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1
Chen, Jihao, Shun Bo Zhao e Ji Tao Yao. "The Connection Form of New-Built and Existing Bridge Effect on Transverse Distribution of Vehicle Load". Advanced Materials Research 250-253 (maggio 2011): 3008–11. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.3008.
Testo completoAbstract (sommario):
Connection the upper components and disconnection the other components is widely used in the expressway hollow slab bridge widening and reconstruction. How to design the transverse joint between newly-built and existing bridges is a key problem in the renovation of prestressed concrete bridges. In this paper, combined with a freeway widening project, 2 kinds of different connection forms were compared by their transverse distribution influence lines, which were calculated by finite element method. The results show that the new and old bridges are working together after widening, which makes vehicle loads of the slabs of the old bridge are reduced, especially the side slab of old bride which was next to the slab of newly-built bridge dropped by nearly 50%. So the bridge widening strengthens the safety of old bridge. And the weak connection of the bridge is always the connection of newly-built bridge and existing bridge, which is accorded with practical situation. So the particular attention should be given to the connection. It provides a basis for widening the old bridge and a reference for widening and maintenance the same kind of bridges.
2
Greenfield, Tina M., e Eugene S. Takle. "Bridge Frost Prediction by Heat and Mass Transfer Methods". Journal of Applied Meteorology and Climatology 45, n. 3 (1 marzo 2006): 517–25. http://dx.doi.org/10.1175/jam2356.1.
Testo completoAbstract (sommario):
Abstract Frost on roadways and bridges can present hazardous conditions to motorists, particularly when it occurs in patches or on bridges when adjacent roadways are clear of frost. To minimize materials costs, vehicle corrosion, and negative environmental impacts, frost-suppression chemicals should be applied only when, where, and in the appropriate amounts needed to maintain roadways in a safe condition for motorists. Accurate forecasts of frost onset times, frost intensity, and frost disappearance (e.g., melting or sublimation) are needed to help roadway maintenance personnel decide when, where, and how much frost-suppression chemical to use. A finite-difference algorithm (BridgeT) has been developed that simulates vertical heat transfer in a bridge based on evolving meteorological conditions at its top and bottom as supplied by a weather forecast model. BridgeT simulates bridge temperatures at numerous points within the bridge (including its upper and lower surface) at each time step of the weather forecast model and calculates volume per unit area (i.e., depth) of deposited, melted, or sublimed frost. This model produces forecasts of bridge surface temperature, frost depth, and bridge condition (i.e., dry, wet, icy/snowy). Bridge frost predictions and bridge surface temperature are compared with observed and measured values to assess BridgeT's skill in forecasting bridge frost and associated conditions.
3
Mohandas G.V e Sitansu k.Panda. "Hair pin bends of epicardial coronary arteries - a unique feature in multiple myocardial bridges". International Journal of Research in Pharmaceutical Sciences 10, n. 3 (26 luglio 2019): 2250–54. http://dx.doi.org/10.26452/ijrps.v10i3.1460.
Testo completoAbstract (sommario):
Myocardial bridge(MB) is an anatomical variant. Sometimes MB can cause compression over the coronary arteries and causes ischemic heart diseases.MB associated with bends of coronary arteries double the risk of coronary artery disease. So the present study aimed to find out the incidence of bends of the coronary artery along with the myocardial bridging. 100 heart specimens were obtained from routine dissection conducted for undergraduate students in the department of Anatomy IMS & SUM Hospital Bhubaneswar. After the simple dissecting procedure, epicardial coronary arteries, their branches and myocardial bridges and hairpin bends of coronary arteries were observed. Myocardial bridges present 41 (41%) over Left anterior descending artery(LAD) only.Among 41 hearts single myocardial bridge present in 37((90.25%) hearts, double myocardial bridge were present in 3((7.31%) hearts and triple myocardial bridges present in only one heart(2.44%). Hairpin bends of the coronary artery were present in double and triple myocardial bridged hearts only. No hairpin bends of the coronary artery was observed in the single myocardial bridge. Hair pin bends of the coronary arteries are the unique features of the myocardial bridges in multiple myocardial bridges, i.e. double and triple myocardial bridges. However, hairpin bends of coronary arteries were absent in single myocardial bridged hearts.
4
Tasnic, Mihail, e Ilia Catereniuc. "Some morphological aspects of myocardial bridges". Moldovan Medical Journal 64, n. 2 (maggio 2021): 58–64. http://dx.doi.org/10.52418/moldovan-med-j.64-2.21.11.
Testo completoAbstract (sommario):
Background: Myocardial bridges are variants of the intramyocardial position of the coronary arteries. In the specialty literature, hot topics in cardiovascular field are myocardial infarction and non-obstructive coronary artery disease with frequent connection with myocardial bridges. Material and methods: The morphological study was based on the analysis of 200 human hearts and fragments of coronary arteries. The retrospective study was focused on the analysis of 6168 coronary angiography reports, to identify patients with myocardial bridges, their preferred location, the degree of systolic stenosis, the association between myocardial bridges and proximal to bridge and under the bridge coronary atherosclerosis. Results: The complete myocardial bridges were described in 62% of the analyzed hearts and only in 5.3% of the total number of studied coronarographies. In the majority of cases, the complete myocardial bridges covered the anterior interventricular branch. The degree of subpontine arterial systolic stenosis varied within 10-95%. The comparative study did not determine any correlations between the degree of subpontine vascular compression and the degree of the left ventricular myocardial hypertrophy. In 32% of cases were described proximal to bridge atherosclerotic plaques and only in one case (0.5%) – distal to bridge atherosclerotic plaques, located immediately under the bridge. Conclusions: The research findings underline the differences in anatomical and angiographic incidence of myocardial bridges, and the inability of all bridges to reduce the lumen of under bridged artery. Current study emphasizes attention to the topography of bridges, the correlation with ventricular hypertrophy and coronary atherosclerosis.
5
Maryono e Eka Juliar. "METODE PLAKSANAAN PEKERJAAN SLAB PADA JEMBATAN CILUTUNG DI KEC. TOMO KAB. SUMEDANG". SEMINAR TEKNOLOGI MAJALENGKA (STIMA) 7 (27 settembre 2023): 54–64. http://dx.doi.org/10.31949/stima.v7i0.882.
Testo completoAbstract (sommario):
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.
6
Xiang, Zhong Fu, e Yong Zeng. "Chongqing Bridge and its Combination Bridge". Applied Mechanics and Materials 147 (dicembre 2011): 45–49. http://dx.doi.org/10.4028/www.scientific.net/amm.147.45.
Testo completoAbstract (sommario):
A brief introduction is given about the history and current situation of Chongqing Bridge. Several combination bridges are introduced in detail about structure characteristic and innovation: Chongqing Wushan Yangtze River Bridge--steel tube- concrete composite arch bridge; Twinning of Chongqing Yangtze River Bridge--steel-concrete composite rigid frame bridge; Chaotianmen Yangtze River Bridge --steel truss - arch composite bridge; Caiyuanba Yangtze River Bridge --Rigid Frame - Tied Arch Bridge.
7
Abdillah, Rifqi Aulia, Sholihin As’ad e Senot Sangadji. "Allocation Priority Determination System for Provincial Bridge Maintenance Fund in Special Region of Yogyakarta By Examining Physical Conditions, Operational Cost and Volume of Traffic". International Journal of Science and Applied Science: Conference Series 2, n. 1 (10 dicembre 2017): 300. http://dx.doi.org/10.20961/ijsascs.v2i1.16732.
Testo completoAbstract (sommario):
<p class="Abstract">The maintenance of bridges is relatively expensive. Those may lead the maintenance program into a classical problem which is limited of the fund. Therefore, the priority level of bridges maintenance is needed in order to attain an effective and efficient fund usage toward prevalent condition of every bridges in Special Region of Yogyakarta. The objective of this research was to provide the maintenance fund for provincial bridges in Special Region of Yogyakarta. The research covered 10 bridges in Special Region of Yogyakarta. The Assessments method for bridge physical condition was based on guide of Bridge Management System (BMS). As the bridge physical condition was known, the maintenance measure and its needed maintenance cost can be determined. The allocation of fund for each bridge was calculated based on Dynamic Programming Method. The result can be draw that by 5 million rupiah the maintenance fund for each of those 10 bridge of Yogyakarta Special Region is 5 million rupiah for Demak Ijo Bridge, 13 million rupiah for Bedingin Bridge, 10 million rupiah for Denggung Bridge, 5 million rupiah for Ngentak Bridge, 5 million rupiah for Karang Semut Bridge, 8 million rupiah for 2rd Kronggahan Bridge, 7 million rupiah for Besi Bridge, 8 million rupiah for Cebongan Bridge, 2 million rupiah for Kembang Songo Bridge, 2 million rupiah for 1st Kronggahan Bridge. Those allocation system provide 78,7% an average percentage on provincial bridges in Special Region of Yogyakarta. </p>
8
Sukenik, Shahar, Yoav Boyarski e Daniel Harries. "Effect of salt on the formation of salt-bridges in β-hairpin peptides". Chem. Commun. 50, n. 60 (2014): 8193–96. http://dx.doi.org/10.1039/c4cc03195d.
