WorldWideScience

Sample records for bridges

  1. Bridges

    NARCIS (Netherlands)

    Zant, W.

    2017-01-01

    We estimate to what extent bridges in Mozambique lead to transport cost reductions and attribute these reductions to key determinants, in particular road distance, road quality and crossing borders. For identification we exploit the introduction of a road bridge over the Zambezi river, in August

  2. Railroad Bridges

    Data.gov (United States)

    Department of Homeland Security — Bridges-Rail in the United States According to The National Bridge Inspection Standards published in the Code of Federal Regulations (23 CFR 650.3), a bridge isA...

  3. Myocardial Bridge

    Science.gov (United States)

    ... Sudden Cardiac Arrest Valve Disease Vulnerable Plaque Myocardial Bridge Related terms: myocardium, coronary arteries, myocardial ischemia Your ... surface of the heart. What is a myocardial bridge? A myocardial bridge is a band of heart ...

  4. Myocardial Bridging

    Directory of Open Access Journals (Sweden)

    Shi-Min Yuan

    2016-02-01

    Full Text Available Abstract Myocardial bridging is rare. Myocardial bridges are most commonly localized in the middle segment of the left anterior descending coronary artery. The anatomic features of the bridges vary significantly. Alterations of the endothelial morphology and the vasoactive agents impact on the progression of atherosclerosis of myocardial bridging. Patients may present with chest pain, myocardial infarction, arrhythmia and even sudden death. Patients who respond poorly to the medical treatment with β-blockers warrant a surgical intervention. Myotomy is a preferred surgical procedure for the symptomatic patients. Coronary stent deployment has been in limited use due to the unsatisfactory long-term results.

  5. Bridge Management Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper bridge management systems are discussed with special emphasis on management systems for reinforced concrete bridges. Management systems for prestressed concrete bridges, steel bridges, or composite bridges can be developed in a similar way....

  6. National Bridge Inventory (NBI) Bridges

    Data.gov (United States)

    Department of Homeland Security — The NBI is a collection of information (database) describing the more than 600,000 of the Nation's bridges located on public roads, including Interstate Highways,...

  7. Building Bridges

    DEFF Research Database (Denmark)

    The report Building Bridges adresses the questions why, how and for whom academic audience research has public value, from the different points of view of the four working groups in the COST Action IS0906 Transforming Audiences, Transforming Societies – “New Media Genres, Media Literacy and Trust...... in the Media”, “Audience Interactivity and Participation”, “The Role of Media and ICT Use for Evolving Social Relationships” and “Audience Transformations and Social Integration”. Building Bridges is the result of an ongoing dialogue between the Action and non-academic stakeholders in the field of audience...

  8. Bridged graphite oxide materials

    Science.gov (United States)

    Herrera-Alonso, Margarita (Inventor); McAllister, Michael J. (Inventor); Aksay, Ilhan A. (Inventor); Prud'homme, Robert K. (Inventor)

    2010-01-01

    Bridged graphite oxide material comprising graphite sheets bridged by at least one diamine bridging group. The bridged graphite oxide material may be incorporated in polymer composites or used in adsorption media.

  9. Mathematical bridges

    CERN Document Server

    Andreescu, Titu; Tetiva, Marian

    2017-01-01

    Building bridges between classical results and contemporary nonstandard problems, Mathematical Bridges embraces important topics in analysis and algebra from a problem-solving perspective. Blending old and new techniques, tactics and strategies used in solving challenging mathematical problems, readers will discover numerous genuine mathematical gems throughout that will heighten their appreciation of the inherent beauty of mathematics. Most of the problems are original to the authors and are intertwined in a well-motivated exposition driven by representative examples. The book is structured to assist the reader in formulating and proving conjectures, as well as devising solutions to important mathematical problems by making connections between various concepts and ideas from different areas of mathematics. Instructors and educators teaching problem-solving courses or organizing mathematics clubs, as well as motivated mathematics students from high school juniors to college seniors, will find Mathematical Bri...

  10. Bridge resource program.

    Science.gov (United States)

    2013-09-01

    The mission of Rutgers Universitys Center for Advanced Infrastructure and Transportation (CAIT) Bridge Resource Program (BRP) is to provide bridge engineering support to the New Jersey Department of Transportation (NJDOT)s Bridge Engineering an...

  11. Bridging consent: from toll bridges to lift bridges?

    Directory of Open Access Journals (Sweden)

    Knoppers Bartha

    2011-10-01

    Full Text Available Abstract Background The ability to share human biological samples, associated data and results across disease-specific and population-based human research biobanks is becoming increasingly important for research into disease development and translation. Although informed consent often does not anticipate such cross-domain sharing, it is important to examine its plausibility. The purpose of this study was to explore the feasibility of bridging consent between disease-specific and population-based research. Comparative analyses of 1 current ethical and legal frameworks governing consent and 2 informed consent models found in disease-specific and population-based research were conducted. Discussion Ethical and legal frameworks governing consent dissuade cross-domain data sharing. Paradoxically, analysis of consent models for disease-specific and population-based research reveals such a high degree of similarity that bridging consent could be possible if additional information regarding bridging was incorporated into consent forms. We submit that bridging of consent could be supported if current trends endorsing a new interpretation of consent are adopted. To illustrate this we sketch potential bridging consent scenarios. Summary A bridging consent, respectful of the spirit of initial consent, is feasible and would require only small changes to the content of consents currently being used. Under a bridging consent approach, the initial data and samples collection can serve an identified research project as well as contribute to the creation of a resource for a range of other projects.

  12. Bridge vehicle impact assessment.

    Science.gov (United States)

    2011-12-01

    Bridges in New York State have been experiencing close to 200 bridge hits a year. These : accidents are attributed to numerous factors including: improperly stored equipment on trucks; : violation of vehicle posting signs; illegal commercial vehicles...

  13. Movable bridge maintenance monitoring.

    Science.gov (United States)

    2013-10-01

    Movable bridges have particular maintenance issues, which cost considerably more than those of fixed bridges, : mostly because of the complex interaction of the mechanical, electrical and structural components. In order to track : maintenance and ope...

  14. Cable Supported Bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    Cable supported bridges in the form of suspension bridges and cable-stayed bridges are distinguished by their ability to overcome large spans.The book concentrates on the synthesis of cable supported bridges, covering both design and construction aspects. The analytical part covers simple methods...... to quantify the different structural configurations and allows a preliminary optimization of the main structure.Included are the most recent advances in structural design, corrosion protection of cables, aerodynamic safety, and erection procedures....

  15. Bridge Crossing Simulator

    Science.gov (United States)

    2014-10-07

    support the durability testing of Military Bridging and Gap Crossing Equipment. 15. SUBJECT TERMS Bridge Crossing Simulator Trilateral Design... Trilateral Design and Test Code for Military Bridging and Gap Crossing Equipment (TDTC) 1* is derived based on the number of samples the test bridge...Automotive and Armaments Command TARDEC U.S. Army Tank-Automotive Research, Development and Engineering Center TDTC Trilateral Design and Test Code

  16. Principles of Bridge Reliability

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, Andrzej S.

    The paper gives a brief introduction to the basic principles of structural reliability theory and its application to bridge engineering. Fundamental concepts like failure probability and reliability index are introduced. Ultimate as well as serviceability limit states for bridges are formulated......, and as an example the reliability profile and a sensitivity analyses for a corroded reinforced concrete bridge is shown....

  17. [Composite (etched) bridge].

    Science.gov (United States)

    de Kloet, H J; van Pelt, A W

    1996-11-01

    An adhesive or resin-bonded bridge is a tooth saving construction for the replacement of a lost tooth, especially when the abutment teeth are relatively sound. In this article an overview is presented of the different types of resin-bonded bridges, their advantages and disadvantages and their indications. The direct methods are very suited for the immediate replacement of a lost anterior tooth. The all composite adhesive bridge has a survival rate that is surprisingly good.

  18. Bridging the Gap

    DEFF Research Database (Denmark)

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska

    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures.......Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures....

  19. Bridge health monitoring metrics : updating the bridge deficiency algorithm.

    Science.gov (United States)

    2009-10-01

    As part of its bridge management system, the Alabama Department of Transportation (ALDOT) must decide how best to spend its bridge replacement funds. In making these decisions, ALDOT managers currently use a deficiency algorithm to rank bridges that ...

  20. Covered Bridge Security Manual

    Science.gov (United States)

    Brett Phares; Terry Wipf; Ryan Sievers; Travis Hosteng

    2013-01-01

    The design, construction, and use of covered timber bridges is all but a lost art in these days of pre-stressed concrete, high-performance steel, and the significant growth both in the volume and size of vehicles. Furthermore, many of the existing covered timber bridges are preserved only because of their status on the National Registry of Historic Places or the...

  1. Bridges Expansion Joints

    OpenAIRE

    Sergey W. Kozlachkow

    2012-01-01

    The survey is concerned with the expansion joints, used in bridge constructions to compensate medium and significant operational linear and spatial displacements between adjacent spans or between bridge span and pier. The analysis of design features of these types of expansion joints, their advantages and disadvantages, based on operational experience justified the necessity to design constructions, meeting the modern demands imposed to expansion joints.

  2. Students design composite bridges

    NARCIS (Netherlands)

    Stark, J.W.B.; Galjaard, J.C.; Brekelmans, J.W.P.M.

    1999-01-01

    The paper gives an overview of recent research on steel-concrete composite bridge design by students of Delft University of Technology doing their master's thesis. Primary objective of this research was to find possibilities for application of steel-concrete composite bridges in the Netherlands,

  3. Bridge the Gap

    DEFF Research Database (Denmark)

    Marselis, Randi Lorenz

    2017-01-01

    This article focuses on photo projects organised for teenage refugees by the Society for Humanistic Photography (Berlin, Germany). These projects, named Bridge the Gap I (2015), and Bridge the Gap II (2016), were carried out in Berlin and brought together teenagers with refugee and German...

  4. Virtual Bridge Design Challenge

    Science.gov (United States)

    Mitts, Charles R.

    2013-01-01

    This design/problem-solving activity challenges students to design a replacement bridge for one that has been designated as either structurally deficient or functionally obsolete. The Aycock MS Technology/STEM Magnet Program Virtual Bridge Design Challenge is an authentic introduction to the engineering design process. It is a socially relevant…

  5. Linguistic Barriers and Bridges

    DEFF Research Database (Denmark)

    Thuesen, Frederik

    2016-01-01

    The influence of language on social capital in low-skill and ethnically diverse workplaces has thus far received very limited attention within the sociology of work. As the ethnically diverse workplace is an important social space for the construction of social relations bridging different social...... communication related to collaboration and ‘small talk’ may provide linguistic bridges to social capital formation....

  6. Long Span Bridges in Scandinavia

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1998-01-01

    is found in Scandinavia - the 1210 m span of the Höga Kusten Bridge in Sweden.The Kvarnsund Bridge in Norway was at the completion in 1991 the longest cable-stayed bridge in the world, and the span of 530 m is still thge longest for cable-stayed bridges in concrete. The Øresund Bridge with its sapn of 490...... m is the longest among cable-stayed bridges for both road and railway traffic....

  7. Sustainable Bridge Infrastructure Procurement

    DEFF Research Database (Denmark)

    Safi, Mohammed; Du, Guangli; Simonsson, Peter

    2016-01-01

    The lack of a flexible but systematic approach for integrating lifecycle aspects into bridge investment decisions is a major obstacle hindering the procurement of sustainable bridge infrastructures. This paper addresses this obstacle by introducing a holistic approach that agencies could use to p...... to procure the most “sustainable” (lifecycle-efficient) bridge through a fair design-build (D-B) tendering process, considering all the main aspects: life-cycle cost (LCC), service life-span, aesthetic demands and environmental impacts (LCA).......The lack of a flexible but systematic approach for integrating lifecycle aspects into bridge investment decisions is a major obstacle hindering the procurement of sustainable bridge infrastructures. This paper addresses this obstacle by introducing a holistic approach that agencies could use...

  8. Bridge technology report

    CERN Document Server

    2013-01-01

    Please note this is a Short Discount publication. As LANs have proliferated, new technologies and system concepts have come to the fore. One of the key issues is how to interconnect networks. One means of interconnection is to use a 'bridge'. Other competing technologies are repeaters, routers, and gateways. Bridges permit traffic isolation, connect network segments together and operate at the MAC layer. Further, because they operate at the MAC layer, they can handle a variety of protocols such as TCP/IP, SNA, and X.25. This report focuses on the specific technology of bridging two netw

  9. Sustainable Bridge Infrastructure Procurement

    DEFF Research Database (Denmark)

    Safi, Mohammed; Du, Guangli; Simonsson, Peter

    2016-01-01

    The lack of a flexible but systematic approach for integrating lifecycle aspects into bridge investment decisions is a major obstacle hindering the procurement of sustainable bridge infrastructures. This paper addresses this obstacle by introducing a holistic approach that agencies could use to p...... to procure the most “sustainable” (lifecycle-efficient) bridge through a fair design-build (D-B) tendering process, considering all the main aspects: life-cycle cost (LCC), service life-span, aesthetic demands and environmental impacts (LCA)....

  10. The Cultural Bridge Model.

    Science.gov (United States)

    West, Edith A.

    1993-01-01

    Offers a cultural bridge model that would enhance the health care of the American Indian population. Suggests that transcultural nursing should transcend the realm of thought and become an integrated part of daily practice. (Author)

  11. Bridged Race Population Estimates

    Data.gov (United States)

    U.S. Department of Health & Human Services — Population estimates from "bridging" the 31 race categories used in Census 2000, as specified in the 1997 Office of Management and Budget (OMB) race and ethnicity...

  12. State's First Bridge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Article with details on the state's first bridge that crossed the Noxubee River adjacent to the Noxubee National Wildlife Refuge Boundary. Details also included...

  13. Forward Affect Bridge.

    Science.gov (United States)

    Bonshtein, Udi; Torem, Moshe

    2017-01-01

    This article presents a modification of the affect bridge technique. The Forward Affect Bridge enables practitioners to create and maintain hope when it is missing. Hope is relevant for diminishing avoidance and being involved with necessary activities. The main idea is to build up a positive atmosphere in the here and now (relying on rapport), to amplify it, and to project it forward. By using clinical vignettes, the authors illustrate these techniques.

  14. Bridges Expansion Joints

    Directory of Open Access Journals (Sweden)

    Sergey W. Kozlachkow

    2012-05-01

    Full Text Available The survey is concerned with the expansion joints, used in bridge constructions to compensate medium and significant operational linear and spatial displacements between adjacent spans or between bridge span and pier. The analysis of design features of these types of expansion joints, their advantages and disadvantages, based on operational experience justified the necessity to design constructions, meeting the modern demands imposed to expansion joints.

  15. Active Control of Suspension Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper some recent research on active control of very long suspension bridges, is presented. The presentation is based on research work at Aalborg University, Denmark. The active control system is based on movable flaps attached to the bridge girder. Wind load on bridges with or without...... flaps attached to the girder is briefly presented. A simple active control system is discussed. Results from wind tunnel experiments with a bridge section show that flaps can be used effectively to control bridge girder vibrations. Flutter conditions for suspension bridges with and without flaps...

  16. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Bridge-to-bridge radiotelephone installation. 80.1007 Section 80.1007 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Bridge-to-Bridge Act § 80.1007 Bridge-to-bridge radiotelephone installation. Use of the bridge-to-bridge...

  17. Istanbul Bridge Conference 2014

    CERN Document Server

    Gülkan, Polat; Mahmoud, Khaled

    2016-01-01

      The book includes peer-reviewed contributions selected from presentations given at the Istanbul Bridge Conference 2014, held from August 11 – 13 in Istanbul, Turkey. It reports on the current challenges in bridge engineering faced by professionals around the globe, giving a special emphasis to recently developed techniques, innovations and opportunities. The book covers key topics in the field, including modeling and analysis methods; construction and erection techniques; design for extreme events and condition assessment and structural health monitoring. There is a balanced presentation of theory, research and practice. This book, which provides the readers with a comprehensive and timely reference guide on current practices in bridge engineering, is intended for professionals, academic researchers and students alike.

  18. Bridging the Gap

    DEFF Research Database (Denmark)

    Dahlberg, Rasmus

    2016-01-01

    The fixed link between Denmark and Sweden connects two busy cities and a large international airport with many of its travelers and employees. 18,000 vehicles and 160 passenger trains transport each day more than 70,000 people across the combined road and rail Øresund Bridge and through the Øresund...... Tunnel, approximately 25,000 of them critical to the regional work market. Even though the risk analysis states that the likelihood of a long-term closure (100C days) is very low Danish and Swedish transport authorities have demanded that the infrastructure operator conducts a survey of the preparedness...... in its final report to the Danish and Swedish transport authorities while drawing upon experiences from two recent comparable cases of infrastructure disruptions: The Champlain Bridge (2009) and the Forth Road Bridge (2015)....

  19. Development of bridge girder movement criteria for accelerated bridge construction.

    Science.gov (United States)

    2014-06-01

    End diaphragms connect multiple girders to form a bridge superstructure system for effective resistance to earthquake loads. Concrete : girder bridges that include end diaphragms consistently proved to perform well during previous earthquake events. ...

  20. Bridge-Vehicle Impact Assessment

    Science.gov (United States)

    2011-08-01

    Bridges in New York State have been experiencing close to 200 bridge hits a year. These : accidents are attributed to numerous factors including: improperly stored equipment on trucks; : violation of vehicle posting signs; illegal commercial vehicles...

  1. Existing Steel Railway Bridges Evaluation

    Directory of Open Access Journals (Sweden)

    Vičan Josef

    2016-12-01

    Full Text Available The article describes general principles and basis of evaluation of existing railway bridges based on the concept of load-carrying capacity determination. Compared to the design of a new bridge, the modified reliability level for existing bridges evaluation should be considered due to implementation of the additional data related to bridge condition and behaviour obtained from regular inspections. Based on those data respecting the bridge remaining lifetime, a modification of partial safety factors for actions and materials could be respected in the bridge evaluation process. A great attention is also paid to the specific problems of determination of load-caring capacity of steel railway bridges in service. Recommendation for global analysis and methodology for existing steel bridge superstructure load-carrying capacity determination are described too.

  2. Colorado statewide historic bridge inventory.

    Science.gov (United States)

    2011-05-01

    The purpose of the Colorado statewide historic bridge inventory was to document and evaluate the National : Register of Historic Places eligibility all on-system highway bridges and grade separation structures built in : Colorado between 1959 and 196...

  3. Strengthening bridges using composite materials.

    Science.gov (United States)

    1998-03-01

    The objective of this research project is to outline methodologies for using Fiber Reinforced Polymer (FRP) composites to strengthen and rehabilitate reinforced concrete bridge elements. : Infrastructure deterioration and bridge strengthening techniq...

  4. Virginia Bridge Information Systems Laboratory.

    Science.gov (United States)

    2014-06-01

    This report presents the results of applied data mining of legacy bridge databases, focusing on the Pontis and : National Bridge Inventory databases maintained by the Virginia Department of Transportation (VDOT). Data : analysis was performed using a...

  5. Uncontrolled concrete bridge parapet cracking.

    Science.gov (United States)

    2013-06-01

    The Ohio Department of Transportation has recently identified the problem of wide-spread premature cracking of concrete bridge : parapets throughout its District 12 region (Northeast Ohio). Many of the bridge decks that contain these prematurely crac...

  6. Building a Straw Bridge

    Science.gov (United States)

    Teaching Science, 2015

    2015-01-01

    This project is for a team of students (groups of two or three are ideal) to design and construct a model of a single-span bridge, using plastic drinking straws as the building material. All steps of the design, construction, testing and critiquing stages should be recorded by students in a journal. Students may like to include labelled diagrams,…

  7. Bridge the Gap.

    Science.gov (United States)

    Klein, Mel; Cufaude, Jeffrey B.

