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Journal articles on the topic 'Cantilever bridges'
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1
Li, Xiao Ke, Jun Lian Yin, and Shi Ming Liu. "Static Analysis of Prestressed Concrete Cantilever Bridge." Applied Mechanics and Materials 438-439 (October 2013): 913–16. http://dx.doi.org/10.4028/www.scientific.net/amm.438-439.913.
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Due to geological conditions at abutment, working mechanism and economy, a prestressed concrete bridge with double cantilevers is designed. Main dimensions and drawings are introduced and static analytical results of prestressed concrete cantilever bridge are discussed. The numerical model was built by the integrated solution system for bridge and civil Engineering-MIDAS/Civil. The main loads which affect internal force and deflection at key sections of bridge are studied, such as mid-point, support point and free end of cantilever bridge. The rules which loads affect internal forces and deflections are revealed. The results show that dead weight is an important load to control internal force and deformation of bridge with double cantilevers. The design and numerical results would give some references to the optimization of similar bridges.
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Liu, Chun Lei, and Su Juan Dai. "The Best Position to Determine the Hinge in the Cantilever Bridge." Applied Mechanics and Materials 578-579 (July 2014): 814–17. http://dx.doi.org/10.4028/www.scientific.net/amm.578-579.814.
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The simple-supported beam bridge is a common structure form widely used in small and medium span bridges. When the span is longer, the maximum bending moment is accordingly bigger. The maximum positive and negative bending moment numerical of beam decreases obviously because of cantilever bridge with cantilever beams to reduce the amount of materials. This article analyzes the current commonly used cantilever bridge with large span. The two-span cantilever bridge is analyzed under various loads about the internal force according to the condition of the absolute value of the maximum positive and negative bending moment being equal. It carries on the contrast and analysis about simple-supported beam bridges and obtains the best location of the hinge in the cantilever bridge. Moreover, it provides some reference for the optimum design of similar bridges and projects.
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Rajeshirke, Shriket P., Prof Yogesh R. Suryawanshi, and Prof Dr Navnath V. Khadake. "Comparative Study of Balance Cantilever Bridge and Extradosed Bridge." International Journal for Research in Applied Science and Engineering Technology 10, no. 5 (May 31, 2022): 3365–75. http://dx.doi.org/10.22214/ijraset.2022.43126.
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Abstract: Now a days, in India Balance Cantilever bridges are widely used in hilly region were supporting from the bottom is difficult. The name Balance Cantilever Bridge is arrived due to the application of construction methodology which balances out the cantilever portion. It is one of the most effective methods of building bridges without the need of false work. Balanced cantilever bridges are used for special requirements like construction over traffic, short lead time compared to steel and use local labour and materials. Extradosed bridge is a unique idea bridge between Girder Bridge and cable-stayed bridge. A balanced cantilever bridge with construction stage analysis consideration a model is prepared in the Midas Civil software and analysed, we can see how it considers construction stage analysis with creep & shrinkage effect. The construction stage analysis in the Midas Civil considers shrinkage and creep during construction stages to simulate the construction process of a incremental stage. As most of the literature covers either balance cantilever bridge or extradosed bridge, this paper introduces and attempt to summaries comparative study of balance cantilever and extra dose bridge with its span arrangement, span by depth ratio, prestressing steel etc. Keywords: Construction stage, balance cantilever , extradosed, prestress
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Bukhari, Meisan Ali, Ola Hisham Fatani, Juman Alhusain Alrifai, Safa Wajdi Kabli, Manar Ali Alhomood, Mona Hassan Alnomani, Abdullah Musri Al Abu Saber, et al. "Advantages and disadvantages of cantilever bridges." International Journal Of Community Medicine And Public Health 9, no. 1 (December 27, 2021): 359. http://dx.doi.org/10.18203/2394-6040.ijcmph20214865.
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Utilizing cantilever bridges to perform fixed partial prostheses has been reported in the literature based on the increasing demands in this field to improve the outcomes and relieve extensive therapeutic approaches associated with complete oral rehabilitation. The current evidence indicates that cantilever bridges can effectively replace missing teeth with more favorable outcomes than removable partial dentures. However, evidence also shows that decreasing the number and size of cantilevered pontics and increasing abutment teeth are necessary to enhance the outcomes. Furthermore, if the occlusion is harmonious and stable, it has been demonstrated that cantilever bridges can be applied with the minimal periodontal ligament, which adds to its favorable outcomes. However, it should be noted that cantilever bridges are not applicable for all patients as it needs proper oral health status to be installed. Besides, it might also be associated with complications that may lead to failure. Therefore, further studies are still needed.
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Machelski, Czesław. "Concrete creep effects during bridge span construction using cantilever concreting technology." Roads and Bridges - Drogi i Mosty 18, no. 3 (October 1, 2009): 193–210. http://dx.doi.org/10.7409/rabdim.019.013.
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A characteristic feature of many long-span cantilever prestressed concrete bridges are excessive deflections of their spans due to the rheological processes in the concrete and in the prestressing steel. Such bridges are subject to monitoring during which geodetic surveys are usually conducted. The latter reveal changes in the deflection curves of the spans. In this paper span displacements resulting from concrete creep are analysed. A specific situation occurring when the span static scheme is changed from the cantilever (assembly stage) to continuous beam (exploitation stage) is considered. Assuming a regular three-span structure, a general solution to the problem is obtained for the following bridge parameters: dead load, span length, and the variable concrete creep index. The proposed algorithm is used in calculation examples in which different creep index distributions along the cantilevers are assumed. The results of the analyses are compared with the behaviour of a monitored existing bridge of this type. The analyses presented in this paper can be useful for the design of spans and the assessment of the safety of such bridges which are in service.
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WU, Min-jie, Xiao-jing WANG, Li-dong ZOU, Wei-hua XU, and Xiang-hao ZHANG. "Evaluation of the therapeutic efficiency of mandibular anterior implant-supported fixed bridges with cantilevers." Chinese Medical Journal 126, no. 24 (December 20, 2013): 4665–69. http://dx.doi.org/10.3760/cma.j.issn.0366-6999.20131291.
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Background Dental implant technology has developed rapidly in recent years. However, the use of implant-supported fixed bridges with cantilevers has been controversial. The purpose of this study was to evaluate the clinical results of the mandibular anterior implant-supported fixed bridges with a cantilever. Method Thirty-three patients (15 males, 18 females; mean age, 42.6 years; range 20-54 years) with two missing anterior mandibular teeth had single implant-supported fixed bridges with a cantilever. Clinical examination was recorded and radiographs were taken. The mean duration of follow-up was 30 months (15-44 months). Results All implants survived. Loosening or fracture of the prosthesis was not observed. All patients were satisfied with the treatment. The mean bone resorption values after 12, 24, and 36 months of implant loading were 0.94, 1.18 and 1.35 mm respectively. The changes of gingival papilla height ranged from 0 to 0.5 mm. There was significant difference between 1-year and 2 or 3 years restoration groups regarding the average gingival height changes (P <0.05). Conclusion After careful and precise selection of patients, restoration with a single implant-supported fixed bridge with a cantilever can be recommended if two anterior mandibular teeth are missing.
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Maryono and Eka Juliar. "METODE PLAKSANAAN PEKERJAAN SLAB PADA JEMBATAN CILUTUNG DI KEC. TOMO KAB. SUMEDANG." SEMINAR TEKNOLOGI MAJALENGKA (STIMA) 7 (September 27, 2023): 54–64. http://dx.doi.org/10.31949/stima.v7i0.882.