Testo completoAbstract (sommario):
The formation of salt-bridges in β-hairpin peptides is measured in increasing salt concentrations, indicating a decrease in the salt-bridged population due to charge–charge screening, as well as non-cooperative salt-bridge triads.
9
Yan, Bin, Wenfei Kuang, Rui Gan, Haoran Xie e Jie Huang. "Track–Bridge Interaction of CWR on Chinese Large-Span Bridge of High-Speed Railway". Applied Sciences 12, n. 18 (10 settembre 2022): 9100. http://dx.doi.org/10.3390/app12189100.
Testo completoAbstract (sommario):
The track–bridge interaction is a fundamental concern in the field of railway engineering, which plays an important role in the optimization design of railway bridges, especially for heavy-haul railway and high-speed railway bridges. This paper systematically introduces the research status of the CWR track–bridge interaction for large-span bridges of high-speed railway in China. The evolution process of the track–bridge interaction model from the simplest elastic bar and linear longitudinal resistance model to the complex beam–rail interaction model considering the loading history is described. In this paper, the modeling methods of the track–bridge interaction model for five types of long-span railway bridges, namely simply supported beam bridge, continuous beam bridge, cable-stayed bridge, arch bridge, and suspension bridge, are systematically introduced, and the characteristics of longitudinal force distribution under the track–bridge interaction are analyzed. This paper discusses the practical application of the theory of the track–bridge interaction on extra-large-span bridges from the aspects of system dynamic performance evaluation and system safety evaluation. The practical application of track–bridge interaction theory under special conditions such as earthquake load, complex temperature load, shrinkage and creep load, and superposition of multiple loads is emphasized. It provides guidance for the further improvement of the track–bridge interaction model and the design of large-span high-speed railway bridges in the future.
10
Marasabessy, Erwin. "IMPLEMENTATION OF BRIDGE MANAGEMENT SYSTEM ON INTERURBAN BRIDGE IN MALUKU PROVINCE". Journal of the Civil Engineering Forum 1, n. 2 (16 luglio 2017): 63. http://dx.doi.org/10.22146/jcef.23999.
Testo completoAbstract (sommario):
Bridges as transport infrastructures play a vital role in smoothing traffic flows. The success of a bridge in playing its role and serving its function depends on its management. The Directorate General of Highways of the Ministry of Public Work has used a system to manage bridges known as the Bridge Management System (BMS). The system allows a systematic plan and provides a uniform procedure for all bridge operation activities on the national and provincial level. Data from Implementation Agency of National Inter-Urban Roads of Area IX, Northern Maluku in 2011 indicates that the total length of national roads in Maluku Province is 15,238.01 M, with a total of 562 bridges. In Ambon Island, especially, there are 52 bridges totaling 1,176.25 m in length. The study was conducted at several inter-urban bridges in Maluku Province of Ambon Island: Wai Batu Merah, Wai Ruhu, Wai Lawa, Wai Yari and Wai Tua bridges. Assessment of bridge structure conditions was conducted visually to determine the conditions of the existing bridges comprehensively by referring to the Bridge Management System (BMS) complemented with a computer-based Bridge Management Information System (BMIS). Condition scores for the five bridges—Wai Batu Merah, Wai Ruhu, Wai Lawa, Wai Yari, and Wai Tua, according to Bridge Management System, are 2, 1, 2, 1, and 2 respectively. The scores of the five bridges indicate that their physical condition can be categorized as good or with minor defects. Based on technical screening, the proposed treatment for Wai Batu Merah, Wai Ruhu, Wai Lawa, dan Wai Tua bridges is the rehabilitation of their sub-elements. As for the Wai Yari Bridge, the treatment will be maintained regularly. The defect repair costs are IDR 149,138,238.00, IDR 81,048,000.00, IDR 174,579,106.10, IDR 79,233,324.01 and IDR 238,323,258.60 for Wai Batu, Wai Ruhu, Wai Lawa, Wai Yari, and Wai Tua Bridges, respectively.
11
Rath, Michael, Franz Untermarzoner e Johann Kollegger. "On the Torsional Behavior of the Longitudinal Bridge Girders Used in the LT-Bridge Construction Method". Applied Sciences 13, n. 11 (30 maggio 2023): 6657. http://dx.doi.org/10.3390/app13116657.
Testo completoAbstract (sommario):
A new bridge construction method, combining semi-precast elements and in situ concrete, has been developed at TU Wien, with the aim of decreasing erection time. In the course of construction using this new method, structural conditions arise that render a more detailed investigation necessary. By connecting a precast, thin-walled box girder to a bridge segment located on a pier by means of post-tensioning, a joint is created. By casting in situ concrete on the bottom and top slabs, the joint can be bridged with longitudinal reinforcement; however, the unreinforced vertical joints in the webs remain. This detail is a specific characteristic of the LT-bridge construction method and needs to be further investigated and assessed, as the question arises as to how this circumstance affects the torsional bearing behavior of the bridge superstructure. Torsion tests described in the literature consider ordinary box girders with longitudinal reinforcement or post-tensioned segmental bridges without longitudinal reinforcement at the joints. Therefore, the new reinforcement layout at the joints had to be investigated experimentally. Two large-scale thin-walled box girders—one without joints in the webs and the other with unreinforced joints in the webs—were tested, allowing for a direct comparison of conventionally manufactured bridges and those erected with the new bridge construction method. Furthermore, we investigated whether the results of common calculation methods corresponded to the experimental findings.
12
Liu, Jinqiang, Xichan Hu, Kehan Bao, Jin-Kwang Kim, Catherine Zhang, Songtao Jia e Feng Qiao. "The cooperative assembly of shelterin bridge provides a kinetic gateway that controls telomere length homeostasis". Nucleic Acids Research 49, n. 14 (13 luglio 2021): 8110–19. http://dx.doi.org/10.1093/nar/gkab550.
Testo completoAbstract (sommario):
Abstract Shelterin is a six-protein complex that coats chromosome ends to ensure their proper protection and maintenance. Similar to the human shelterin, fission yeast shelterin is composed of telomeric double- and single-stranded DNA-binding proteins, Taz1 and Pot1, respectively, bridged by Rap1, Poz1 and Tpz1. The assembly of the proteinaceous Tpz1-Poz1-Rap1 complex occurs cooperatively and disruption of this shelterin bridge leads to unregulated telomere elongation. However, how this biophysical property of bridge assembly is integrated into shelterin function is not known. Here, utilizing synthetic bridges with a range of binding properties, we find that synthetic shelterin bridge lacking cooperativity requires a linker pair that matches the native bridge in complex lifespan but has dramatically higher affinity. We find that cooperative assembly confers kinetic properties on the shelterin bridge allowing disassembly to function as a molecular timer, regulating the duration of the telomere open state, and consequently telomere lengthening to achieve a defined species-specific length range.
13
Zhao, Weixiang, Yanyan Zhao, Zhuojun Li e Bing Qin. "Knowledge-Bridged Causal Interaction Network for Causal Emotion Entailment". Proceedings of the AAAI Conference on Artificial Intelligence 37, n. 11 (26 giugno 2023): 14020–28. http://dx.doi.org/10.1609/aaai.v37i11.26641.