    1989-01-01

    This document consists of two paired articles: the first, "Preparing Faculty Out of Class Experiences," by Mel Klein, and the second, "Help Advisers Be More Than Ghost Signatures," by Jeffrey B. Calfaude. Each article shares insights on how faculty advisers "bridge the gap" between students and faculty. When faculty members are asked to advise…

  8. Bridging the gap

    Science.gov (United States)

    2012-08-01

    Astronomy is flourishing in China, with impressive achievements in instrument design and construction matched by a higher international research profile. Yet there remains a mismatch between the facilities available and those needed to progress. Sue Bowler wonders how the country will bridge the gap.

  9. Quantum Bidding in Bridge

    Directory of Open Access Journals (Sweden)

    Sadiq Muhammad

    2014-06-01

    Full Text Available Quantum methods allow us to reduce communication complexity of some computational tasks, with several separated partners, beyond classical constraints. Nevertheless, experimental demonstrations of this have thus far been limited to some abstract problems, far away from real-life tasks. We show here, and demonstrate experimentally, that the power of reduction of communication complexity can be harnessed to gain an advantage in a famous, immensely popular, card game—bridge. The essence of a winning strategy in bridge is efficient communication between the partners. The rules of the game allow only a specific form of communication, of very low complexity (effectively, one has strong limitations on the number of exchanged bits. Surprisingly, our quantum technique does not violate the existing rules of the game (as there is no increase in information flow. We show that our quantum bridge auction corresponds to a biased nonlocal Clauser-Horne-Shimony-Holt game, which is equivalent to a 2→1 quantum random access code. Thus, our experiment is also a realization of such protocols. However, this correspondence is not complete, which enables the bridge players to have efficient strategies regardless of the quality of their detectors.

  10. Bridge over troubled water?

    DEFF Research Database (Denmark)

    Svendsen, Gunnar Lind Haase; Nannestad, Peter; Svendsen, Gert Tinggaard

    2008-01-01

    The problem of integrating non-Western immigrants into Western welfare states is the focus of this paper. To address this issue, we suggest a social capital approach in which we apply the conceptual pair of bridging social capital (BR), which connects an individual to the broader social structure...

  11. Bridging the Gap?

    Science.gov (United States)

    Salter, Colin

    2009-01-01

    The political context of the conversion of the Historic Tramway Bridge, adjacent to Sandon Point in Bulli (NSW, Australia), and how this was exploited to serve predetermined ends, illustrates that technologies can be designed to have particular social (and political) effects. Through reflection on this relatively small engineering project, this…

  12. Revised Rules for Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Jensen, F. M.; Middleton, C.

    This paper is based on research performed for the Highway Agency, London, UK under the project DPU/9/44 "Revision of Bridge Assessment Rules Based on Whole Life Performance: Concrete Bridges" It contains details of a methodology which can be used to generate Whole Life (WL) reliability profiles....... These WL reliability profiles may be used to establish revised rules for Concrete Bridges....

  13. Bridge the Gap

    DEFF Research Database (Denmark)

    Marselis, Randi Lorenz

    2017-01-01

    This article focuses on photo projects organised for teenage refugees by the Society for Humanistic Photography (Berlin, Germany). These projects, named Bridge the Gap I (2015), and Bridge the Gap II (2016), were carried out in Berlin and brought together teenagers with refugee and German-majorit...... was produced – and sometimes not produced - within the projects. The importance of memory work in the context of refugee resettlement is often overlooked, but is particularly relevant when cultural encounters are organised in museums and exhibition galleries.......-majority backgrounds to experiment with digital photography and create joint exhibitions. Drawing on concepts from memory studies, such as travelling memory and multidirectional memory, the author examines the projects as interventions in German and Berlin memory cultures, and examines how multidirectional memory...

  14. Bridging Classroom Language Ethnography

    OpenAIRE

    Grenfell, Michael James

    2012-01-01

    PUBLISHED Paper #5: Bridging Classroom Language Ethnography, New Literacy Studies and Bourdieu?s Social Philosophy: Principles and Practice The purpose of this paper is to analyze and synthesize the various ways that classroom language ethnography, NLS, and Bourdieu?s social philosophy, were integrated. The goal of the analysis and synthesis is to provide a fresh perspective and fruitful insights on literacy in all its manifestations that provides the foundations for a more robust...

  15. Simulation of multivariate diffusion bridges

    DEFF Research Database (Denmark)

    Bladt, Mogens; Finch, Samuel; Sørensen, Michael

    We propose simple methods for multivariate diffusion bridge simulation, which plays a fundamental role in simulation-based likelihood and Bayesian inference for stochastic differential equations. By a novel application of classical coupling methods, the new approach generalizes a previously...... proposed simulation method for one-dimensional bridges to the mulit-variate setting. First a method of simulating approzimate, but often very accurate, diffusion bridges is proposed. These approximate bridges are used as proposal for easily implementable MCMC algorithms that produce exact diffusion bridges....... The new method is much more generally applicable than previous methods. Another advantage is that the new method works well for diffusion bridges in long intervals because the computational complexity of the method is linear in the length of the interval. In a simulation study the new method performs well...

  16. Morphological aspects of myocardial bridges

    Directory of Open Access Journals (Sweden)

    Almira Lujinović

    2013-11-01

    Full Text Available Although some myocardial bridges can be asymptomatic, their presence often causes coronary disease either through direct compression of the “tunnel” segment or through stimulation and accelerated development of atherosclerosis in the segment proximally to the myocardial bridge. The studied material contained 30 human hearts received from the Department of Anatomy. The hearts were preserved 3 to 5 days in 10% formalin solution. Thereafter, the fatty tissue was removed and arterial blood vessels prepared by careful dissection with special reference to the presence of the myocardial bridges. Length and thickness of the bridges were measured by the precise electronic caliper. The angle between the myocardial bridge fibre axis and other axis of the crossed blood vessel was measured by a goniometer. The presence of the bridges was confirmed in 53.33% of the researched material, most frequently (43.33% above the anterior interventricular branch. The mean length of the bridges was 14.64±9.03 mm and the mean thickness was 1.23±1.32 mm. Myocardial bridge fibres pass over the descending blood vessel at the angle of 10-90 degrees. The results obtained on a limited sample suggest that the muscular index of myocardial bridge is the highest for bridges located on RIA, but that the difference is not significant in relation to bridges located on other branches. The results obtained suggest that bridges located on other branches, not only those on RIA, could have a great contractive power and, consequently, a great compressive force, which would be exerted on the wall of a crossed blood vessel.

  17. MODERN ASPECTS OF BRIDGES MONITORING

    Directory of Open Access Journals (Sweden)

    M. I. Kazakevych

    2007-12-01

    Full Text Available The major concepts of the elaboration and realization of the bridge construction monitoring systemic approach are presented in this paper. The main peculiarity of the bridge monitoring modern aspect is pointed out here, namely, the transition from the demands of providing the reliability to the demands of providing the whole complex of the structure consumer qualities. The criteria of diagnostics of the bridge exploitation reliability as the fundamental aim of monitoring are formulated here.

  18. Bridging the Gap.

    Science.gov (United States)

    Webb, Michele

    2016-01-01

    The view from the top of Hoover Dam looking south over the Colorado River was breathtaking! My friend and I stood there in silence, taking it all in. I had visited Hoover Dam on many occasions, but this visit was the first time I had seen the arch bridge that carries US Route 93 over the river and joins Nevada and Arizona states. It was a beautiful day, the temperature was perfect, and there was a slight breeze coming from Lake Mead behind us as we took in the view.

  19. Bridging the Emissions Gap

    OpenAIRE

    Blok, K.

    2012-01-01

    The analyses in Chapters 2 and 3 of this report concluded that the emissions gap in 2020 will likely be between 8 and 13 GtCO2e. The chapters also estimated the difference between BaU emissions in 2020 and the emissions level consistent with a “likely” chance of staying within the 2°C target to be 14 GtCO2e. This chapter explores the potential for bridging this gap using a sector policy approach. Firstly, the chapter provides a summary and update of the estimated emission reduction potential ...

  20. Bridging biometrics and forensics

    Science.gov (United States)

    Yan, Yanjun; Osadciw, Lisa Ann

    2008-02-01

    This paper is a survey on biometrics and forensics, especially on the techniques and applications of face recognition in forensics. This paper describes the differences and connections between biometrics and forensics, and bridges each other by formulating the conditions when biometrics can be applied in forensics. Under these conditions, face recognition, as a non-intrusive and non-contact biometrics, is discussed in detail as an illustration of applying biometrics in forensics. The discussion on face recognition covers different approaches, feature extractions, and decision procedures. The advantages and limitations of biometrics in forensic applications are also addressed.

  1. 33 CFR 115.40 - Bridge repairs.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which do...

  2. Comprehensive evaluation of fracture critical bridges.

    Science.gov (United States)

    2014-02-01

    Two-girder steel bridges are classified as fracture critical bridges based on the definition given in the AASHTO LRFD Bridge Design Specifications. In a fracture critical bridge a failure of a tension member leads to collapse of the bridge. However, ...

  3. Environmental life cycle assessment comparison between two bridge types: reinforced concrete bridge and steel composite bridge

    DEFF Research Database (Denmark)

    Du, Guangli; Karoumi, Raid

    2013-01-01

    The concept of sustainable construction has attracted an increased attention. Bridge infrastructures and their belonged construction activities consume considerable material and energy, which is responsible for large environmental burdens. However, the environmental assessment of bridges has...... not been integrated into the decision-making process. This paper presents a systematic LCA method for quantifying the environmental impacts for bridges. The comparison study is performed between a reinforced concrete bridge and a steel bridge as an alternative design, with several key maintenance and EOL...... scenarios outlined. LCA study is performed with the ReCiPe methodology with life cycle inventories data from public database. Five selected mid-point level impact categories and the energy consumption are presented. The result shows that the steel bridge has a better environmental performance due...

  4. 47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Operator requirements of the Bridge-to-Bridge... Requirements § 80.163 Operator requirements of the Bridge-to-Bridge Act. Each ship subject to the Bridge-to-Bridge Act must have on board a radio operator who holds a restricted radiotelephone operator permit or...

  5. 47 CFR 80.331 - Bridge-to-bridge communication procedure.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Bridge-to-bridge communication procedure. 80..., Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a) Vessels subject to the Bridge-to-Bridge Act transmitting on the designated navigational frequency must conduct...

  6. Field performance of timber bridges. 7, Connell Lake stress-laminated deck bridge

    Science.gov (United States)

    L. E. Hislop; M. A. Ritter

    The Connell Lake bridge was constructed in early 1991 on the Tongass National Forest, Alaska, as a demonstration bridge under the Timber Bridge Initiative. The bridge is a stress-laminated deck structure with an approximate 36-ft length and 18-ft width and is the first known stress-laminated timber bridge constructed in Alaska. Performance of the bridge was monitored...

  7. Design of piles for integral abutment bridges.

    Science.gov (United States)

    1984-08-01

    More and more, integral abutment bridges are being used in place : of the more traditional bridge designs with expansion releases. In : this study, states which use integral abutment bridges were surveyed : to determine their current practice in the ...

  8. Developing deterioration models for Nebraska bridges.

    Science.gov (United States)

    2011-07-01

    Nebraska Bridge Management System (NBMS) was developed in 1999 to assist in optimizing budget allocation for : the maintenance, rehabilitation and replacement needs of highway bridges. This requires the prediction of bridge : deterioration to calcula...

  9. Monitoring bridge scour using fiber optic sensors.

    Science.gov (United States)

    2015-04-01

    The scouring process excavates and carries away materials from the bed and banks of streams, and from : around the piers and abutments of bridges. Scour undermines bridges and may cause bridge failures due to : structural instability. In the last 30 ...

  10. Faster bridge construction using precast substructures : brief.

    Science.gov (United States)

    2011-07-01

    Bridge replacement often requires road closures and detours that frustrate road users. It remains a key goal of Wisconsin DOT to reduce construction-related road use interruptions. This will be a challenge with bridges: Bridge inspections in 2007 ide...

  11. The violin bridge as filter.

    Science.gov (United States)

    Bissinger, George

    2006-07-01

    The violin bridge filter role was investigated using modal and acoustic measurements on 12 quality-rated violins combined with systematic bridge rocking frequency f(rock) and wing mass decrements deltam on four bridges for two other violins. No isolated bridge resonances were observed; bridge motions were complex (including a "squat" mode near 0.8 kHz) except for low frequency rigid body pivot motions, all more or less resembling rocking motion at higher frequencies. A conspicuous broad peak near 2.3 kHz in bridge driving point mobility (labeled BH) was seen for good and bad violins. Similar structure was seen in averaged bridge, bridge feet, corpus mobilities and averaged radiativity. No correlation between violin quality and BH driving point, averaged corpus mobility magnitude, or radiativity was found. Increasing averaged-over-f(rock) deltam(g) from 0 to 0.12 generally increased radiativity across the spectrum. Decreasing averaged-over-deltam f(rock) from 3.6 to 2.6 kHz produced consistent decreases in radiativity between 3 and 4.2 kHz, but only few-percent decreases in BH frequency. The lowest f(rock) values were accompanied by significantly reduced radiation from the Helmholtz A0 mode near 280 Hz; this, combined with reduced high frequency output, created overall radiativity profiles quite similar to "bad" violins among the quality-rated violins.

  12. Crashworthy railing for timber bridges

    Science.gov (United States)

    Michael A. Ritter; Ronald K. Faller; Sheila Rimal. Duwadi

    1999-01-01

    Bridge railing systems in the United States have historically beers designed based on static load criteria given in the American Association of State Highway and Transportation 0fficials (AASHTO) Standard Specifications for Highway Bridges. In the past decade, full-scale vehicle crash testing has been recognized as a more appropriate and reliable method of evaluating...

  13. Fatigue tests on aluminium bridges

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.; Straalen, IJ.J. van

    2004-01-01

    Traffic bridges are subjected to variable loads and should therefore be checked on fatigue. Especially low weight materials, like aluminium, are sensitive to fatigue, because the variable load is a substantial part of the total load. This paper shows the structural design of an aluminium bridge

  14. Steel-soil composite bridge

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2017-01-01

    viability, while their environmental performance is overlooked. Today’s designers are urged to seek new design options to reduce the environmental burdens. Sweden owns more than 24574 bridges and most of them are short spans. Among them, the slab frame bridge (CFB) is a common solution. Soil steel composite...

  15. Vulnerability of bridges to fire

    DEFF Research Database (Denmark)

    Giuliani, Luisa; Crosti, C.; Gentili, F.

    2012-01-01

    Even if recent effort in developing methodology and measures for design structures against fire and explosions has been mostly focused on buildings, bridges can also be very sensitive to those actions, as witnesses by some recent bridge accidents, which caused major economic losses and also endan...

  16. Crossing borders via mental bridges

    DEFF Research Database (Denmark)

    Keil, Dirk

    administration, and in specific on the attempt to initiate and promote cross-border regional integration via the building of mental bridges between Danish and German parts of the Femern Belt Region. Here one of the first projects aiming primarily at building mental bridges in the Femern Belt Region...

  17. Electrothermally Tunable Bridge Resonator

    KAUST Repository

    Hajjaj, Amal Z.

    2016-12-05

    This paper demonstrates experimentally, theoretically, and numerically a wide-range tunability of an in-plane clamped-clamped microbeam, bridge, and resonator compressed by a force due to electrothermal actuation. We demonstrate that a single resonator can be operated at a wide range of frequencies. The microbeam is actuated electrothermally, by passing a DC current through it. We show that when increasing the electrothermal voltage, the compressive stress inside the microbeam increases, which leads eventually to its buckling. Before buckling, the fundamental frequency decreases until it drops to very low values, almost to zero. After buckling, the fundamental frequency increases, which is shown to be as high as twice the original resonance frequency. Analytical results based on the Galerkin discretization of the Euler Bernoulli beam theory are generated and compared to the experimental data and to simulation results of a multi-physics finite-element model. A good agreement is found among all the results.

  18. Bridging the Evaluation Gap

    Directory of Open Access Journals (Sweden)

    Paul Wouters

    2017-02-01

    Full Text Available Paul Wouters’ essay is concerned with bridging the gap between what we value in our academic work and how we are assessed in formal evaluation exercises. He reflects on the recent evaluation of his own center, and reminds us that it is productive to see evaluations not as the (obviously impossible attempt to produce a true representation of past work, but rather as the exploration and performance of “who one wants to be.” Reflecting on why STS should do more than just play along to survive in the indicator game, he suggests that our field should contribute to changing its very rules. In this endeavor, the attitude and sensibilities developed in our field may be more important than any specific theoretical concepts or methodologies.

  19. Design without thermal bridges

    Directory of Open Access Journals (Sweden)

    Maltseva Irina

    2018-01-01

    Full Text Available The main focus of the article is on the quality design and implementation of the thermal insulation of buildings. Shells of buildings consist not only of conventional structures (wall, roof, ceiling, but also of edges, corners, joints and places of disruption of the outer thermal insulation shell integrity (due to through passage of pipelines, ventilation ducts and etc.. In all these places, heat losses are generally increased in comparison with conventional surfaces. Some of them are easily taken into account by calculation, using a special method proposed by the authors. Other thermal bridges due to unfavorable structural details can be avoided by observing the rules and recommendations that are classified and discussed in detail in this article.

  20. Looking Beyond the Bridge

    DEFF Research Database (Denmark)

    Jahn, Elke; Rosholm, Michael

    We perform a comprehensive analysis of the stepping-stone effect of temporary agency employment on unemployed workers. Using the timing-of-events approach, we not only investigate whether agency employment is a bridge into regular employment but also analyze its effect on post-unemployment wages...... and job stability for unemployed Danish workers. We find evidence of large positive treatment effects, particularly for immigrants. There is also some indication that higher treatment intensity increases the likelihood of leav-ing unemployment for regular jobs. Our results show that agency employment...... is even more effective in tight labor markets, where firms use agency employment primarily to screen po-tential candidates for permanent posts. Finally, our results suggest that agency employment may improve subsequent match quality in terms of wages and job duration....

  1. Bridge Creek IMW database - Bridge Creek Restoration and Monitoring Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The incised and degraded habitat of Bridge Creek is thought to be limiting a population of ESA-listed steelhead (Oncorhynchus mykiss). A logical restoration approach...

  2. Compilation of accelerated bridge construction (ABC) bridges : final report.

    Science.gov (United States)

    2016-01-01

    Development of accelerated bridge construction (ABC) technologies has been occurring across the country, many times in : isolation. Although FHWA and others have worked to facilitate communication between these efforts, there was not a : comprehensiv...

  3. Thermal bridges of modern windows

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Møller, Eva B.; Nielsen, Anker

    2013-01-01

    With its focus on reduced energy consumption, contemporary housing construction requires a highly insulated and airtight building envelope with as few thermal bridges as possible.Windows must be carefully designed, as thermal bridges can lead to surface condensation or mold growth, even...... if the window has an U-factor of 1 W/(m2·K) or lower. This paper describes the development of modern, energy efficient Danish windows with reduced thermal bridges. It focuses on materials, geometry, and sealing of window panes based on a literature review. Examples of modern windows are presented. Experience...

  4. Reliability Assessment of Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Middleton, C. R.

    This paper is partly based on research performed for the Highways Agency, London, UK under the project DPU/9/44 "Revision of Bridge Assessment Rules Based on Whole Life Performance: concrete bridges". It contains the details of a methodology which can be used to generate Whole Life (WL) reliability...... profiles. These WL reliability profiles may be used to establish revised rules for concrete bridges. This paper is to some extend based on Thoft-Christensen et. al. [1996], Thoft-Christensen [1996] et. al. and Thoft-Christensen [1996]....

