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1
Seyed Khoei, Amir, Reza Akbari, Shahrokh Maalek, and Alireza Gharighoran. "Assessment of Design and Retrofitting Solutions on the Progressive Collapse of Hongqi Bridge." Shock and Vibration 2020 (September 15, 2020): 1–13. http://dx.doi.org/10.1155/2020/4932721.
Повний текст джерелаАнотація:
In 2009, the Hongqi Bridge, a multispan reinforced concrete bridge located in Zhuzhou, Hunan Province, China, collapsed progressively in the form of domino, due to extreme effect of deck to pier, during demolition process of the bridge. In this study, progressive collapse of Hongqi Bridge was investigated using nonlinear dynamic analysis in the Applied Element Method, which has been proven as one of the best methods that can follow the collapse behavior of structures. Good agreements were obtained between numerical results and field observations as well as previously reported results. After verifying the bridge collapse procedure, the effects of different alternatives for superstructure and substructure systems on the progressive collapse procedure were investigated. In addition, application of restrainers at the connection of deck to abutment was studied as an effective solution in order to prevent collapse propagation and to minimize associated damages. The results of the study showed that all chosen methods and factors could be helpful and effective in the procedure of collapse propagation for this kind of bridge.
2
Yau, Nie Jia, and Hsien Ke Liao. "Indices for Fast Assessment of Bridge Condition in Taiwan." Applied Mechanics and Materials 752-753 (April 2015): 689–97. http://dx.doi.org/10.4028/www.scientific.net/amm.752-753.689.
Повний текст джерелаАнотація:
Developed in 2000, the Taiwan Bridge Management System (TBMS) is an internet-based, nation-wide bridge management system used by all of the bridge management agencies in Taiwan. Currently, the TBMS has an inventory of more than 24,300 bridges with 14 years of visual inspection data and maintenance records. The inspection data of each bridge are input into the TBMS at least once per two years. In order to have a fast assessment of bridge condition in resisting natural disasters and traffic loads, five indices are established in this research: (1) Degree of flood resistance (DF), (2) Degree of mudflow resistance (DM), (3) Degree of earthquake resistance (DE), (4) Degree of loads resistance (DL), and (5) Degree of collapse resistance (DC). Calculation of these five indices is based on the inventory and visual inspection data of each bridge without further thorough site investigation. These indices are used for screening or sieving bridges out of the TBMS inventory that are potentially vulnerable to natural disasters or traffic loads, thus maintenance efforts can be put on such bridges to improve the efficiency of bridge management.
3
Sokolović, Neda M., Milica Petrović, Ana Kontić, Suzana Koprivica, and Nenad Šekularac. "Inspection and Assessment of Masonry Arch Bridges: Ivanjica Case Study." Sustainability 13, no. 23 (December 2, 2021): 13363. http://dx.doi.org/10.3390/su132313363.
Повний текст джерелаАнотація:
The importance of masonry arch bridges as a traffic network element calls for a thorough analysis focused on both structural stability and loading capacity of these historical structures, considering the usage of these bridges in contemporary traffic conditions. This paper focuses on the analysis of longitudinal cracks in a single span masonry arch bridge to evaluate its influence on structural behaviour of the system. As longitudinal cracks do not necessarily present an inevitable collapse mechanism, analysis of the causes is crucial for evaluating the serviceability and functionality of the bridge investigated. The methodology is based on the following: literature review, observation of the stone bridge in Ivanjica, geological testing of the site, geophysical testing of the bridge, laboratory testing of mechanical characteristics of stone used for the bridge construction and biological analysis of the samples of implemented materials on the bridge. Finite element analysis of the bridge was conducted to define the causes of the longitudinal cracks. The 3D simulation model was based on the data collected through observation and experimental analysis. This paper provides extensive research on a single span masonry bridge, examining how different deterioration mechanisms, in conjunction, can lead to the appearance of cracks in masonry arch bridges and provide remedial measures accordingly.
4
Lei, Zheng Bao, Hai Liang Cheng, Mu Xi Lei, and Guo Bin Liu. "Research on Security of Bridge Crashed by Vessels in Xiangjiang Bridge." Applied Mechanics and Materials 204-208 (October 2012): 2119–22. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.2119.
Повний текст джерелаАнотація:
To study the ship collision security of Xiangjiang bridge, this paper base on the risk assessment criteria of the AASHTO guide. First of all, annual frequency of Xiangjiang bridge element collapse is calculated by using the method of AASHTO guide; Furthermore, the safety of the Xiangjiang bridge is evaluated in according to AASHTO Guide. Calculation and analysis results show that Annual frequency of Xiangjiang bridge element collapse is more than annual 0.0001.
5
Tan, Ji-Shuang, Khalid Elbaz, Zhi-Feng Wang, Jack Shui Shen, and Jun Chen. "Lessons Learnt from Bridge Collapse: A View of Sustainable Management." Sustainability 12, no. 3 (February 7, 2020): 1205. http://dx.doi.org/10.3390/su12031205.
Повний текст джерелаАнотація:
Bridge failure is one of the worst infrastructural disasters. This paper investigates the risk of bridge infrastructures in the view of sustainable management. Statistics on bridge failures from 2009 to 2019 in China show that most of these failures are related to anthropic factors. The collapse of the Zijin Bridge on 14 June 2019 in Heyuan City of Guangdong Province, China is used as a case to perform detailed analysis. Superficially, bridge collapse is a technical problem rather than a management problem. However, the deep reason for this kind of bridge failure may be due to the lack of sustainable management. In order to verify this point of view, both fault tree analysis (FTA) and strategic environmental assessment (SEA) for the bridge failure and later impact on society are conducted. According to the FTA results, the failure of the arch foot is the direct trigger of the Zijin Bridge collapse. Since a lack of real-time monitoring, risk assessment and other management issues are potential factors causing bridge collapse, strategic environmental assessment (SEA) is used to investigate the management issues related to the economy, culture, human health and environmental sustainability in more depth. The low total SEA result shows poor project management and a high safety risk. Finally, the specific managerial measures are proposed to improve the sustainability of infrastructures.
6
Guo, Xuan, Zheyu Zhang, and ZhiQiang Chen. "Mainshock-Integrated Aftershock Vulnerability Assessment of Bridge Structures." Applied Sciences 10, no. 19 (September 29, 2020): 6843. http://dx.doi.org/10.3390/app10196843.
Повний текст джерелаАнотація:
Seismic fragility analysis is often conducted to quantify the vulnerability of civil structures under earthquake excitation. In recent years, besides mainshocks, strong aftershocks have been often witnessed to induce structural damage to engineered structures, including bridges. How to accurately and straightforwardly quantify the vulnerability of bridges due to sequential mainshocks and aftershocks is essential for an efficient assessment of bridge performance. While recognizing the limitation of existing methods, this paper proposes a mainshock integrated aftershock fragility function model, which empirically encodes the effects of mainshocks and retains the simple form of traditional fragility curves. A pile foundation-supported bridge system is modeled considering seismic soil-structure interaction to demonstrate the proposed fragility model. Numerical examples show that the resulting fragility curves incorporate the initial value for the probability of collapse of the bridge system due to a mainshock and the effects of the variable aftershocks conditional on the mainshock. Statistical analysis confirms that the proposed model fits the simulated vulnerability data (e.g., seismic intensities of aftershocks and the response demands conditional a select mainshock ground motion) both accurately and robustly.
7
Zhang, Wei, Shuoyu Liu, Wenwen Luo, Liping Wang, Bo Geng, and Zhenxing Zheng. "A New Approach for Probabilistic Risk Assessment of Ship Collision with Riverside Bridges." Advances in Civil Engineering 2020 (November 16, 2020): 1–12. http://dx.doi.org/10.1155/2020/8357494.