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Cilutung Bridge is one of the bridges located on Jalan Raya Tolengas, Tolengas, Tomo District, Sumedang Regency. Bridges have various types of bridges, namely girder bridges, arch bridges, truss bridges, suspension bridges. The bridge component is divided into two, namely the superstructure and the substructure. The structure of the bridge generally includes: sidewalks, vehicle floor slabs, girders, diaphragm beams, and platforms. The structure under the bridge generally includes: the base of the bridge (abutments), bridge pillars (piers) and foundations. The bridge slab is a horizontal structural element that functions to distribute dead and live loads to the vertical support frame of a structural system. The stages of implementing the bridge slab work are 1. Preparatory work, 2. Steel bridge deck installation, 3. Steel bridge deck grouting work, 4. Cantilever slab formwork assembly, 5. Slab and parapet reinforcement assembly, 6. Cantilever slab formwork installation, 7. Check completeness and measurement, 8. Bridge slab reinforcement installation, 9. Bridge parapet reinforcement installation, 10. Bridge slab formwork installation 11. Measurement, 12. Block out deck drain installation, 13. Bridge slab floor cleaning, 14. Inspection, 15. Bridge slab casting, 16. Slump and quality check, 17. Formwork demolition work, 18. Maintenance and tidiness.
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Pisarek, Bartosz, and Czesław Machelski. "Rheological Effects in the Bridges Constructed with Cantilever Method." Romanian Journal of Transport Infrastructure 9, no. 1 (July 1, 2020): 77–93. http://dx.doi.org/10.2478/rjti-2020-0005.
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Abstract A characteristic feature of bridges made using cantilever concreting technology is their excessive deflections, which are a result of rheological processes in concrete and prestressing steel. These deflections can be caused by the destruction of the material, e.g. concrete cracking, as well as the changing of the static scheme of the bridge structure, such as the subsidence of supports. The final result of a structure’s operation is changes in its grade line, which in this paper are considered as the deflection line of a bridge’s span. The purpose of the paper is to determine the participation of a structure’s rotation over supports in the deformation of the span with the largest length. The authors proposed an algorithm for determining the deflection function and rotation angles, which were obtained on the basis of changes in the curvature of the beam. It is characterised by an accurate mapping of the rheological processes that occur in the bridge, which is calculated on the basis of the changes of the grade line obtained from geodetic measurements on site. The paper proposes a general geometric indicator of the box cross-section cantilever, which is calculated for the construction phase, and a different indicator for the operation phase. They can be used for comparative analyses of various bridges. The analysis of deflections in cantilever bridges during the operation phase of their longest spans indicates that there is a significant influence of the angles of rotation over the supports. In the paper, such a group of bridges is qualified as unstable, in which the static scheme changes from a determinate cantilever state (the construction phase) into a multi-span system with different span lengths (the operation phase).
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Nguyen, Duy Tien, Xuan Tung Nguyen, and Van Minh Ngo. "Survey and analysis long term deflection of cantilever bridge in Vietnam." IOP Conference Series: Materials Science and Engineering 1258, no. 1 (October 1, 2022): 012063. http://dx.doi.org/10.1088/1757-899x/1258/1/012063.
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The deflection and camber of bridge, especially of the box girder bridge as well as their effected factors have been important research topics since the end of the last century. In Vietnam, the box girder bridge constructed by cantilever method had been introduced since the 1990s and become popular in the last twenty years. After more than two decades of exploitation, these bridges face various problems such as over deflection, cracks... To clarify the actual deflection of the cantilevered box girder bridge and the effected factors such as creep and shinkage, the survey of long-term deflection of such box girder bridge (Hung Ha bridge) has been carried out and compare with the numerical analysis. The results show the significant effect of creep and shinkage to the long-term deflection of the cantilevered box girder bridge.
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Petzek, Edward, Anamaria Butiscă, and Luiza Toma. "Eye Bars - Pins Connections." Advanced Materials Research 814 (September 2013): 222–29. http://dx.doi.org/10.4028/www.scientific.net/amr.814.222.
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This type of connections was used from the beginning of the steel constructions and is very efficient in some typical cases. Connections with eye bars and pins were used initially in suspension bridges, cantilever truss girders and other structures. In modern steel structures this type of connection is often used in cases when simple solutions are necessary like scaffoldings, mobile structures, emergency bridges, etc, or cases in which a certain rotation (pin connection) is desired like structures on cables, chimney, cable stayed bridges and bowstring bridges. At the end of the 19th century and the beginning of the 20th century, when the technology of foundation was not yet developed, engineers preferred the cantilever arrangement (known also as the Gerber system) to the continuous bridge, because it has favourable moments along its length and is not subjected to settlement stresses. It is important to mention that the cantilever truss girder is easier to analyse. However a cantilever arrangement requires special hinge connections and is less rigid than a continuous one. Some famous bridges have been built in this system. One of these structures of the past is the Traians bridge over the Mures in Arad, erected in 1910. The main cantilever truss has the following spans: L = 50,05 + 85,30 + 50,05 = 185,40 m. After two World Wars and other damages the bridge is still in operation for usual traffic - cars and tramways (with restrictions for trucks). The bridge is a historical monument of the engineering science and has a remarkable aesthetic aspect and an emblematical importance for the city of Arad. One of the aspects of the rehabilitation project is the analysis of the Gerber hinge which consists of lug plates and bolts in order to assure the movement of the suspended central part of the structure. These elements have to support the reaction force from all the loads on the bridge and they have a complex stress distribution. Due to the different events, the increasing of the traffic and traffic loads, the existence of cracks in these plates is possible and probable. The paper includes also the evaluation of the technical state of the bridge, stress evaluation based on 3D analysis, assessment of the remaining fatigue life.
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Ramesh, GC, BG Prasanna, K. Kesava Reddy, and TV Shree Harsha. "Clinical Evaluation of Conventional Cantilever and Resin Bonded Cantilever Fixed Partial Dentures: A Comparative Study." Journal of Contemporary Dental Practice 13, no. 6 (2012): 793–98. http://dx.doi.org/10.5005/jp-journals-10024-1231.
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ABSTRACT Introduction Ever since the introduction of the minimal preparation fixed partial dentures, the major concern of the clinicians has been its longevity. Aims and objective The objective of the present study was to compare the clinical performance of resin bonded cantilever bridges with conventional cantilever bridges for a period of 1 year and to evaluate the periodontal changes of abutment teeth using radio visio graphy. Materials and methods Fourteen patients with missing first or second premolar were selected for the study. The patients were divided into 2 groups, conventional cantilever group and resin bonded cantilever group. Results The results were analyzed using Student's t test and Mann-Whitney U test. The clinical success rate for both the groups was 100%. The amount of bone loss at 6 months for conventional group was 0.11 mm and for resin bonded bridge group was 0.10 mm. The amount of bone loss at 1 year for conventional cantilever group was 0.14 mm and for resin bonded fixed partial denture group was 0.16 mm. There was no statistical difference between both the groups. The results showed that the resin bonded cantilever bridges can be used for the treatment of missing posterior tooth. How to cite this article Prasanna BG, Reddy KK, Harsha TVS, Ramesh GC. Clinical Evaluation of Conventional Cantilever and Resin Bonded Cantilever Fixed Partial Dentures: A Comparative Study. J Contemp Dent Pract 2012;13(6):793-798.
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Li, Hongxu, Yong Huang, and Endong Guo. "Construction Stage Seismic Vulnerability Evaluation of a Continuous Girder Bridge with the Cast-in-Place Cantilever Construction Method." Advances in Civil Engineering 2021 (September 3, 2021): 1–14. http://dx.doi.org/10.1155/2021/9915947.