  5. Complex Testing of the Bridges

    Directory of Open Access Journals (Sweden)

    Savić Adrijana

    2016-01-01

    Full Text Available This article describes the process of examining bridges. AB road bridge, founded on the columns by the Karpoš system and damaged due to erosive action of the river, is given as an example. The first tests of the bridge are conducted on the impact load of V 300, because of the appearance of longitudinal cracks. The results of the columns testing are presented in this paper, as well as the rehabilitation measures thus increasing the load capacity of the column.

  6. A bridge monitoring tool based on bridge and vehicle accelerations

    OpenAIRE

    Hester, David; González, Arturo

    2014-01-01

    Previous research on damage detection based on the response of a structure to a moving load has reported decay in accuracy with increasing load speed. Using a 3D vehicle – bridge interaction model, this paper shows that the area under the filtered acceleration response of the bridge increases with increasing damage, even at highway load speeds. Once a datum reading is established, the area under subsequent readings can be monitored and compared with the baseline reading, if an increase is obs...

  7. The stories of two bridges in Ghana

    DEFF Research Database (Denmark)

    Andreasen, Jørgen

    2004-01-01

    Public participation in bridge building was promoted by un habitat in the village of Mankrong. The neighbouring village did not participate in the construction of their bridge. The first flooding washed the second bridge down while the "participative bridge" stood up....

  8. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Enevoldsen, I.

    Vibration of a bridge structure due to the passage of vehicles is an important consideration in the design of bridges. Further, a common problem in bridge engineering practice in these years is the upgrading of minor highway bridges (=5-20 m) to carry heavier loads partly due to a tendency of hea...

  9. Interstate-35 bridge instrumentation renaissance.

    Science.gov (United States)

    2012-09-01

    An updated, accelerometer-based, sensor and data acquisition system was installed and verified on the I-35 Walnut Creek Bridge in Purcell, Oklahoma. The data collection system also includes a microwave communication system to move sensor and video da...

  10. Caltrans bridge inspection aerial robot.

    Science.gov (United States)

    2008-10-01

    The California Department of Transportation (Caltrans) project resulted in the development of a twin-motor, : single duct, electric-powered Aerobot designed of carrying video cameras up to 200 feet in elevation to enable : close inspection of bridges...

  11. Energy harvesting on highway bridges.

    Science.gov (United States)

    2011-01-01

    A concept for harvesting energy from the traffic-induced loadings on a highway bridge using piezoelectric : materials to generate electricity was explored through the prototype stage. A total of sixteen lead-zirconate : titanate (PZT) Type 5A piezoel...

  12. Milton-Madison Bridge Project

    OpenAIRE

    Hetrick, Kevin; Bunselmeier, Jason

    2013-01-01

    INDOT will provide a brief introduction to the Madison Milton Ohio River Bridge Project, discuss the project development process, the design/build procurement and the construction during this presentation.

  13. Preventative maintenance program for bridges.

    Science.gov (United States)

    2015-07-01

    The Kentucky Transportation Cabinets (KYTC) bridge inventory is rapidly aging. As such, the Cabinet : needs to identify and implement relevant preventative maintenance (PM) actions to extend the useful : service lives of those structures. Maintena...

  14. Bridge Aesthetics and Structural Honesty

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    In bridges the overall form must be chosen with due respect to the transmission of forces if efficient structures shall be created, The design must therefore be governed by experienced structural engineers - in some cases assisted by aesthetic advisers on specific issues. Some basic requirements ...... decisive for choosing the form of trusses, arches and cable-stayed bridges are outlined, and several examples show bridges designed without giving priority to the structural aspects.......In bridges the overall form must be chosen with due respect to the transmission of forces if efficient structures shall be created, The design must therefore be governed by experienced structural engineers - in some cases assisted by aesthetic advisers on specific issues. Some basic requirements...

  15. GFRP reinforced concrete bridge decks.

    Science.gov (United States)

    2000-07-01

    This report investigates the application of glass fiber reinforced polymer (GFRP) rebars in concrete bridge decks as a potential replacement or supplement to conventional steel rebars. Tests were conducted to determine the material properties of the ...

  16. We Must Be Bridge Builders.

    Science.gov (United States)

    Andringa, Robert C.

    1982-01-01

    Higher education, and trustees in particular, must be "bridge builders" among academe, government, and business communities. Trustees must also be the mediators and a reconciling force when the public and independent campuses lose sight of their common cause. (MLW)

  17. VEXAG's Venus Bridge Focus Group

    Science.gov (United States)

    Cutts, J. A.

    2017-11-01

    VEXAG’s Venus Bridge Focus Group is investigating whether viable Venus missions can be conducted within a $200M cost-cap. Progress reports on mission concept studies of combined in situ and orbiter missions will be presented.

  18. Development of inspection robots for bridge cables.

    Science.gov (United States)

    Yun, Hae-Bum; Kim, Se-Hoon; Wu, Liuliu; Lee, Jong-Jae

    2013-01-01

    This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented.

  19. Development of Inspection Robots for Bridge Cables

    Directory of Open Access Journals (Sweden)

    Hae-Bum Yun

    2013-01-01

    Full Text Available This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented.

  20. 33 CFR 118.100 - Retroreflective panels on bridge piers.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Retroreflective panels on bridge... SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.100 Retroreflective panels on bridge piers. The... 12 inches square. (c) To mark bridge piers or channel sides on bridges not required to have bridge...

  1. 47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Watch required by the Bridge-to-Bridge Act. 80... Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch requirement contained in § 80.148, all vessels subject to the Bridge-to-Bridge Act must keep a watch on the designated...

  2. Constraint Ornstein-Uhlenbeck bridges

    Science.gov (United States)

    Mazzolo, Alain

    2017-09-01

    In this paper, we study the Ornstein-Uhlenbeck bridge process (i.e., the Ornstein-Uhlenbeck process conditioned to start and end at fixed points) constraints to have a fixed area under its path. We present both anticipative (in this case, we need the knowledge of the future of the path) and non-anticipative versions of the stochastic process. We obtain the anticipative description thanks to the theory of generalized Gaussian bridges while the non-anticipative representation comes from the theory of stochastic control. For this last representation, a stochastic differential equation is derived which leads to an effective Langevin equation. Finally, we extend our theoretical findings to linear bridge processes.

  3. Excitation Methods for Bridge Structures

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, C.R.; Duffy, T.A.; Cornwell, P.J.; Doebling, S.W.

    1999-02-08

    This paper summarizes the various methods that have been used to excited bridge structures during dynamic testing. The excitation methods fall into the general categories of ambient excitation methods and measured-input excitation methods. During ambient excitation the input to the bridge is not directly measured. In contrast, as the category label implies, measured-input excitations are usually applied at a single location where the force input to the structure can be monitored. Issues associated with using these various types of measurements are discussed along with a general description of the various excitation methods.

  4. Bridging the Vector Calculus Gap

    Science.gov (United States)

    Dray, Tevian; Manogue, Corinne

    2003-05-01

    As with Britain and America, mathematicians and physicists are separated from each other by a common language. In a nutshell, mathematics is about functions, but physics is about things. For the last several years, we have led an NSF-supported effort to "bridge the vector calculus gap" between mathematics and physics. The unifying theme we have discovered is to emphasize geometric reasoning, not (just) algebraic computation. In this talk, we will illustrate the language differences between mathematicians and physicists, and how we are trying reconcile them in the classroom. For further information about the project go to: http://www.physics.orst.edu/bridge

  5. Morphometry of the osteodural bridge and the myodural bridge of ...

    African Journals Online (AJOL)

    The osteodural bridge, the connective tissue between the axis and dura can be measured radiographically. The aim of the study was therefore to determine if there is a relationship between their lengths. Thirty formalin fixed cadavers were meticulously dissected at the department of Human Anatomy, University of Nairobi, ...

  6. Laboratory and field testing of an accelerated bridge construction demonstration bridge : US Highway 6 bridge over Keg Creek.

    Science.gov (United States)

    2013-04-01

    The US Highway 6 Bridge over Keg Creek outside of Council Bluffs, Iowa is a demonstration bridge site chosen to put into practice : newly-developed Accelerated Bridge Construction (ABC) concepts. One of these new concepts is the use of prefabricated ...

  7. An Expert System for Concrete Bridge Management

    DEFF Research Database (Denmark)

    Brito, J. de; Branco, F. A.; Thoft-Christensen, Palle

    1997-01-01

    The importance of bridge repair versus new bridge construction has risen in recent decades due to high deterioration rates that have been observed in these structures. Budgets both for building new bridges and keeping the existing ones are always limited. To help rational decision-making, bridge...... management systems are presently being implemented by bridge authorities in several countries. The prototype of an expert system for concrete bridge management is presented in this paper, with its functionality relying on two modules. The inspection module relies on a periodic acquisition of field...... information complemented by a knowledge-based interactive system, BRIDGE-1. To optimize management strategies at the headquarters, the BRIDGE-2 module was implemented, including three submodules: inspection strategy, maintenance and repair....

  8. Meeting Environmental Requirements after a Bridge Collapse

    Science.gov (United States)

    2008-08-01

    This report is intended to assist transportation and environmental professionals in the event of a bridge collapse or similar emergency. It analyzes the environmental review process in five cases of bridge reconstruction following collapse in Florida...

  9. Risk Mitigation for Highway and Railway Bridges

    Science.gov (United States)

    2009-02-01

    Performance of the transportation network strongly depends on the performance of bridges. Bridges constitute a vital part of the transportation infrastructure system and they are vulnerable to extreme events such as natural disasters (i.e., hurricane...

  10. Mechanisms involved in symptomatic myocardial bridging

    NARCIS (Netherlands)

    Hazenberg, A. J. C.; Jessurun, G. A. J.; Tio, R. A.

    Background. In patients with extensive myocardial bridging, evaluation of its clinical significance remains a challenge. Hypothesis. Sequential invasive testing is feasible and gives more insight into the pathophysiological mechanism of bridging-related angina. Methods. Twelve patients with chest

  11. Developing county bridge repair and retrofit techniques.

    Science.gov (United States)

    2013-08-01

    Oklahoma rated first in the Nation in the percentage of bridges that are structurally deficient or : functionally obsolete. According to Federal Highway Administration data, Oklahoma uses : approximately 23,250 bridges maintained by state, County, Ci...

  12. Forensic testing of a double tee bridge.

    Science.gov (United States)

    2014-12-01

    This report describes an investigation to quantify the behavior of precast, prestressed concrete double-tee bridge : girders made with lightweight concrete. As part of the investigation, three bridge girders were salvaged from a : decommissioned brid...

  13. Microfluidic Wheatstone bridge for rapid sample analysis.

    Science.gov (United States)

    Tanyeri, Melikhan; Ranka, Mikhil; Sittipolkul, Natawan; Schroeder, Charles M

    2011-12-21

    We developed a microfluidic analogue of the classic Wheatstone bridge circuit for automated, real-time sampling of solutions in a flow-through device format. We demonstrate precise control of flow rate and flow direction in the "bridge" microchannel using an on-chip membrane valve, which functions as an integrated "variable resistor". We implement an automated feedback control mechanism in order to dynamically adjust valve opening, thereby manipulating the pressure drop across the bridge and precisely controlling fluid flow in the bridge channel. At a critical valve opening, the flow in the bridge channel can be completely stopped by balancing the flow resistances in the Wheatstone bridge device, which facilitates rapid, on-demand fluid sampling in the bridge channel. In this article, we present the underlying mechanism for device operation and report key design parameters that determine device performance. Overall, the microfluidic Wheatstone bridge represents a new and versatile method for on-chip flow control and sample manipulation.

  14. The Wien Bridge Oscillator Family

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2006-01-01

    A tutorial in which the Wien bridge family of oscillators is defined and investigated. Oscillators which do not fit into the Barkhausen criterion topology may be designed. A design procedure based on initial complex pole quality factor is reported. The dynamic transfer characteristic...

  15. Architectural engineering of FRP bridges

    NARCIS (Netherlands)

    Smits, J.E.P.

    2014-01-01

    This paper deals with the use of Fibre Reinforced Polymers (FRP's) in architectural and structural bridge design. The challenges and opportunities that come with this relatively new material are discussed. An inventory is made of recent engineers' solutions in FRP, followed by a discussion on

  16. Official English: Bridge or Barrier?

    Science.gov (United States)

    Krashen, Stephen

    2000-01-01

    Discusses the official English movement in the United States. Provides suggestions for groups that really want to help immigrants acquire English, by building bridges and not barriers. These include the following: (1) joining private and charitable organizations in helping make English-as-a-Second-Language classes available; (2) support libraries;…

  17. Accelerated bridge paint test program.

    Science.gov (United States)

    2011-07-06

    The accelerated bridge paint (AB-Paint) program evaluated a new Sherwin-Williams two-coat, : fast-curing paint system. The system is comprised of an organic zinc-rich primer (SW Corothane I : Galvapac One-Pack Zinc-Rich Primer B65 G11) and a polyurea...

  18. Exodermic bridge deck performance evaluation.

    Science.gov (United States)

    2010-07-01

    In 1998, the Wisconsin DOT completed a two"leaf bascule bridge in Green Bay with an exodermic deck system. The exodermic deck consisted of 4.5"in thick cast"in"place reinforced concrete supported by a 5.19"in tall unfilled steel grid. The concrete an...

  19. Intercellular bridges in vertebrate gastrulation.

    Directory of Open Access Journals (Sweden)

    Luca Caneparo

    Full Text Available The developing zebrafish embryo has been the subject of many studies of regional patterning, stereotypical cell movements and changes in cell shape. To better study the morphological features of cells during gastrulation, we generated mosaic embryos expressing membrane attached Dendra2 to highlight cellular boundaries. We find that intercellular bridges join a significant fraction of epiblast cells in the zebrafish embryo, reaching several cell diameters in length and spanning across different regions of the developing embryos. These intercellular bridges are distinct from the cellular protrusions previously reported as extending from hypoblast cells (1-2 cellular diameters in length or epiblast cells (which were shorter. Most of the intercellular bridges were formed at pre-gastrula stages by the daughters of a dividing cell maintaining a membrane tether as they move apart after mitosis. These intercellular bridges persist during gastrulation and can mediate the transfer of proteins between distant cells. These findings reveal a surprising feature of the cellular landscape in zebrafish embryos and open new possibilities for cell-cell communication during gastrulation, with implications for modeling, cellular mechanics, and morphogenetic signaling.

  20. Detection of Ultrafine Anaphase Bridges

    DEFF Research Database (Denmark)

    Bizard, Anna H; Nielsen, Christian F; Hickson, Ian D

    2018-01-01

    Ultrafine anaphase bridges (UFBs) are thin DNA threads linking the separating sister chromatids in the anaphase of mitosis. UFBs are thought to form when topological DNA entanglements between two chromatids are not resolved prior to anaphase onset. In contrast to other markers of defective...

  1. Field performance of timber bridges. 5, Little Salmon Creek stress-laminated deck bridge

    Science.gov (United States)

    M. A. Ritter; J. A. Kainz; G. J. Porter

    The Little Salmon Creek bridge was constructed in November 1988 on the Allegheny National Forest in Pennsylvania. The bridge is a simple span, single-lane, stress-laminated deck superstructure that is approximately 26-ft long and 16-ft wide. The bridge is unique in that it is the first known stress-laminated timber bridge to be constructed of hardwood lumber. The...

  2. Field performance of timber bridges. 6, Hoffman Run stress-laminated deck bridge

    Science.gov (United States)

    M. A. Ritter; P. D. Hilbrich Lee; G. J. Porter

    The Hoffman Run bridge, located just outside Dahoga, Pennsylvania, was constructed in October 1990. The bridge is a simple-span, single-lane, stress-laminated deck superstructure that is approximately 26 ft long and 16 ft wide. It is the second stress-laminated timber bridge to be constructed of hardwood lumber in Pennsylvania. The performance of the bridge was...

  3. 77 FR 53251 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation

    Science.gov (United States)

    2012-08-31

    ... Rehabilitation AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice. SUMMARY: Section 1114 of the... used in new Federal-aid bridge construction and bridge rehabilitation projects. As part of the SAFETEA... bridge construction and bridge rehabilitation projects. Data on Federal-aid and non-Federal-aid highway...

  4. Designing timber bridge superstructures : a comparison of U.S. and Canadian bridge codes.

    Science.gov (United States)

    James Scott Groenier; James P. Wacker

    2008-01-01

    Several changes relating to timber bridges have been incorporated into the AASHTO-LRFD Bridge Design Specifications recently. In addition, the Federal Highway Administration is strongly encouraging an LRFD-based design approach for all new bridges in the United States. The Bridge Design Code in Canada was one of the first to adopt the limit states design philosophy,...

  5. Bridge Programs in Illinois: Results of the 2010 Illinois Bridge Status Survey

    Science.gov (United States)

    Taylor, J. L.; Harmon, T.

    2010-01-01

    This report provides a summary of major results of the Illinois Bridge Status Survey, administered online between April and June 2010. The purpose of the survey was to understand the extent to which bridge programs are being implemented in Illinois, as well as to build an online directory of bridge programs. Bridge programs are an emerging…

  6. Hydrodynamic forces on inundated bridge decks

    Science.gov (United States)

    2009-05-01

    The hydrodynamic forces experienced by an inundated bridge deck have great importance in the design of bridges. Specifically, the drag force, lift force, and the moment acting on the bridge deck under various levels of inundation and a range of flow ...

  7. Spread prestressed concrete slab beam bridges.

    Science.gov (United States)

    2015-04-01

    TxDOT uses prestressed slab beam bridges for short-span bridges ranging from approximately 3050 ft in : length. These bridges have precast, pretensioned slab beams placed immediately adjacent to one another : with a cast-in-place slab made composi...

  8. 49 CFR 236.713 - Bridge, movable.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Bridge, movable. 236.713 Section 236.713 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Bridge, movable. That section of a structure bridging a navigable waterway so designed that it may be...

  9. The Akashi Kaikyo Bridge and the Storebælt Bridge

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    With the completion of the Akashi Kaikyo Bridge and the Storebælt East Bridge the development of the suspension bridge technology in the 20th century has manifested itself in two impressive structures. With the present echnology may bridges of similar (and also more modest) dimensions will undoub......With the completion of the Akashi Kaikyo Bridge and the Storebælt East Bridge the development of the suspension bridge technology in the 20th century has manifested itself in two impressive structures. With the present echnology may bridges of similar (and also more modest) dimensions...... will undoubtedly be built far into the next century. For bridges going beyond the spans of existing bridges it is, however, likely that new concepts will be developed....

  10. ESTIMATION OF ECONOMIC EXPEDIENCY OF «BRIDGE-PRE-BRIDGE TERRITORY» SYSTEM

    Directory of Open Access Journals (Sweden)

    A. A. Lapko

    2008-01-01

    Full Text Available The paper considers principles that form «Bridge-Pre-Bridge Territory» system. The method is proposed for calculation of expenses on technical research for development of projects on usage of pre-bridge territories. Usage of site class number for natural conditions makes it possible to estimate investment attractiveness of «Bridge-Pre-Bridge Territory» system.

  11. Implementation of Bridge Management System on Interurban Bridge in Maluku Province

    OpenAIRE

    Erwin Marasabessy

    2015-01-01

    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 Ag...

  12. Field performance of timber bridges. 4, Graves Crossing stress-laminated deck bridge

    Science.gov (United States)

    J. P. Wacker; M. A. Ritter

    The Graves Crossing bridge was constructed October 1991 in Antrim County, Michigan, as part of the demonstration timber bridge program sponsored by the USDA Forest Service. The bridge is a two-span continuous, stress-laminated deck superstructure and it is 36-ft long and 26-ft wide. The bridge is one of the first stress-laminated deck bridges to be built of sawn lumber...