Повний текст джерелаАнотація:
The configuration of riverside bridges, such as the spatial distribution, wading status, and ship accessibility of piers, is generally different from river-crossing bridges. Thus, the ship collision risk of riverside bridges cannot be assessed using conventional assessment methods applicable to river-crossing bridges. The aim of this paper is, therefore, to develop a new probabilistic method for assessing the risk of ship collision with riverside bridges. First, a fully probabilistic framework for assessing the ship-bridge collision risk is presented. Second, a new probabilistic hazard analysis model of ship collision with riverside bridges is proposed, based on a combined study of riverside bridge characterization and an improved yaw ship collision model. A simplified empirical model for evaluating ship-bridge collision force is then adopted, and the probabilistic distribution of the collision force is obtained based on Monte Carlo simulation. Furthermore, finite element simulation is conducted to estimate the collapse probability of piers. Finally, the method developed is applied to the probabilistic assessment of ship collision risk with riverside bridges located at Shabin Road, Chongqing, China. The results show that the risk of ship-bridge collision at Shabin Road is low to moderate. The example demonstrated indicates that the methodology introduced in this paper is capable of assessing the ship-bridge collision risk in a concise and rapid way.
8
Skokandić, Dominik, Anđelko Vlašić, Marija Kušter Marić, Mladen Srbić, and Ana Mandić Ivanković. "Seismic Assessment and Retrofitting of Existing Road Bridges: State of the Art Review." Materials 15, no. 7 (March 30, 2022): 2523. http://dx.doi.org/10.3390/ma15072523.
Повний текст джерелаАнотація:
The load-carrying capacity assessment of existing road bridges, is a growing challenge for civil engineers worldwide due to the age and condition of these critical parts of the infrastructure network. The critical loading event for road bridges is the live load; however, in earthquake-prone areas bridges generally require an additional seismic evaluation and often retrofitting in order to meet more stringent design codes. This paper provides a review of state-of-the-art methods for the seismic assessment and retrofitting of existing road bridges which are not covered by current design codes (Eurocode). The implementation of these methods is presented through two case studies in Croatia. The first case study is an example of how seismic assessment and retrofitting proposals should be conducted during a regular inspection. On the other hand, the second case study bridge is an example of an urgent assessment and temporary retrofit after a catastrophic earthquake. Both bridges were built in the 1960s and are located on state highways; the first one is a reinforced concrete bridge constructed monolithically on V-shaped piers, while the second is an older composite girder bridge located in Sisak-Moslavina County. The bridge was severely damaged during recent earthquakes in the county, requiring urgent assessment and subsequent strengthening of the substructure to prevent its collapse.
9
Selman, Mudhafer H. "Highway Bridge Load-Bearing Capacity Assessment Under Chinese and British Methodologies." Advanced Materials Research 378-379 (October 2011): 353–57. http://dx.doi.org/10.4028/www.scientific.net/amr.378-379.353.
Повний текст джерелаАнотація:
The purpose of assessment of structures is to check their adequacy for specific loading levels and to identify those bridges that have an unacceptable risk of failure, either in part or complete collapse, under extreme circumstances of loading and material condition [1]. In this study, a comparison was made between new Chinese bridge load-bearing capacity assessment method and The British Highway Agency method. Load-bearing capacity assessment results were generated for bridges super structure and analyzed for moment and shear load effect. Also the study included a comparison of the main component of load-bearing capacity calculation, factored live load, factored dead load, and factored capacity. The comparison shows that the British Method produced lower moment and shear bridges carrying capacity factor than Chinese Method.
10
Milillo, Pietro, Giorgia Giardina, Daniele Perissin, Giovanni Milillo, Alessandro Coletta, and Carlo Terranova. "Pre-Collapse Space Geodetic Observations of Critical Infrastructure: The Morandi Bridge, Genoa, Italy." Remote Sensing 11, no. 12 (June 12, 2019): 1403. http://dx.doi.org/10.3390/rs11121403.
Повний текст джерелаАнотація:
We present a methodology for the assessment of possible pre-failure bridge deformations, based on Synthetic Aperture Radar (SAR) observations. We apply this methodology to obtain a detailed 15-year survey of the Morandi bridge (Polcevera Viaduct) in the form of relative displacements across the structure prior to its collapse on August 14th 2018. We generated a displacement map for the structure from space-based SAR measurements acquired by the Italian constellation COSMO-SkyMed and the European constellation Sentinel-1A/B over the period 2009–2018. Historical satellite datasets include Envisat data spanning 2003–2011. The map reveals that the bridge was undergoing an increased magnitude of deformations over time prior to its collapse. This technique shows that the deck next to the collapsed pier was characterized since 2015 by increasing relative displacements. The COSMO-SkyMed dataset reveals the increased deformation magnitude over time of several points located near the strands of this deck between 12th March 2017 and August 2018.
11
Holický, Milan, and Jiří Kolísko. "Categorization of Bridges by Failure Consequences." Advances in Science and Technology 108 (July 27, 2021): 53–57. http://dx.doi.org/10.4028/www.scientific.net/ast.108.53.
Повний текст джерелаАнотація:
Categorization of bridge constructions by the failure consequences due to loss of ultimate capacity or serviceability is a difficult task that can be resolved using two different approaches: elementary method using currently valid standards advanced method based on risk assessment. The elementary method is grounded on subjective assessment of bridge malfunctioning or collapse. The bridge is classified into an appropriate category (consequence class) in accordance with the most severe consequence. It is a simple procedure that may be applied without the need of demanding mathematical procedures. However, the resulting categorization may be affected by uncertainties in the assessment of consequences. The advanced method is based on a comprehensive analysis of bridge malfunctioning using a procedure of risk assessment. This method takes account of the occurrence probability of unfavourable events and the significance of individual consequences. Classification of a bridge construction into an appropriate category depends on the resulting risk of the bridge failure. This more laborious approach provides credible results without excessive uncertainties. The most adverse difficulty of the method is a combination of some consequences like the loss of life and economic costs. Both the above-mentioned approaches to the categorization of bridges by failure consequences can be effectively used depending on the type of bridge, on the intensity of exploitation, on expected consequences, and on social impacts of bridge malfunctioning.
12
Lee, Jungwhee, Keunki Choi, and Chulhun Chung. "Numerical Analysis-Based Blast Resistance Performance Assessment of Cable-Stayed Bridge Components Subjected to Blast Loads." Applied Sciences 10, no. 23 (November 28, 2020): 8511. http://dx.doi.org/10.3390/app10238511.
Повний текст джерелаАнотація:
Cable-stayed bridges are infrastructure facilities of a highly public nature; therefore, it is essential to ensure operational safety and prompt response in the event of a collapse or damage, which are caused by natural and social disasters. Among social disasters, blast accidents can occur in cable-stayed bridges as a result of explosions produced by vehicle collisions or terrorist attacks; this can lead to the degradation in their structural performances and subsequent collapse. In this research, a procedure to assess structural blast-resistance performance is suggested based on a numerical analysis approach, and the feasibility of the procedure is demonstrated by performing an example assessment. The suggested procedure includes (1) selection of major structural components that severely affect the global structural behavior, (2) set-up blast hazard scenarios consisting of various blast levels and locations, and (3) assessment of the components using numerical blast simulation. By performing an example assessment, the critical blast level for each component could be determined and the blast location that affects the considering components the most severely could be found as well. The scenario-based assessment process employed in this study is expected to facilitate the evaluation of bridge structures under blasts in both existing bridges and future designs.