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To evaluate the vulnerability of bridges at various construction stages under the action of strong earthquakes, the incremental dynamic analysis (IDA) method is applied, and the vulnerabilities of a continuous girder case study bridge with the cast-in-place cantilever construction method, which owns five main construction stages, are evaluated and compared. The results show the following: With the increase in the peak ground acceleration (PGA), the vulnerabilities of bridges at different construction stages all increase. The fragility and vulnerability are mainly determined by the structural mechanical system condition and the mode shapes but not the modal frequency. For the working condition of seismic PGA of 0.4 g, (1) the bridge at the substructure construction stage may only experience slight or moderate damage with the exceedance probability of 8% to 5% and the mean loss ratio being only about 5%; (2) the vulnerabilities of bridges at the middle cantilever construction stage and the long cantilever construction stage are similar, the collapse damage exceedance probability is about 80%, and the mean loss ratio is about 65%; and (3) the vulnerabilities of bridges at the middle span closure construction stage and the bridge completion construction stage are nearly the same, the collapse damage exceedance probability is about 98%, and the mean loss ratio can reach 80%. The research results explore a new method for evaluating the vulnerability of bridges at different construction stages, which can provide suggestions for seismic damage defense and seismic insurance risk evaluation.
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Xie, Lan, Xuhui He, Yingxin Hu, Xiaojun Wei, and Lian Shen. "Wooden cantilever covered bridges in Anhua, China." BioResources 18, no. 2 (April 28, 2023): 4182–94. http://dx.doi.org/10.15376/biores.18.2.4182-4194.
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Wooden cantilever covered bridges are known for their marvelous shapes and manufacturing technique. Many wooden cantilever covered bridges were constructed during Ming and Qing Dynasties in Anhua province, China, due to the “Tea-Horse Trade” policy. The excellent performance of wooden materials and exquisite building techniques have kept these wooden bridges well-preserved and worthy of investigation. This paper conducted a comprehensive review of wooden cantilever covered bridges in Anhua, especially for the eight bridges listed as historical and cultural heritage protected at the provincial or the national level. The discussions covered the historical background of the bridges, their locations and dimensions, and the details of their structures including the cantilever systems, corridors, and roofs. Moreover, the cultural background was introduced to better understand the meaning of the decorations carved on the bridges and the logic of location selections.
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Peng, Long Fan, and Zhi Da Li. "Analysis on the Deflection of Cantilever Construction Based on Viscoelasticity." Advanced Materials Research 1030-1032 (September 2014): 1078–81. http://dx.doi.org/10.4028/www.scientific.net/amr.1030-1032.1078.
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The creep of concrete in the construction process of deformation influential, especially in the cantilever pouring construction, short age of concrete, creep effect more apparent. Meaning for cantilever construction of Bridges, creep analysis must be properly considered section at different time of loading values and the concrete ages of different segments. In this paper, based on the viscoelastic problem of cantilever construction of concrete creep analysis method, analyzes the deflection of cantilever construction process of a rigid-frame bridge, and compared with the actual measured value.
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Onsa, Eltayeb Hassan, Elsafi Mohamed Adam, Abdalla Khogali Ahmed, and Mohamed Elmontasir Elbagir. "Long-term Deflections in Balanced Cantilever Prestressed Concrete Bridges." FES Journal of Engineering Sciences 4, no. 1 (December 6, 2009): 22. http://dx.doi.org/10.52981/fjes.v4i1.41.
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Long-term deflections in balanced cantilever prestressed concrete bridges are reviewed. Burri and Shambat Bridges are taken as cases study to calculate long-term deflection. The two bridges were constructed at Khartoum State in the years 1972 and 1962, respectively. Due to the shortage of the basic data regarding the two bridges the AASHTO-LRFD is used to estimate and calculate the missing data in the two bridges. The Moment Area method is used to calculate the long-term deflections due to the dead load, live load and prestressing force. The calculated long-term deflections are compared with measured live load deflections obtained from load tests made by a Chinese contractor requested to evaluate the two bridges. Remarkable differences between theoretical and measured deflection at the end of cantilevers are encountered. The differences are probably due to the basic assumptions made in the formulations of deflection calculations. Some adjustments in the long-term deflection formulae are suggested to bring the calculated deflections in compatibility with measured ones.
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Narwani, Shweta, Naveen S. Yadav, Puja Hazari, Vrinda Saxena, Abdulrahman H. Alzahrani, Ahmed Alamoudi, Bassam Zidane, et al. "Comparison of Tensile Bond Strength of Fixed-Fixed Versus Cantilever Single- and Double-Abutted Resin-Bonded Bridges Dental Prosthesis." Materials 15, no. 16 (August 19, 2022): 5744. http://dx.doi.org/10.3390/ma15165744.
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Resin-bonded fixed dental prostheses (RBFDP) are minimally invasive alternatives to traditional full-coverage fixed partial dentures as they rely on resin cements for retention. This study compared and evaluated the tensile bond strength of three different resin-bonded bridge designs, namely, three-unit fixed-fixed, two-unit cantilever single abutment, and three-unit cantilever double-abutted resin-bonded bridge. Furthermore, the study attempted to compare the tensile bond strengths of the Maryland and Rochette types of resin-bonded bridges. Based on the inclusion and exclusion criteria, a total of seventy-five extracted maxillary incisors were collected and later were mounted on the acrylic blocks. Three distinct resin-bonded metal frameworks were designed: three-unit fixed-fixed (n = 30), two-unit cantilever single abutment (n = 30), and a three-unit cantilever double abutment (n = 30). The main groups were further divided into two subgroups based on the retainer design such as Rochette and Maryland. The different prosthesis designs were cemented to the prepared teeth. Later, abutment preparations were made on all specimens keeping the preparation as minimally invasive and esthetic oriented. Impression of the preparations were made using polyvinyl siloxane impression material, followed by pouring cast using die stone. A U-shaped handle of 1.5 mm diameter sprue wax with a 3 mm hole in between was attached to the occlusal surface of each pattern. The wax patterns were sprued and cast in a cobalt–chromium alloy. The castings were cleaned by sandblasting, followed by finishing and polishing. Lastly, based on the study group, specimens for Rochette bridge were perforated to provide mechanical retention between resin cement and metal, whereas the remaining 15 specimens were sandblasted on the palatal side to provide mechanical retention (Maryland bridge). In order to evaluate the tensile bond strength, the specimens were subjected to tensile forces on a universal testing machine with a uniform crosshead speed. The fixed-fixed partial prosthesis proved superior to both cantilever designs, whereas the single abutment cantilever design showed the lowest tensile bond strength. Maryland bridges uniformly showed higher bond strengths across all framework designs. Within the limitations of this study, the three-unit fixed-fixed design and Maryland bridges had greater bond strengths, implying that they may demonstrate lower clinical failure than cantilever designs and Rochette bridges.
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Abraham, Dulcy M., and Daniel W. Halpin. "Simulation of the construction of cable-stayed bridges." Canadian Journal of Civil Engineering 25, no. 3 (June 1, 1998): 490–99. http://dx.doi.org/10.1139/l97-109.
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Cable-stayed bridges are ideal for spanning natural barriers of wide rivers, deep valleys, or ravines, and for pedestrian bridges crossing wide interstate highways. Modern construction of cable-stayed bridges makes use of the segmental balanced cantilever techniques and involves many repetitive cycles of placing the concrete segments (both cast-in-place and precast) and supporting cables. It provides a fertile area for the application of computer simulation techniques for the planning and analysis of the process, particularly for studying the interaction of resources used in the construction phase and also for assessing the productivity of the construction processes. This paper employs MicroCYCLONE, a microcomputer-based simulation program, for the modeling and simulation of the construction of two cable-stayed bridges: the Dame Point Bridge in the state of Florida, U.S.A., and the Tsukuhara Bridge in Hyuougo, Japan. The paper will also provide a brief explanation of the suspended long traveler method used on the Tsukuhara Bridge, the simulation models developed to analyze the construction processes, and the results of sensitivity analyses.Key words: simulation, modeling, construction, cable-stayed bridges, resources, productivity, balanced cantilever construction.