  13. Survival analysis on bridges for modeling bridge replacement and evaluating bridge performance

    OpenAIRE

    Beng, Si Soon; Matsumoto, Takashi

    2012-01-01

    A sustainable civil infrastructure is a prerequisite for achieving sustainability in infrastructure development. However, the finite lifetime of infrastructure indicates a latent mass-maintenance problem in some countries which had experienced mass-construction of infrastructure during high economic growth. To achieve optimal infrastructure management for overcoming this mass-maintenance problem, life prediction of infrastructure is indispensable. Hence, in this research, bridg...

  14. Strengthening Bridges with Prestressed CFRP Strips

    Science.gov (United States)

    Siwowski, Tomasz; Żółtowski, Piotr

    2012-06-01

    Limitation of bridge's carrying bearing capacity due to aging and deterioration is a common problem faced by road administration and drivers. Rehabilitation of bridges including strengthening may be applied in order to maintain or upgrade existing bridge parameters. The case studies of strengthening of two small bridges with high modulus prestressed CFRP strips have been presented in the paper. The first one - reinforced concrete slab bridge - and the other - composite steel-concrete girder bridge - have been successfully upgraded with quite new technology. In both cases the additional CFRP reinforcement let increasing of bridge carrying capacity from 15 till 40 metric tons. The CFRP strip prestressing system named Neoxe Prestressing System (NPS), developed by multi-disciplinary team and tested at full scale in Rzeszow University of Technology, has been also described in the paper.

  15. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Enevoldsen, I.

    of heavier trucks moving at larger speeds, and partly because the authorities want to permit transportation of special heavy goods at a larger part of the road net. These needs will in many cases cause the strengthening of the bridges becomes necessary. In order to keep the expenses of such strengthening......Vibration of a bridge structure due to the passage of vehicles is an important consideration in the design of bridges. Further, a common problem in bridge engineering practice in these years is the upgrading of minor highway bridges (=5-20 m) to carry heavier loads partly due to a tendency...... the numerical models for the mathematical models of the vehicles and the bridge from which the load amplification factors can be estimated assuming that the dynamic parameters of the vehicles and the modal parameters of the bridge are known....

  16. Melanoma and immunotherapy bridge 2015

    OpenAIRE

    Nanda, Vashisht G. Y.; Peng, Weiyi; Hwu, Patrick; Davies, Michael A.; Ciliberto, Gennaro; Fattore, Luigi; Malpicci, Debora; Aurisicchio, Luigi; Ascierto, Paolo Antonio; Croce, Carlo M.; Mancini, Rita; Spranger, Stefani; Gajewski, Thomas F; Wang, Yangyang; FERRONE, SOLDANO

    2016-01-01

    Table of contents MELANOMA BRIDGE 2015 KEYNOTE SPEAKER PRESENTATIONS Molecular and immuno-advances K1 Immunologic and metabolic consequences of PI3K/AKT/mTOR activation in melanoma Vashisht G. Y. Nanda, Weiyi Peng, Patrick Hwu, Michael A. Davies K2 Non-mutational adaptive changes in melanoma cells exposed to BRAF and MEK inhibitors help the establishment of drug resistance Gennaro Ciliberto, Luigi Fattore, Debora Malpicci, Luigi Aurisicchio, Paolo Antonio Ascierto, Carlo M. Croce, Rita Mancin...

  17. Inspection Strategies for Concrete Bridges

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    1989-01-01

    In this paper an optimal inspection strategy for concrete bridges based on periodic routine and detailed inspections is presented. The failure mode considered is corrosion of the reinforcement due to chlorides. A simple modelling of the corrosion and of the inspection strategy is presented....... The optimal inspection strategy is determined from an optimization problem, where the design variables are time intervals between detailed inspections and the concrete cover. The strategy is illustrated on a simple structure, namely a reinforced concrete beam....

  18. Severe ASR damaged concrete bridges

    DEFF Research Database (Denmark)

    Antonio Barbosa, Ricardo; Gustenhoff Hansen, Søren

    2015-01-01

    Technical University of Denmark (DTU) and University of Southern Denmark (SDU) have conducted several full-scale experiments with severe ASR deteriorated bridges. This paper presents few and preliminary results from both the shear tests and the measuring of the material properties. The shear test...... show that the shear capacity is almost unaffected of ASR despite significant reduction in compressive concrete strength. Furthermore, measurements show a significant tensile reinforcement strain developed due to ASR expansion....

  19. Bridging boundaries: CORBA in perspective.

    OpenAIRE

    Cahill, Vinny; Baker, Sean; Nixon, Paddy

    1997-01-01

    peer-reviewed peer-reviewed applications that cross the boundaries of different computing machines, operating systems, and programming languages are increasingly the norm. As a result, the need for what might be called ???bridging technologies??? to develop software that works across heterogeneous environments has become more compelling. The Common Object Request Broker Architecture is one such technology that is both robust and commercially available. CORBA essentially describes...

  20. Bridging boundaries: CORBA in perspective.

    OpenAIRE

    Cahill, Vinny

    1997-01-01

    PUBLISHED pplications that cross the boundaries of different computing machines, operating systems, and programming languages are increasingly the norm. As a result, the need for what might be called ?bridging technologies? to develop software that works across heterogeneous environments has become more compelling. The Common Object Request Broker Architecture is one such technology that is both robust and commercially available. CORBA essentially describes how client app...

  1. Electronic shearography for bridge inspection

    Science.gov (United States)

    Satpathi, Debashis; Maji, Arup K.

    1995-04-01

    Electronic shearography (ES) is a laser based non-destructive testing method that has the potential to be developed into a commercial bridge monitoring technique. The primary advantage of ES over other similar techniques like electronic speckle pattern interferometry (ESPI) is its decreased sensitivity to in-plane rigid body movement and vibrations. Bridge inspection with ES has proven to be a daunting task so far. The main problem has been the inability of the method to handle the large deflections and vibrations that might be expected in a typical bridge subjected to normal service loads. Earlier research has shown that the extent of in-plane movement that can be tolerated by the system is dependent on the speckle size. The speckle size also affects the fringe quality by imposing resolution requirements on the imaging device. This article shall undertake the study of speckle size as a function of the focal length of the imaging lens, object distance and illumination wavelength using high resolution holographic film and a high magnification optical microscope.

  2. Road Bridges and Culverts, Bridge dataset only includes bridges maintained by Johnson County Public Works in the unincorporated areas, Published in Not Provided, Johnson County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Road Bridges and Culverts dataset current as of unknown. Bridge dataset only includes bridges maintained by Johnson County Public Works in the unincorporated areas.

  3. Thermal bridges - calculations, thermal bridge values and impact on energy consumption; Kuldebroer - Beregning, kuldebroverdier og innvirkning paa energibruk

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsen, Arild; Thue, Jan Vincent; Blom, Peter; Dalehaug, Arvid; Aurlien, Tormod; Grynning, Steinar; Uvsloekk, Sivert

    2008-07-01

    This report presents the following: Definition of thermal bridge; Possible consequences of thermal bridges; Methods to decide thermal bridge value, inclusive by numerical calculation; Thermal bridge values for different constructions; A proposal for dynamic Thermal bridge atlas. The project report shows thermal bridge values for different constructions such as window insertion, transition between wall/ceiling, wall/floor, corners and ridge. Thermal bridge values for different kind of floor such as concrete, LECA and hollow core. (AG). refs., figs., tabs

  4. Horizontal bridges in polar dielectric liquids

    Energy Technology Data Exchange (ETDEWEB)

    Woisetschlaeger, Jakob [Graz University of Technology, Experimental Turbomachinery Research and Optical Measurement Group, Institute for Thermal Turbomachinery and Machine Dynamics, Graz (Austria); Wexler, Adam D.; Fuchs, Elmar C. [Wetsus, Center of Excellence for Sustainable Water Technology, Leeuwarden (Netherlands); Holler, Gert [Graz University of Technology, Institute of Electrical Measurement and Measurement Signal Processing, Graz (Austria); Eisenhut, Mathias [Graz University of Technology, Institute of Analytical Chemistry and Food Chemistry, Graz (Austria); Gatterer, Karl [Graz University of Technology, Institute of Physical and Theoretical Chemistry, Graz (Austria)

    2012-01-15

    When a high-voltage direct-current is applied to two beakers filled with polar liquid dielectrica like water or methanol, a horizontal bridge forms between the two beakers. By repeating a version of Pellat's experiment, it is shown that a horizontal bridge is stable by the action of electrohydrodynamic pressure. Thus, the static and dynamic properties of the phenomenon called a 'floating water bridge' can be explained by the gradient of Maxwell pressure, replenishing the liquid within the bridge against any drainage mechanism. It is also shown that a number of liquids can form stable and long horizontal bridges. The stability of such a connection, and the asymmetry in mass flow through such bridges caused by the formation of ion clouds in the vicinity of the electrodes, is also discussed by two further experiments. (orig.)

  5. Railway bridge defects and degradation mechanisms

    OpenAIRE

    Bień, J.; Jakubowski, K.; Kamiński, T.; Kmita, J.; Kmita, P.; Cruz, Paulo J.S.; Maksymowicz, M.

    2007-01-01

    Development of cooperation within European Union stimulates intensive integration between all components of European transportation system. One of the important fields of integration is railway bridge engineering, a part of railway transportation system. Proposed classification of degradation mechanisms against their effects as bridge structure defects can be a basis for the unified assessment of bridge condition. Presented terminology and classifications elaborated in the European research p...

  6. Bridge windshield design to avoid aeroelastic phenomena

    OpenAIRE

    Ogueta Gutiérrez, Mikel; Franchini Longhi, Sebastian Nicolas

    2014-01-01

    Since in 1940 the Tacoma Narrows Bridge was destroyed by the wind, aeroelastic instabilities have been recognized as one of the most challenging aspects of bridge design. They can produce long-term fatigue failure through vortex induced vibrations, or sudden collapse through self-excited flutter. These vibrations may also cause discomfort for the users and temporary closure of the bridge. Wind tunnel studies are a very helpful tool to understand these phenomena. By means of them, the critical...

  7. Bridge engineering handbook construction and maintenance

    CERN Document Server

    Chen, Wai-Fah

    2014-01-01

    Over 140 experts, 14 countries, and 89 chapters are represented in the second edition of the Bridge Engineering Handbook. This extensive collection highlights bridge engineering specimens from around the world, contains detailed information on bridge engineering, and thoroughly explains the concepts and practical applications surrounding the subject.Published in five books: Fundamentals, Superstructure Design, Substructure Design, Seismic Design, and Construction and Maintenance, this new edition provides numerous worked-out examples that give readers step-by-step design procedures, includes c

  8. Measurement of Deflection Line on Bridges

    Science.gov (United States)

    Urban, Rudolf; Štroner, Martin

    2013-12-01

    Prestressed concrete bridges are very sensitive to the increase in long-term deflections. Reliable forecasts of deflections of bridge structures during construction and durability are crucial for achieving good durability. The main results of measurements are the changes of the deflection line of the bridge structures, which places special demands on the measurement procedure. Results from measurements are very useful for the improvement of mathematical prediction methods of behaviour of long span prestressed concrete structures.

  9. SSI-bridge : soil bridge interaction during long-duration earthquake motions.

    Science.gov (United States)

    2014-09-01

    The seismic response of a complete soil-bridge system during shallow, crustal and subduction zone earthquakes is the topic of this report. Specifically, the effects of earthquake duration on the seismic performance of soil-bridge systems are examined...

  10. Development of a precast bridge deck overhang system for the rock creek bridge.

    Science.gov (United States)

    2008-12-01

    Precast, prestressed panels are commonly used at interior beams for bridges in Texas. The use of these : panels provides ease of construction, sufficient capacity, and good economy for the construction of : bridges in Texas. Current practice for the ...

  11. Evaluation of the Buena Vista IBRD bridge : a furthering of accelerated bridge construction in Iowa.

    Science.gov (United States)

    2012-02-01

    The need to construct bridges that last longer, are less expensive, and take less time to build has increased. The importance of accelerated bridge construction (ABC) technologies has been realized by the Federal Highway Administration (FHWA) and the...

  12. Review of Energy Harvesters Utilizing Bridge Vibrations

    Directory of Open Access Journals (Sweden)

    Farid Ullah Khan

    2016-01-01

    Full Text Available For health monitoring of bridges, wireless acceleration sensor nodes (WASNs are normally used. In bridge environment, several forms of energy are available for operating WASNs that include wind, solar, acoustic, and vibration energy. However, only bridge vibration has the tendency to be utilized for embedded WASNs application in bridge structures. This paper reports on the recent advancements in the area of vibration energy harvesters (VEHs utilizing bridge oscillations. The bridge vibration is narrowband (1 to 40 Hz with low acceleration levels (0.01 to 3.8 g. For utilization of bridge vibration, electromagnetic based vibration energy harvesters (EM-VEHs and piezoelectric based vibration energy harvesters (PE-VEHs have been developed. The power generation of the reported EM-VEHs is in the range from 0.7 to 1450000 μW. However, the power production by the developed PE-VEHs ranges from 0.6 to 7700 μW. The overall size of most of the bridge VEHs is quite comparable and is in mesoscale. The resonant frequencies of EM-VEHs are on the lower side (0.13 to 27 Hz in comparison to PE-VEHs (1 to 120 Hz. The power densities reported for these bridge VEHs range from 0.01 to 9539.5 μW/cm3 and are quite enough to operate most of the commercial WASNs.

  13. A Polish approach to FRP bridges

    Science.gov (United States)

    Siwowski, Tomasz; Rajchel, Mateusz

    2017-12-01

    The paper presents initial results of a new approach to FRP composite bridge construction that is presently being developed and tested in Poland. The concept combines lightweight concrete with FRP composites to create a durable highly optimised structure. The paper describes the bridge system itself and presents the research results on its development. The basic design is presented together with research results on its development: FEM analysis and a range of static test results of full-scale bridge beam experiments. The paper finishes with some test results of a full scale bridge that was constructed near Rzeszow in December 2015.

  14. A data management infrastructure for bridge monitoring

    Science.gov (United States)

    Jeong, Seongwoon; Byun, Jaewook; Kim, Daeyoung; Sohn, Hoon; Bae, In Hwan; Law, Kincho H.

    2015-04-01

    This paper discusses a data management infrastructure framework for bridge monitoring applications. As sensor technologies mature and become economically affordable, their deployment for bridge monitoring will continue to grow. Data management becomes a critical issue not only for storing the sensor data but also for integrating with the bridge model to support other functions, such as management, maintenance and inspection. The focus of this study is on the effective data management of bridge information and sensor data, which is crucial to structural health monitoring and life cycle management of bridge structures. We review the state-of-the-art of bridge information modeling and sensor data management, and propose a data management framework for bridge monitoring based on NoSQL database technologies that have been shown useful in handling high volume, time-series data and to flexibly deal with unstructured data schema. Specifically, Apache Cassandra and Mongo DB are deployed for the prototype implementation of the framework. This paper describes the database design for an XML-based Bridge Information Modeling (BrIM) schema, and the representation of sensor data using Sensor Model Language (SensorML). The proposed prototype data management framework is validated using data collected from the Yeongjong Bridge in Incheon, Korea.

  15. Nanoclusters a bridge across disciplines

    CERN Document Server

    Jena, Purusottam

    2010-01-01

    This comprehensive book on Nanoclusters comprises sixteen authoritative chapters written by leading researchers in the field. It provides insight into topics that are currently at the cutting edge of cluster science, with the main focus on metal and metal compound systems that are of particular interest in materials science, and also on aspects related to biology and medicine. While there are numerous books on clusters, the focus on clusters as a bridge across disciplines sets this book apart from others. Delivers cutting edge coverage of cluster science Covers a broad range of topics in

  16. Detecting global bridges in networks

    OpenAIRE

    Jensen, Pablo; Morini, Matteo; Karsai, Márton; Venturini, Tommaso; Vespignani, Alessandro; Jacomy, Mathieu; Cointet, Jean-Philippe; Mercklé, Pierre; Fleury, Eric

    2015-01-01

    International audience; The identification of nodes occupying important positions in a network structure is crucial for the understanding of the associated real-world system. Usually, betweenness centrality is used to evaluate a node capacity to connect different graph regions. However, we argue here that this measure is not adapted for that task, as it gives equal weight to “local” centers (i.e. nodes of high degree central to a single region) and to “global” bridges, which connect different...

  17. A bridge to advanced mathematics

    CERN Document Server

    Sentilles, Dennis

    2011-01-01

    This helpful workbook-style ""bridge"" book introduces students to the foundations of advanced mathematics, spanning the gap between a practically oriented calculus sequence and subsequent courses in algebra and analysis with a more theoretical slant. Part 1 focuses on logic and number systems, providing the most basic tools, examples, and motivation for the manner, method, and concerns of higher mathematics. Part 2 covers sets, relations, functions, infinite sets, and mathematical proofs and reasoning. Author Dennis Sentilles also discusses the history and development of mathematics as well a

  18. Field performance of timber bridges. 9, Big Erick`s stress-laminated deck bridge

    Science.gov (United States)

    J. A. Kainz; J. P. Wacker; M. Nelson

    The Big Erickas bridge was constructed during September 1992 in Baraga County, Michigan. The bridge is 72 ft long, 16 ft wide, and consists of three simple spans: two stress-laminated deck approach spans and a stress-laminated box center span. The bridge is unique in that it is one of the first known stress-laminated timber bridge applications to use Eastern Hemlock...

  19. Bridge characterization and structural health monitoring: a suspension bridge case study

    OpenAIRE

    Houel, Adrien; Orcesi, André; LECONTE, Renaud

    2012-01-01

    Detecting and assessing the severity of structural damage is one major objective when monitoring a bridge. In particular, when some degradation phenomena threaten the bridge safety, the goal can be to assess monitoring critical components, which allows checking a safety threshold is not reached until some repair/rehabilitation actions are performed. This paper describes an overall monitoring-based decision process, illustrated with the case of a suspension bridge in France, the Teil Bridge ne...

  20. 33 CFR 118.85 - Lights on vertical lift bridges.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lights on vertical lift bridges... BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.85 Lights on vertical lift bridges. (a) Lift span lights. The vertical lift span of every vertical lift bridge shall be lighted so that the center of the...

  1. 23 CFR 650.409 - Evaluation of bridge inventory.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Evaluation of bridge inventory. 650.409 Section 650.409... Evaluation of bridge inventory. (a) Sufficiency rating of bridges. Upon receipt and evaluation of the bridge inventory, a sufficiency rating will be assigned to each bridge by the Secretary in accordance with the...

  2. 33 CFR 115.50 - Application for bridge permits.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Application for bridge permits... BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.50 Application for bridge permits. (a) Approval of plans. An application for authorization to construct a bridge across navigable waters...

  3. 33 CFR 118.90 - Bridges crossing channel obliquely.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bridges crossing channel... SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.90 Bridges crossing channel obliquely. Bridges crossing a body of water at an angle other than 90° with the axis of the channel shall be lighted in...

  4. Finite element of multilayer surfacing systems on orthotropic steel bridges

    NARCIS (Netherlands)

    Li, J.; Liu, X.; Scarpas, A.; Tzimiris, G.

    2013-01-01

    Light weight orthotropic steel bridge decks have been widely utilized for bridges in seismic zones, movable bridges and long span bridges. In the last three decades, severe problems were reported in relation to asphaltic surfacing materials on orthotropic steel deck bridges. Earlier investigations

  5. Advanced bridge safety initiative : FRP flexural retrofit for concrete slab bridges - task 4 deliverables.

    Science.gov (United States)

    2014-06-01

    Concrete slab bridges are being examined as part of the MaineDOT Advanced Bridge Safety Initiative. Under Tasks : 1 3 a finite element analysis program is developed, validated and applied to twenty bridges. : Task 4 investigates and develops a no...

  6. 76 FR 55160 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation

    Science.gov (United States)

    2011-09-06

    ... Rehabilitation AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice. SUMMARY: Section 1114 of the... used in new Federal-aid bridge construction and bridge rehabilitation projects. As part of the SAFETEA... rehabilitation projects. Data on Federal-aid and non-Federal-aid highway bridges are included in the report for...