Testo completoAbstract (sommario):
Causal Emotion Entailment aims to identify causal utterances that are responsible for the target utterance with a non-neutral emotion in conversations. Previous works are limited in thorough understanding of the conversational context and accurate reasoning of the emotion cause. To this end, we propose Knowledge-Bridged Causal Interaction Network (KBCIN) with commonsense knowledge (CSK) leveraged as three bridges. Specifically, we construct a conversational graph for each conversation and leverage the event-centered CSK as the semantics-level bridge (S-bridge) to capture the deep inter-utterance dependencies in the conversational context via the CSK-Enhanced Graph Attention module. Moreover, social-interaction CSK serves as emotion-level bridge (E-bridge) and action-level bridge (A-bridge) to connect candidate utterances with the target one, which provides explicit causal clues for the Emotional Interaction module and Actional Interaction module to reason the target emotion. Experimental results show that our model achieves better performance over most baseline models. Our source code is publicly available at https://github.com/circle-hit/KBCIN.
14
Udaypuray, Naman. "ANALYSIS OF A PRECAST SEGMENTAL BRIDGE WITH RCC BRIDGE USING CSI BRIDGE SOFTWARE: A REVIEW". International Scientific Journal of Engineering and Management 03, n. 03 (23 marzo 2024): 1–9. http://dx.doi.org/10.55041/isjem01488.
Testo completoAbstract (sommario):
Bridges are those structures which built to span physical obstructions without closing the way underneath such as a water body, valley, or roads the purpose is to provide passage over obstructions. Precast bridges with segmental structure are commonly used for long span, due to researchers increasing interest in bridge modeling by using various span condition to check deflection of segmental bridge and RCC bridge, segmental bridge shows better results in comparison to RCC bridge, which is economical for longer spans, as the span increases then the most important factor dead load also increases. In This Paper We Are Conduction A Research On “Analysis Of A Precast Segmental Bridge With Rcc Bridge Using Csi Bridge Software”.
15
Hearn, George. "Use of Bridge Element Condition Reports to Measure Performance of Bridge Preservation". Transportation Research Record: Journal of the Transportation Research Board 2612, n. 1 (gennaio 2017): 141–51. http://dx.doi.org/10.3141/2612-16.
Testo completoAbstract (sommario):
A method to measure the performance of bridge preservation through the use of bridge–level element condition reports is demonstrated. The performance measure makes bridge-by-bridge evaluations of the relative conditions of elements that are major assemblies of bridges and elements that affect the exposure of major assemblies to deterioration. In an evaluation of performance, a bridge can be in a state of good preservation, at risk of deteriorating to poor condition, or already in poor condition. Bridge condition reports from 50 U.S. states are used in this evaluation of the performance of bridge preservation. The bridge element reports conform to the FHWA specification for bridge element reports and employ AASHTO national bridge elements and bridge management elements. Bridge preservation is good for 53% of National Highway System bridges by deck area. The performance of preservation is evaluated for major assemblies of bridges and for bridge construction materials in relation to coatings, wearing surfaces, and joints.
16
., Shantnu, e Dr Pankaj Singh. "Study on Cable Stayed Bridge and Its Application in India". SMART MOVES JOURNAL IJOSCIENCE 4, n. 8 (26 ottobre 2019): 22–24. http://dx.doi.org/10.24113/ijoscience.v4i8.284.
Testo completoAbstract (sommario):
Bridges are the structures built across any obstacles to connect its two end to allow free movement. Bridges have played a vital and key role in the development of human civilization since thousand of years. Existence of ram setu is an example of presence of bridge technology in ancient time. Bridges are often classified as arch bridge, suspension bridge, Girder Bridge, truss bridge and cable stayed bridge. Advancement in technology has led to development from arch bridge to cable stayed bridge. In present time cable stayed bridge technology are the most favorite and preferable type across the world. Cable stayed bridge construction methodology has various advantages over other types including important one like of being economical and aesthetical appearance. This paper is an attempt to analyze the cable stayed bridge and its various use in India.
17
Sigdel, Lila Dhar, Ahmed Al-Qarawi, Chin Jian Leo, Samanthika Liyanapathirana e Pan Hu. "Geotechnical Design Practices and Soil–Structure Interaction Effects of an Integral Bridge System: A Review". Applied Sciences 11, n. 15 (2 agosto 2021): 7131. http://dx.doi.org/10.3390/app11157131.
Testo completoAbstract (sommario):
Integral bridges are a class of bridges with integral or semi-integral abutments, designed without expansion joints in the bridge deck of the superstructure. The significance of an integral bridge design is that it avoids durability and recurring maintenance issues with bridge joints, and maybe bearings, which are prevalent in traditional bridges. Integral bridges are less costly to construct. They require less maintenance and therefore cause less traffic disruptions that incur socio-economic costs. As a consequence, integral bridges are becoming the first choice of bridge design for short-to-medium length bridges in many countries, including the UK, USA, Europe, Australia, New Zealand and many other Asian countries. However, integral bridge designs are not without challenges: issues that concern concrete creep, shrinkage, temperature effects, bridge skew, structural constraints, as well as soil–structure interactions are amplified in integral bridges. The increased cyclic soil–structure interactions between the bridge structure and soil will lead to adverse soil ratcheting and settlement bump at the bridge approach. If movements from bridge superstructures were also transferred to pile-supported substructures, there is a risk that the pile–soil interactions may lead to pile fatigue failure. These issues complicate the geotechnical aspects of integral bridges. The aim of this paper is to present a comprehensive review of current geotechnical design practices and the amelioration of soil–structure interactions of integral bridges.
18
Li, Xiaofei, Qinghang Meng, Mengpu Wei, Heming Sun, Tian Zhang e Rongrong Su. "Identification of Underwater Structural Bridge Damage and BIM-Based Bridge Damage Management". Applied Sciences 13, n. 3 (19 gennaio 2023): 1348. http://dx.doi.org/10.3390/app13031348.
Testo completoAbstract (sommario):
The number of bridges in operation has increased. Along with the increase in the length of time bridges are in service, the structural safety of the bridges also decreases. Bridge substructure is a key component of bridges, but there are few studies on safety management and identification of water bridge substructure damage. Deep learning is a focus of research in the field of target detection, and this document lightens YOLO-v4 to achieve precise and intelligent determination of concrete cracks. This was combined with a point cloud algorithm to provide a three-dimensional estimate of faulty lesions. Finally, the BIM was combined with the method of identifying the underwater structure of the deck. Based on Revit, an integrated management system for underwater bridge structures is put in place. Performing detailed bridge damage management includes (1) 3D visualization of the bridge detail model view, (2) establishment of a bridge damage database, (3) bridge damage management, and (4) management of the comprehensive underwater bridge inspection cycle.
19
Huang, Rong Yau, e Ping Fu Chen. "The Influential Factors and Association Rules for Bridge Deck Deterioration - Case Study of National Bridge Inventory Data". Applied Mechanics and Materials 94-96 (settembre 2011): 2276–79. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.2276.
Testo completoAbstract (sommario):
Bridge is the hub of a road, playing an important role in transportation. With the age of bridges increasing in recent years, the condition of bridges is deteriorating. Bridge deterioration usually results from multiple factors. Studies in exploring the factors leading to bridge deterioration and its state estimation are booming. However, studies in the relationship between bridge deterioration and external environment by using database are still limited. Since 1992, National Bridge Inventory (NBI) has collected basic and historical information of bridges in every state, a very rich database which should include some valuable knowledge. Hence, through clustering and classifying in data mining, this study explores association rules for bridge deterioration, which is displayed in decision tree with clear routes for reference. Using association rules developed by thus study, bridge maintenance personnel can understand the future state of the bridge under their jurisdiction, respond to risks and costs of bridge deterioration, extend the service life of bridges, and protect the safety of road users.
20
Zhu, Zewen, Kuai Ye, Xinhua Yu, Zefang Lin, Gangzong Xu, Zhenyou Guo, Shoushan Lu, Biao Nie e Huapeng Chen. "State-Based Technical Condition Assessment and Prediction of Concrete Box Girder Bridges". Buildings 14, n. 2 (18 febbraio 2024): 543. http://dx.doi.org/10.3390/buildings14020543.