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Cui, Feng Kun, Xu Chang Luo, and Feng Hui Dong. "Reliability Analysis of Pre-Stressed Concrete Continuous Girder Bridges Using Cantilever Construction on Different Codes." Applied Mechanics and Materials 744-746 (March 2015): 799–802. http://dx.doi.org/10.4028/www.scientific.net/amm.744-746.799.
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The object of this paper analyzes the reliability level of pre-stressed concrete continuous girder bridges designed with the Chinese codes including the code for design of highway reinforced concrete and pre-stressed concrete bridges and culverts of JTG D62-2004 and JTJ 023-85 using cantilever construction method. Typical cross-sections used in the example bridge are considered at service stage. Load and resistance parameters are treated as random variables. The statistical parameters are based on the available literature, test data and survey results. Reliability indices are calculated by iterations using the first-order second-moment method. The calculated results indicate that the reliability indices on the code of D62-2004 vary considerably to the code of JTJ 023-85. And it could provide the references for the reinforcement of old bridges and the design of new bridges using the cantilever construction.
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Miao, Shouju, Xiaojian Zhan, Yangbing Yuan, and Lijun Jia. "A Study of the Mechanical Properties of Polyester Fiber Concrete Continuous Rigid Frame Bridge during Construction." Buildings 13, no. 11 (November 14, 2023): 2849. http://dx.doi.org/10.3390/buildings13112849.
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This study investigates the mechanical performance of a polyester fiber concrete continuous rigid frame bridge during construction and the spatial stress distribution of the 0# block box girder, with a focus on the backdrop of the bridge in Pipa Zhou, Jiangxi Province. Stress monitoring at critical cross-sections during bridge construction was combined with FE simulations to analyze the stress and alignment deviation variations along the cantilevered construction process of the bridges. Subsequently, after validating the accuracy of the whole bridge model, the actual internal force of the box girder cross-section was extracted to act on the 0# block box girder solid model, and the spatial force of the 0# block box girder under the state of maximal cantilever and the completed bridge was further investigated. The results indicate that during cantilever construction, the top, and bottom plates of the box girder were subjected to compression, with the bottom plates having relatively low compression stress close to the critical values for compression and tension. Attention should be paid to controlling tensile stress application. After reaching a quarter of the bridge’s span in construction, the alignment deviation of the main beam increases, necessitating enhanced monitoring and adjustments of the main beam elevation. Furthermore, FE analysis shows that under maximum cantilever and the completed bridge states, the stress variations of the top and bottom plates of the 0# block box girder remain consistent, with the top plate stress varying by no more than 2.5 MPa and the bottom plate stress varying by approximately 1 MPa. Moreover, the 0# block box girder shrinkage cracks were mainly located in the bottom and web plate, and the number of cracks in the 0# block box girder with polyester fibers was reduced compared to the cracks in the ordinary concrete box girder.
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Zhang, Wei, Zong Lin Wang, and Fadhil Naser Ali. "Shear Stiffness of Segmental Joints in Cantilever Casting Concrete Bridges." Advanced Materials Research 250-253 (May 2011): 2460–67. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.2460.
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Joints between segments in cantilever casting concrete bridges require special attention in design and construction. These joints introduce discontinuity in the bridge; furthermore weaken the connection stiffness and strength of corresponding section, which may lead to excessive downwarping of bridge. Experiments were conducted to assess the shear stiffness of segmental joints section. The parameters studied included monolithic non-joints, joints roughened, joints roughened with shear-key. It was found that the shear stiffness of jointed section is largely lower than that of non-jointed section; however, the shear-key can effectively enhance the shear strength and especially shear stiffness of the joints section. Measures are proposed for shear-key design, and may provide a rational basis for the design of cantilever casting concrete bridges.
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Yuan, Ming, and Dong Huang Yan. "Optimization on Closure Scheme of Multi-Span Prestressed Concrete Box-Girder Bridge." Advanced Materials Research 163-167 (December 2010): 2369–75. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.2369.
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The stress state of finished bridge and service stage is influenced by various closure schemes in cantilever construction of multi-span prestressed concrete box-girder bridge. Two typical bridges—multi-span prestressed concrete continuous rigid frame bridge and girder bridge are investigated, The stress state in different closure schemes are analyzed using finite element(FE) analysis. Meanwhile, compared the healthy monitoring data, it has been found that taking the closure sequence from side span to middle span in cantilever construction of multi-span prestressed concrete box-girder bridge can lower stress of girder and pier in finished bridge stage, as well as reducing deformation of girder in service stage. Hence, the closure sequence from side span to middle span is more suitable for cantilever construction of multi-span prestressed concrete box-girder bridge.
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Liu, Jiang, Yongjian Liu, Lei Jiang, and Ning Zhang. "Long-term field test of temperature gradients on the composite girder of a long-span cable-stayed bridge." Advances in Structural Engineering 22, no. 13 (May 29, 2019): 2785–98. http://dx.doi.org/10.1177/1369433219851300.
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Bridges are inevitably affected by daily, seasonal and annual air temperature and solar radiation. The thermal effects on bridges, especially for long-span cable-stayed bridges with composite girders, are significant and complicated. The evaluation of temperature distribution has been a primary concern to bridge engineers and researchers. This article presents a more than one-year temperature database of a long-span cable-stayed bridge with a small cantilever length-to-web depth ratio in the composite girder. Uniform temperature, linear temperature difference, thermal curvature, and self-equilibrated thermal stress are considered to imply the characteristics of the temperature distribution in such composite girders. Two profiles (profile 1 and profile 2) for positive vertical temperature gradient and one profile (profile 3) for negative vertical temperature gradient are proposed. The extreme temperature differences with a 100-year return period are determined for each profile with extreme value analysis. Among the three profiles, profile 2 is unique for composite girders with a small cantilever length-to-web depth ratio. Based on parametric studies, profile 2 is revised with the cantilever length-to-web depth ratio for wide applications. Finally, comparisons of vertical temperature gradients are made between the investigated composite girder and the recommendations in Chinese Specification.
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Tang, Xian Yuan, Qiang Hu, and Yong He Yu. "Seismic Research of Continuous Rigid Frame Bridge under Cantilever Construction Method." Advanced Materials Research 368-373 (October 2011): 673–77. http://dx.doi.org/10.4028/www.scientific.net/amr.368-373.673.
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To research the effect of earthquakes of different magnitudes on continuous rigid frame bridge under cantilever construction method, combined with the newly promulgated seismic design rules of highway bridges in China, finite element model has been built by Midas software by using the response spectrum method and dynamic time history analysis method to analyze cantilever construction method of the various stages of seismic response analysis. The results indicate that the bending moments of root segments of cantilever beams and the bottom sections of piers change greatly. So it should be attached importance to in design.
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Che, Xiao Jun, and Xie Dong Zhang. "Stability Impact Analysis of Random Dead Load Distribution to T-Rigid Frame Bridge Swivel Construction." Applied Mechanics and Materials 361-363 (August 2013): 1348–52. http://dx.doi.org/10.4028/www.scientific.net/amm.361-363.1348.