  7. 75 FR 62181 - Annual Materials Report on New Bridge Construction and Bridge Rehabilitation

    Science.gov (United States)

    2010-10-07

    ... Rehabilitation AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice. SUMMARY: Section 1114 of the... materials used in new Federal-aid bridge construction and bridge rehabilitation projects. As part of the... rehabilitation projects. Data on Federal-aid and non-Federal-aid highway bridges are included in the report for...

  8. Bridge Workshop : Enhancing Bridge Performance, February 21-22, 2008, Reston, Virginia : workshop report

    Science.gov (United States)

    Sreenivas Alampalli; Sheila Rimal Duwadi; Reagan Sentelle Herman; Danielle D. Kleinhans; Khaled Mahmoud; James C. Ray; James P. Wacker; Nur Yazdani

    2008-01-01

    The participants to the workshop were given the charge to discuss (1) bridge design issues including best practices in design and detailing that could be used to improve durability, extend service life and prevent premature deterioration, (2) performance measures needed to better determine bridge condition, (3) technologies that could be used to monitor bridge life and...

  9. Field performance of timber bridges. 15, Pueblo County, Colorado, stress-laminated deck bridge

    Science.gov (United States)

    L. E. Hislop

    The Pueblo County 204B bridge was constructed in March 1990 in Pueblo, Colorado, as a demonstration bridge under the USDA Forest Service Timber Bridge Initiative. The stress-laminated deck superstructure is approximately 10 m long, 9 m wide, and 406 mm deep, with a skew of 10 degrees. Performance monitoring was conducted for 3 years, beginning at...

  10. 49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Movable bridge, interlocking of signal appliances with bridge devices. 236.312 Section 236.312 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Interlocking Standards § 236.312 Movable bridge, interlocking of signal...

  11. Light-weight aluminium bridges and bridge decks. An overview of recent applications

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.; Kluyver, D. de

    2008-01-01

    The last decades have shown a large increase in the application of aluminium alloys for light-weight bridges. For bridge construction, aluminium alloys have some specific advantages, but also some points of attention. This paper deals with some recent projects of aluminium bridges, and for these

  12. A bridge with a view, a view with a bridge : Identifying design considerations for bridges to strengthen regional identity

    NARCIS (Netherlands)

    Smits, J.E.P.; van der Hoeven, F.D.

    2015-01-01

    This paper discusses design considerations for creating high quality infrastructural artefacts with an emphasis on bridges. The authors pursue a design study and analysis approach to highlight the specifics of infrastructure design for regional identity, based on their own work on a bridge

  13. Salt-bridge energetics in halophilic proteins.

    Directory of Open Access Journals (Sweden)

    Arnab Nayek

    Full Text Available Halophilic proteins have greater abundance of acidic over basic and very low bulky hydrophobic residues. Classical electrostatic stabilization was suggested as the key determinant for halophilic adaptation of protein. However, contribution of specific electrostatic interactions (i.e. salt-bridges to overall stability of halophilic proteins is yet to be understood. To understand this, we use Adaptive-Poison-Boltzmann-Solver Methods along with our home-built automation to workout net as well as associated component energy terms such as desolvation energy, bridge energy and background energy for 275 salt-bridges from 20 extremely halophilic proteins. We then perform extensive statistical analysis on general and energetic attributes on these salt-bridges. On average, 8 salt-bridges per 150 residues protein were observed which is almost twice than earlier report. Overall contributions of salt-bridges are -3.0 kcal mol-1. Majority (78% of salt-bridges in our dataset are stable and conserved in nature. Although, average contributions of component energy terms are equal, their individual details vary greatly from one another indicating their sensitivity to local micro-environment. Notably, 35% of salt-bridges in our database are buried and stable. Greater desolvation penalty of these buried salt-bridges are counteracted by stable network salt-bridges apart from favorable equal contributions of bridge and background terms. Recruitment of extensive network salt-bridges (46% with a net contribution of -5.0 kcal mol-1 per salt-bridge, seems to be a halophilic design wherein favorable average contribution of background term (-10 kcal mol-1 exceeds than that of bridge term (-7 kcal mol-1. Interiors of proteins from halophiles are seen to possess relatively higher abundance of charge and polar side chains than that of mesophiles which seems to be satisfied by cooperative network salt-bridges. Overall, our theoretical analyses provide insight into halophilic

  14. Bridging history and social psychology

    DEFF Research Database (Denmark)

    Glaveanu, Vlad Petre; Yamamoto, Koji

    2012-01-01

    This special issue aims to bridge history and social psychology by bringing together historians and social psychologists in an exercise of reading and learning from each other’s work. This interdisciplinary exercise is not only timely but of great importance for both disciplines. Social psycholog......This special issue aims to bridge history and social psychology by bringing together historians and social psychologists in an exercise of reading and learning from each other’s work. This interdisciplinary exercise is not only timely but of great importance for both disciplines. Social...... psychologists can benefit from engaging with historical sources by being able to contextualise their findings and enrich their theoretical models. It is not only that all social and psychological phenomena have a history but this history is very much part of present-day and future developments. On the other...... hand historians can enhance their analysis of historical sources by drawing upon the conceptual tools developed in social psychology. They can “test” these tools and contribute to their validation and enrichment from completely different perspectives. Most important, as contributions to this special...

  15. Field Testing and Load Rating of a Short-Span Thermoplastic Bridge System, Bridge T-8519

    Science.gov (United States)

    2010-11-01

    33 mm x 12 mm). Cable Length: 10 ft (3 m) standard, any length available. Material: Aluminum Circuit: Full Wheatstone bridge with four active 350Ω...ER D C/ G SL T R- 10 -4 8 Field Testing and Load Rating of a Short-Span Thermoplastic Bridge System, Bridge T-8519 G eo te ch ni ca l a...unlimited. ERDC/GSL TR-10-48 November 2010 Field Testing and Load Rating of a Short-Span Thermoplastic Bridge System, Bridge T-8519 Brett

  16. Development of improved connection details for adjacent prestressed member bridges.

    Science.gov (United States)

    2017-06-01

    Adjacent prestressed member girder bridges are economical systems for short spans and generally come in two types: adjacent box beam bridges and adjacent voided slab bridges. Each type provides the advantages of having low clearances because of their...

  17. Implementation of sustainability in bridge design, construction and maintenance.

    Science.gov (United States)

    2012-12-01

    The focus of this research is to develop a framework for more sustainable design and construction : processes for new bridges, and sustainable maintenance practices for existing bridges. The framework : includes a green rating system for bridges. The...

  18. Real time assessment of dynamic loads on bridges.

    Science.gov (United States)

    2013-05-01

    Highway bridges are an important class of civil structures that are subject to continuously : acting and varying dynamic loads due to traffic. A large number of highway bridges in the US : (bridges on interstate highways or state highways which have ...

  19. 0-6722 : spread prestressed concrete slab beam bridges.

    Science.gov (United States)

    2014-08-01

    The Texas Department of Transportation uses : precast prestressed concrete slab beam bridges for : shorter-span bridges of approximately 3050 ft in : length. Conventional slab beam bridges have slab : beams placed immediately adjacent to one anoth...

  20. Design aids of NU I-girders bridges.

    Science.gov (United States)

    2010-05-01

    Precast prestressed concrete I-Girder bridges have become the most dominant bridge system in the United States. In the early design : stages, preliminary design becomes a vital first step in designing an economical bridge. Within the state of Nebrask...

  1. Long-term behavior of integral abutment bridges : [technical summary].

    Science.gov (United States)

    2011-01-01

    Integral abutment bridges, a type of jointless bridge, are the construction option of choice when designing highway bridges in many parts of the country. Rather than providing an expansion joint to separate the substructure from the superstructure to...

  2. Methods and tools for diagnosing bridge structures

    Directory of Open Access Journals (Sweden)

    С.Ф. Філоненко

    2008-03-01

    Full Text Available  In the paper is reviewed the methods and means, which used at technical diagnostic of bridge designs. The general approaches to technical diagnostic, the main methods, primary converters and hardwares, which used on static and dynamic tests of bridge designs are reviewed.

  3. Kings Covered Bridge rehabilitation, Somerset County, PA

    Science.gov (United States)

    William J. Collins; David C. Fischetti; Arnold M. Jr. Graton; Len Lichvar; Branden Diehl; James P. Wacker; Ed Cesa; Ed Stoltz; Emory L. Kemp; Samer H. Petro; Leon Buckwalter; John McNamara

    2005-01-01

    Kings Covered Bridge over Laurel Creek in Somerset County, Pennsylvania is approximately 114-foot clear span multiple Kingpost Truss with nail-laminated arches. This timber bridge is historically significant because it retains its original features of the 1860’s since the 1930s when it was spared from modernization by the construction of an adjacent steel highway...

  4. Neighborhood Bridges: 2010-2011 Evaluation Report

    Science.gov (United States)

    Ingram, Debra

    2011-01-01

    In 2010-2011, students in twenty-five classrooms from eleven schools in the Minneapolis-Saint Paul metropolitan area participated in The Children's Theatre Company's Neighborhood Bridges (Bridges) program. The Children's Theatre Company contracted with the University of Minnesota's Center for Applied Research and Educational Improvement (CAREI) to…

  5. Bridges Over Troubled Waters: Theoretical Linguistics And ...

    African Journals Online (AJOL)

    This paper tries to construct a bridge between the concerns of theoretical linguistics and those of multilingualism and code-switching (CS) research. It argues that the primary special point of interaction between these fields lies in the question of potential equivalence between elements or categories, bridging across ...

  6. History of cable-stayed bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

    The principle of supporting a bridge deck by inclined tension members leading to towers on either side of the span has been known for centuries. However, the real development of cable-stayed bridges did not begin before the 1950s. Since then the free span has been increased from 183 m in the Strö...

  7. Re-Assessment of Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper two aspects of re-assessment of the reliability of concrete bridges are discussed namely modelling of the corrosion of reinforcement and updating of uncertain variables. The main reason for deterioration of concrete bridges is corrosion of the reinforcement. Therefore, modelling...

  8. Analysis of Biaxially Stressed Bridge Deck Plates

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Bondum, Tommi Højer

    2012-01-01

    The ultimate state analysis of bridge deck plates at the intersection zone between main girders and transverse beams is complicated by biaxial membrane stresses, which may be in compression or tension in either direction depending on the bridge configuration and the specific location. This paper...

  9. Construction of CCC resistance ratio bridge

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Z.; Jensen, D.H.; Holtoug, J.U. [Danish Institute of Fundamental Metrology, Lynbgy (Denmark)

    1994-12-31

    The paper introduces the cryogenic current comparator (CCC) resistance ratio bridge being built at DFM, which is designed to relate the value of quantized hall resistance R{sub H}(i) to room temperature resistance standards. The CCC is an overlapping tube type with copper wire. A double constant current source is used to supply for the CCC resistance ratio bridge.

  10. Shear assessment of reinforced concrete slab bridges

    NARCIS (Netherlands)

    Lantsoght, E.O.L.; Van der Veen, C.; Walraven, J.C.; De Boer, A.

    2013-01-01

    The capacity of reinforced concrete solid slab bridges in shear is assessed by comparing the design beam shear resistance to the design value of the applied shear force due to the permanent actions and live loads. Results from experiments on half-scale continuous slab bridges are used to develop a

  11. Lifetime Reliability Assessment of Concrete Slab Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    A procedure for lifetime assesment of the reliability of short concrete slab bridges is presented in the paper. Corrosion of the reinforcement is the deterioration mechanism used for estimating the reliability profiles for such bridges. The importance of using sensitivity measures is stressed...

  12. Disturbance indicator benchmark for urban bridge construction

    NARCIS (Netherlands)

    Brouwer, J.; Vogel, R.; Thodesen, C.

    2013-01-01

    European bridges are today in a state of particular concern with over 50% of European urban bridges being more than 40 years old and thus requiring considerable maintenance or possibly even replacement [1]. This means that interventions in the present infrastructure have to be made while ensuring

  13. Planar Hall effect bridge magnetic field sensors

    DEFF Research Database (Denmark)

    Henriksen, A.D.; Dalslet, Bjarke Thomas; Skieller, D.H.

    2010-01-01

    Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can...... Hall effect bridge sensors....

  14. New regulations on railroad bridge safety: opportunities and challenges for railroad bridge monitoring

    Science.gov (United States)

    Moreu, Fernando; LaFave, James M.; Spencer, Billie F.

    2012-04-01

    New federal regulations now mandate North American railroad bridge owners to closely assess the structural capacity of their bridges. Consequently, railroad companies are currently looking into developing and exploring monitoring systems for specific bridges, to help them improve and develop bridge safety in order to help comply with this new rule. The first part of this paper explains the significance of the new federal law. The new rule comes from the Federal Railroad Administration (FRA), Department of Transportation (DOT), and it falls under the 49 Code of Federal Regulations (CFR), Parts 213 and 2371. It requires railroad track owners to know the safe capacity of their bridges and to additionally conduct special inspections if either weather or other exceptional conditions make them necessary to ensure safe railroad bridge operations. The second part of this paper will cover past and current studies about the viability of bridge health monitoring, and actual structural monitoring experiences for railroad bridges. Finally, lessons learned from these monitoring examples, as well as recommendations for future applications, are suggested, including wireless monitoring strategies for railroad bridges such as: campaign sensing inspections (periodic monitoring); bridge replacement observations (short term monitoring); and permanent bridge instrumentation (long term monitoring).

  15. Seismic response of steel suspension bridge

    Energy Technology Data Exchange (ETDEWEB)

    McCallen, D.B. [Lawrence Livermore National Lab., CA (United States); Astaneh-Asl, A. [California Univ., Berkeley, CA (United States). Dept. of Civil and Environmental Engineering

    1996-11-01

    Performing accurate, realistic numerical simulations of the seismic response of long-span bridges presents a significant challenge to the fields of earthquake engineering and seismology. Suspension bridges in particular represent some of the largest and most important man-made structures and ensuring the seismic integrity of these mega-structures is contingent on accurate estimations of earthquake ground motions and accurate computational simulations of the structure/foundation system response. A cooperative, multi-year research project between the Univ. of California and LLNL was recently initiated to study engineering and seismological issues essential for simulating the response of major structures. Part of this research project is focused on the response of the long-span bridges with the San Francisco-Oakland Bay Bridge serving as a case study. This paper reports on the status of this multi-disciplinary research project with emphasis on the numerical simulation of the transient seismic response of the Bay Bridge.

  16. Optimum Maintenance Strategies for Highway Bridges

    DEFF Research Database (Denmark)

    Frangopol, Dan M.; Thoft-Christensen, Palle; Das, Parag C.

    As bridges become older and maintenance costs become higher, transportation agencies are facing challenges related to implementation of optimal bridge management programs based on life cycle cost considerations. A reliability-based approach is necessary to find optimal solutions based on minimum...... expected life-cycle costs or maximum life-cycle benefits. This is because many maintenance activities can be associated with significant costs, but their effects on bridge safety can be minor. In this paper, the program of an investigation on optimum maintenance strategies for different bridge types...... is described. The end result of this investigation will be a general reliability-based framework to be used by the UK Highways Agency in order to plan optimal strategies for the maintenance of its bridge network so as to optimize whole-life costs....

  17. Building bridges … and accelerators

    CERN Multimedia

    2009-01-01

    Lyn Evans, the LHC project leader, was awarded an honorary doctorate from the University of Geneva (UNIGE) to celebrate his role not just in building accelerators, but also in building bridges between nations. He was one of four notables honoured at the event on Friday 5 June, coinciding with the University’s 450th Anniversary. Lyn Evans arriving at the ceremony with Archbishop Desmond Tutu. "It was a big surprise when I found out I’d been nominated," recounts Evans, "but it was an even bigger surprise to find out with whom I’d been nominated". At the ceremony Evans was awarded the honorary doctorate along with three others: Archbishop Desmond Tutu, who was acclaimed for his fight against apartheid in South Africa, Mary Robinson, first woman president of Ireland and former United Nations’ high commissioner of human rights, and Pascal Lamy, Director-General of the World Trade Organization. The award ceremony, known as the �...

  18. Noise Considerations in Resistance Bridges

    DEFF Research Database (Denmark)

    Diamond, Joseph M.

    1963-01-01

    A signal-to-noise analysis is made of the Wheatstone bridge, where the unknown and standard resistors may be at different temperatures, a situation which occurs in resistance thermometry. The limiting condition is assumed to be dissipation in the unknown resistor. It is shown that the ratio arms......, namely, noise in the loss resistance of the step-up device, and grid current noise. There is therefore an optimum step-up ratio, which has been found. The step-up device is permitted to have a different temperature from the unknown and standard resistors, to evaluate the advantage of cooling it...... should be low in resistance compared with the unknown resistor, while the standard resistor should be high. This is true to an extreme degree when the unknown resistor is at liquid helium temperatures, and the standard resistor at room temperature. This factor is much less important in high temperature...

  19. Superconducting micronets: The Wheatstone bridge

    Energy Technology Data Exchange (ETDEWEB)

    Ammann, C.; Erdoes, P. [Institute of Theoretical Physics, University of Lausanne, CH-1015 Lausanne (Switzerland); Haley, S.B. [Department of Electrical and Computer Engineering, University of California, Davis, California 95616 (United States)

    1995-05-01

    Using the Ginzburg-Landau theory, a particular superconducting (sc) micronet, called the Wheatstone bridge, is studied. This planar micronet is made of two nodes connected by three thin sc wires. A magnetic field is applied perpendicularly to its plane. The sc-normal second-order phase transition is characterized by only two configurations of the order parameter: {ital cphi}{sub {ital A}}={ital cphi}{sub {ital B}} and {ital cphi}{sub {ital A}}={minus}{ital cphi}{sub {ital B}}, where {ital cphi}{sub {ital A}} and {ital cphi}{sub {ital B}} are the order parameters at the nodes. For temperatures near {ital T}{sub {ital c}}, we show that only the {ital cphi}{sub {ital A}}={ital cphi}{sub {ital B}} configuration is admissible for fluxes near {Phi}={ital n}{Phi}{sub 0}, where {ital n} is an integer and {Phi}{sub 0} is the flux quantum. Finally, the exact solution of the nonlinear Ginzburg-Landau equations for one-dimensional systems is numerically fitted to the boundary conditions of the Wheatstone bridge for the two configurations {ital cphi}{sub {ital A}}={ital cphi}{sub {ital B}} and {ital cphi}{sub {ital A}}={minus}{phi}{sub {ital B}}. Graphs of the Gibbs energy and of the spontaneous supercurrent, which for these two configurations is always a screening supercurrent, are given as functions of the total flux. A discontinuous transition between configurations occurs as a function of the flux.

  20. Implementation of Bridge Management System on Interurban Bridge in Maluku Province

    Directory of Open Access Journals (Sweden)

    Erwin Marasabessy

    2015-05-01

    Full Text Available 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.

  1. Track-Bridge Longitudinal Interaction of Continuous Welded Rails on Arch Bridge

    Directory of Open Access Journals (Sweden)

    Rong Chen

    2013-01-01

    Full Text Available 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.

  2. Signal and noise in bridging PCR

    Directory of Open Access Journals (Sweden)

    Thaler David S

    2002-07-01

    Full Text Available Abstract Background In a variant of the standard PCR reaction termed bridging, or jumping, PCR the primer-bound sequences are originally on separate template molecules. Bridging can occur if, and only if, the templates contain a region of sequence similarity. A 3' end of synthesis in one round of synthesis that terminates in this region of similarity can prime on the other. In principle, Bridging PCR (BPCR can detect a subpopulation of one template that terminates synthesis in the region of sequence shared by the other template. This study considers the sensitivity and noise of BPCR as a quantitative assay for backbone interruptions. Bridging synthesis is also important to some methods for computing with DNA. Results In this study, BPCR was tested over a 328 base pair segment of the E. coli lac operon and a signal to noise ratio (S/N of approximately 10 was obtained under normal PCR conditions with Taq polymerase. With special precautions in the case of Taq or by using the Stoffel fragment the S/N was improved to 100, i.e. 1 part of cut input DNA yielded the same output as 100 parts of intact input DNA. Conclusions In the E. coli lac operator region studied here, depending on details of protocol, between 3 and 30% per kilobase of final PCR product resulted from bridging. Other systems are expected to differ in the proportion of product that is bridged consequent to PCR protocol and the sequence analyzed. In many cases physical bridging during PCR will have no informational consequence because the bridged templates are of identical sequence, but in a number of special cases bridging creates, or, destroys, information.