13
Bayrak, Hakan, and Ferhat Akgül. "Reliability analysis of a reinforced concrete bridge under moving loads." Challenge Journal of Concrete Research Letters 11, no. 2 (June 17, 2020): 31. http://dx.doi.org/10.20528/cjcrl.2020.02.002.
Повний текст джерелаАнотація:
This study presents a reliability analysis procedure for a reinforced concrete bridge exposed to different moving loads. Bridges are one of the important part of transportation infrastructure systems. As bridges age, structural weakening due to heavy traffic and aggressive environmental factors lead to an increase in repair frequency and decrease in load carrying capacity. Therefore, bridges require periodic maintenance and repair in order to function and be reliable throughout their lifetimes. In other words, condition and safety of the bridges must be monitored at regular time intervals to avoid the disadvantages of deterioration. Otherwise, sudden collapse of a bridge may lead to irreversible loss of life and property. Therefore, the importance of the structural assessment of bridges is rapidly increasing in developed countries. In this study, reliability analysis which is one of the structural performance prediction method is applied to a reinforced concrete bridge subjected to the different moving loads. The aim of this study is to observe the safety of the bridge for the effect of the increasing traffic factor over the years.
14
Ohsumi, Michio, Toshiaki Nanazawa, Shunsuke Tanimoto, and Mitsuhiko Nakata. "Development of a Seismic-Performance Assessment Method and Retrofitting Technology Against the Liquefaction of Existing Bridges." Journal of Disaster Research 14, no. 2 (March 1, 2019): 269–78. http://dx.doi.org/10.20965/jdr.2019.p0269.
Повний текст джерелаАнотація:
In the past, earthquakes have caused critical damage to bridges built on liquefiable ground, resulting in their collapse or long-term closures. In particular, for existing bridges designed in an age when the liquefaction influence was not considered, appropriate measures should be taken as necessary. However, there are many existing stocks of bridges, which require expensive foundation reinforcement. Therefore, it is crucial to appropriately choose bridge foundations for which anti-seismic measures are a high priority and implement the measures efficiently and successively. The present study aims to develop a seismic-performance assessment method and retrofitting technology for coping with liquefiable ground. For this purpose, a large shaking-table experiment was conducted to determine the effects of the liquefiable ground on bridge-foundation behavior and verify the effect of the retrofitting technology. Based on disaster-case analyses and the results of the shaking-table experiment, a seismic-performance assessment method applicable to practical designing was proposed.
15
Nobile, Lucio, Veronica Bartolomeo, and Mario Bonagura. "Structural Analysis of Historic Masonry Arch Bridges: Case Study of Clemente Bridge on Savio River." Key Engineering Materials 488-489 (September 2011): 674–77. http://dx.doi.org/10.4028/www.scientific.net/kem.488-489.674.
Повний текст джерелаАнотація:
The Clemente Bridge is a multi-span masonry arch bridge built during the 18th century on Savio River in Cesena. The aim of this paper is to assess its static capacity under live loads prescribed by Italian Standards in force. The analysis is performed employing RING 3.0, a computational tool based on Limit State Analysis. This method allows to individuate the minimum adequacy factor, that is the multiplier on vehicle loads required to cause collapse. In this way, a first assessment on the bridge safety can be obtained.
16
Bhattarai, Tulsiram, and Rajan Suwal. "Seismic Vulnerability Assessment of Hammer Head and Multicolumn Bridge Pier using Fragility Curve." Journal of Structural Technology 7, no. 1 (February 7, 2022): 24–32. http://dx.doi.org/10.46610/jost.2022.v07i01.004.
Повний текст джерелаАнотація:
Beingan earthquake-prone country, Nepal has seen numerous high-magnitude earthquakes in recent years, resulting significant damage to the bridge and its components. Even after an earthquake, bridges should be able to be used for emergency and rescue operations. Fragility curves are an important technique for measuring the seismic vulnerability of bridges. Hence, this research is focused on the use of analytical method for development of fragility curve for generally used type of pier in Nepal which is hammerhead pier and multicolumn pier. Capacity of bridge is determined by non-linear static analysis and Demand parameter is estimated using non-linear time history analysis. The assumption of a log normal distribution is used to characterize fragility functions. The probability of exceedance of Slight, Moderate, Extensive and collapse damage states for hammerhead pier are 98.28%, 59.36%, 12.29%, 5.11% and 80.11%, 15.07%, 1.54%, 0.42% for MCE and DBE and those values for multicolumn pier are 97.79%, 37.91%, 5.49%, 2.01% and 72.35%, 4.22%, 0.33%, 0.08% for MCE and DBE respectively.
17
Pizarro, Alonso, Salvatore Manfreda, and Enrico Tubaldi. "The Science behind Scour at Bridge Foundations: A Review." Water 12, no. 2 (January 30, 2020): 374. http://dx.doi.org/10.3390/w12020374.
Повний текст джерелаАнотація:
Foundation scour is among the main causes of bridge collapse worldwide, resulting in significant direct and indirect losses. A vast amount of research has been carried out during the last decades on the physics and modelling of this phenomenon. The purpose of this paper is, therefore, to provide an up-to-date, comprehensive, and holistic literature review of the problem of scour at bridge foundations, with a focus on the following topics: (i) sediment particle motion; (ii) physical modelling and controlling dimensionless scour parameters; (iii) scour estimates encompassing empirical models, numerical frameworks, data-driven methods, and non-deterministic approaches; (iv) bridge scour monitoring including successful examples of case studies; (v) current approach for assessment and design of bridges against scour; and, (vi) research needs and future avenues.
18
Wang, Tong, Yang Liu, Qiyuan Li, Peng Du, Xiaogong Zheng, and Qingfei Gao. "State-of-the-Art Review of the Resilience of Urban Bridge Networks." Sustainability 15, no. 2 (January 5, 2023): 989. http://dx.doi.org/10.3390/su15020989.
Повний текст джерелаАнотація:
With the rapid advancement of the urbanization process, the bridge networks in cities are becoming increasingly optimized, playing an important role in ensuring the normal operation of cities. However, with the gradual deterioration of bridges and the further attenuation of their capacity, many bridges are prone to damage or even collapse under extreme loads. After a natural disaster or human-derived accident occurs in a city, the normal operation of the bridge network in the city will play an irreplaceable role in emergency rescue and long-term recovery after the disaster. In this paper, the resilience of urban bridge networks, as a comprehensive indicator that integrates predisaster early warning, disaster response and postdisaster recovery information, is considered. This indicator has been applied in many disciplines, such as civil engineering, sociology, management and economics. The concept of resilience is expounded, and functional and resilience assessment indicators for bridge networks are established. Additionally, the research progress on bridge network resilience is described. Finally, combined with research hotspots such as big data, artificial intelligence and bridge structural health monitoring, the development trends and prospects of bridge network resilience research are discussed.
19
George, Jofin, and Arun Menon. "A mechanism-based assessment framework for masonry arch bridges under scour-induced support rotation." Advances in Structural Engineering 24, no. 12 (April 16, 2021): 2637–51. http://dx.doi.org/10.1177/13694332211009325.
Повний текст джерелаАнотація:
Increase in the frequency of flash floods owed to climate change, excessive sand mining, and urbanisation of watersheds has accelerated the need to quantify the structural effect of scour-induced structural damages in masonry arch bridges. The structural effects of scour-induced rotation are unaddressed in literature. In this context, a mechanism-based framework based on limit state principles is developed for masonry arch bridges subjected to scour-induced rotation. Critical collapse mechanisms caused by scour-induced rotation are identified, and analysis framework is developed using rigid-body kinematics. The spectrum of bridges under consideration is classified into subsets, and an assessment scheme is developed using fragility curves as a function of scouring location as well as bridge typology.