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Due to limitations of construction conditions, the swivel construction method is the preferred even required program across the highway and railway bridges. The constant contained eccentricity of swivel bridge cantilever state has a great impact on the overturning stability of swivel process. Combined with the T configuration swivel bridge engineering instance, based on the basis of data collected loads, loads theoretical model, in line with the objective variation and the scientific process and selecting the representative value of the load was explored, the cantilever pouring weight corresponding probability distribution model was analyzed, and the impact to the stability of the bridge swivel construction process was studied. The analysis of data can ensure the bridge maximum cantilever state security, as well as to provide the basis for command and decision-making of the swivel stage.
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Theryo, Teddy S. "The Development of Extradosed Bridge Concept from a Vision to a Reality." Civil Engineering Dimension 23, no. 1 (April 20, 2021): 62–66. http://dx.doi.org/10.9744/ced.23.1.62-66.
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The development of Extradosed bridge from a vision to a real project is presented in this paper. Mathivat of France who is recognized as the inventor of this bridge type, envisioned a new bridge type suitable for medium span ranges in 1979. He suggested that some of the cantilever tendons in balanced cantilever bridge can be deviated to the top deck supported by short tower resemble stay cables. The structural benefit of this idea is increasing positive moment capacity by increasing eccentricity over the pier and enhanced shear capacity. Therefore, with the same conditions, longer span can be designed. Due to small angle of stay cables, the cable allowable stress at serviceability is about the same level with balanced cantilever bridge and no significant penalty on fatigue resistance unlike stay cables for conventional cable stayed bridges. The Extradosed bridge offers economic benefit for medium span range and aesthetically pleasing.
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Wu, Ding. "Analysis of Fatigue Fracture Accidents of Welded I-beam Bridges, Key Technology and Demolition Method in Australia." Journal of Engineering Research and Reports 25, no. 9 (September 25, 2023): 39–44. http://dx.doi.org/10.9734/jerr/2023/v25i9979.
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When Germany built Bendorf Bridge over the Rhine River, the cantilever pouring construction method was adopted, and the cantilever pouring method and cantilever assembly construction method were adopted. The continuous improvement, innovation and perfection of the method make this method widely used. At present, our country has made rapid progress in science and technology. New changes have been made in the prestressed design of concrete Bridges, as well as in the analysis and testing of structures, as well as in materials and processes. Great progress has been made in the design and construction of prestressed concrete Bridges.
In the construction of continuous steel Bridges, the width and weight of block 0 are changed with the size of the bridge span, for example, the higher the pier of the bridge built over the river valley, the more difficult the construction. When the two are put together, it will become the most important part of the construction, so the construction personnel should be extremely concerned about it. For the construction of No. 0 block, the following two construction processes are generally adopted, one is the support method. The second is the bracket method. Among them, the support method is divided into two kinds, respectively: full support and steel pipe pile support.
The bracket method involves a little more variety, the most important of which are: welded ox legs, embedded Beret pieces and counterthreading I beam method. In these construction methods, the I-beam method has been widely used, and its main advantages are that its bracket steel is tough, fast construction and wide range of application. Based on this, this paper studies the fatigue fracture accidents of welded I-beam Bridges in Australia for reference.
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Lambropoulos, Sergios, Georgios Konstantinidis, Christos Georganopoulos, Dimitrios Konstantinidis, and Fani Antoniou. "Multispan Balanced Cantilever Bridges: Egnatia Motorway." IABSE Symposium Report 88, no. 6 (January 1, 2004): 96–101. http://dx.doi.org/10.2749/222137804796291593.
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Zheng, Yu Guo, and Wan Cheng Yuan. "Study on Dynamic Characteristics of Long Span Continuous Bridge from Construction to Completion Constructed by Cantilever Method Based on Perspective of Earthquake Resistance." Advanced Materials Research 368-373 (October 2011): 988–92. http://dx.doi.org/10.4028/www.scientific.net/amr.368-373.988.
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Based on the perspective of earthquake resistance, the dynamic characteristics from construction to completion is analyzed and compared with each other for three typical long span continuous girder bridges with different types of piers constructed by balanced cantilever method, the vase-type solid pier, the thin-wall type hollow pier and the double-column type solid pier. The variation law of the dynamic characteristics along with the construction stages is obtained and the comparison law of the dynamic characteristics is obtained among the three bridges. It shows in a great degree that the seismic performance analysis and the seismic design nowadays, which are only based on the 1st period and mode in the completion state of the bridge, are not reasonable very much. The seismic performance analysis and the seismic design should consider all construction stages for the bridge constructed by the balanced cantilever method.
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Marzouk, Mohamed, Hisham Zein El-Dein, and Moheeb El-Said. "APPLICATION OF COMPUTER SIMULATION TO CONSTRUCTION OF INCREMENTAL LAUNCHING BRIDGES." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 13, no. 1 (March 31, 2007): 27–36. http://dx.doi.org/10.3846/13923730.2007.9636416.
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Construction of bridges is associated with uncertainties that rise due to unavailability of resources, equipment breakdown and/or working environment. Bridge construction techniques can be grouped into six main categories: 1) cast‐in‐situ on false work, 2) cantilever carriage, 3) stepping formwork, 4) launching girder, 5) pre‐cast balanced cantilever, and 6) incremental launching. The latter technique is characterised by minimising the use of falsework. Further, the fabrication and casting of bridge segments are executed at a stationary location, named casting yard (which includes several facilities), deck form, concrete mixing unit, and pumping system. This paper presents a special purpose simulation model to capture the uncertainty associated with bridge construction. The model accounts for the interaction between the different involved resources in construction of bridges using incremental launching technique. The paper describes two methods (single form and multiple forms) of execution used for the segments fabrication. The proposed simulation model utilises STROBOSCOPE as a simulation engine and is coded by Visual Basic 6.0. An actual case study is presented to illustrate the capabilities of the developed model and validate its performance.
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Kosim, Willy, and FX Supartono. "ANALISIS JEMBATAN BETON PRATEGANG BOX GIRDER DENGAN METODE BALANCED CANTILEVER." JMTS: Jurnal Mitra Teknik Sipil 3, no. 2 (May 17, 2020): 375. http://dx.doi.org/10.24912/jmts.v3i2.6947.
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Indonesia is a country that has a large population, causing severe traffic jam. Therefore, the bridge is an important part in Indonesia to overcome the traffic jam. The choice of method is very important in bridge construction ,so it does not interfere with the routines of the people. Bridges using the balanced cantilever method become the choice that is often used in bridge construction, because this construction method does not require direct contact with the ground. However, prestressed concrete bridge with this construction method requires more sophisticated technology and adequate work. The girder used is a box girder because the torque resistance is quite high and its self weight relatively lighter. Box girders in the balanced cantilever method can also be made to vary in height and become smaller at the end of the cantilever, therefore reducing the weight due to self weight. At this writing, stress analysis during the construction period and after construction is complete, the box girder prestressed concrete bridges using the balanced cantilever method will be carried out with the Midas Civil program in accordance with the loading standards in SNI 1725: 2016, ASTM in the use of materials, and CEB-FIP in determining creep and shrinkage.Indonesia merupakan negara yang memiliki jumlah penduduk yang banyak, sehingga menimbulkan kemacetan lalu lintas yang sangat parah. Oleh karena itu, jembatan merupakan bagian penting di Indonesia untuk mengatasi kemacetan tersebut. Pemilihan metode menjadi sangat penting dalam konstruksi jembatan agar tidak mengganggu rutinitas dari masyarakat. Jembatan dengan metode balanced cantilever menjadi pilihan yang sering digunakan dalam pembangunan jembatan, karena metode konstruksi ini tidak memerlukan kontak langsung dengan tanah. Namun, jembatan beton prategang dengan metode konstruksi ini memerlukan teknologi yang lebih canggih dan kemampuan kerja yang memadai. Gelagar yang digunakan adalah box girder karena ketahanan torsi yang cukup tinggi dan berat sendiri yang relatif lebih ringan. Box girder pada metode balanced cantilever juga dapat dibuat bervariasi tingginya dan mengecil pada ujung kantilever, sehingga mengurangi berat akibat diri sendiri. Pada penulisan ini, analisis tegangan selama masa konstruksi dan setelah konstruksi selesai, jembatan beton prategang box girder dengan metode balanced cantilever akan dilakukan dengan program Midas Civil sesuai dengan standar pembebanan pada SNI 1725 : 2016, astm dalam penggunaan material, dan CEB-FIP dalam menentukan creep dan shrinkage.