  3. The BRIDG project: a technical report.

    Science.gov (United States)

    Fridsma, Douglas B; Evans, Julie; Hastak, Smita; Mead, Charles N

    2008-01-01

    The Biomedical Research Integrated Domain Group (BRIDG) project is a collaborative initiative between the National Cancer Institute (NCI), the Clinical Data Interchange Standards Consortium (CDISC), the Regulated Clinical Research Information Management Technical Committee (RCRIM TC) of Health Level 7 (HL7), and the Food and Drug Administration (FDA) to develop a model of the shared understanding of the semantics of clinical research. The BRIDG project is based on open-source collaborative principles and an implementation-independent, use-case driven approach to model development. In the BRIDG model, declarative and procedural knowledge are represented using the Unified Modeling Language (UML) class, activity and state diagrams. The BRIDG model currently contains harmonized semantics from four project use cases: the caXchange project and the patient study calendar project from caBIG; the standard data tabular model (SDTM) from CDISC; and the regulated products submission model (RPS) from HL7. Scalable harmonization processes have been developed to expand the model with content from additional use cases. The first official release of the BRIDG model was published in June 2007. Use of the BRIDG model by the NCI has supported the rapid development of semantic interoperability across applications within the caBIG program. The BRIDG project has brought together different standards communities to clarify the semantics of clinical research across pharmaceutical, regulatory, and research organizations. Currently, the NCI uses the BRIDG model to support interoperable application development in the caBIG, and CDISC and HL7 are using the BRIDG model to support standards development.

  4. Myocardial bridges: a prospective forensic autopsy study.

    Science.gov (United States)

    Micić-Labudović, Jelena; Atanasijević, Tatjana; Popović, Vesna; Mihailović, Zoran; Nikolić, Slobodan; Puzović, Dragana

    2015-01-01

    When the coronary artery, located subepicardially, submerges into the myocardium and appears again subepicardially after a short intramural course, it represents an embedded coronary artery, while the part of the myocardium above is a myocardial bridge. We investigated the frequency of the embedded left coronary artery (LAD) in the autopsy material considering the descending branch of the LAD to be the most important one in the nourishment of the myocardium and myocardial bridges to be the most frequent in its area, as well as clinically important. A prospective autopsy study of 975 cases was performed, including both, natural (21.33%) and violent (78.67%) deaths. The sample consisted of 74.56% males and 25.44%females. In order to discover myocardyal bridges and their characteristics, the hearts were examined by both transverse cuts and longitudinal openings of the LAD. Myocardial bridge was found in 78 cases (8.00%), more commonly in males (9.35%) than females (4.03%).The average length of the myocardial bridge was 21.85±16.10mm and thickness 3.744±1.48 mm. The common localization of the myocardial bridge was the proximal half of the LAD (89.74%).The upper part of the artery, proximal to the bridge, was a common site of atherosclerotic changes. Myocardial bridge was found in 12.50% of natural deaths, but in 13.38% out of all cases of sudden cardiac deaths. Therefore, the presence of the myocardial bridge by itself is not predominant, but it is certainly a contributing factor to a sudden cardiac death.

  5. Building the Clinical Bridge: An Australian Success

    Directory of Open Access Journals (Sweden)

    Marianne Wallis

    2012-01-01

    Full Text Available Nursing effectiveness science includes primary, secondary, and translational, clinically focused research activities which aim to improve patient or client outcomes. It is imperative, for the successful conduct of a program of nursing effectiveness science, that a clinical bridge is established between academic and healthcare service facilities. An Australian example of the development of a robust clinical bridge through the use of jointly funded positions at the professorial level is outlined. In addition, an analysis of the practical application of Lewin’s model of change management and the contribution of both servant and transformational leadership styles to the bridge building process is provided.

  6. INFLUENCE OF MOVING LOADS ON CURVED BRIDGES

    OpenAIRE

    Thamer A. Z*, Jabbbar S. A

    2016-01-01

    The behavior of a curved slab bridge decks with uniform thickness under moving load is investigated in this study. Three radii of curvature "R" are used (25, 50 and 75m) along with the straight bridge, R = ∞. The decks are simply supported or clamped along the radial edges and free at the circular edges. The AASHTO[1] standard axle load of the truck H20-44 is used and assumed to move in three track positions on the bridge. The finite element method is employed for the analysis and the ANSYS 5...

  7. Calculations in bridge aeroelasticity via CFD

    Energy Technology Data Exchange (ETDEWEB)

    Brar, P.S.; Raul, R.; Scanlan, R.H. [Johns Hopkins Univ., Baltimore, MD (United States)

    1996-12-31

    The central focus of the present study is the numerical calculation of flutter derivatives. These aeroelastic coefficients play an important role in determining the stability or instability of long, flexible structures under ambient wind loading. A class of Civil Engineering structures most susceptible to such an instability are long-span bridges of the cable-stayed or suspended-span variety. The disastrous collapse of the Tacoma Narrows suspension bridge in the recent past, due to a flutter instability, has been a big impetus in motivating studies in flutter of bridge decks.

  8. Transformation of the bridge during drop separation

    Science.gov (United States)

    Chashechkin, Yu. D.; Prokhorov, V. E.

    2016-05-01

    The geometry of flows during separation of pendant drops of liquids with significantly different physical properties (alcohol, water, glycerin, oil) has been studied by high-speed video recording. The dynamics of the processes involving the formation of bridges of two characteristic shapes—slightly nonuniform in thickness and with thinning of the upper and lower ends—has been investigated. It has been shown that the shape change of the separated bridge has a number of stages determined by the properties of the liquid. As a result, the bridge is transformed into a small drop—a satellite drop.

  9. Active Control of Long Bridges Using Flaps

    DEFF Research Database (Denmark)

    Hansen, H. I.; Thoft-Christensen, Palle

    The main problem in designing ultra-long span suspension bridges is flutter. A solution to this problem might be to introduce an active flap control system to increase the flutter wind velocity. The investigated flap control system consists of flaps integrated in the bridge girder so each flap...... is the streamlined part of the edge of the girder. Additional aerodynamic derivatives are shown for the flaps and it is shown how methods already developed can be used to estimate the flutter wind velocity for a bridge section with flaps. As an example, the flutter wind velocity is calculated for different flap...

  10. Robustness and health monitoring of existing bridges

    OpenAIRE

    Casas Rius, Joan Ramon

    2015-01-01

    The paper shows how the robustness concept, mainly developed and thought for the design of new structures, and the monitoring by suitable sensors based on fiber optics can also play a relevant role in the safety and management of existing bridges. A new approach of robustness more related to the long-term and service life of bridges is presented and its advantages in the decision-making process during the management of existing bridges are highlighted and afterwards applied on a real brid...

  11. Human Errors and Bridge Management Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, A. S.

    Human errors are divided in two groups. The first group contains human errors, which effect the reliability directly. The second group contains human errors, which will not directly effect the reliability of the structure. The methodology used to estimate so-called reliability distributions...... on basis of reliability profiles for bridges without human errors are extended to include bridges with human errors. The first rehabilitation distributions for bridges without and with human errors are combined into a joint first rehabilitation distribution. The methodology presented is illustrated...

  12. Gust loading on streamlined bridge decks

    DEFF Research Database (Denmark)

    Larose, Guy; Mann, Jakob

    1998-01-01

    The current analytical description of the buffeting action of wind on long-span bridges is based on the strip assumption. However, recent experiments on closed-box girder bridge decks have shown that this assumption is not valid and is the source of an important part of the error margin...... of the analytical prediction methods. In this paper, an analytical model that departs from the strip assumption is used to describe the gust loading on a thin airfoil. A parallel is drawn between the analytical model and direct measurements of gust loading on motionless closed-box girder bridge decks. Empirical...

  13. Micromechanical model of cross-over fibre bridging - Prediction of mixed mode bridging laws

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Gamstedt, E.K.; Østergaard, Rasmus Christian

    2008-01-01

    The fracture resistance of fibre composites can be greatly enhanced by crack bridging. In situ observations of mixed mode crack growth in a unidirectional carbon-fibre/epoxy composite reveal crack bridging by single fibres and by beam-like ligaments consisting of several fibres. Based...... on the observed bridging mechanism, a micromechanical model is developed for the prediction of macroscopic mixed mode bridging laws (stress-opening laws). The model predicts a high normal stress for very small openings, decreasing rapidly with increasing normal and tangential crack opening displacements....... In contrast, the shear stress increases rapidly, approaching a constant value with increasing normal and tangential openings. The solutions for the bridging laws and the resulting toughening due to the bridging stresses are obtained in closed analytical form....

  14. Field performance of timber bridges. 17, Ciphers stress-laminated deck bridge

    Science.gov (United States)

    James P. Wacker; James A. Kainz; Michael A. Ritter

    In September 1989, the Ciphers bridge was constructed within the Beltrami Island State Forest in Roseau County, Minnesota. The bridge superstructure is a two-span continuous stress-laminated deck that is approximately 12.19 m long, 5.49 m wide, and 305 mm deep (40 ft long, 18 ft wide, and 12 in. deep). The bridge is one of the first to utilize red pine sawn lumber for...

  15. Field performance of timber bridges. 8, Lynches Woods Park stress-laminated deck bridge

    Science.gov (United States)

    J. P. Wacker; M. A. Ritter; D. Conger

    The Lynches Woods Park bridge was constructed during the summer of 1990 in Newberry, South Carolina. It is a single-span, single-lane, stress-laminated deck superstructure that measures approximately 30 ft long, 16 ft wide, and 14 in. deep. The bridge is unique in that is one of the first known stress-laminated deck bridges to be constructed of Southern Pine lumber...

  16. Field performance of timber bridges. 10, Sanborn Brook stress-laminated deck bridge

    Science.gov (United States)

    P. D. Hilbrich Lee; J. P. Wacker; M. A. Ritter

    The Sanborn Brook bridge was constructed in August 1991, 10 miles northeast of Concord, New Hampshire, as part of the demonstration timber bridge program of the USDA Forest Service. The bridge is a simple-span, double-lane, stress-laminated deck superstructure constructed from Southern Pine lumber and is approximately 25 ft long and 28 ft wide with a skew of 14 degrees...

  17. Field performance of timber bridges. 12, Christian Hollow stress-laminated box-beam bridge

    Science.gov (United States)

    J. P. Wacker; S. C. Catherman; R. G. Winnett

    In January 1992, the Christian Hollow bridge was constructed in Steuben County, New York. The bridge is a single-span, stress-laminated box-beam superstructure that is 9.1 m long, 9.8 m wide, and 502 mm deep (30 ft long, 32 ft wide, and 19-3/4 in. deep). The performance of the bridge was continuously monitored for 28 months, beginning shortly after installation....

  18. Field performance of timber bridges. 16, North Siwell Road stress-laminated bridge

    Science.gov (United States)

    J. A. Kainz

    The North Siwell Road bridge was constructed during December 1994 in Hinds County, Mississippi. The bridge is a single-span, stress-laminated T-beam structure that measures 9.1 m (30 ft) long and 8.7 m (28.5 ft) wide. Performance of the bridge was monitored for 24 months, beginning at the time of installation. Monitoring involved gathering and evaluating data relative...

  19. Carbon-based tendons in the Dintelhaven Bridge, the Netherlands

    NARCIS (Netherlands)

    Vervuurt, A.H.J.M.; Kaptijn, N.; Grundlehner, W.B.

    2003-01-01

    In mid-2001 the final two bridges over the River Dintelhaven in the harbour area of Rotterdam were put into use. Both bridges are concrete box girder bridges and have been erected using the balanced cantilever method. In the first bridge, with a main span of about 185 m, four (external) tendons each

  20. Detection of salt bridges to lysines in solution in barnase

    DEFF Research Database (Denmark)

    Hansen, Poul Erik; Williamson, Michael P.; Hounslow, Andrea M.

    2013-01-01

    We show that salt bridges involving lysines can be detected by deuterium isotope effects on NMR chemical shifts of the sidechain amine. Lys27 in the ribonuclease barnase is salt bridged, and mutation of Arg69 to Lys retains a partially buried salt bridge. The salt bridges are functionally important....

  1. Inspection Based Evaluation of a Danish Road Bridge

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper it is shown how an inspection-based evaluation of a Danish road bridge may be performed using the BRIDGE1 and BRIDGE2 bridge management systems produced within the EC-supported research programme "Assessment of Performance and Optimal Strategies for Inspection and Maintenance...

  2. Precast alternative for flat slab bridges : final report.

    Science.gov (United States)

    2013-10-26

    The cast-in-place (CIP) concrete slab bridge and the hollow core flat slab bridge are two very common bridge types utilized by the : South Carolina Department of Transportation (SCDOT). The CIP bridge is durable but has a long construction time while...

  3. 49 CFR 236.766 - Locking, movable bridge.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge. ...

  4. 23 CFR 650.705 - Application for discretionary bridge funds.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Application for discretionary bridge funds. 650.705... TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Discretionary Bridge Candidate Rating Factor § 650.705 Application for discretionary bridge funds. Each year through its field offices, the FHWA will...

  5. 33 CFR 118.140 - Painting bridge piers.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Painting bridge piers. 118.140... BRIDGE LIGHTING AND OTHER SIGNALS § 118.140 Painting bridge piers. The District Commander may require painting the sides of bridge channel piers below the superstructure facing traffic white or yellow when...

  6. Bridge deck resurfacing using Rosphalt 50.

    Science.gov (United States)

    2006-10-01

    Most bridge decks in Maine are comprised of Reinforced Portland Cement Concrete (RPCC). Although a : durable product, RPCC is permeable and susceptible to chloride penetration leading to corrosion of the : steel reinforcement and eventual cracking of...

  7. Simplifying Bridge Expansion Joint Design and Maintenance

    Science.gov (United States)

    2011-10-19

    This report presents a study focused on identifying the most durable expansion joints for the South : Carolina Department of Transportation. This is performed by proposing a degradation model for the : expansion joints and updating it based on bridge...

  8. Assuring bridge safety and serviceability in Europe

    Science.gov (United States)

    2010-08-01

    U.S. engineers need advanced tools and protocols to better assess and assure safety and serviceability of bridges. The Federal Highway Administration, American Association of State Highway and Transportation Officials, and National Cooperative Highwa...

  9. Improved bridge joint materials and design details.

    Science.gov (United States)

    2017-06-01

    Expansion joints accommodate bridge movements that result from factors such as thermal expansion and contraction, concrete shrinkage, creep effects, live loading, settlement of the foundation and substructure, and environmental stressors. Expansion j...

  10. Aesthetic coatings for steel bridge components.

    Science.gov (United States)

    2013-11-01

    The effectiveness of aesthetic coating systems for steel bridges was studied. Twelve 2-coat, 3-coat, and duplex : coating systems were selected and subjected to a series of accelerated weathering and mechanical tests to : determine their performance....

  11. Aesthetic coatings for Wisconsin bridge components : [brief].

    Science.gov (United States)

    2014-03-01

    Over the past several years, the Wisconsin Department of Transportation (WisDOT) has : experienced performance-related issues with aesthetic and protective coatings used on : Wisconsin bridges. Public agencies make significant investments in coating ...

  12. Allegheny County-Owned Bridges Centerlines

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset shows the bridges owned by Allegheny County. If viewing this description on the Western Pennsylvania Regional Data Center’s open data portal...

  13. Allegheny County-Owned Bridges Points

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset shows the location of bridges owned by Allegheny County as centroids. If viewing this description on the Western Pennsylvania Regional Data Center’s...

  14. Multimedia package for LRFD concrete bridge design.

    Science.gov (United States)

    2009-02-01

    This Project developed a Load and Resistance Factor Design (LRFD) multimedia package to provide a practical introduction and an in-depth understanding of the technological advances in the design of concrete bridges. This package can be used to train ...

  15. Phase and widening construction of steel bridges.

    Science.gov (United States)

    2014-03-01

    Phase construction is used to maintain traffic without interruption and generally refers to sequenced construction where a portion of the bridge is under construction while the remainder continues to carry traffic. The method typically results in two...

  16. Strengthening steel bridge girders using CFRP.

    Science.gov (United States)

    2010-06-01

    While traditional retrofitting methods for steel bridge girders could be time consuming and uneconomical, an alternative repair method is suggested using Carbon Fiber Reinforced Polymers (CFRP) laminate strips, providing engineers with a competitive ...

  17. VT Long Structures - Bridges and Culverts

    Data.gov (United States)

    Vermont Center for Geographic Information — Inspection data for structures (bridge and culvert) greater than 20 feet in length inspected on both State and local road systems. Stewards: Information Technology,...

  18. Bridge condition assessment using remote sensors.

    Science.gov (United States)

    2013-02-01

    The challenges of a deteriorating and aged infrastructure continue to challenge transportation : authorities as they align maintenance and replacement priorities with decreasing funds. The : United States is home to nearly 600,000 highway bridges of ...

  19. The future of rapid bridge deck replacement.

    Science.gov (United States)

    2015-06-01

    Replacing aging, deteriorated infrastructure often requires road closures and traffic detours which impose : inconvenience and delay on commerce and members of the motoring public. Accelerated bridge construction : techniques often use precast member...

  20. Seismic retrofit guidelines for Utah highway bridges.

    Science.gov (United States)

    2009-05-01

    Much of Utahs population dwells in a seismically active region, and many of the bridges connecting transportation lifelines predate the rigorous seismic design standards that have been developed in the past 10-20 years. Seismic retrofitting method...

  1. Life-cycle assessment of Nebraska bridges.

    Science.gov (United States)

    2013-05-01

    Life-cycle cost analysis (LCCA) is a necessary component in bridge management systems (BMSs) for : assessing investment decisions and identifying the most cost-effective improvement alternatives. The : LCCA helps to identify the lowest cost alternati...

  2. Life cycle costs for Alaska bridges.

    Science.gov (United States)

    2014-08-01

    A study was implemented to assist the Alaska Department of Transportation and Public Facilities (ADOT&PF) with life cycle costs for : the Alaska Highway Bridge Inventory. The study consisted of two parts. Part 1 involved working with regional offices...

  3. Deterioration and cost information for bridge management.

    Science.gov (United States)

    2012-05-01

    This study applies contract bid tabulations and elementlevel condition records to develop elementlevel actions, : costs for actions, transition probabilities for models of deterioration of bridge elements, and transition probabilities : for imp...

  4. Structural monitoring of Rigolets Pass Bridge.

    Science.gov (United States)

    2009-10-01

    The overall objective of this research project was to evaluate the structural behavior of prestressed highperformance : concrete (HPC) long-span bulb-tee girders utilized in Louisiana bridge construction. To : accomplish this objective, one span of t...

  5. Wheatstone bridge technique for magnetostriction measurements.

    Science.gov (United States)

    Sullivan, M

    1980-03-01

    A basic Wheatstone bridge, with additional electronic instrumentation, has been used in the measurement of magnetostriction. This method allows a resolution of approximately 10% on measurements of magnetostrictions less than 0.75 parts per million.

  6. Behavior of micropiles in bridge bent applications.

    Science.gov (United States)

    2010-12-01

    This project concerned the behavior of micropiles under lateral loads. The North Carolina Department of Transportation was specifically interested in the use of micropiles to support bridge bents. In this configuration micropiles would be subjected t...