20
Li, Xinran, Shengtao Su, Yingxue Li, and Bohui Liu. "Research on Detection and Safety Evaluation System of Huimin Lane Bridge based on BIM." Highlights in Science, Engineering and Technology 28 (December 31, 2022): 316–21. http://dx.doi.org/10.54097/hset.v28i.4166.
Повний текст джерелаАнотація:
With the continuous improvement of the national social and economic level the size and quantity of various types of infrastructure in our country have been improved and the community has put forward higher requirements on the level and quality of the construction. In recent years the bridge collapse accidents occur frequently, but our country bridge inspection and safety assessment of the system was established late, our country bridge structure health monitoring system research and application began in the 90. of the 20th century, the implementation of large-scale infrastructure construction projects, bridge health monitoring system also will be rapid development this paper discusses the based on BIM bridge inspection and safety assessment system, and puts forward some practical measures, provides the reference for improving bridge inspection and safety assessment of the system operation level.
21
Martin, MA, CEM, CFM, MASCE, Daniel W. "Bridging emergency management: A professional assessment of the Minneapolis bridge collapse and other infrastructure failures." Journal of Emergency Management 5, no. 6 (November 1, 2007): 41. http://dx.doi.org/10.5055/jem.2007.0031.
Повний текст джерелаАнотація:
To many in the emergency management profession, the Minneapolis bridge collapse was an epic event that has raised the situational awareness of our crumbling infrastructure. Although this event provided insight to the emergency management community, the vast majority in the civil engineering profession has long recognized the failing integrity of our aging and overburdened infrastructure and the cataclysmic result of its failure. The Minneapolis bridge collapse is a result of the failure, as a profession and a society, to proactively raise awareness of all hazards and to address emerging threats. These hazards include those risks that are created by our technological advances and lack of essential maintenance of these vital national assets.
22
Pang, Yutao, and Lingxu Li. "Seismic collapse assessment of bridge piers constructed with steel fibers reinforced concrete." PLOS ONE 13, no. 7 (July 10, 2018): e0200072. http://dx.doi.org/10.1371/journal.pone.0200072.
Повний текст джерела
23
Wu, Ying, and Pengzhen Lu. "Comparative Analysis and Evaluation of Bridge Construction Risk with Multiple Intelligent Algorithms." Mathematical Problems in Engineering 2022 (June 15, 2022): 1–12. http://dx.doi.org/10.1155/2022/2638273.
Повний текст джерелаАнотація:
Bridge collapse in the construction process is one of the most common bridge accidents; we can see the importance of construction to ensure bridge safety. Site construction safety management mainly relies on checklist evaluation, but the evaluation results are often affected by the ability and experience of the evaluator. Using an artificial intelligence algorithm to realize rapid and accurate risk assessment of the bridge construction process is an effective way and development direction to solve the above problems. In view of the uncertain factors in the process of bridge construction, this paper analyzes and classifies the man-made and environmental risk factors that affect the bridge construction stage by using the 4M1E analysis method. Typical artificial intelligence algorithms are used to construct risk assessment models for bridge construction. And the random forest algorithm is used to analyze and verify the construction example of the FIU bridge.
24
Li, Shuai, Farshad Hedayati Dezfuli, Jingquan Wang, and M. Shahria Alam. "Performance-based seismic loss assessment of isolated simply-supported highway bridges retrofitted with different shape memory alloy cable restrainers in a life-cycle context." Journal of Intelligent Material Systems and Structures 31, no. 8 (March 4, 2020): 1053–75. http://dx.doi.org/10.1177/1045389x20906018.
Повний текст джерелаАнотація:
Shape memory alloy cables have emerged as an alternative to conventional steel cable restrainers for preventing the bridge spans from unseating during an extreme earthquake. Feasibility of high-cost NiTi shape memory alloy restrainers in retrofitting the bridges has been numerically investigated, and promising results have been published; however, considering the economic impacts, the effect of different types of shape memory alloy such as Cu-based and Fe-based shape memory alloy restrainers has not been discussed yet. The objective of this study is to address this problem in detail in order to propose the most cost-effective shape memory alloy restrainer suitable for bridge engineering applications. Seismic fragility and life-cycle loss (both direct and indirect) assessments are analytically performed on an isolated simply-supported highway bridge retrofitted by four types of shape memory alloy restrainers (i.e. NiTi, FeNiCoAlTaB, CuAlMn, and FeMnAlNi). Results showed that for all retrofitted bridges performed in the range of design displacement, the effect of type of shape memory alloy is significant on the damage probability and long-term seismic loss of the bridges. All the bridges retrofitted with shape memory alloy restrainers have a very low probability of collapse (less than 7%). It is also found that the bridge retrofitted with Fe-based shape memory alloy restrainers (SMA-II and SMA-IV) performed better as compared to the other cases. Compared to the bridge without restrainers and with NiTi shape memory alloy restrainers, Fe-based shape memory alloy restrainers can reduce the long-term loss by about 87% and 11%, respectively, at the design earthquake event specified in CHBDC-2014. The probabilistic risk analysis of highway bridges retrofitted with shape memory alloy restrainers can aid in paving the way toward widespread application of such smart materials in structural applications.
25
He, Zhi Yong, and Jian Jun Zhang. "Study of Bridge Health Monitoring Scheme Based on GPS Multi-Antenna Technique." Advanced Materials Research 433-440 (January 2012): 3400–3402. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.3400.
Повний текст джерелаАнотація:
Ongoing bridge collapse in both at home and abroad, makes people pay increasingly attention to bridge health monitoring. Bridge health monitoring which based on the GPS multiple antenna technology, GPRS wireless communications technology and so on, warning systems including GPS deformation monitoring subsystem, multiple antennas and safety assessment subsystem structure, can achieve bridge deformation data automatic acquisition, processing, analysis and structural safety evaluation and Internet remote transmission, automatic alarm function. Compared with the traditional method, the system has high accuracy and good data continuity, convenient operation, less investment etc, also has good social and economic benefits and broad application prospect.
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Wang, Feng, Chuan Xiong, Zijian Wang, Congmin Guo, Hua Bai, and Jiawu Li. "A Quick Assessment and Optimization Method for a Flutter Aerodynamic Measure of a Typical Flat Box Girder." Shock and Vibration 2020 (August 12, 2020): 1–11. http://dx.doi.org/10.1155/2020/8823921.
Повний текст джерелаАнотація:
Flutter is one of the most serious wind-induced vibration phenomena for long-span bridges and may cause the collapse of a bridge (e.g., the Old Tacoma Bridge, 1940). The selection and optimization of flutter aerodynamic measures are difficult in wind tunnel tests. It usually takes a long time and consumes more experimental materials. This paper presents a quick assessment and design optimization method for the flutter stability of a typical flat box girder of the long-span bridges. Numerical analysis could provide a reference for wind tunnel tests and improve the efficiency of the test process. Based on the modal energy exchange in the flutter microvibration process, the global energy input and local energy input are analyzed to investigate the vibration suppression mechanism of a flat steel box girder with an upper central stabilizer. Based on the comparison between the experimental and numerical data, a quick assessment method for the optimization work is proposed. It is practical to predict the effects of flutter suppression measures by numerical analysis. Thus, a wind tunnel test procedure for flutter aerodynamic measures is proposed which could save time and experimental materials.
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Saadeghvaziri, M. Ala, and Saeid Rashidi. "Seismic Design and Retrofit Issues for Bridges in New Jersey." Transportation Research Record: Journal of the Transportation Research Board 1594, no. 1 (January 1997): 94–104. http://dx.doi.org/10.3141/1594-10.
