any scenarios. The feasibility of two models is further verified by three numerical examples and field tests on two real-world arch bridges.

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48

Pu, Guang Ning, Li Jun Li, and Yu Zhao. "Numerical Simulation Analysis of Beam-Reduction and Rib-Addition Strengthening Method of Hollow Slab Bridges." Advanced Materials Research 546-547 (July 2012): 57–65. http://dx.doi.org/10.4028/www.scientific.net/amr.546-547.57.

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For the purpose of the study of the mechanical mechanism of beam-reduction and rib-addition strengthening method as well as the difference between hinged beam method and rigidly connected beam method, finite element models are established for hollow slab bridge before and after strengthening respectively with the finite element software Ansys. The stress distributions on hollow slab bridge before and after strengthening are compared through numerical simulation analysis. The improvement effects of beam-reduction and rib-addition method on the transverse connection and stress state of hollow slab bridge are analyzed at the same time. It is proved that this strengthening method is of obvious effect and the bearing capacity of the existing bridge can be greatly enhanced. Meanwhile, the result of numerical simulation analysis shows that the beam-reduction and rib-addition hinged beam method and rigidly connected beam method have the similar effects. Both of them result in much improvement of transverse distribution and enhancement of transverse connection. But the rigidly connected beam method has a better overall rigidity and a tighter transverse connection. Its improvement effect on the stress state of the old beam slab is superior to that of the hinged beam method.

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49

Jaeger, Leslie G., and Baidar Bakht. "Effect of butt joints on the flexural stiffness of laminated timber bridges." Canadian Journal of Civil Engineering 17, no. 5 (October 1, 1990): 859–64. http://dx.doi.org/10.1139/l90-096.

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Prestressed and nailed laminated timber bridge decks are made from laminates which, because of their being usually shorter in length than the deck span, are butt-jointed at regular intervals. In calculating deflections of such decks, it is usual to ignore the reduction in flexural rigidity of the deck caused by the presence of the butt joint. The effect of butt joints on the flexural rigidity of the laminated deck is studied analytically, and it is shown that the deflections of a deck having such joints may be significantly larger than those of a deck without them. A simple method is presented to account conservatively for the presence of butt joints in the calculation of the deflections of a prestressed laminated timber deck. Key words: timber bridge, laminated deck, butt joint, prestressed wood deck.

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Zhang, Li Fang, Ying Wang, Ying Ge Lei, and Yun Chang. "Analysis on Live Load Distribution Factors of Widened Hollow Core Slab Bridges." Materials Science Forum 953 (May 2019): 215–22. http://dx.doi.org/10.4028/www.scientific.net/msf.953.215.

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There are some studies on live load distribution factors(LLDF) of hollow core slab bridges which mainly consider the influence of connecting method and rigidity, while the effects of span length and skew angle have not been fully involved. Influenced by the trend of road and river, the hollow core slab bridges are often skewed with rivers. So it is essential to study the span length and skew angle effects in bridge widening. Based on a highway widening project, some representative hollow core slab bridges are selected for widening analysis. Theoretical method and finite element method are used to analysis the LLDF of slab bridges before and after widening. Finite element method(FEM) can give high precision in LLDF calculating. The influences of span length, connecting stiffness and skew angle are studied. The result indicates that no matter before or after widening the LLDF become smaller with the increase of span length. After widening, the LLDF of the half slabs near to the widening seam reduce obviously and with the span length increases the variation becomes more obviously. The connecting stiffness brings small influence to the LLDF in hollow core slab bridges. And with the increase of skew angle, the LLDF of the new side slab changes obviously, but the variation of LLDF of original slabs is not obviously according to skew angle.

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Journal articles on the topic 'The rigidity of bridges'

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