Testo completoAbstract (sommario):
The technical condition of bridges has become a crucial issue for organizing the maintenance and repairs in bridge management systems. It is of great practical engineering significance to construct an effective model for predicting the technical condition degradation of the bridge through the use of the historical inspection data. Based on the semi-Markov random process, this paper proposes a useful deterioration prediction model for bridges in the highway network. From the historical inspection data of the prefabricated concrete box girder bridges, the degradation curves of technical condition rating are obtained. The effect of bridge length on degradation rate of the prefabricated concrete box girder bridges is analyzed. According to the Weibull distribution parameters of different condition grades, the technical state degradation models for a bridge group and an individual bridge are proposed to predict the performance of the overall bridge and superstructure of the bridge. The results show that with the increase in bridge length, the degradation rate of bridge technical condition increases. The degradation rate of the technical condition of the superstructure is faster than that of the overall bridge. The proposed semi-Markov stochastic degradation model for the bridge group can not only predict the different condition ratings of the bridges at any time, but also predict the future deterioration trend of an individual bridge under any ratings.
21
Radnić, Jure, Domagoj Matešan e Ivan Banović. "Bridges with multiple structural systems: The example of Trilj Bridge reconstruction in Croatia". Bridge Structures 17, n. 1-2 (11 giugno 2021): 65–75. http://dx.doi.org/10.3233/brs-210185.
Testo completoAbstract (sommario):
Development of multiple structural systems for bridges is useful in the design of new bridges and rehabilitation of existing bridges. This paper briefly presents some existing bridges with multiple structural systems and succinctly discusses design ideas for bridges with such systems. As an example of a bridge with multiple structural systems, the paper presents the reconstruction of a pedestrian suspension bridge in the City of Trilj, Croatia. The new bridge’s load-bearing structure is composed of several structural systems. Namely, the reconstructed bridge is a combination of suspension, cable-stayed and stress-ribbon bridge, which is laterally restrained with horizontal tensioned ropes. Numerical analysis was conducted on the renovated bridge. The results have shown an acceptable levels of stresses and deflections verifying the structural safety of the restored bridge. It is believed that this example of the bridge renovation may be useful in the design of new and strengthening of existing similar bridges.
22
Köken, Ali, e Ahmed Ali Abdulqader Farhad. "Investigation of the Effect of the Deck Material on the Cost in Cable-Stayed Bridges with Different Spans". Romanian Journal of Transport Infrastructure 10, n. 1 (1 luglio 2021): 11–33. http://dx.doi.org/10.2478/rjti-2021-0002.
Testo completoAbstract (sommario):
Abstract Recent developments in the social sphere also cause an increase in transportation activities. Increased transport activities lead to the construction of new roads and bridges. Different bridge construction systems are available to overcome large span obstacles. Cable-stayed bridges are more advantageous construction systems than other bridge type building carrier systems in overcoming large spans through suspension cables. Therefore, it is also widely preferred by designers. The biggest factor in the development of cable-stayed bridges is undoubtedly steel cables. Cable-stayed bridges are bridge structures that become lighter with the increase of the span, which has a more expanded flexibility, and that includes a cable system with the effect of nonlinear factors. Costs of cable-stayed bridges vary according to different spans. The span as well as the deck material used in the bridge system have a great effect on the cost. In cable-stayed bridge systems, decks are constructed of reinforced concrete and steel. The costs of cable-stayed bridges are widely discussed around the world; therefore, the effect of the span and deck material on the cost of cable-stayed bridges is being investigated. The main bearing elements of such bridges are cables, decks, and towers, and among these elements, the tower bridge carries all the weight of the bridge, even other external loads such as vehicle, wind, etc. In this study, the three-dimensional model of the cable, deck and tower elements that make up the cable-stayed bridge system was created and analysed using the CSI Bridge Program. The AASHTO LRFD Standards, which are widely used in the analysis of bridge systems with the CSI Bridge program and the design of bridge systems in the world, were used. In the study, the analysis and designs of cable-stayed bridges with reinforced concrete and steel deck at 250, 500, 750, 1000, 1500, 2000 meters span were carried out. The amount of materials and costs used in the analysis and design of the cable-stayed bridge systems were obtained and the results were interpreted.
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Rajeshirke, Shriket P., Prof Yogesh R. Suryawanshi e 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, n. 5 (31 maggio 2022): 3365–75. http://dx.doi.org/10.22214/ijraset.2022.43126.
Testo completoAbstract (sommario):
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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Wang, Xiao Chun, Ben Ning Qu, Jiao Long Peng e Meng Xi Geng. "Dynamic Characteristics Simulation and Analysis for the Stable Type Suspension Bridge". Applied Mechanics and Materials 444-445 (ottobre 2013): 173–77. http://dx.doi.org/10.4028/www.scientific.net/amm.444-445.173.
Testo completoAbstract (sommario):
Under the background of a stable type suspension bridge (A suspension bridge with a inverse-tensional system), the effect of inverse-tensional system for suspension bridge is studied. Using finite element method, three-dimensional finite element model of stable type suspension bridge and a common suspension bridge is established by fish bone model consisting of beam elements respectively. The finite element characteristic equation of two bridges is solved with Block Lanczos method respectively. 20 order eigenpairs of two kind of suspension bridges are obtained. The inherent characteristics of the two type bridges are analyzed comparatively. The results showed that due to the effect of inverse-tensional structures, the overall stiffness of the stable suspension bridge is better than common suspension bridge obviously, which can effectively suppress the torsional vibration of the suspension bridge.
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Russo, Francesco M., Terry J. Wipf e F. Wayne Klaiber. "Cost-Effective Structures for Off-System Bridges". Transportation Research Record: Journal of the Transportation Research Board 1819, n. 1 (gennaio 2003): 397–404. http://dx.doi.org/10.3141/1819b-50.
Testo completoAbstract (sommario):
Nearly half of the 587,000 bridges in excess of 6.1 m (20 ft) long on public roads in the United States are located off the Federal Aid System, are on local rural and urban roads or rural minor collectors, and are classified as off-system bridges. Approximately one-third of the off-system bridges are structurally deficient or functionally obsolete. The majority of states with large bridge populations are rural states with large percentages of structures owned by counties and other local agencies. Many of these bridges are on low-volume roads. Given the size of the deficient bridge population and the concentration of these bridges largely on locally owned networks, a recent NCHRP synthesis (NCHRP 32-08, Cost Effective Structures for Off-System Bridges) has explored the current practices regarding the maintenance, rehabilitation, and replacement of off-system bridges. The administrative aspects of off-system bridge ownership and management were explored, including sources and problems of funding, bridge asset management, design policies for off-system bridges, exploration of the environmental process, and discussions of interagency partnering and coordination problems. A significant body of work exists on effective bridge maintenance and rehabilitation. A significant discussion of bridge strengthening, including specific techniques used on low-volume-road bridges, was also examined. Concerning bridge replacements, the literature and owner survey were used to provide information on successful concepts currently being used. In addition to successful bridge replacement options, discussion of the use of standard plans, design aids, and software is promoted as leading to standard and efficient low-volume-road bridge replacements.
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Alamsyah, Danny Ferdian, M. Ikhsan Setiawan e Sapto Budi Wasono. "Bridge Condition Analysis To Determine Handling Priorities With The Bridge Management System (BMS) Method". ADRI International Journal of Civil Engineering 6, n. 2 (31 agosto 2021): 56–62. http://dx.doi.org/10.29138/aijce.v6i2.43.
Testo completoAbstract (sommario):
To maintain the importance of the role of bridges in supporting the economy, it is necessary to have a bridge management system so that efforts are made to maintain the condition of the bridge so that it always functions properly. One of the bridge management systems developed by the Directorate General of Highways in 1993 is the Bridge Management System (BMS). The method used in assessing the damaged condition of this bridge is the Bridge Management System (BMS) and refers to the Bridge Inventory Inspection Guidelines (Pd. T-21-2005-B) issued by the Ministry of Public Works. The bridge that will be analyzed this time there is 4 types of bridge types, namely bridges with a plate top structure, concrete girders, steel girders, and box culvert with a length of each bridge that is 2-17 meters, a width of 5-10 meters, and a total span of 1 -2 pieces. Based on the priority scale from the author, the condition values of 4 bridges using the Bridge Management System (BMS) method are Sengon Bridge A = 2 (damages that require monitoring/maintenance in the future), Dayu Bridge = 2 (damages that require monitoring/maintenance in the future), Sekaru Bridge 9 = 1 (minor damage), and Duiker Sembung 2 = 0 (new bridge and no damage).
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Ellobody, Ehab. "Finite element modelling and design of composite bridges with profiled steel sheeting". Advances in Structural Engineering 20, n. 9 (1 dicembre 2016): 1406–30. http://dx.doi.org/10.1177/1369433216678865.