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An overview of guidelines and requirements for seismic design of new bridges and retrofit of existing ones in New Jersey is presented. The results of an ongoing study on seismic assessment of existing bridges in New Jersey are also presented. It is shown that for many older bridges the seismic capacity in the transverse direction is minimal and the bearings can be damaged. However, because of the redundancy of multi-girder bridges, failure of the bearings may not cause collapse of the bridge as long as the columns and piers possess adequate ductility and strength. Circular columns do have adequate lateral reinforcement, but square columns lack the needed ductility demand. In the longitudinal direction, again, failure of the bearings because of shear failure of the bolts is a strong possibility. Unlike in the transverse direction, because of impact and separation of adjacent spans and inadequacy of seat width at the abutments and the tops of piers, loss of span and total failure of the bridge can occur. Therefore, it is important that essential bridges be retrofitted in the longitudinal direction, as proposed. Future research and development needs are also discussed
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Godart, Bruno F., Jacques Berthellemy, and Jean Pierre Lucas. "Diagnosis, Assessment and Repair of the Mathilde Bridge Close to Collapse during a Fire." Structural Engineering International 25, no. 3 (August 1, 2015): 331–38. http://dx.doi.org/10.2749/101686615x14210663188691.
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Hu, Ya-Chao, Ying-Hua Tan, and Feng Xi. "Failure assessment and virtual scenario reproduction of the progressive collapse of the FIU bridge." Engineering Structures 227 (January 2021): 111423. http://dx.doi.org/10.1016/j.engstruct.2020.111423.
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Wang, Chung Sheng, Xiao Hong Dong, Wen Hui Miao, and Gan Li. "Fatigue Safety Evaluation of Existing Reinforced Concrete Bridges." Key Engineering Materials 413-414 (June 2009): 749–56. http://dx.doi.org/10.4028/www.scientific.net/kem.413-414.749.
Повний текст джерелаАнотація:
Generally, fatigue has not been considered as a key problem in the design of reinforced concrete bridges. Until the 1960s, reinforcement was mild steel and the stresses permitted in the steel bar and the concrete were such that fatigue and fracture failure was believed to be impossible. With the developments of reinforced concrete structures, higher working stresses were permitted and, in particular, high yield reinforcing bars were introduced. Design rules were issued to control cracking and to prohibit welding of reinforcement unless the risk of fatigue was negligible. In recent years, great deals of researches have been carried out, leading to a better understanding of the fatigue behaviors in concrete structures. Some studies showed that fatigue could occur in reinforced concrete structures in combination with other causes of deterioration. In the past eight years, considerable increases in traffic intensity and wheel loads have caused obviously fatigue damage in reinforced concrete structures in China. Some reinforced concrete bridges were damaged seriously, leading to the whole bridge collapse sometimes because of overloading and oversize trucks. So how to evaluate the fatigue safety of existing reinforced concrete bridges is an urgent problem in China. In the current paper, the assessment models of existing reinforced concrete bridges based on S-N curve and fracture mechanics approach were proposed considering the effect of overloading and oversize trucks. Finally the assessment method based on S-N curve and in-situ monitoring data was applied to a case study bridge.
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Yan, Bo, Yu Hui Zhou, Fei Liu, and Zhi Gang Jiang. "Numerical Study on Damage Mechanism of PRC T-Beam under Close-In Blast Loading." Applied Mechanics and Materials 730 (January 2015): 55–64. http://dx.doi.org/10.4028/www.scientific.net/amm.730.55.
Повний текст джерелаАнотація:
The RC beam damage induced by blast loading might lead to partial or total collapse of bridges. Improved understanding of damage mechanism of the RC beam under blast loading helps advances in the analysis and assessment of bridge damage effects. In this paper, the damage mechanism of prestressed reinforced concrete (PRC) T-beam under close-in blast loading is investigated numerically with a three-dimensional numerical model. The model is validated by comparing simulating results with the experimental data reported by other researchers. Intensive numerical simulations are then carried out to reproduce the damage process of the T-beam as well as to investigate the damage mode and mechanism of the PRC T-beam components.
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Maroni, Andrea, Enrico Tubaldi, Neil Ferguson, Alessandro Tarantino, Hazel McDonald, and Daniele Zonta. "Electromagnetic Sensors for Underwater Scour Monitoring." Sensors 20, no. 15 (July 23, 2020): 4096. http://dx.doi.org/10.3390/s20154096.
Повний текст джерелаАнотація:
Scour jeopardises the safety of many civil engineering structures with foundations in riverbeds and it is the leading cause for the collapse of bridges worldwide. Current approaches for bridge scour risk management rely mainly on visual inspections, which provide unreliable estimates of scour and of its effects, also considering the difficulties in visually monitoring the riverbed erosion around submerged foundations. Thus, there is a need to introduce systems capable of continuously monitoring the evolution of scour at bridge foundations, even during extreme flood events. This paper illustrates the development and deployment of a scour monitoring system consisting of smart probes equipped with electromagnetic sensors. This is the first application of this type of sensing probes to a real case-study for continuous scour monitoring. Designed to observe changes in the permittivity of the medium around bridge foundations, the sensors allow for detection of scour depths and the assessment of whether the scour hole has been refilled. The monitoring system was installed on the A76 200 Bridge in New Cumnock (S-W Scotland) and has provided a continuous recording of the scour for nearly two years. The scour data registered after a peak flood event (validated against actual measurements of scour during a bridge inspection) show the potential of the technology in providing continuous scour measures, even during extreme flood events, thus avoiding the deployment of divers for underwater examination.
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Dunai, László, and Balázs Kövesdi. "Damage assessment of the historical Széchenyi Chain Bridge." Journal of Computational and Applied Mechanics 15, no. 2 (2020): 101–14. http://dx.doi.org/10.32973/jcam.2020.007.
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The Széchenyi Chain Bridge is a 170-year-old historical structure located in the downtown of Budapest. The superstructure of the bridge was reconstructed several times in its history and currently the renewal process of the bridge is under consideration. According to the current plans main girders, chain elements and cross-girders will remain the old structure and the deck system will be replaced by a new orthotropic steel deck. The Budapest University of Technology and Economics, Department of Structural Engineering was involved in the design process and in the assessment of the remaining elements’ condition within the last 5 years. During the project authors were faced with numerous specific important and challenging structural problems, modelling specialties, advanced design methods and research interest. The main part of these unusual characteristics come from the layout of the historical structure, long time traffic and corrosion problems. One of the most important questions during the structural analysis is the condition and rotational capacity of the pins between the chain elements. The chain system is more than 100 years old and the rotational capacity of the pins is questionable due to corrosion and friction. This phenomenon significantly influences the static behaviour of the chain elements and the whole suspending system. The current paper presents the numerical and on-site experimental program on the investigation of the rotational capacity of the pins. A second important question was related to the condition of current deck system. Significant corrosion damage was observed on the steel stringers which might cause damage or local collapse of the bridge deck under public transportation loads. Advanced numerical model using probabilistic analysis (FORM) and measurement based corrosion models are applied to make a risk assessment of the deck system's capability to maintain and keep the current traffic on the bridge before the deck will be replaced. Via this bridge inspection and investigation project the authors would like to demonstrate the application of advanced numerical modelling based design techniques and the industrial application of research models for lifetime assessment and risk analysis of historical structures.
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Huang, Jerry I., Bret Peterson, Kate Bellevue, Nicolas Lee, Sean Smith, and Safa Herfat. "Biomechanical Assessment of the Dorsal Spanning Bridge Plate in Distal Radius Fracture Fixation: Implications for Immediate Weight-Bearing." HAND 13, no. 3 (April 7, 2017): 336–40. http://dx.doi.org/10.1177/1558944717701235.