  7. VT Short Structures - Bridges and Culverts

    Data.gov (United States)

    Vermont Center for Geographic Information — Inspection data for structures (bridge and culvert) between 6 feet and 20 feet in length inspected on State road system. Stewards: Information Technology, Data...

  8. Myocardial bridges: a prospective forensic autopsy study

    National Research Council Canada - National Science Library

    Micić-Labudović, Jelena; Atanasijević, Tatjana; Popović, Vesna; Mihailović, Zoran; Nikolić, Slobodan; Puzović, Dragana

    2015-01-01

    ...) in the autopsy material considering the descending branch of the LAD to be the most important one in the nourishment of the myocardium and myocardial bridges to be the most frequent in its area...

  9. Bridging the Health Data Divide.

    Science.gov (United States)

    Celi, Leo Anthony; Davidzon, Guido; Johnson, Alistair Ew; Komorowski, Matthieu; Marshall, Dominic C; Nair, Sunil S; Phillips, Colin T; Pollard, Tom J; Raffa, Jesse D; Salciccioli, Justin D; Salgueiro, Francisco Muge; Stone, David J

    2016-12-20

    Fundamental quality, safety, and cost problems have not been resolved by the increasing digitization of health care. This digitization has progressed alongside the presence of a persistent divide between clinicians, the domain experts, and the technical experts, such as data scientists. The disconnect between clinicians and data scientists translates into a waste of research and health care resources, slow uptake of innovations, and poorer outcomes than are desirable and achievable. The divide can be narrowed by creating a culture of collaboration between these two disciplines, exemplified by events such as datathons. However, in order to more fully and meaningfully bridge the divide, the infrastructure of medical education, publication, and funding processes must evolve to support and enhance a learning health care system. ©Leo Anthony Celi, Guido Davidzon, Alistair EW Johnson, Matthieu Komorowski, Dominic C Marshall, Sunil S Nair, Colin T Phillips, Tom J Pollard, Jesse D Raffa, Justin D Salciccioli, Francisco Muge Salgueiro, David J Stone. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 20.12.2016.

  10. Bonds and bridges : social and poverty

    OpenAIRE

    Narayan, Deepa

    1999-01-01

    Using the lens of social capital-especially bridging or cross-cutting ties that cut across social groups and between social groups and government-provides new insights into policy design. Solidarity within social groups creates ties (bonding social capital) that bring people and resources together. In unequal societies, ties that cut across groups (bridging social capital) are essential for social cohesion and for poverty reduction. The nature of interaction between state and society is chara...

  11. Thermal Bridge Effects in Walls Separating Rowhouses

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

    In this report the thermal bridge effects at internal wall/roof junctions in rowhouses are evaluated. The analysis is performed using a numerical calculation programme, and different solutions are evaluated with respect to extra heat loss and internal surface temperatures.......In this report the thermal bridge effects at internal wall/roof junctions in rowhouses are evaluated. The analysis is performed using a numerical calculation programme, and different solutions are evaluated with respect to extra heat loss and internal surface temperatures....

  12. Analysis of the FRP bridge behavior

    OpenAIRE

    Antolinc, David

    2008-01-01

    The study focuses on the load-carrying behavior of hybrid fiber reinforced thin-walled main bridge beams with the sandwich deck panels on top. Firsty, there is a comprehensive overview of the composite materials and their constitutions (matrix, fibers), mainly to show their mechanical advantages and disadvantages with possibilities for using them in civil engineering applications. Followins which is a short state-of-the-art review of the all-FRP bridges constructed in the past. For a better u...

  13. Retrofitting of bridge hollow piers with CFRP

    OpenAIRE

    Pedro Delgado; Patrício Rocha; João Pedrosa; António Arêde; Nelson Vila Pouca; Miguel Santos; Aníbal Costa; Raimundo Delgado

    2007-01-01

    Hollow bridge piers generally have large section dimensions, with reinforcement barsspread along both wall faces. Unlike common solid section columns, quite often the shear effect hasgreat importance on the pier behavior. Therefore, it is of particular relevance that special attention isgiven to this issue when the assessment and retrofit of RC hollow section piers is envisaged. Representativeof typical bridge construction, RC piers were tested at LESE ¿ the Laboratory of Earthquakeand Struct...

  14. I-5/Gilman advanced technology bridge project

    Science.gov (United States)

    Lanza di Scalea, Francesco; Karbhari, Vistasp M.; Seible, Frieder

    2000-04-01

    The UCSD led I-5/Gilman Advanced Technology Bridge Project will design and construct a fully functional traffic bridge of advanced composite materials across Interstate 5 in La Jolla, California. Its objective is to demonstrate the use of advanced composite technologies developed by the aerospace industry in commercial applications to increase the life expectancy of new structures and for the rehabilitation of aging infrastructure components. The structure will be a 450 ft long, 60 ft wide cable-stayed bridge supported by a 150 ft A-frame pylon with two vehicular lanes, two bicycle lanes, pedestrian walkways and utility tunnels. The longitudinal girders and pylon will be carbon fiber shells filled with concrete. The transverse deck system will consist of hollow glass/carbon hybrid tubes and a polypropylene fiber reinforced concrete deck with an arch action. Selected cables will be composite. The bridge's structural behavior will be monitored to determine how advanced composite materials perform in civil infrastructure applications. The bridge will be instrumented to obtain performance and structural health data in real time and, where possible, in a remote fashion. The sensors applied to the bridge will include electrical resistance strain gages, fiberoptic Bragg gratings and accelerometers.

  15. Wind tunnel test of musi VI bridge

    Science.gov (United States)

    Permata, Robby; Andika, Matza Gusto; Syariefatunnisa, Risdhiawan, Eri; Hermawan, Budi; Noordiana, Indra

    2017-11-01

    Musi VI Bridge is planned to cross the Musi River in Palembang City, South Sumatera Province, Indonesia. The main span is a steel arch type with 200 m length and side span length is 75 m. Finite element analysis results showed that the bridge has frequency ratio for torsional and heaving mode (torsional frequency/heaving frequency)=1.14. This close to unity value rises concern about aerodynamic behaviour and stability of the bridge deck under wind loading. Sectional static and free vibration wind tunnel test were performed to clarify this phenomena in B2TA3 facility in Serpong, Indonesia. The test followed the draft of Guide of Wind Tunnel Test for Bridges developed by Indonesian Ministry of Public Works. Results from wind tunnel testing show that the bridge is safe from flutter instability and no coupled motion vibration observed. Therefore, low value of frequency ratio has no effect to aerodynamic behaviour of the bridge deck. Vortex-induced vibration in heaving mode occurred in relatively low wind velocity with permissible maximum amplitude value.

  16. Precast Pearl-Chain concrete arch bridges

    DEFF Research Database (Denmark)

    Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup

    2015-01-01

    A Pearl-Chain Bridge is a closed-spandrel arch bridge consisting of a number of straight pre-fabricated so called Super-Light Deck elements put together in an arch shape by post-tensioning cables. Several Pearl-Chain arches can be positioned adjacent to each other by a crane to achieve a bridge...... the technology was used. We also study other important components and details in the Pearl-Chain Bridge concept and review the effects of different types of loads. A theoretical case study of a circular 30 m span Pearl-Chain Bridge is presented showing the influence of a number of parameters: The number of post......-tensioning cables, the rise to span ratio, the height of the filling, and the height of the Super-Light Decks. We find that Pearl-Chain Bridges can be adjusted to resist specific moment loads by changing the normal force in the arch cross section by altering the above parameters. It is also found that the negative...

  17. The I-35W bridge Project Website

    DEFF Research Database (Denmark)

    Kampf, Constance

    How can websites be used to rebuild trust?  In August 2007, the Interstate Highway 35-W bridge in Minneapolis, MN collapsed during rush hour.  Although many people were rescued and casualties were as limited as could be expected due to quick and effective intervention, the image of a major bridge...... of the rhetorical processes operating via the project website as an element in the socio-technical design of the bridge, and the emergence of the Project Website as both a Project Management tool and a web genre.......How can websites be used to rebuild trust?  In August 2007, the Interstate Highway 35-W bridge in Minneapolis, MN collapsed during rush hour.  Although many people were rescued and casualties were as limited as could be expected due to quick and effective intervention, the image of a major bridge...... collapsing during rush hour damaged the Minnesota Department of Transportation's reputation and resulted in the loss of public trust for the organization.  The ensuing bridge reconstruction project included a project website intended to rebuild this trust through transparency, community involvement...

  18. Bridge and steel structures. History and vision on bridge erection; Kyoryo kokozobutsu. Kasetsu gijutsu no shorai

    Energy Technology Data Exchange (ETDEWEB)

    Mukai, S.; Hayashi, T. [Sumitomo Heavy Industries, Ltd., Tokyo (Japan)

    1998-08-20

    This paper describes the progress of bridge erection technology. It introduces the results of cable erection, rotated/extruded erection, and cantilever erection. The cable erection is a multi point suspension erection using cables. For the rotated/extruded erection, the monolithic construction is conducted on a working yard set in a right angle to the construction position, and the horizontal beams of the bridge piers (corbel girders) are constructed by the rotated method using a slewing base incorporated around the bridge piers at one side. For the construction of stiffening girders of Innoshima-ohashi Bridge of Honshu-Shikoku Joint Bridge in 1978, trussed face bar blocks were extruded from the main tower in order using a travel crane. For the suspension bridges and cable stayed bridges, main towers were erected using various types of cranes. The erection of Tamashima-ohashi Bridge with a weight of 500 ton using an offshore floating crane is introduced as a large block method. Analysis methods and measurement techniques at the site are used in order to analyze the shape in each step under the erection and to ensure the accurate final complete shape. Reduction of the construction cost, improvement of erection technology, and technology development for large-scale projects are subjects in the future. 22 refs., 8 figs., 1 tab.

  19. Phase II : correlation between experimental and finite element analysis : Alaska bridge 255-Chulitna River bridge.

    Science.gov (United States)

    2014-09-01

    In this study, we will monitor the behavior of the Alaska Chulitna Bridge for the specific purpose of assisting the DOT in performing an accurate : condition assessment of this bridge. : Based on the state-of-the-art SHM knowledge and technologies wi...

  20. Field performance of timber bridges. 11, Spearfish Creek stress-laminated box-beam bridge

    Science.gov (United States)

    J. P. Wacker; M. A. Ritter; K. Stanfill-McMillan

    The Spearfish Creek bridge was constructed in 1992 in Spearfish, South Dakota. It is a single-span, stress-laminated, box-beam superstructure. Performance of the bridge is being monitored for 5 years, beginning at installation. This report summarizes results for the first 3-1/2 years of monitoring and includes information on the design, construction, and field...

  1. Bridge employment after early retirement: a bridge to better postretirement well-being of older adults?

    NARCIS (Netherlands)

    Dingemans, E.

    2012-01-01

    Using a retirement arrangement does not necessarily mean that people retire fulltime. The phenomenon of bridge employment, already studied in the US, becomes increasingly popular among older adults in the Netherlands. The question is to what extent bridge employment can be beneficial for well-being

  2. Research and development of weathering resistant bridge steel of Shougang

    Science.gov (United States)

    Yang, Yongda; Wang, Yanfeng; Huang, Leqing; Di, Guobiao; Ma, Changwen; Ma, Qingshen

    2017-09-01

    To introduce the composition design and mechanical properties and microstructure of the weathering bridge steel which would be used for bridge of Guanting reservoir. We adopt cyclic immersion corrosion test to study corrosion resistance difference of weathering bridge steel and common bridge steel. At the same corrosion time, the weight loss and corrosion rate of weathering bridge steel are lower than the common bridge steel's. Testing phase composition of rust layer by X-ray diffraction, two kinds of test steel's rust layer is mainly composed of Goethite and Fe3O4 and Fe2O3. At the same corrosion time, the percentage composition of goethite in rust layer of weathering bridge steel are significantly higher than common bridge steel's, the higher goethite content is, the compacter rust layer structure is. The compact rust layer would prevent the water and air passing the rust layer, and then preventing the further corrosion reaction, improving the corrosion resistance performance of weathering bridge steel.

  3. Ecological bridges and barriers in pelagic ecosystems

    Science.gov (United States)

    Briscoe, Dana K.; Hobday, Alistair J.; Carlisle, Aaron; Scales, Kylie; Eveson, J. Paige; Arrizabalaga, Haritz; Druon, Jean Noel; Fromentin, Jean-Marc

    2017-06-01

    Many highly mobile species are known to use persistent pathways or corridors to move between habitat patches in which conditions are favorable for particular activities, such as breeding or foraging. In the marine realm, environmental variability can lead to the development of temporary periods of anomalous oceanographic conditions that can connect individuals to areas of habitat outside a population's usual range, or alternatively, restrict individuals from areas usually within their range, thus acting as ecological bridges or ecological barriers. These temporary features can result in novel or irregular trophic interactions and changes in population spatial dynamics, and, therefore, may have significant implications for management of marine ecosystems. Here, we provide evidence of ecological bridges and barriers in different ocean regions, drawing upon five case studies in which particular oceanographic conditions have facilitated or restricted the movements of individuals from highly migratory species. We discuss the potential population-level significance of ecological bridges and barriers, with respect to the life history characteristics of different species, and inter- and intra-population variability in habitat use. Finally, we summarize the persistence of bridge dynamics with time, our ability to monitor bridges and barriers in a changing climate, and implications for forecasting future climate-mediated ecosystem change.

  4. Toward an Egyptian Bridge Management System

    Directory of Open Access Journals (Sweden)

    Ahmed M. Saleh

    2013-12-01

    Full Text Available A prototype bridge management system for concrete bridges in Egypt (EBRMS is built and tested. The proposed system has the ability to record different inventory data, has tools for condition rating, priority ranking and cost optimization at both bridge and network levels. Condition rating is based on the type, extent, and severity of defects and urgency of intervention, all based on observations made during the inspections. It also takes into account the importance of the deteriorated elements. Priority ranking is evaluated on the basis of a knowledge-base stored in the system. It is calculated using four parameters: condition rating; remaining service life; safety index; and impact of the structure on the network. The developed framework of EBRMS consists of three main modules: database and inspections, condition rating and decision making modules. Details of each of the system capabilities are based on the published research work, mainly on the BRIME project. Testing and verification of the proposed scheme are carried out using a virtual bridge network and available published data as the knowledge base. Twelve actual bridges of different types (slab and beam, box girder and slab types at different locations and under varying service conditions are assumed in the virtual network. Various scenarios of damage states, imposed policies and budget constraints were assumed for testing and validation. All results were reasonable and within acceptable domain.

  5. A probabilistic bridge safety evaluation against floods.

    Science.gov (United States)

    Liao, Kuo-Wei; Muto, Yasunori; Chen, Wei-Lun; Wu, Bang-Ho

    2016-01-01

    To further capture the influences of uncertain factors on river bridge safety evaluation, a probabilistic approach is adopted. Because this is a systematic and nonlinear problem, MPP-based reliability analyses are not suitable. A sampling approach such as a Monte Carlo simulation (MCS) or importance sampling is often adopted. To enhance the efficiency of the sampling approach, this study utilizes Bayesian least squares support vector machines to construct a response surface followed by an MCS, providing a more precise safety index. Although there are several factors impacting the flood-resistant reliability of a bridge, previous experiences and studies show that the reliability of the bridge itself plays a key role. Thus, the goal of this study is to analyze the system reliability of a selected bridge that includes five limit states. The random variables considered here include the water surface elevation, water velocity, local scour depth, soil property and wind load. Because the first three variables are deeply affected by river hydraulics, a probabilistic HEC-RAS-based simulation is performed to capture the uncertainties in those random variables. The accuracy and variation of our solutions are confirmed by a direct MCS to ensure the applicability of the proposed approach. The results of a numerical example indicate that the proposed approach can efficiently provide an accurate bridge safety evaluation and maintain satisfactory variation.

  6. Reconstruction of the Old Bridge of Mostar

    Directory of Open Access Journals (Sweden)

    M. Popovac

    2006-01-01

    Full Text Available The Old Bridge of Mostar was built in 1566 by Hajrudin, a student of Kodza Mimar Sinan, the greatest Ottoman architect. It is a stone bridge of very slender and elegant shapes: its profile and its skyline are so thin and so high over the river waters that it is hard to believe that such a structure could be made out of huge stone blocks. The Bridge was destroyed in November 1993 by shelling during the recent war events. Its reconstruction was one of the biggest and most complicated projects involving UNESCO, The World Bank and many local and international experts. The task was to build a New Old Bridge – precisely the same in all details as the Old one. After many studies, tests and shape determinations, the project was completed and the actual reconstruction work could begin. Ancient techniques and methods, original materials and a perfectly reconstructed shape gave this Bridge its new life in post-war Mostar.

  7. Bridges in the random-cluster model

    Directory of Open Access Journals (Sweden)

    Eren Metin Elçi

    2016-02-01

    Full Text Available The random-cluster model, a correlated bond percolation model, unifies a range of important models of statistical mechanics in one description, including independent bond percolation, the Potts model and uniform spanning trees. By introducing a classification of edges based on their relevance to the connectivity we study the stability of clusters in this model. We prove several exact relations for general graphs that allow us to derive unambiguously the finite-size scaling behavior of the density of bridges and non-bridges. For percolation, we are also able to characterize the point for which clusters become maximally fragile and show that it is connected to the concept of the bridge load. Combining our exact treatment with further results from conformal field theory, we uncover a surprising behavior of the (normalized variance of the number of (non-bridges, showing that it diverges in two dimensions below the value 4cos2⁡(π/3=0.2315891⋯ of the cluster coupling q. Finally, we show that a partial or complete pruning of bridges from clusters enables estimates of the backbone fractal dimension that are much less encumbered by finite-size corrections than more conventional approaches.

  8. Assessment of the Reliability of Concrete Bridges

    DEFF Research Database (Denmark)

    Middleton, C. R.; Thoft-Christensen, Palle

    Although there has been a considerable amount of research into different aspects of concrete bridge reliability, it has still not been widely adopted in professional practice other than in the development and calibration of codes. This situation appears to be changing as there has been a signific......Although there has been a considerable amount of research into different aspects of concrete bridge reliability, it has still not been widely adopted in professional practice other than in the development and calibration of codes. This situation appears to be changing as there has been...... in the wake of ever increasing traffic loads and volumes, and an ageing population of bridges subject to various mechanisms of deterioration. The goal is to optimise the allocation of limited resources whilst maintaining their bridges in a safe and serviceable condition. Reliability analysis is one tool being...... adopted to assist in achieving this goal. Rather than review the specific research on this subject this paper examines a number of key issues related to the practical application of reliability analysis to the assessment of concrete bridges....

  9. Nonlinear seismic analysis of continuous RC bridge

    Directory of Open Access Journals (Sweden)

    Čokić Miloš M.

    2017-01-01

    Full Text Available Nonlinear static analysis, known as a pushover method (NSPA is oftenly used to study the behaviour of a bridge structure under the seismic action. It is shown that the Equivalent Linearization Method - ELM, recommended in FEMA 440, is appropriate for the response analysis of the bridge columns, with different geometric characteristics, quantity and distribution of steel reinforcement. The subject of analysis is a bridge structure with a carriageway plate - a continuous beam with three spans, with the 24 + 40 + 24 m range. Main girder is made of prestressed concrete and it has a box cross section of a constant height. It is important to study the behaviour, not only in the transverse, but also in the longitudinal direction of the bridge axis, when analysing the bridge columns exposed to horizontal seismic actions. The columns were designed according to EN1992, parts 1 and 2. Seismic action analysis is conducted according to EN 1998: 2004 standard. Response spectrum type 1, for the ground type B, was applied and the analysis also includes 20% of traffic load. The analysis includes the values of columns displacement and ductility. To describe the behaviour of elements under the earthquake action in both - longitudinal and transverse direction, pushover curves were formed.