Testo completoAbstract (sommario):
This article discusses the non-linear analysis and design of highway composite bridges with profiled steel sheeting. A three-dimensional finite element model has been developed for the composite bridges, which accounted for the bridge geometries, material non-linearities of the bridge components, bridge boundary conditions, shear connection, interactions among bridge components and bridge bracing systems. The simply supported composite bridge has a span of 48 m, a width of 13 m and a depth of 2.3 m. The bridge components were designed following the European code for steel–concrete composite bridges. The live load acting on the bridge was load model 1, which represents the static and dynamic effects of vertical loading due to normal road traffic as specified in the European code. The finite element model of the composite bridge was developed depending on additional finite element models, developed by the author, and validated against tests reported in the literature on full-scale composite bridges and composite bridge components. The tests had different geometries, different boundary conditions, different loading conditions and different failure modes. Failure loads, load–mid-span deflection relationships, load–end slip relationships, failure modes, stress contours of the composite bridge as well as of the modelled tests were predicted from the finite element analysis and compared well against test results. The comparison with test results has shown that the finite element models can be effectively used to provide more accurate analyses and better understanding for the behaviour and design of composite bridges with profiled steel sheeting. A parametric study was conducted on the composite bridge highlighting the effects of the change in structural steel strength and concrete strength on the behaviour and design of the composite bridge. This study has shown that the design rules specified in the European code are accurate and conservative for the design of highway steel–concrete composite bridges.
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Nezhad, Mehdi Dezfuli, Reza Raoufi e Ahmad Dalvand. "A Network-Based Importance Measurement Index for Bridge Security Risk Assessment and Prioritisation". Baltic Journal of Road and Bridge Engineering 17, n. 1 (28 marzo 2022): 1–30. http://dx.doi.org/10.7250/bjrbe.2022-17.549.
Testo completoAbstract (sommario):
In the related literature, conventional approaches to assessing security risk and prioritising bridges have focused on unique characteristics. Although the unique characteristics appropriately reflect the economic and social consequences of failure, they neglect the consequences of a bridge failure at the network level. If network owners and operators prioritise bridges solely based on their unique characteristics, bridges with low object-level importance and high network-level importance have very low chances to get priority. In this paper, a bridge importance measurement index α(e) has been presented, prioritising bridges based on their unique characteristics, location and network topology. To describe how to use this index α(e), three numerical examples were provided. While the first example was related to a simple hypothetical network, the second and third examples were real networks related to the bridges of Wroclaw city. Using these examples, the results of bridge prioritisation obtained in the unique-characteristics-only state were compared to the state in which α(e) had been used. Results showed that considering the location of the bridge and the topological characteristics of the network change the bridges prioritisation. For instance, in the second example, it was observed that the use of the α(e), made bridge Bolesława Krzywoustego the essential bridge, while bridge Grunwaldzki was the essential bridge under the previous prioritisation made by researchers. However, the results of the third example showed that bridge Milenijny, which was considered the essential network bridge as stated in the previous prioritisation made by researchers, was again selected as the most critical bridge based on the α(e).
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Cao, Hengtao, Yao Lu e Daihai Chen. "Analysis of Vehicle-Bridge Coupling Vibration Characteristics of Curved Girder Bridges". Applied Sciences 14, n. 5 (29 febbraio 2024): 2021. http://dx.doi.org/10.3390/app14052021.
Testo completoAbstract (sommario):
When vehicles move on a bridge, the coupling effect between vehicles and bridges can affect driving safety and comfort, especially for curved bridges, therefore, choosing reasonable design parameters for curved bridges is crucial. In this article, a three-span curved continuous box-girder bridge was taken as the research object; the entire process of vehicle-bridge coupling vibration of highway curved girder bridges was conducted via numerical simulation and the vehicle-bridge coupling vibration analysis program Cmck 1.0 was developed. Then, the influence factors such as curvature radius, constraint mode, and vehicle characteristics on the vehicle-bridge coupling vibration of curved girder bridges were explored. The results showed that as the curvature radius increased, the dynamic response of the bridge offered a gradually decreasing trend and compared to the vertical dynamic response, the torsional response was more sensitive to the influence of the curvature radius. Different constraint methods significantly impacted the dynamic response of bridges, and the vertical and torsional dynamic responses of bridges under general constraint arrangement of straight bridges were increased compared to those under boundary conditions for curved beam bridges. As the axle load of the car decreases, the bridge mid-span vertical and torsional dynamic responses showed a decreasing trend. In contrast, the lateral dynamic response gradually increased.
30
Qin, Sifeng. "Recent hydraulic bridge failures in China: review and discussion". Revista de la construcción 21, n. 2 (2022): 193–203. http://dx.doi.org/10.7764/rdlc.21.2.193.
Testo completoAbstract (sommario):
This paper studies 123 hydraulic bridge failures in China from 1998 to 2018. The geographic distribution, age distribution, bridge type distribution, time distribution and the hydraulic bridge failure causes are analyzed. Six typical failure cases of hydraulic bridges are analyzed in detail. 100 hydraulic bridge failures occurred in southern China so hydraulic bridge failures are much more common in this area. The average service life of these bridges is 28.9 years. The beam bridge accounts for the largest proportion of hydraulic bridge failure because 71 (57.7%) beam bridges were destroyed by flood. Hydraulic bridge failure mainly occurred between 2009 and 2014, which was related to the impact of the Wenchuan earthquake. The incidents major causes include unexpected flood, earthquake, old bridge, over sand exploitation, low awareness of hydraulic bridge damage, extreme morphology of the river, etc. There are both natural factors and man-made factors. These results show that three aspects should be paid attention to: (1) unexpected flood; (2) appropriate bridge type; and (3) extreme morphology of the river.
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Passfield, Robert W. "Philip Louis Pratley (1884-1958): bridge design engineer". Canadian Journal of Civil Engineering 34, n. 5 (1 maggio 2007): 637–50. http://dx.doi.org/10.1139/l06-130.
Testo completoAbstract (sommario):
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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Zhang, Tian, Haonan Chen, Xinjia Cui, Pengfei Li e Yunfeng Zou. "Condition Rating Prediction for Highway Bridge Based on Elman Neural Networks and Markov Chains". Applied Sciences 14, n. 4 (9 febbraio 2024): 1444. http://dx.doi.org/10.3390/app14041444.
Testo completoAbstract (sommario):
Bridges are a critical component of transportation infrastructure, playing a vital role in connectivity. The safe operation of bridges demands significant resource and capital investment, particularly as the operation phase is the most extended period in a bridge’s life cycle. Therefore, the efficient allocation of resources and funds is crucial for the maintenance and repair of bridges. This study addresses the need to predict changes in bridge condition over time. The commonly used state-based Markov chain method for bridge condition rating prediction is straightforward but limited by its assumptions of homogeneity and memorylessness. To improve upon this, we propose a novel method that integrates an Elman neural network with a Markov chain to predict the bridge condition rating. Initially, the ReliefF algorithm conducts a sensitivity analysis on bridge features to obtain the importance ranking of these features that affect the bridge condition. Next, six significant features are selected for data classification: bridge age, average daily truck traffic volume, material type, skew angle between bridges and roads, bridge deck structure type, and bridge type. The Elman neural network is then trained to train a prediction model for bridge condition ratings using the classified data, which can predict the condition levels of bridges. The Markov chain’s transition probability matrix is derived using a genetic algorithm to match the deterioration curve predicted by the Elman neural network. This proposed method, when applied to actual bridge data, demonstrates its effectiveness as evidenced by the condition rating of an actual bridge.
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Ryż, Karol, e Łukasz Flaga. "Selected construction and technological problems of middle span length steel bridges based on examples over the Danube and Dnieper river". Budownictwo i Architektura 7, n. 2 (13 dicembre 2010): 005–23. http://dx.doi.org/10.35784/bud-arch.2263.
Testo completoAbstract (sommario):
Every example of bridge both the aesthetic appearance and technological solutions are unique. Differences are a result of a various historical events, neighbour impact and evolving capabilities of bridge building. Based on the unique features of bridge examples taken into consideration one reveals evolution technology of bridge building in time. The aim is to present some examples of steel bridges which have been considered successful. Bridges are still in use. Each of them was created in different period of time. It shows the altered bridge building idea, fluctuation of trend. The successful design was able to have been improved during time when increasing road traffic forced engineers to adapt bridges into new conditions. Bridge builders found a positive solution to every appeared problem. It help to preserve bridges from being rebuild and clearly showed that bridge building is the finest domain of civil engineering.