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Background: The goal of this study was to compare the biomechanical stability of a 2.4-mm dorsal spanning bridge plate with a volar locking plate (VLP) in a distal radius fracture model, during simulated crutch weight-bearing. Methods: Five paired cadaveric forearms were tested. A 1-cm dorsal wedge osteotomy was created to simulate an unstable distal radius fracture with dorsal comminution. Fractures were fixed with a VLP or a dorsal bridge plate (DBP). Specimens were mounted to a crutch handle, and optical motion-tracking sensors were attached to the proximal and distal segments. Specimens were loaded in compression at 1 mm/s on a servohydraulic test frame until failure, defined as 2 mm of gap site displacement. Results: The VLP construct was significantly more stable to axial load in a crutch weight-bearing model compared with the DBP plate (VLP: 493 N vs DBP: 332 N). Stiffness was higher in the VLP constructs, but this was not statistically significant (VLP: 51.4 N/mm vs DBP: 32.4 N/mm). With the crutch weight-bearing model, DBP failed consistently with wrist flexion and plate bending, whereas VLP failed with axial compression at the fracture site and dorsal collapse. Conclusions: Dorsal spanning bridge plating is effective as an internal spanning fixator in treating highly comminuted intra-articular distal radius fracture and prevents axial collapse at the radiocarpal joint. However, bridge plating may not offer advantages in early weight-bearing or transfer in polytrauma patients, with less axial stability in our crutch weight-bearing model compared with volar plating. A stiffer 3.5-mm DBP or use of a DBP construct without the central holes may be considered for distal radius fractures if the goal is early crutch weight-bearing through the injured extremity.
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Leng, Yanling, Jinquan Zhang, Ruinian Jiang, and Yangjian Xiao. "Experimental Study on the System Performance of Adjacent Precast Concrete Box Beam Bridges." Advances in Civil Engineering 2020 (March 13, 2020): 1–13. http://dx.doi.org/10.1155/2020/9708327.
Повний текст джерелаАнотація:
Analyses of catastrophic collapse of some adjacent precast concrete box beam bridges reveal the fact that the hinge joints between the adjacent beams were not sufficiently designed. The joint failure caused by deterioration is the result of system reliability deficiency of this type of bridges. To understand the system performance of the bridges, the redundancy and robustness of a bridge model with a scale of 1 ∶ 2, based on the prototype design drawings for 10-meter adjacent box beam bridges in China, were assessed through a system safety evaluation procedure. The result confirmed the assumption that the redundancy and robustness of certain adjacent precast concrete beam bridges did not meet the pertinent requirements proposed in National Cooperative Highway Research Program (NCHRP) reports 406, 458, and 776 as a result of hinge joint failure. To address the current design deficiencies, a system factor is recommended in this paper to calculate the nominal resistance that reflects the level of redundancy of this type of bridges. In addition, a new framework is proposed to address the particular structural feature and topology of adjacent precast concrete beam bridges for the assessment of structural redundancy and robustness, which can reduce the computation complexity compared to existing approaches. The full-range load test performed in this research verified the previous research results on bridge system safety that were mainly based on theoretical analysis and simulations.
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Fiandaca, Dario, Alberto Di Matteo, Bernardo Patella, Nadia Moukri, Rosalinda Inguanta, Daniel Llort, Antonio Mulone, Angelo Mulone, Soughah Alsamahi, and Antonina Pirrotta. "An Integrated Approach for Structural Health Monitoring and Damage Detection of Bridges: An Experimental Assessment." Applied Sciences 12, no. 24 (December 19, 2022): 13018. http://dx.doi.org/10.3390/app122413018.
Повний текст джерелаАнотація:
The issue of monitoring the structural condition of bridges is becoming a top priority worldwide. As is well known, any infrastructure undergoes a progressive deterioration of its structural conditions due to aging by normal service loads and environmental conditions. At the same time, it may suffer serious damages or collapse due to natural phenomena such as earthquakes or strong winds. For this reason, it is essential to rely on efficient and widespread monitoring techniques applied throughout the entire road network. This paper aims to introduce an integrated procedure for structural and material monitoring. With regard to structural monitoring, an innovative approach for monitoring based on Vehicle by Bridge Interaction (VBI) will be proposed. Furthermore, with regard to material monitoring, to evaluate concrete degradation, a non-invasive method based on the continuous monitoring of the pH, as well as chloride and sulfate ions concentration in the concrete, is presented.
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Parghi, Anant, and M. Shahria Alam. "Seismic collapse assessment of non-seismically designed circular RC bridge piers retrofitted with FRP composites." Composite Structures 160 (January 2017): 901–16. http://dx.doi.org/10.1016/j.compstruct.2016.10.094.
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Wu, Fangwen, Jianfei Luo, Wei Zheng, Cheng Cai, Jun Dai, Yajun Wen, and Quanyou Ji. "Performance-Based Seismic Fragility and Residual Seismic Resistance Study of a Long-Span Suspension Bridge." Advances in Civil Engineering 2020 (September 30, 2020): 1–16. http://dx.doi.org/10.1155/2020/8822955.
Повний текст джерелаАнотація:
Earthquakes can cause serious damage to traffic infrastructure and even induce the collapse of bridges, which is even worse. At the same time, earthquakes are key factors to the overall service capacity of the traffic network. Therefore, mastering the failure mechanism and evaluating accurate residual seismic resistance of a bridge under earthquakes are of great significance to the rapid recovery of traffic network function. For this reason, a performance-based methodology for the evaluation of the residual seismic resistance of a suspension bridge is proposed. In this paper, we provide the fragility curves of the key sections of the pier by incremental dynamic analysis (IDA), mathematical statistical analysis, and the damage law and obtained the failure state of the structure and the overall seismic capacity residual ratio and the stage seismic capacity residual ratio of the structure. Then, based on the research results of IDA, the reserve seismic capacity is analyzed as well. The research results explore a new method to accurately estimate the residual seismic capacity for resilience assessment.
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Lin, Kaiqi, You-Lin Xu, Xinzheng Lu, Zhongguo Guan, and Jianzhong Li. "Digital twin-based collapse fragility assessment of a long-span cable-stayed bridge under strong earthquakes." Automation in Construction 123 (March 2021): 103547. http://dx.doi.org/10.1016/j.autcon.2020.103547.
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Pinka, Miroslav, and Martin Stolárik. "Seismic Response Hydraulic Hammer on the Secundary Lining Tunnel / Seizmická Odezva Hydraulického Bouracího Kladiva Na Definitivní Ostění Tunelu." Transactions of the VŠB – Technical University of Ostrava, Civil Engineering Series 12, no. 2 (December 1, 2012): 132–42. http://dx.doi.org/10.2478/v10160-012-0027-1.
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Abstract Construction and subsequent tunnels collapse of the Jablunkovsk’s pass are already among well known of the professional public. After the collapse left part of the tunnel already standing with secondary lining. The second part was temporarilied concrete secured stopper and heavy bridge formwork. During the progress of work was already reached that stage when plug must be removed. The stopper was removed by combination of blasting operations and hydraulic hammer. This article deals with seismic effect hydraulic hammer. It is therefore a unique measuring effect of vibration on the final tunnel lining. A vibration downturn was monitored in the first meters of the lining and the records were evaluated in the amplitude and frequency resort. This assessment was made on the basis CSN 73 0040.
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Memari, Ali M., Harry G. Harris, Ahmad A. Hamid, and Andrew Scanlon. "Seismic Evaluation of an Elevated Highway Bridge in a Low Seismic Region – a Case Study." Open Civil Engineering Journal 4, no. 1 (September 23, 2010): 72–87. http://dx.doi.org/10.2174/1874149501004010072.