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Aravind Ramesh Gaikwad and Vaibhav Shelar. "Study on non-linear analysis of arch bridges subjected to ground motion." World Journal of Advanced Engineering Technology and Sciences 9, no. 1 (June 30, 2023): 211–19. http://dx.doi.org/10.30574/wjaets.2023.9.1.0161.
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Thanks to the cantilever launching technique, arch bridge building has once again become popular throughout the world. Today, these structures are one of the three main types of long-span bridges, along with suspension and cable-stayed bridges. Arch bridge structures have a complex behavior during powerful earthquakes because the arch rib is an element that is primarily susceptible to a large axial compression force brought on by dead loads. The nonlinear dynamic analysis of an arch bridge using STAAD Pro V8i software with earthquake loading is the subject of this research. Due to their easy load bearing qualities, arch bridges with short and medium spans are currently being constructed frequently for traffic bypass. Therefore, it is necessary to assess its stability in the event of a powerful earthquake. The STAAD-modeled arch bridge's nonlinear, time history analysis. The research in this study uses pro. For Time History analysis, data from the Bhuj Earthquake of 2001 is used, and the Rudramata Bridge, which collapsed during the Bhuj Earthquake, is researched. The primary focus of this study is on the analysis of the displacement, time-velocity, and time- acceleration responses of an arch bridge to lateral loads. And the results demonstrate that the displacement for the arch bridge is less than that for the Rudramata Bridge in all three directions.
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Mone, Bhargav, Prof P. S. Mote, and Prof Dr Navnath V. Khadake. "Comparative Study of Wide Deck Box Girder Bridge Superstructures." International Journal for Research in Applied Science and Engineering Technology 10, no. 5 (May 31, 2022): 3376–85. http://dx.doi.org/10.22214/ijraset.2022.43128.
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Abstract: Box Girder superstructures are most popular type amongst all other type bridge superstructures and are extensively used. Nowadays to provide better riding quality and in order to reduce number of substructures and foundations for more clear space underneath, long span continuous or integral type bridge superstructures are preferred. For longer span bridges to reduce dead load and to utilize material to its capacity cellular sections are the most efficient sections in this regard. Box girder is one of the cellular sections. In metropolitan cities one of the restrictions is the availability of land to widen the existing roads. Present trend is to use wide deck bridge superstructure to utilize surface level and elevated level space more efficiently. Bridge aesthetics are also important as bridges are located in metro cities, tourist’s places. In wide deck bridges, ribbed cantilever slab or cantilever with supporting struts are used to impart transverse stiffness while further reducing dead load of the superstructure deck. Three different types of box girder superstructures are studied to inspect their behaviour in longitudinal and in transverse direction. Analysis of three different types of box girder superstructures has been carried out using software CSI SAP2000 and analysis results are presented and compared. In this parametric study various parameters of mechanical behaviour such as deflection, shear lag, effects, bending stresses in transverse direction are compared. Keywords: Box girder, Cellular sections, mechanical behaviour, shear lag, Bridge aesthetics
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Sallam, Hanaa, Lamia Sayed Kheiralla, and Alzahra Aldawakly. "Microstrains Around Standard and Mini Implants Supporting Different Bridge Designs." Journal of Oral Implantology 38, no. 3 (June 1, 2012): 221–29. http://dx.doi.org/10.1563/aaid-joi-d-10-00020.
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The purpose of the study was to analyze microstrains around small- versus standard-diameter implants used in restoration of thin wiry ridge through different bridge designs. Additionally, influence of the site of occlusal vertical loading was evaluated using strain gauges. Two models simulating mandibular unilateral free-end saddle were fabricated. Two standard-size implants (3.75 × 13 mm) were inserted in one model in the position of the second premolar and first molar to support 2 3-unit cantilever bridges (NiCr alloy). On the other model, a standard implant and a mini implant (3.0 × 13 mm) were inserted in the position of the second premolar and second molar, respectively, to support 2 fixed-fixed 3-unit NiCr bridges. Four strain gauges were mounted buccally, lingually, mesially, and distally adjacent to each implant. The prostheses were temporarily cemented. A 300 N vertical load was applied on the middle of the horizontal runner bar connecting the prosthetic units and on the center of the pontics. Microstrains were recorded and analyzed. Cantilever bridges recorded higher microstrains than fixed-fixed bridges for both loading conditions. Yet, for both designs, loading on the horizontal runner bars, which apply an equal load on all bridge units simultaneously, resulted in significantly lower microstrain values than applying the load only on the pontics. Mini implant revealed greater strain values than standard implant supporting the same fixed partial denture. The best treatment option that produced the least microstrains was the fixed-fixed bridge with a mini implant as a terminal abutment. Mini implants induced higher microstrains than standard implants.
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Navrátil, Jaroslav, and Miloš Zich. "Long-term deflections of cantilever segmental bridges." Baltic Journal of Road and Bridge Engineering 8, no. 3 (September 13, 2013): 190–95. http://dx.doi.org/10.3846/bjrbe.2013.24.
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Petroski, Henry. "The Rise and Fall of Cantilever Bridges." American Scientist 106, no. 6 (2018): 336. http://dx.doi.org/10.1511/2018.106.6.336.
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Sobrino, Juan. "Cost -effectiveness of balanced cantilever girder bridges versus cable supported bridges." IABSE Symposium Report 101, no. 5 (September 1, 2013): 1–8. http://dx.doi.org/10.2749/222137813808627695.
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Márquez-Peñaranda, J. F., J. R. Pineda-Rodríguez, and J. P. Rojas-Suárez. "An application of physics: simply supported bridges made of post-tensioned concrete and structural steel beams." Journal of Physics: Conference Series 2153, no. 1 (January 1, 2022): 012004. http://dx.doi.org/10.1088/1742-6596/2153/1/012004.
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Abstract Bridges represent an important application of physics capable of solving real transportation problems. Knowledge of convenience of different mechanical solutions when analyzing and designing bridge is needed. For these reasons, this work is focused on the study of convenience of using two types of bridges. Simply supported short-medium span bridges (30 m to 45 m) are usually excessively long when choosing reinforced concrete solutions and usually short for other types of structures such as cable-stayed or cantilever bridges. The suitability of simply supported bridges leads to the need of studying their cost benefit ratios. This work studies the cost benefit ratio for post-tensioned concrete beams and structural steel girders in simply supported straight bridges. Eight models built of type I sections were used in both cases to analyze the bridges using a software based on the stiffness method. Span of each bridge was set to 30 m, 35 m, 40 m, and 45 m. The convenience of each type of bridge was done comparing the total and the cost per linear meter of each solution (post-tensioned and structural steel). Comparison was done using material consumption, labor, and construction processes costs only. Also, allowable vertical displacement given by current bridge design standards was verified.