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Chen, Rong, Ping Wang e Xian-kui Wei. "Track-Bridge Longitudinal Interaction of Continuous Welded Rails on Arch Bridge". Mathematical Problems in Engineering 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/494137.
Testo completoAbstract (sommario):
Taking arch bridges, including deck, half-through, and through arch bridges (short for DAB, HTAB, and TAB) as examples, mechanics analysis models of longitudinal interaction between continuously welded rails (short for CWRs) and arch bridges are established. Based on the finite element method (FEM), the longitudinal interaction calculation software of CWR on arch bridges has been developed. Focusing on an HTAB, the tension, compression, and deflection conditions are calculated and analyzed. The results show that the mechanics analysis models of three types of arch bridges can truly reflect the real state of the structure; the calculation software can be used for systematic research of the CWR on arch bridge; as for HTAB, temperature difference of arch rib has a small effect on rail tension/compression, and arch bridge can be simplified as a continuous beam for rail tension/compression additional force calculation; in calculation of deflection conditions of HTAB, it is suggested that train loads are arranged on half span and full span and take the direction of load entering bridge into account. Additionally, the deflection additional force variation of CFST basket handle arch bridge is different from that of ordinary bridge.
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Ranf, R. T., M. O. Eberhard e S. Malone. "Post-earthquake Prioritization of Bridge Inspections". Earthquake Spectra 23, n. 1 (febbraio 2007): 131–46. http://dx.doi.org/10.1193/1.2428313.
Testo completoAbstract (sommario):
Bridge damage reports from the 2001 Nisqually earthquake were correlated with estimates of ground-motion intensity at each bridge site (obtained from ShakeMaps) and with bridge properties listed in the Washington State Bridge Inventory. Of the ground-motion parameters considered, the percentage of bridges damaged correlated best with the spectral acceleration at a period of 0.3 s. Bridges constructed before the 1940s, movable bridges, and older trusses were particularly vulnerable. These bridge types were underestimated by the HAZUS procedure, which categorizes movable bridges and older trusses as “other” bridges. An inspection prioritization strategy was developed that combines ShakeMaps, the bridge inventory and newly developed fragility curves. For the Nisqually earthquake, this prioritization strategy would have made it possible to identify 80% of the moderately damaged bridges by inspecting only 481 (14%) of the 3,407 bridges within the boundaries of the ShakeMap. To identify these bridges using a prioritization strategy based solely on epicentral distance, it would have been necessary to inspect 1,447 (42%) bridges. To help the Washington State Department of Transportation (WSDOT) rapidly identify damaged bridges, the prioritization procedure has been incorporated within the Pacific Northwest Seismic Network (PNSN) ground-motion processing and notification software.
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Hidayat, Irpan. "Analisis Perhitungan Jembatan Gelagar I pada Jembatan Jalan Raya dan Jembatan Kereta Api". ComTech: Computer, Mathematics and Engineering Applications 4, n. 1 (30 giugno 2013): 517. http://dx.doi.org/10.21512/comtech.v4i1.2797.
Testo completoAbstract (sommario):
The bridge is a means of connecting roads which is disconnected by barriers of the river, valley, sea, road or railway. Classified by functionality, bridges can be divided into highway bridge and railroad bridge. This study discusses whether the use of I-girder with 210 m height can be used on highway bridges and railway bridges. A comparison is done on the analysis of bridge structure calculation of 50 m spans and loads used in both the function of the bridge. For highway bridge, loads are grouped into three, which are self weight girder, additional dead load and live load. The additional dead loads for highway bridge are plate, deck slab, asphalt, and the diaphragm, while for the live load is load D which consists of a Uniform Distributed Load (UDL) and Knife Edge Load (KEL) based on "Pembebanan Untuk Jembatan RSNI T-02-2005". The load grouping for railway bridge equals to highway bridge. The analysis on the railway bridges does not use asphalt, and is replaced with a load of ballast on the track and the additional dead load. Live load on the structure of the railway bridge is the load based on Rencana Muatan 1921 (RM.1921). From the calculation of the I-girder bridge spans 50 m and girder height 210 cm for railway bridge, the stress on the lower beam is over the limit stress allowed. These results identified that the I-girder height 210 cm at the railway bridge has not been able to resist the loads on the railway bridge.
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Kumar, Prince, Deepak Bandewar e Sachin Jat. "Analysis of Cable Stayed Bridge and Girder Bridge Considering Seismic Forces and I.R.C. Loading". International Journal for Research in Applied Science and Engineering Technology 10, n. 9 (30 settembre 2022): 967–75. http://dx.doi.org/10.22214/ijraset.2022.46749.
Testo completoAbstract (sommario):
Abstract: A bridge is a structure which is built over some physical obstacles such as a body of water, valley, road and railway, its purpose is to provide crossing over that obstacle. Numerous bridges are in exist namely Arch Bridge, Girder Bridge, Suspension bridge, Cable stayed Bridge, etc. Design of bridges varies depending on the function of the bridge, the nature of the terrain where the bridge is constructed and anchored, the funds available to build it. Structural analysis is a process to analyze a structural system to predict its responses and behaviour by using physical laws and mathematical equations. The main objective of structural analysis is to determine internal forces, stresses and deformation of structure under various load effects. In the present work, Girder Bridge and Cable stayed bridge are modelled and comparative analysis is carried out for dynamically loading conditions. A comparison is made between the bridges for dead load, live load and combined load.
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Yang, Zige. "Study on the History and Present Situation of Cable-stayed Bridge Structures in China". Highlights in Science, Engineering and Technology 28 (31 dicembre 2022): 141–46. http://dx.doi.org/10.54097/hset.v28i.4099.
Testo completoAbstract (sommario):
With the improvement of force mode, the development of material characteristics and technologies, the Cable-stayed Bridge structures are used more and more widely. In 1975, Yunyang Bridge, the first experimental Cable-stayed Bridge of China, was completed. In the following decades, China has greatly increased the span of bridges and the height of towers. During construction, the materials used to build bridge structures are more diverse and safer. In 2017, the Hong Kong-Zhuhai-Macao Bridge, representing the most advanced bridge-building technology in China at the time, was born. In this paper, the history of ancient Cable-stayed Bridges is firstly introduced. Then, several Cable-stayed Bridges which have great influence are researched, respectively. Finally, this paper compares Yunyang Bridge and Hong Kong-Zhuhai-Macao Bridge in-depth from three aspects: comparison of the construction scales, comparison of the construction materials and comparison of the cable technologies. The results show the progress of bridge industry in the past 42 years of China.
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Yermakova, Inna, e Maxim Nechyporenko. "REUSE OF BRIDGE GIRDERS AS BRIDGE SPAN STRUCTURES OF TEMPORARY BRIDGES". Dorogi i mosti 2021, n. 24 (1 ottobre 2021): 97–111. http://dx.doi.org/10.36100/dorogimosti2021.24.097.
Testo completoAbstract (sommario):
Introduction. This article presents the results of study of the quality of girders that were used for the construction of temporary road bridge. In the bridge construction practice there is a need to use girders in the construction of road bridges on local roads that can be reused in temporary bridges construction. It is important when using such structures to determine their reliability for long-term operation. The cost of bridge girders is up to 60% of the cost of a new bridge, so the reuse of utilizedsed girders is economically feasible. Utilized girders can be reused on local roads and temporary bridges. Problem statement. To determine the usability of utilized girders in temporary bridges construction and provide recommendations for the girders reuse and possible bridge design structures. Materials and methods. The following works were performed during the inspection: visual inspection of the girders at places of their storage after dismounting; measurement of the basic sizes of girders; determination of concrete strength by non-destructive test method; determination of the number of working reinforcement and the protective layer thickness; measurements of pH of concrete of a protective layer were performed; registration of existing defects was performed. The following measurements were performed during the tests: general displacements and deformations of structural elements of the structures; relative deformations of cross sections; local deformations (displacements in joints). Results. According to the results of tests and calculations, the bearing capacity of the bridge span structure was determined. After analyzing the results of experimental and theoretical studies, conclusions were made regarding the operational performance of the girders of the bridge span structure. Conclusions. Girders in the 1st, the 2nd and the 3rd technical state can be considered suitable for bridge span structures unreservedly. Girders in the 4th technical state, need repairing and reinforcement for reuse in bridge span structures. They cannot be used without repairing. Girders in the 5th technical state cannot be used in the span structures of road bridges. They can be used, for example, as transition slabs, or for pedestrian bridges and crossings, or can be used for testing the technology of bridge structures repairing. Thus, tests of bridge girders and full-size joints testify that the accepted design decision provides the needed bearing capacity of girders and of the bridge span structure as a whole. This confirms the sufficient reliability of utilized girders in the further work. Practice shows that it is also needed to pay great attention to the following: firstly- to the methods of dismantling the girders without damage; secondly — to the proper storage of girders after dismantling.