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This paper presents the results of the seismic evaluation of an elevated seven-span bridge with tall piers in western Pennsylvania. The bridge was modeled using the SEISAB software, and the analysis used modal superposition method. Various modeling strategies related to piers, abutments, expansion joints, fixed joints, rocker bearings, and hanger supports were studied. Several modeling options were made to capture different behavior responses under seismic loading conditions. The force and displacement demands are compared, and an assessment is made with respect to the potential for damage based on the analysis results. The result of the study shows that for the level of earthquakes expected in the region, columns will not be overstressed. Furthermore, the analysis results show that displacements of the superstructure should not be of concern in light of the fact that there is sufficient bearing seat width and that concrete pedestals have been added in front of the bearing supports to presumably prevent the walking off of the bearing from the support. The study concludes that considering the low level of earthquakes expected in PA, the potential for collapse of the superstructure due to bearing support failure is negligible. The paper contributes to better understanding of the behavior of tall and elevated highway bridges in low seismic regions. The results of the study reinforce the view that decisions on seismic retrofit of such bridges in low seismic regions should not be based on column tie spacing.
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Hadizadeh-Bazaz, Mehrdad, Ignacio J. Navarro, and Víctor Yepes. "Life-Cycle Cost Assessment Using the Power Spectral Density Function in a Coastal Concrete Bridge." Journal of Marine Science and Engineering 11, no. 2 (February 16, 2023): 433. http://dx.doi.org/10.3390/jmse11020433.
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Recently, the repair and maintenance of structures has been necessary to prevent these structures’ sudden collapse and to prevent human and financial damage. A natural factor in marine environments that destroys structures and reduces their life is the presence of chloride ions. So regular health monitoring of concrete coastal buildings for on-time repair is essential. This study investigates the performance of the power spectral density (PSD) method as a non-destructive damage-detection method to monitor the location and amount of damage caused by chloride ions during a structure’s life using different approaches according to life-cycle assessment (LCA) and life-cycle cost assessment (LCCA). In this regard, chloride corrosion damage dependent on zone distance from seawater was first calculated to obtain the service life of each part of a coastal concrete bridge according to the conventional method. Based on rebar corrosion each year, the next stage forecasted the bridge’s concrete deterioration. The PSD method monitored the annual loss of reinforcement cross-sectional area, changes in dynamic characteristics such as stiffness and mass, and the bridge structure’s life using sensitivity equations and the linear-least-squares algorithm. Finally, according to the location and quality of damage in each year of bridge life until the end of life, LCC and maintenance and repair costs of the PSD method were compared with the conventional method. The results showed that this strategy was very effective at lowering and optimizing the costs of maintenance and repair caused by chloride corrosion.
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Martínez-Mártinez, Luis Horacio, Gustavo Mendoza-Chavez, David Joaquin Delgado-Hernandez, David De León Escobedo, Elia Mercedes Alonso Guzmán, Wilfrido Martínez Molina, Eleazar Arreygue-Rocha, Hugo L. Chavez-García, and Juan Carlos Arteaga-Arcos. "Advances of a FEM for the Failure Probability Evaluation of Masonry Vehicular Bridge Support Piers." Advanced Materials Research 538-541 (June 2012): 580–85. http://dx.doi.org/10.4028/www.scientific.net/amr.538-541.580.
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One of the responsibilities of a Civil Engineer is to make decisions regarding preservation of infrastructure; therefore, there have been established concepts such as risk and risk analysis. Risk analysis, is a methodology applied to determine and evaluate the risk magnitude. From the structural engineering point of view, it is required that any structure become secure, this means that the capacity to withstand external actions (strength) will be higher than these actions (loads). In order to determine the structural safety, it is required to define the failure of the structure that it is not strongly related with the collapse of the structure; the failure criteria needs to be fixed depending on the use of the building and the consequences associated with the interruption of services provided by the facility. The failure then, is calculated by means of a limit state function in where it is established the failure criteria; failure is reached when a specific condition (strength) is surpassed by the actions over the structure. The present work aims to propose a preliminary Finite Element Model (FEM) that represents a pier used as support for vehicular bridges. This FEM is required for the assessment of mechanical behavior of the structure that will be used for the determination of the limit state function needed for risk assessment. Most of the simulations with FEM presented in literature are very used for modeling of masonry walls, but it is not usual to model structures such as bridge piers.
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Demirel, Ismail Ozan, and Alper Aldemir. "Simplified Approach for Seismic Performance Assessment of Dry-Joint Masonry Arch Bridges." Buildings 11, no. 7 (July 20, 2021): 313. http://dx.doi.org/10.3390/buildings11070313.
Повний текст джерелаАнотація:
The seismic performance assessment of dry-joint masonry arches is challenging because of their unique structural characteristics. Widely used assessment methods developed for frame-type structures require the use of a material-dependent section response. In contrast, the response of a dry-joint arch is not dependent on the material capacity but characterized by the sustainment of stability, primarily depending on rigid body rotation or sliding motion at the interfaces between the adjacent voussoirs. A hybrid methodology, combining a simple finite element micro model with principles of limit analysis method, is proposed in this work for the seismic performance assessment of these structures. The nonlinearity is concentrated at interfaces of the model by means of shear and compression-only axial springs. Kinematic conditions yielding a possible collapse mechanism were traced at every step of the time history analysis by checking the failure of individual interfaces. The procedure is applied to an ancient dry-joint Roman arch bridge in close proximity to the North Anatolian fault subject to significant seismic risk. Along with the performance of the system in its current state, the effects of retrofitting measures were investigated in the scope of this study.
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Limongelli, M. P., M. Previtali, L. Cantini, S. Carosio, J. C. Matos, J. M. Isoird, H. Wenzel, and C. Pellegrino. "LIFECYCLE MANAGEMENT, MONITORING AND ASSESSMENT FOR SAFE LARGE-SCALE INFRASTRUCTURES: CHALLENGES AND NEEDS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W11 (May 4, 2019): 727–34. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w11-727-2019.
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<p><strong>Abstract.</strong> Many European infrastructures dating back to ’50 and ’60 of the last century like bridges and viaducts are approaching the end of their design lifetime. In most European countries costs related to maintenance of infrastructures reach a quite high percentage of the construction budget and additional costs in terms of traffic delay are due to downtime related to the inspection and maintenance interventions. In the last 30 years, the rate of deterioration of these infrastructures has increased due to increased traffic loads, climate change related events and man-made hazards. A sustainable approach to infrastructures management over their lifecycle plays a key role in reducing the impact of mobility on safety (over 50&thinsp;000 fatalities in EU per year) and the impact of greenhouse gases emission related to fossil fuels. The events related to the recent collapse of the Morandi bridge in Italy tragically highlighted the sheer need to improve resilience of aging transport infrastructures, in order to increase the safety for people and goods and to reduce losses of functionality and the related consequences. In this focus Structural Health Monitoring (SHM) is one of the key strategies with a great potential to provide a new approach to performance assessment and maintenance over the life cycle for an efficient, safe, resilient and sustainable management of the infrastructures. In this paper research efforts, needs and challenges in terms of performance monitoring, assessment and standardization are described and discussed.</p>
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Spinney, Jennifer A., and Karen E. Pennesi. "When the river started underneath the land: social constructions of a ‘severe’ weather event in Pangnirtung, Nunavut, Canada." Polar Record 49, no. 4 (June 15, 2012): 362–72. http://dx.doi.org/10.1017/s0032247412000320.