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Artese, Serena, and Raffaele Zinno. "TLS for Dynamic Measurement of the Elastic Line of Bridges." Applied Sciences 10, no. 3 (February 10, 2020): 1182. http://dx.doi.org/10.3390/app10031182.
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The evaluation of the structural health of a bridge and the monitoring of its bearing capacity are performed by measuring different parameters. The most important ones are the displacements due to fixed or mobile loads, whose monitoring can be performed using several methods, both conventional and innovative. Terrestrial Laser Scanner (TLS) is effectively used to obtain the displacements of the decks for static loads, while for dynamic measurements, several punctual sensors are in general used. The proposed system uses a TLS, set as a line scanner and positioned under the bridge deck. The TLS acquires a vertical section of the intrados, or a line along a section to be monitored. The instantaneous deviations between the lines detected in dynamic conditions and the reference one acquired with the unloaded bridge, allow to extract the displacements and, consequently, the elastic curve. The synchronization of TLS acquisitions and load location, obtained from a Global Navigation Satellite System GNSS receiver or from a video, is an important feature of the method. Three tests were carried out on as many bridges. The first was performed during the maneuvers of a heavy truck traveling on a bridge characterized by a simply supported metal structure deck. The second concerned a prestressed concrete bridge with cantilever beams. The third concerned the pylon of a cantilever spar cable-stayed bridge during a load test. The results show high precision and confirm the usefulness of this method both for performing dynamic tests and for monitoring bridges.
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Won, Jeong-Hun, Kwang-Il Cho, Ji-Hyun Yoon, and Sang-Hyo Kim. "Innovative Key-Segment Closing Method Using Thermal Prestressing Technique for Partially Earth-Anchored Cable-Stayed Bridges." Advances in Structural Engineering 11, no. 5 (October 2008): 549–64. http://dx.doi.org/10.1260/136943308786412041.
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This paper proposes an innovative key-segment closing method for partially earth-anchored cable-stayed bridges erected using free cantilever construction method, and examines its feasibility by performing a construction sequence analysis. The proposed method is based on the thermal prestressing technique, which gives an artificial heat to the girder in a cantilever state, in order to introduce the closing force required for connecting the key-segment to the adjacent segment by means of thermal expansion. The new method not only provides a feasible closing method for partially earth-anchored cable-stayed bridges, but also has a significant effect in reducing the axial force in the girders. A construction sequence analysis of an example bridge shows that the axial forces in the girders and the uplift forces at the bearings are reduced by a considerable amount due to application of the thermal prestressing method, whereas the member forces of cables and pylons are slightly changed. Therefore, it is verified from this study that the structural capacities of the girders and the bearings of the partially earth-anchored cable-stayed bridges can be effectively enhanced by application of the proposed method.
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Boacă, Gh, and M. C. Scutaru. "Topographic Monitoring of the Operational Behaviour of the Longest Cantilever Viaduct in Romania." IOP Conference Series: Materials Science and Engineering 1304, no. 1 (March 1, 2024): 012022. http://dx.doi.org/10.1088/1757-899x/1304/1/012022.
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Abstract Over time, bridges have been built to fulfil different roles. With the development of industry came the need to build new transit routes linking industrial areas to cities or freight routes. The peak period of industrial development in Romania was in the 1960s, when a large number of bridges were built and put into operation. One of these bridges is the Sidex viaduct, located in Galaţi. The construction has a total length of 1,070 m, with 15 spans of different lengths (47.40 m + 13 * 75.00 m + 47.40 m). The resistance structure is made of 7 prestressed concrete frames linked together by joints located at the level of the cantilevers, the structure being the largest cantilever viaduct in operation in our country. The present article focuses on the presentation of the implementation of a special monitoring program of the viaduct’s in-service performance. For this purpose, special technologies have been used, such as topographic monitoring of the evolution of structural displacements at the most representative points of the structure, an implementation that we develop in detail.
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Wang, Lifeng, Hongwei Jiang, and Dongpo He. "The Application of the Grey Neural Network in the Deflection Control of PC Rigid Frame Continuous Box Girder Bridges." Open Civil Engineering Journal 8, no. 1 (December 31, 2014): 416–19. http://dx.doi.org/10.2174/1874149501408010416.
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Deflection control is the crucial procedure in construction control of cantilever prestressed concrete continuous girder bridge. This paper summarizes the advantages of Grey theory’s poor information processing and abilities of Neural Network’s self-learning and adaption, and the combinational algorithm of grey Neural Network is applied to the prestressed concrete bridge cantilever construction control process. Firstly, GM (1, 1) model and BP artificial Neural Network algorithm to predict the elevation of construction process are introduced respectively. In addition, the elevation prediction model of rigid-framed-continuous girder bridge is established. By practicing in the construction control project of LongHua Bridge, the method is testified to be feasible. The results indicate that, the combinational algorithm of Gray Neural Network to predict the construction elevation has higher reliability and accuracy which can be an effective tool of construction control for the same type bridges.
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Passfield, Robert W. "Philip Louis Pratley (1884-1958): bridge design engineer." Canadian Journal of Civil Engineering 34, no. 5 (May 1, 2007): 637–50. http://dx.doi.org/10.1139/l06-130.
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During his career as a consulting engineer, Philip Louis Pratley of Montréal, Quebec, was responsible for the design and erection of many of Canada's most outstanding long-span highway bridges. Among them are the Jacques Cartier Bridge (1930) at Montréal; the Île d'Orléans Bridge (1935) at Québec City, Quebec; the Lions' Gate Bridge (1938) at Vancouver, British Columbia; the Angus L. Macdonald Bridge (1955) at Halifax, Nova Scotia; and the Burlington Bay Skyway Bridge (1958) at Hamilton, Ontario. For over 40 years Pratley was at the forefront of his profession in Canada in designing and supervising the erection of bridge structures that embodied the latest state-of-the-art advances in design theory, construction technologies, and structural materials; his published technical writings conveyed the latest developments in bridge design and construction practice. Two of his structures; namely, the Jacques Cartier Bridge and the Lions' Gate Bridge, have attained a symbolic importance as national icons. The present article provides an overview of his outstanding career as a bridge design engineer. Key words: Philip Pratley, Monsarrat & Pratley, bridge design, suspension bridges, cantilever bridges.
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Vercher, Jose, Carlos Lerma, Marisol Vidal, and Enrique Gil. "Analysis of Energy Efficiency in Construction Solutions at the Façade-Slab Connection." Advanced Materials Research 787 (September 2013): 731–35. http://dx.doi.org/10.4028/www.scientific.net/amr.787.731.
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Façade-slab connection is the main thermal bridge of buildings. In this work, different options are analyzed according to the location of the thermal insulation. Heat loss is measured for each option. According to thermal analysis performed we conclude that cover the buildings façade completely without interruption at the slabs front is essential to avoid thermal bridges. The new option that interrupts the cantilever to put insulation on the entire façade is just effective to isolate the entire cantilever and is an easier constructive solution. This insulation continuity is needed to prevent ceiling condensation, since the energy saving is not important compared to windows thermal loss.
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Zhang, Yichi, Tianyi Zhang, and Yi Su. "Buffeting Characteristics of a Long-Span Cable-Stayed Bridge Crossing a Deep Canyon during Erection: Response Evaluation and Vibration Control." Buildings 14, no. 2 (January 23, 2024): 305. http://dx.doi.org/10.3390/buildings14020305.