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Naser, Ali Fadhil. "Comparative Study of Seismic Design for Different Bridges Structures". Jurnal Kejuruteraan 34, n. 1 (30 gennaio 2022): 59–71. http://dx.doi.org/10.17576/jkukm-2022-34(1)-06.
Testo completoAbstract (sommario):
The main objective of this study is to compare the structural members capacity between different types of bridges structures under seismic load. The results of seismic modal analysis showed that the models of box girder bridge, precast T girder bridge, and U steel girder bridge had the higher values of natural frequency comparing with others bridges structures under seismic load. Pushover analysis in transvers direction showed that bent No. 2 of bridges structures which was located in the middle of bridges superstructure was displaced in transvers direction more than bent No. 1 and bent No. 3. In longitudinal direction, Precast I girder bridge had higher value of longitudinal displacement comparing with others bridges structures, and it was more than the maximum value of transvers displacement. The results of demand and capacity ratio showed that bent No. 2 was the critical structural member which had values of demand/capacity ratio more than 1.0 or near from it especially precast I girder bridge, precast T girder bridge, and U steel bridge, indicating that these types of bridges will be subjected to failure in bent No. 2. Therefore, there was needing to redesign the bents of these types of bridges by increasing the numbers of piers, using high strength materials in construction of bents, and increasing of dimensions of piers and pier caps. The results of internal forces showed that bent No. 2 was subjected to the maximum values of axial force, horizontal shear, and bending moment for all types of bridges structures. Also, it can be seen that the models of precast I girder bridge, precast T girder bridge, and U steel bridge had the higher values of forces comparing to others models, indicating that these results agree with results of demand/capacity ratio and pushover analysis method.
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He, Xiaoxue. "Analysis of common diseases, monitoring, and maintenance of cable-stayed bridges". Theoretical and Natural Science 19, n. 1 (8 dicembre 2023): 211–21. http://dx.doi.org/10.54254/2753-8818/19/20230553.
Testo completoAbstract (sommario):
The tide of bridge building has passed. Nowadays, the monitoring and maintenance of bridges is very important for their safety, durability, and applicability, and it is the focus of the worlds attention and research. This paper analyzes the common diseases and maintenance strategies of common cable-stayed bridges and cable-stayed bridges in coastal areas. This paper includes system composition, sensor layout, sensor types, monitoring objects, structural health status evaluation, and daily maintenance, as well as Sutong Bridge, Changmen Grand Bridge, and Ganjiang Grand Bridge of Changgan Passenger Transport in Ganzhou and other concrete examples. The modules and functions of structural health status assessment and the application of the bridge health monitoring system, such as early warning and assessment in the daily monitoring of cable-stayed bridges, are introduced. And Changmen Grand Bridge, Ganjiang Grand Bridge of Changgan Passenger Transport in Ganzhou, and Sutong Bridge are compared and analyzed according to the arrangement of measuring points, monitoring objects, and corresponding sensors. Finally, this paper briefly discusses the basic methods of preventive maintenance, BIM, and other related intelligent monitoring methods.
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Paikun, Amir Hamzah, Selfin Anugrah Amdania e Shcherbak Petr Nikolaevich. "Analysis of abutment safety factors against landslides on the Cipeundeuy bridge - Sukatani, Indonesia". INTERNATIONAL JOURNAL ENGINEERING AND APPLIED TECHNOLOGY (IJEAT) 4, n. 1 (29 maggio 2021): 1–10. http://dx.doi.org/10.52005/ijeat.v4i1.46.
Testo completoAbstract (sommario):
Bridges are connecting access between one region and another, and play an important role in transportation to facilitate community economic activities. The river bridge has very steep cliffs, and these cliffs often occur in landslides, therefore this study is very important to determine the safety of the bridge. This study aims to determine the safety of the bridge abutment structure which is the head of the bridge with the function of continuing the load on the bridge foundation. This analysis is limited to only calculating the stability and safety of bridge abutments with reinforced concrete structures. The analysis uses methods and formulas referring to Indonesian national standards, namely RSNI T-02-2005 regarding loading for bridges, RSNI T-12-2004 concerning concrete structure planning for bridges, SNI 03-2833-200X concerning earthquake resistance planning standards for bridges. The data used are drawing data and technical specifications used on the bridge, then the data is verified against planning consultants, project implementers, and observations at the location. The results of the analysis stated that the bridge abutment was declared safe from soil thrust and other forces, but did not have a good safety factor against shear forces. Landslides that occur can be resisted by the bridge abutments. This research is expected to be followed up by policymakers to repair bridges so that they are resistant to maximum shear forces, and provide safety signs from landslides to relieve public anxiety when crossing bridges, as well as provide reinforcement for the cliffs around the bridge.
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Phadatare, Sudiksha, Shruti Patil, Yash Jadhav, Rupali Khairnar e Prof Sayali Konkane. "Design and Implementation of Real Time Monitoring of Bridge by Using Sensor Technology". International Journal for Research in Applied Science and Engineering Technology 11, n. 3 (31 marzo 2023): 2113–16. http://dx.doi.org/10.22214/ijraset.2023.49602.
Testo completoAbstract (sommario):
Abstract: Now a day’s bridges are important as per travel aspect since it make passing of river or a ground easier in the travel and transport. But the bridges may collapse anytime due to flood to the river or due to aging and lead to disaster. Hence it is important to monitor the bridge conditions every time. Such type of bridge is dangerous to travel or use. The people who are using the bridge, they may face the unpredictable situations due to damaging of bridges. Hence, continuously monitoring the bridges is necessary for the better health of bridge. In this proposed system, we can see real time monitoring of bridge where we can detect flood, crack detection, load on the bridge, by using different sensors. Here, sensors help us to give information about bridge conditions to alert the user. This system contains water level sensors, load sensor, jumping wire for providing the information about real-time condition of bridge. The user of bridge gets the alert about the bridge conditions via LCD screen, LED and Buzzer. These all sensors, wire and alert devices are connected to microprocessor Arduino Uno .This system make sure to provide alert to all users so that many people who are going to use the bridge get protected from biggest accidents. In this way this system is helpful to save the life of people.
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Leal Junior, José Wilson, e Leandro Gomes Domingos. "Economic evaluation of the wooden bridges replacement for steel-reinforced concrete composite bridges in the Balsas-MA rural zones". CONTRIBUCIONES A LAS CIENCIAS SOCIALES 17, n. 2 (14 febbraio 2024): e4576. http://dx.doi.org/10.55905/revconv.17n.2-089.
Testo completoAbstract (sommario):
A river is a natural obstacle in the passage between two points. One way to overcome this obstacle is building a bridge that can be made of rock, wood, steel, concrete, or a combination of these materials. In Balsas, Maranhão’s country town, it is common to use wooden bridges to connect rural communities to each other and to the city’s downtown. However, heavy vehicle traffic has led to the collapse of these bridges, causing isolation and disruption to these communities. The study purpose was to economic evaluation of the wooden bridges replacement for steel-reinforced concrete composite bridges in Balsas, as composite structures are more resistant to applied loads when compared to wooden bridges built in the region. Therefore, replacing budgets for wooden bridge were made and compared with composite bridges construction. The results indicated that composite bridges have a higher cost, but, when analyzing the proposition economically, through net present value, internal rate of return, discounted payback, and cost-benefit, it was found that the proposition is economically viable when the wooden bridge service life lasts for one year. Therefore, it can be concluded that replacing the wooden bridge with a composite bridge is necessary for bridges with a higher collapse incidence. Nevertheless, if the problems caused by isolation due to the collapse of the wooden bridge are considered, replacing the wooden bridge with composite bridges is necessary.