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ABSTRACTIn June 2008, the community of Pangnirtung, Nunavut, Canada experienced a rainstorm that caused structural damage to the community's bridge and extensive permafrost erosion along the Duval River. The local government characterised the event as ‘severe’ and focused their attention on the bridge collapse, in contrast to the residents, who described this particular consequence as inconvenient at worst and at best, exciting. Instead residents expressed greater concern for the permafrost erosion and the uncertainty this posed for community well-being. This article follows an 11 week anthropological field trip to Pangnirtung in the summer of 2009 and is based on 31 semi-structured interviews, two focus group discussions, and participant observation. We explore how social processes influence subjective constructions of what constitutes ‘severe’ weather in the community, and attempt to explain how such constructions lead to differing perceptions of vulnerability to ‘severe’ weather events. Contributing factors including the normalisation of threat, local beliefs regarding change and uncertainty, as well as the communication of risk information are discussed along with the different coping strategies used by government and residents in managing their perceived levels of vulnerability. The research shows the importance of understanding the role social processes play in shaping local conceptions of ‘severe’ and perceptions of vulnerability to ‘severe’ weather events. This study enhances understandings of difference within populations and adds to the growing body of literature that demonstrates the need to incorporate locally relevant indices when conducting vulnerability assessment.
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Wang, Zhengnan, Xiaowei Deng, Xiheng Luo, Xinzhi Dang, and Junjun Guo. "Aftershock Fragility Assessment of Continuous RC Girder Bridges Using a Modified Damage Index." Buildings 12, no. 10 (October 12, 2022): 1675. http://dx.doi.org/10.3390/buildings12101675.
Повний текст джерелаАнотація:
Aftershock fragility is usually calculated conditioned on a range of potential post-mainshock damage states. The post-mainshock damage can be identified using damage indices, the latter being frequently associated with displacement-based parameters such as the maximum drift ratio or the residual displacement. However, when the reliable simulation of a structural system in a specific post-mainshock damage state is the objective of a numerical study, using such damage indicators may not assure the structure experiencing a homogeneous level of damage due to different mainshocks characteristics, which induce the aftershock fragility results unreliable. Along these lines, the current study presents a damage evaluation methodology mainly used for aftershock fragility assessment. It aims to reduce the variation of damage levels derived by using different mainshock seismic motions. The methodology presented herein includes: (i) the introduction of a damage index defined by comparing the monotonic pushover curve of the intact and post-earthquake damaged structure; (ii) the description of a finite element (FE)-based scheme that enables to quantify of the proposed damage index; and (iii) a deterioration-related modeling technique that can capture both strength and stiffness degrading performance of structural systems exposed to earthquake-induced excitations. The latter is essential to support the FE-based quantification scheme for the damage index. This methodology evaluation methodology can be primarily used for calculating the aftershock fragility assessment for a multi-span RC continuous girder bridge. The back-to-back incremental dynamic analysis framework uses a larger number of mainshock-aftershock artificial sequences to generate the aftershock fragility curves. The AS fragility results obtained via MBDI are compared with that via maximum drift ratio in terms of the ability to reduce the variation of residual capacities obtained using different mainshocks to induce a specific damage state but collapse by the same aftershock. The comparison shows a more robust relationship of MBDI with the residual capacity. It is found that MBDI, as well as its quantification approach proposed in this study, is a more effective damage predictor than the widely used displacement-based indices for AS fragility assessment.
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Harirchian, Ehsan, Kirti Jadhav, Kifaytullah Mohammad, Seyed Ehsan Aghakouchaki Hosseini, and Tom Lahmer. "A Comparative Study of MCDM Methods Integrated with Rapid Visual Seismic Vulnerability Assessment of Existing RC Structures." Applied Sciences 10, no. 18 (September 14, 2020): 6411. http://dx.doi.org/10.3390/app10186411.
Повний текст джерелаАнотація:
Recently, the demand for residence and usage of urban infrastructure has been increased, thereby resulting in the elevation of risk levels of human lives over natural calamities. The occupancy demand has rapidly increased the construction rate, whereas the inadequate design of structures prone to more vulnerability. Buildings constructed before the development of seismic codes have an additional susceptibility to earthquake vibrations. The structural collapse causes an economic loss as well as setbacks for human lives. An application of different theoretical methods to analyze the structural behavior is expensive and time-consuming. Therefore, introducing a rapid vulnerability assessment method to check structural performances is necessary for future developments. The process, as mentioned earlier, is known as Rapid Visual Screening (RVS). This technique has been generated to identify, inventory, and screen structures that are potentially hazardous. Sometimes, poor construction quality does not provide some of the required parameters; in this case, the RVS process turns into a tedious scenario. Hence, to tackle such a situation, multiple-criteria decision-making (MCDM) methods for the seismic vulnerability assessment opens a new gateway. The different parameters required by RVS can be taken in MCDM. MCDM evaluates multiple conflicting criteria in decision making in several fields. This paper has aimed to bridge the gap between RVS and MCDM. Furthermore, to define the correlation between these techniques, implementation of the methodologies from Indian, Turkish, and Federal Emergency Management Agency (FEMA) codes has been done. The effects of seismic vulnerability of structures have been observed and compared.
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Flores-Vidriales, David, Roberto Gómez, and Dante Tolentino. "Stochastic Assessment of Scour Hazard." Water 14, no. 3 (January 18, 2022): 273. http://dx.doi.org/10.3390/w14030273.
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Scour is the most frequent cause of bridge collapses in Mexico. Bridges located along the Mexican Pacific coast are exposed to extreme rainfall originating from tropical storms and hurricanes. Such environmental phenomena trigger sediment loss, which is known as scour. If maintenance actions are not taken after scouring events, the scour depth increases over time until the bridge collapses. A methodology to estimate the scour hazard considering both the scour–fill interaction and the Monte Carlo simulation method is proposed. The general extreme value probability distribution is used to characterize the intensity of the scouring events, the lognormal distribution is used to characterize the sedimentation process (fill), and a homogeneous Poisson process is used to forecast the occurrence of both types of events. Based on the above, several histories of scour–fill depths are made; such simulations are then used to develop time-dependent scour hazard curves. Different hazard curves associated with different time intervals are estimated for a bridge located in Oaxaca, Mexico.
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Keys, Harry J. R., and Paul M. Green. "Ruapehu Lahar New Zealand 18 March 2007: Lessons for Hazard Assessment and Risk Mitigation 1995-2007." Journal of Disaster Research 3, no. 4 (August 1, 2008): 284–96. http://dx.doi.org/10.20965/jdr.2008.p0284.
Повний текст джерелаАнотація:
A moderately large lahar caused by a collapse of a tephra dam over the outlet of Crater Lake occurred 11 years and 4 months after the situation that led to it was first recognized. This allowed sufficient time for the considerable period needed by emergency managers and the Government to learn from scientists about the hazard, assess risks in pragmatic and robust ways, debate and progressively mitigate them. Early involvement of a wide range of agencies and the media was encouraged, enabling transfer of knowledge, development of interagency relationships and provided fora for a mitigation strategy to evolve in the face of sometimes controversial mitigation options. Decisions about options were based primarily on maximizing public safety and long-term utility in a valley subject to frequent, sometimes large, past and future lahars. These decisions, which had a significant political component also considered option suitability in a national park setting. A best-practice alarm system was installed based on acoustic flow monitors. A training levee structure was built to protect a highway and other vulnerable infrastructure and a river system near-by, and a key highway bridge raised and strengthened. Response agencies each prepared their own emergency plans which were then integrated and practiced over 3-4 years, incorporating an increasing readiness triggered by a Warning Level system linking to rising lake levels. Execution of the plans progressed smoothly on 18 March. The outcome showed that community resilience to lahars was achieved by adopting long-term solutions, rather than short-term ones, and carefully considering cultural, social, and technological perspectives, especially in a national park setting. Decision-making procedures that give weight to impartial scientific information, as well as values and legislation, are required for effective disaster mitigation, including an acceptance of an appropriate degree of residual risk.