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The stiffness of a long-span cable-stayed bridge under construction may be much lower than that observed in service, making it more susceptible to wind effects, especially for a bridge designed using high piers crossing a deep canyon. To study the buffeting characteristics of such cable-stayed bridges under construction, a long-span cable-stayed bridge (the main span is 575 m) is taken as the engineering background. In this study, the buffeting responses and vibration countermeasures at three different construction states were systematically studied using time-domain analysis. It was found that the buffeting response enlarges with an increase in the wind attack angle. The RMS values of the vertical buffeting of the bridge deck end are relatively greater at the maximum double cantilever construction state and maximum single cantilever state. At maximum double cantilever construction state, the traditional wind-resistant cable connecting the bridge deck end to the bridge pile cap significantly reduces the vertical buffeting response, while the suppression effect on lateral and torsional buffeting is limited. When the bridge deck nears completion, wind-resistant cables installed at both cantilever ending in the ‘soft connection’ method would effectively suppress the vertical, lateral, and torsional buffeting. The suppression effect of cross-arranged wind-resistant cables is superior to that of the parallel arrangement. It is recommended that a reasonable wind-resistant cable layout scheme according to different construction conditions is selected.
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Chraibi, Rime, Yasmine Hanine, Amine Cherkaoui, and Hicham Soualhi. "Ceramic cantilever bridge: A simplified clinical technique." Journal of Dental Specialities 10, no. 2 (September 15, 2022): 48–51. http://dx.doi.org/10.18231/j.jds.2022.013.
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The anterior single missing tooth is a challenge to the dental surgeon when it comes to functional, aesthetic and biological integration especially when in adolescents or young adults, where passive eruption of the tooth is still active and where implant placement must be postponed. As a temporary or a long-term treatment, a fixed prosthesis can be placed, but in the era of maximum tissue preservation, dental practice is moving towards a harmless and conservative prosthetic therapy “the cantilever bonded bridge”.The indication is limited to the replacement of central or lateral maxillary incisor and mandibular incisors and therefore requires following a precise and rigorous clinical protocol. This article will discuss a simplified clinical realization of the ceramic cantilever bridge.The use of cantilever bonded bridges (single retainer) seems to be an excellent alternative compared to other therapeutic solutions.
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Zhang, Zhe, Quansheng Sun, Chao Zhang, and Xiaoqian Li. "MONITORING AND ANALYSIS OF CANTILEVER JACKING OF HIGH SLOPE PRESTRESSED CONCRETE CONTINUOUS BOX GIRDER." Stavební obzor - Civil Engineering Journal 33, no. 3 (October 30, 2023): 426–42. http://dx.doi.org/10.14311/cej.2023.03.0032.
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Due to the rapid development of the transportation industry and economy, an increasing number of bridges have been unable to meet the demands of traffic. Demolishing and rebuilding bridges can lengthen the construction period, waste a lot of resources, and increase construction costs. Based on the lifting renovation project of the old Harbin Dongsan Ring Expressway viaduct, this paper combines finite element analysis and on-site testing to analyze the construction process. The bridge alignment, elevation, and deviations were monitored during the construction process, and a correction system was developed to address such issues. Structural analysis was conducted to evaluate the internal forces when uneven jacking occurred. The construction process described in this paper can effectively solve the jacking problems of urban continuous bridges with large tonnage, high slopes, and heights. The successful implementation of the jacking retrofitting project has verified the reliability of the measures taken.
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Cámara‐Molina, Javier C., Antonio Romero, Pedro Galvín, Emma Moliner, and María Dolores Martínez‐Rodrigo. "Optimisation of Cantilever Based Energy Harvester Design for Railway Bridges." ce/papers 6, no. 5 (September 2023): 399–406. http://dx.doi.org/10.1002/cepa.2070.
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AbstractIn this paper, the authors investigate energy harvesting on railway bridges. A tuning process based on a statistical analysis of the mechanical energy generated by a lumped‐mass model is presented and validated. A cantilever‐based energy harvester configuration is applied, and the optimal design of 3D printed energy harvesters is studied. The electromechanical behaviour of the device is represented by an analytical model for the estimation of the energy harvested from train‐induced bridge vibrations. A genetic algorithm constrained to geometry and structural integrity is used to solve the optimisation problem. The design flexibility and energy performance are maximised by 3D printing of the substructure of the harvester. An optimal device prototype with PAHT CF15 substructure is designed and manufactured for a real bridge in the Madrid‐Sevilla High‐Speed line. The prototype is experimentally validated under laboratory conditions. Finally, the performance of energy harvesting is evaluated from in situ experimental data measured by the authors. The results allow quantifying the energy harvested in a time window of five hours and twenty‐seven train passages.
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Zheng, Xilong, and Di Guan. "STUDY ON CONSTRUCTION MONITORING AND CONTROL OF MULTI-SPAN PRESTRESSED CONCRETE CONTINUOUS BEAM BRIDGE." Stavební obzor - Civil Engineering Journal 33, no. 1 (April 30, 2024): 65–77. http://dx.doi.org/10.14311/cej.2024.01.0005.
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This article focuses on the construction monitoring and control of a pre-stressed concrete continuous beam bridge, consisting of 13 spans. The goal is to ensure that the bridge structure meets the design requirements throughout the entire construction process. By comparing the theoretical and measured values of the bridge’s alignment and stress during the cantilever construction, closure, and completion phases, it can be observed that the deflection deformation of the bridge is generally in agreement with the theoretical calculations. After the completion of the entire bridge, the measured elevations of each section have an error range of -18mm to 20mm compared to the design elevations, which satisfies the specifications. A comparison analysis of the measured and theoretical stress values at the root and mid-span of the cantilever indicates that the stress difference at the root is within the range of -0.2MPa to 0.2MPa, and the stress differences at the mid-span after completion are 0.03MPa (upper) and 0.09MPa (lower), all of which meet the structural design and code requirements. By establishing a gray GM (1,1) model and using gray system theory, the deflection error during the construction process is predicted and controlled. The prediction accuracy of different methods is compared to determine a reasonable prediction method suitable for long-span pre-stressed continuous beam bridges, providing reference for similar engineering projects.
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Luo, Xu, and Lu Rong Cai. "Reasonable Elevation Calculation of Temporary Pier of Long-Span Steel Trussed Arch Bridges with Semi-Cantilever." Applied Mechanics and Materials 501-504 (January 2014): 1318–22. http://dx.doi.org/10.4028/www.scientific.net/amm.501-504.1318.
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When the scaffold construction method is applied on long-span steel trussed arch bridges, reasonable setting of the temporary pier elevation has significant influence on assembly linearis and safety assembly of long-span steel trussed arch bridges with semi-cantilever. In this paper, in accordance with the manufacturing linearis steel trussed beam bridge and steel truss beam linearis changing during building process, the calculation of temporary pier elevation was studied systematically, and practical function was deduced. Then, the method was applied to a long-span steel trussed arch bridge. The obtained result by in-situ assembly and dismantling presents that: 50 mm preserved method is considered in this paper, which can provide convenience for removing the temporary pier. At the same time, the rationality and reliability of the presented approach are verified. It also can provide reference for similar bridge construction.
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Suo, Wen Jia. "Deformation Analysis of Railway Continuous Curved Rigid Frame Bridges in Construction Control." Advanced Materials Research 953-954 (June 2014): 1418–21. http://dx.doi.org/10.4028/www.scientific.net/amr.953-954.1418.
Full textAbstract:
To study the effects of deformation on bridges, the finite element analysis method was used. The railway continuous curved rigid frame bridge has been taken into account. Both the deadweight, prestress, and creep of the concrete were used for comparative analysis about the effect on displacement and twisting angel, then some practical application conclusions were obtained. The maximum reaction values were produced in different sections under the extreme cantilever stage and the finished bridge stage. Futhermore, the study of structural spatial behaviors is of great importance.