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Wang, Yelu, Yongjun Zhou, Yuxin Xue, Changwei Yao, Kailong Wang e Xuchang Luo. "Failure Analysis for Overall Overturning of Concrete Single-Column Pier Bridges Induced by Temperature and Overloaded Vehicles". Materials 17, n. 11 (30 maggio 2024): 2650. http://dx.doi.org/10.3390/ma17112650.
Testo completoAbstract (sommario):
Several overloaded-induced overturning incidents of girder bridges with single-column piers have occurred in recent years, resulting in significant casualties and economic losses. Temperature, in addition to overloading, may also play a role in exacerbating bridge overturning. To investigate the association between temperature and bridge overturning, an explicit finite element model (EFEM) of a three-span concrete curved continuous bridge considering nonlinearities was developed to simulate overall collapse. The effects of uniform and gradient temperatures on the overall overturning stability of curved and straight bridges were evaluated based on the EFEMs. Furthermore, the temperature–bridge coupling model and temperature–vehicle–bridge coupling model were utilized to examine how gradient temperature influences bridge overturning. The results show that the overall overturning collapse of a bridge follows four stages: stabilization, transition, risk and overturning. Variations in uniform temperature from −30 °C to 60 °C had a negligible effect on the ultimate vehicle weight for bridge overturning, with a variation of less than 1%. As the gradient temperature ranged from −30 °C to 60 °C, curved bridges show less than a 2% variation in ultimate vehicle weights, compared to a range of −6.1% to 11.7% for straight bridges. The torsion caused by positive gradient temperature in curved bridges can exacerbate bridge overturning, while negative gradient temperature in straight bridges can lead the girder to ‘upward warping’, facilitating girder separation from bearings. Monitoring the girder rotation angle and vertical reaction force of bearings can serve as important indicators for comparing the stability of bridges.
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Ge, Ji Ping. "Seismic Performance Analysis of a Continuous Girder Bridge with Precast Segmental Pier". Advanced Materials Research 250-253 (maggio 2011): 1966–70. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.1966.
Testo completoAbstract (sommario):
Based on available research results of precast segmental bridge pier, seismic performance of a continuous girder bridge with precast segmental bridge columns using match-cast dry joints was analyzed with the lumped plastic hinge method verified by experiment, the similarities and differences of seismic performance between the continuous girder bridge with precast segmental bridge columns and that of cast-in-placement reinforced concrete bridge columns were gained. Results show that the maximum displacement response of the continuous girder bridge with precast segmental bridge columns is bigger than that of the continuous girder bridge with cast-in-place reinforced concrete bridge columns. While for the residual displacement, the opposite is true. The reason is that the restoring force exists in the precast segmental bridge pier by the prestress strands. The concentrated plastic hinge method for cast-in-place reinforced concrete bridges could be used to bridges with precast segmental bridge columns.
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Fu, Tao, Kai Wang, Ye Zhou, Xiaoqian Ren, Zhixin Zhu, Yan Li, Yue Sun e Lingxiao Meng. "Optimal Design Method for Vessel-Bridge Collision Based on Life-Cycle Theory". Advances in Materials Science and Engineering 2022 (31 luglio 2022): 1–10. http://dx.doi.org/10.1155/2022/7460796.
Testo completoAbstract (sommario):
As structures crossing waterways, bridges are obstacles to vessels. Vessel-bridge collisions are inevitable. They not only involve the safety of vessel passage but also seriously affect the safe operation of bridges. Vessel-bridge collisions cause not only huge economic losses and casualties but also severe political and environmental losses. Vessel collision safety of existing and new bridges is one of the key technical problems that engineers and bridge managers must solve. Comprehensive consideration of vessel-bridge collision risk loss and structural performance in the design stage to achieve optimal cost over the life cycle is an important aspect of bridge design. Based on the current life-cycle design theory of engineering structures, this paper proposes a theoretical framework for vessel-bridge collision optimization design based on the life cycle, which includes three parts: vessel-bridge collision probability analysis, vessel-bridge collision vulnerability analysis, and vessel-bridge collision hazard. Taking the minimum cost of the bridge structure in the design service life period as the objective function, the optimization design model and design process of vessel-bridge collision based on whole life are established, and the key problems to be solved in each part are expounded.
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Вдовина, Е. В., В. И. Моисеева, А. А. Капошина, А. Я. Коренева e Д. Д. Чернова. "Study of foreign practice of organizing accelerated construction of bridges using high-strength concrete". Экономика и предпринимательство, n. 10(123) (15 novembre 2020): 1314–17. http://dx.doi.org/10.34925/eip.2020.123.10.263.
Testo completoAbstract (sommario):
В настоящее время FHWA успешно использует методы ускоренного строительства мостов (ABC) для ускорения строительства новых мостов и минимизации затрат на материалы, рабочую силу и оборудование. В этом исследовании обсуждается основа новых мостов с использованием сборных мостовых элементов и систем (PBES), включая изготовление сборных / предварительно напряженных элементов с использованием экономичной бетонной смеси с высокими эксплуатационными характеристиками (HPC), разработанной с использованием местных строительных материалов. Успешное использование HPC для изготовления PBES, используемых в методах ABC, позволяет FHWA строить новые мосты при текущих бюджетных ограничениях. Это улучшает общий рейтинг мостовой сети в стране. FHWA is now successfully using Accelerated Bridge Construction (ABC) techniques to accelerate new bridge construction and minimize material, labor and equipment costs. This study discusses the foundations of new bridges using precast bridge members and systems (PBES), including fabrication of precast / prestressed members using cost-effective high performance concrete (HPC) developed using local building materials. The successful use of HPC to fabricate PBES used in ABC techniques allows FHWA to build new bridges under current budget constraints. This improves the overall rating of the bridged network in the country.
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Zhang, Xiao Zhong, Yong Bing Liu, Wei Xin Hu e Jing Song Zhu. "Research of Strength of Dongji Reinforced Concrete T-Beam Bridge". Advanced Materials Research 243-249 (maggio 2011): 2000–2003. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.2000.
Testo completoAbstract (sommario):
Based on the investigation and detection of Dongji Bridge, a reinforced concrete (RC) T-beam bridge, the major diseases of the bridge was identified. The disease characteristics and rules are classified, the strength of the bridge was analyzed by finite element technology. Research is expected to provide scientific and rational basis for maintenance and reinforcement of Dongji bridge and same style bridges, and lay a foundation for further research work for RC T-beam bridges.
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Bunce, Andrew, David Hester e Daniel S. Brennan. "Where is the end of a Bridge (model)?" Journal of Physics: Conference Series 2647, n. 25 (1 giugno 2024): 252024. http://dx.doi.org/10.1088/1742-6596/2647/25/252024.
Testo completoAbstract (sommario):
Abstract Bridge SHM solutions have been developed to assist with the assessment and monitoring of bridges. State of the art bridge SHM solutions tend to be data based, where machine learning algorithms are trained using large, historical bridge datasets, and outlier analysis is subsequently used for anomaly detection. However, most bridges lack the required healthy state data for machine learning approaches to be considered, and many bridges are not in a healthy condition to collect the required data from. A population based structural health monitoring (PBSHM) approach has recently been proposed that seeks to facilitate knowledge transfer between similar structures. The approach proposes that if two structures are similar enough, there could be scope to make SHM inferences between the structures. The ability to make inferences between bridges, which are currently monitored in isolation, would be highly valuable as a bridge management tool, particularly if datasets could be leveraged between bridges through transfer learning. However, before knowledge can be shared between bridges, there is first a need to identify bridges that are similar enough for inferences to be made. The PBSHM approach proposes the use of Irreducible Element (IE) models to describe structures, which allows Attributed Graphs (AG) to generated and compared for similarity using graph theory techniques. The general method for comparing structures was trialled on bridges previously, however the resulting similarity metrics were for the whole bridge as opposed to particular common zones of interest e.g. the deck. This paper instead proposes that bridges be modelled as subsections of structures that interact via shared boundaries (i.e., points of articulation such as bearings), as opposed to whole structures. Bridge datasets are often limited to the part of the bridge that was investigated, i.e., datasets particular to bridge decks, abutments etc. Therefore, the extents of the IE models proposed in this paper are set to only include elements that would pertain to a particular dataset. In particular, two beam and slab bridges are each described with bridge deck, abutment and pier IE models to trial the concept. The revised extents of the bridge IE models reduced the number of elements being compared, resulting in increased resolution graph comparisons being carried out and more meaningful similarity metrics between the bridge parts being achieved.