  10. Suspension Bridge Flutter for Girder with Separate Control Flaps

    DEFF Research Database (Denmark)

    Huynh, T.; Thoft-Christensen, Palle

    Active vibration control of long span suspension bridge flutter using separated control flaps (SFSC) has shown to increase effectively the critical wind speed of bridges. In this paper, an SFSC calculation based on modal equations of the vertical and torsional motions of the bridge girder including...... the flaps is presented. The length of the flaps attached to the girder, the flap configuration and the flap rotational angles are parameters used to increase the critical wind speed of the bridge. To illustrate the theory a numerical example is shown for a suspension bridge of 1000m+2500m+1000m span based...... on the Great Belt Bridge streamlined girder....

  11. MULTIPHASE BLASTING OF THE BRIDGE ACROSS THE DRENICA RIVER

    Directory of Open Access Journals (Sweden)

    Branko Božić

    1989-12-01

    Full Text Available The construction of new bridges on the sites of the existing ones require demolition of the old bridge. Due to closeness of newly erected bridge elements the fundations of old bridges are demolished by multiphase blasting process. The blasting of the piers and anchorages of the bridge across 'the Drenica river carrying the Balačevac—Goleš industrial railway was done in four phases. The piers and anchorages of a new bridge and its construction elements have been erected before (the paper is published in Croatian.

  12. Stability of dynamic response of suspension bridges

    Science.gov (United States)

    Capsoni, Antonio; Ardito, Raffaele; Guerrieri, Andrea

    2017-04-01

    The potential occurrence of internal parametric resonance phenomena has been recently indicated as a potential contributory cause of the appearance of critical dynamic states in long-span suspension bridges. At the same time, suspension bridges, in view of their flexibility, are prone to aeroelastic response, such as vortex shedding, torsional divergence and flutter. In this paper, a non-linear dynamic model of a suspension bridge is devised, with the purpose of providing a first attempt toward a unified framework for the study of aeroelastic and internal resonance instabilities. Inspired by the pioneering work of Herrmann and Hauger, the analyses have been based on a linearized formulation that is able to represent the main structural non-linear effects and the coupling given by aerodynamic forces. The results confirm that the interaction between aeroelastic effects and non-linear internal resonance leads to unstable conditions for wind speeds which can be lower than the critical threshold for standard aeroelastic predictions.

  13. Strategic sensor locations of FPR bridge decks

    Science.gov (United States)

    Wu, Hwai-Chung; Warnemuende, Kraig; Yan, An; Mu, Bin

    2003-07-01

    Advanced fiber-reinforced polymer composite (FRP) has been increasingly used in bridge deck to replace concrete or steel. A FRP bridge deck can be designed to meet AASHTO HS-25 load requirements. FRP decks have many advantages over the conventional reinforced concrete or steel decks owing to their lightweight, high strength and corrosion resistance. However, such new deck system requires extensive monitoring to ensure its designed performance before its widespread acceptance by the bridge community. For inspection and evaluation purpose, a proper monitoring system consisting of various kinds of sensors installed in the FRP deck is critical. This paper provides a framework for designing an efficient monitoring system. The strategic sensor locations are identified based on the stress analysis of the FRP deck.

  14. Building a bridge: engineering spinal cord repair.

    Science.gov (United States)

    Geller, Herbert M; Fawcett, James W

    2002-04-01

    Injuries to the spinal cord that result in disruption of axonal continuity have devastating consequences for injured patients. Current therapies that use biologically active agents to promote neuronal survival and/or growth have had modest success in allowing injured neurons to regrow through the area of the lesion. Strategies for successful regeneration will require an engineering approach. We propose the design of cell-free grafts of biocompatible materials to build a bridge across the injured area through which axons can regenerate. There are three critical regions of this bridge: the on-ramp, the surface of the bridge itself, and the off-ramp. Each of these regions has specific design requirements, which, if met, can promote regeneration of axons in the injured spinal cord. These requirements, and proposed solutions, are discussed.

  15. Variations in bridge construction in commercial laboratories.

    Science.gov (United States)

    Johnson, A; Winstanley, R B; Northeast, S E; Van Noort, R; White, G E

    1991-08-01

    Identical working models for the construction of a porcelain bonded to metal three unit fixed bridge were sent to 30 different commercial dental laboratories in the United Kingdom. The material was sent from general dental practice addresses with the implication for treatment under the National Health Service. Each bridge on its return was examined for acceptability using subjective criteria based on clinical and technical factors. There was a wide variation between bridges which gave cause for concern. Lack of a satisfactory prescription for the laboratories to work to must have played a part in this variation. However, it is stressed that the prescription used in this work was deliberately chosen as representative of that which may be used by clinicians.

  16. Myocardial bridges in dogs. II. Topology

    Directory of Open Access Journals (Sweden)

    Ricardo Coutinho do Amaral

    1996-12-01

    Full Text Available The authors have studied the location of myocardial bridges in 134 hearts of different breed, pure dogs. After injection of Neoprene Latex or gelatine solution, the coronary arteries were dissected. Myocardial bridges (90.43% were observed in branches of the left coronary arteries, and 9.57% in branches of the right coronary arteries. The bridges' locations were: 37.23% in the dorsal portion; 28.72% in the medium portion; 21.28% in the ventral portion; 7.45% in the vertex portion; 3.19% simultaneously in the dorsal and medium portions and 2.13% simultaneously in the medium and ventral portions. Statistical differences were not observed between males and females.

  17. Construction of the Maizuru first bridge (the Ohara bridge); Maizuru ichigosen (Oharakyo) no seko

    Energy Technology Data Exchange (ETDEWEB)

    Otsuki, Y. [Kyoto Prefectural Government Office, Kyoto (Japan); Hirose, T.; Tateyama, A. [Fujita Corp., Tokyo (Japan); Kawano, S. [Sumitomo Construction Co. Ltd., Tokyo (Japan)

    1997-05-30

    This paper describes construction of the Maizuru First Bridge of the Kyoto Traverse Highway. This bridge construction includes the PC three-span continuous rahmen bridge, girders of PC three-span continuous knee brace rahmen bridge, tunnel, and earthworks. The structure in the valley was selected by considering the straight line on plane figure, distance of 50 m under beams, steep terrain, and compaction of carry-in unit of construction materials. The carry-in route was kept by the earlier earthworks for the main road and construction of the tunnel section. Incline facilities generally used for dam constructions were used on the steep slope. For the construction of knee brace piers, temporary column members previously fabricated separately in the factory were constructed at the site, and reinforced concrete placing from the joint of bridge piers was conducted. For the construction of main girders, overhang erection construction method was employed using temporary column members. The PC steel twisted cables were used for the vertical tightening, and the PC steel rods were used for the lateral tightening. After the overhang erection construction of main girders, a jack was placed at the center joint. The reaction forces of temporary columns and auxiliary columns were released by expanding bridge body in the bridge axis direction using horizontal force. Thus, the bending moment generated at the basement of girders was improved. 1 ref., 20 figs., 5 tabs.

  18. Dragon bridge - the world largest dragon-shaped (ARCH steel bridge as element of smart city

    Directory of Open Access Journals (Sweden)

    Chinh Luong Minh

    2016-01-01

    Full Text Available Dragon Bridge - The world’s largest dragon-shaped steel bridge, with an installation cost of $85 million USD, features 6 lanes for two separate directions, 666 meters of undulating steel in the shape of a dragon in the Ly Dynasty, the symbol of prosperity in Vietnamese culture. This unique and beautifully lit bridge, which also breathes fire and sprays water. It’s the purposeful integration of the lighting hardware articulates the dragon’s form, and the fire-breathing dragon head. This project transcends the notion of monumental bridge with dynamic colour-changing lighting, creating an iconic sculpture in the skyline that is both reverent and whimsical. The signature feature of the bridge was the massive undulating support structure resembling a dragon flying over the river. The dragon is prominent in Vietnamese culture as a symbol of power and nobility. Dragon Bridge stands out as a model of innovation. It has received worldwide attention in the design community and from the global media for its unique arch support system. Dragon Bridge serves as an example of how aesthetic quality of a design can serve cultural, economic and functional purposes. The article presents design solutions of the object and the evaluation of the technical condition before putting the facility into service.

  19. Influence of Blasting Vibration on Young Concrete Bridge: A Case Study of Yesanhe Super Large Bridge

    Directory of Open Access Journals (Sweden)

    Ming Chen

    2017-01-01

    Full Text Available Influence of blasting vibration on young concrete structure is an important issue in the field of hydropower engineering, transportation, and so forth. Based on influence of blasting excavation on concrete pouring progress of box girder in nearby Yesanhe Super Large Bridge, which is located in Hubei Province of China, a method combining field test and numerical simulation is used to study influence of blasting vibration on young concrete super large bridge. The results show that blasting excavation of nearby Yesanhe Hydropower Station induced vibration response on Yesanhe Bridge and peak particle velocity (PPV on the bridge was quite small under test conditions. Monitoring data and numerical simulation both indicate that PPV of box girder is 1 to 4 times larger than that of pier foundation; with the extension of bridge cantilever casting section, velocity amplification factors of different parts of the box girder have different changes and duration of vibration in vertical direction increases. Three days after concrete pouring, the impact of concrete ageing on PPV and damage distribution of the bridge is not obvious. When vibration velocity of pier foundation is within 2 cm/s, the maximum tensile and compressive stress of box girder concrete are less than the tensile and compressive strength of concrete, so that blasting vibration unlikely gives impact on the safety of bridge.

  20. Ambient Vibration Test on Reinforced Concrete Bridges

    Directory of Open Access Journals (Sweden)

    Idris Nurul Shazwin

    2016-01-01

    Full Text Available An investigation was carried out to determine dynamic characteristic of reinforced concrete (RC bridges by using ambient vibration test (AVT. The ambient vibration sources on bridges may come from traffic, wind, wave motion and seismic events. AVT describes the dynamic characteristics of the bridge and ground by measuring the natural frequencies using highly sensitive seismometer sensor. This test is beneficial due to light weight equipment and smaller number of operator required, cheap and easy to be handled. It is able to give a true picture of the bridge dynamic behavior without any artificial force excitation when vibration data is recorded. A three-span reinforced concrete bridge located in Sri Medan, Batu Pahat, Johor was measured by using microtremor equipment consist of three units of 1 Hz eigenfrequency passive sensors used in this test was performed in normal operating condition without excitation required from any active sources or short period noise perturbations. Ten measurements were conducted on the bridge deck and ten measurements on the ground surface in order to identify the natural frequencies of the bridge. Several peak frequencies were identified from three components of Fourier Amplitude Spectra (FAS in transverse (North-South, longitudinal (East-West and vertical (Up-Down direction as well as squared average Horizontal to Vertical Spectral Ratio (HVSR of ground response, computed by using Geopsy software. From the result, it was expected the bridge have five vibration modes frequencies in the range of 1.0 Hz and 7.0 Hz with the first two modes in the transverse and longitudinal direction having a frequency 1.0 Hz, the third mode is 2.2 Hz in transverse direction, fourth and fifth mode is 5.8 Hz and 7.0 Hz. For ground natural frequencies are in range 1.0 Hz to 1.3 Hz for North-South direction and 1.0 Hz to 1.6 Hz for East-West direction. Finally the results are compared with several empirical formulas for simple

  1. V. Tormis: "Bridge of Song / Brian Hunt

    Index Scriptorium Estoniae

    Hunt, Brian

    1997-01-01

    Uuest heliplaadist "V. Tormis: "Bridge of Song" - Bridge of Song; Singing aboard ship; Brides Farewell; Kihnu Island Wedding Songs; 17 Estonian Wedding Songs; Three Estonian Game Songs; Four Estonian Lullabies. Estonian Radio Choir / Toomas Kapten. Finlandia 4509 96937-2; 56:52 DDD; "People of Kalevala" - God protect us from war; Vespian Winter; Eagle Flew From the North East; Plague Memory; Vainamoinen's Words of Wisdom; The Seventeenth Rune of Kalevala. National Male Choir of Estonia. Finlandia 0630 12245-2; 56:52 DDD

  2. Dynamics of nearly unstable axisymmetric liquid bridges

    Science.gov (United States)

    Perales, José M.; Vega, José M.

    2011-01-01

    The dynamics of a noncylindrical, axisymmetric, marginally unstable liquid bridge between two equal disks is analyzed in the inviscid limit. The resulting model allows for the weakly nonlinear description of both the (first stage of) breakage for unstable configurations and the (slow) dynamics for stable configurations. The analysis is made for both slender and short liquid brides. In the former range, the dynamics breaks reflection symmetry on the midplane between the supporting disks and can be described by a standard Duffing equation, while for short bridges reflection symmetry is preserved and the equation is still Duffing-like but exhibiting a quadratic nonlinearity. The asymptotic results compare well with existing experiments.

  3. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.; Kirkegaard, Poul Henning; Enevoldsen, I.

    The present paper worked out as a part of a research project on "Dynamic amplification factor of vehicle loadings on smaller bridges" establishes a two-dimensional spectral description of the road roughness surface based on measurements from a Danish road using so-called Profilograph used by Danish...... Road Directorate. The stochastic model for the surface irregularities models, based on observations from the measured data, the deterministic trends in transversal (wheel tracking) as well as longitudinal direction (some longwaved tendency). Further the bumps/expansion joints at the approaches...... to the bridge and the stochastic nature of the surface roughness are included into the model....

  4. Characterization of stormwater runoff from bridges in North Carolina and the effects of bridge runoff on receiving streams

    Science.gov (United States)

    Wagner, Chad; Fitzgerald, Sharon; Lauffer, Matthew

    2015-01-01

    The presentation will provide an overview of a collaborative study between USGS, NC Department of Transportation and URS Corporation to characterize stormwater runoff from bridges in North Carolina and the effects of bridge runoff on receiving streams. This investigation measured bridge deck runoff from 15 bridges for 12-15 storms, stream water-quality data for baseflow and storm conditions at four of the bridge deck sites and streambed sediment chemistry upstream and downstream of 30 bridges across North Carolina. Background on why the study was conducted, objectives and scope and a general summary of the major results and conclusions will be presented.

  5. Application of bridge continuous shape measurement system based on optical fiber sensing technology in bridge post-seismic detection

    Science.gov (United States)

    Yang, Yan; Liu, Fang; Fu, Jinghua; Yang, Dandan

    2017-04-01

    Bridge shape is the important indicator to estimate the safety of the bridge. A bridge shape measurement system based on fiber optic gyroscope is builded up to survey the continuous shape of bridge. This measurement system comprises angular velocity sensor, linear velocity sensor, position sensor and etc. The bridge shape survey using the leveling measurement and bridge continuous shape measurement system was carried out after the earthquake. By comparing the data before and after the earthquake, the numerical values of the two method were similar. The experimental results show that the proposed system is an effective measurement method.

  6. Dragon bridge - the world largest dragon-shaped (ARCH) steel bridge as element of smart city

    OpenAIRE

    Chinh Luong Minh; Adamczak Anna; Krampikowska Aleksandra; Świt Grzegorz

    2016-01-01

    Dragon Bridge - The world’s largest dragon-shaped steel bridge, with an installation cost of $85 million USD, features 6 lanes for two separate directions, 666 meters of undulating steel in the shape of a dragon in the Ly Dynasty, the symbol of prosperity in Vietnamese culture. This unique and beautifully lit bridge, which also breathes fire and sprays water. It’s the purposeful integration of the lighting hardware articulates the dragon’s form, and the fire-breathing dragon head. This projec...

  7. Violin bridge mobility analysis under in-plane excitation.

    Science.gov (United States)

    Zhang, Cheng-Zhong; Zhang, Guang-Ming; Ye, Bang-Yan; Liang, Li-Dong

    2013-11-08

    The vibration of a violin bridge is a dynamic contact vibration with two interfaces: strings-bridge, and bridge feet-top plate. In this paper, the mobility of an isolated bridge under in-plane excitation is explored using finite element modeling based on the contact vibration model. Numerical results show that the dynamic contact stiffness in the two contact interfaces has a great impact on the bridge mobility. A main resonance peak is observed in the frequency range of 2-3 kHz in the frequency response of the isolated bridge when the contact stiffness is smaller than a critical threshold. The main resonance peak frequency is affected by the contact stiffness as well. In order to verify the numerical findings, a novel experimental system is then designed on the basis of a piezoelectric dynamometer for bridge mobility analysis. Experimental results confirm the impact of the dynamic contact stiffness on the bridge mobility.

  8. Violin Bridge Mobility Analysis under In-Plane Excitation

    Directory of Open Access Journals (Sweden)

    Cheng-Zhong Zhang

    2013-11-01

    Full Text Available The vibration of a violin bridge is a dynamic contact vibration with two interfaces: strings-bridge, and bridge feet-top plate. In this paper, the mobility of an isolated bridge under in-plane excitation is explored using finite element modeling based on the contact vibration model. Numerical results show that the dynamic contact stiffness in the two contact interfaces has a great impact on the bridge mobility. A main resonance peak is observed in the frequency range of 2–3 kHz in the frequency response of the isolated bridge when the contact stiffness is smaller than a critical threshold. The main resonance peak frequency is affected by the contact stiffness as well. In order to verify the numerical findings, a novel experimental system is then designed on the basis of a piezoelectric dynamometer for bridge mobility analysis. Experimental results confirm the impact of the dynamic contact stiffness on the bridge mobility.

  9. Determining the effective system damping of highway bridges.

    Science.gov (United States)

    2009-06-01

    This project investigates four methods for modeling modal damping ratios of short-span and isolated : concrete bridges subjected to strong ground motion, which can be used for bridge seismic analysis : and design based on the response spectrum method...

  10. CDC WONDER: Population - Bridged-Race July 1st Estimates

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Population - Bridged-Race July 1st Estimates online databases report bridged-race population estimates of the July 1st resident population of the United States,...

  11. Sealing of Cracks on Florida Bridge Decks with Steel Girders

    Science.gov (United States)

    2012-08-01

    One of the biggest problems affecting bridges is the transverse cracking and deterioration of concrete bridge decks. The causes of early age cracking are primarily attributed to plastic shrinkage, temperature effects, autogenous shrinkage, and drying...

  12. Dynamic properties of stay cables on the Penobscot Narrows bridge.

    Science.gov (United States)

    2014-09-01

    Cable-stayed bridges have been recognized as the most efficient and cost effective structural form for medium to long : span bridges over the past several decades. With their widespread use, cases of serviceability problems associated with : large am...

  13. structural reliability of the nigerian grown abura timber bridge beam

    African Journals Online (AJOL)

    ENGR. J. I. AGUWA

    2013-07-02

    Jul 2, 2013 ... Structural analysis and deterministic design of a timber bridge ... developed and used for reliability analysis of the Nigerian grown Abura timber bridge beam so designed, to ..... Nigerian Standard Organization, Federal.

  14. Triage evaluation of gusset plates in steel truss bridges.

    Science.gov (United States)

    2010-12-01

    Following research into the collapse of the I-35W steel truss bridge in Minneapolis, Minnesota, FHWA released recommendations for load rating the gusset plates of steel truss bridges. The recommendations include evaluation of several limit states, on...

  15. Investigation of mechanistic deterioration modeling for bridge design and management.

    Science.gov (United States)

    2017-04-01

    The ongoing deterioration of highway bridges in Colorado dictates that an effective method for allocating limited management resources be developed. In order to predict bridge deterioration in advance, mechanistic models that analyze the physical pro...

  16. Bridge Deck Runoff: Water Quality Analysis and BMP Effectiveness

    Science.gov (United States)

    2010-12-01

    The Alaska Department of Transportation (ADOT) is responsible for more than 700 bridges - most span water bodies. Are these water bodies affected by stormwater runoff from ADOT bridges? What are the regulatory and economic constraints on the ADOT reg...

  17. Economic impact of closing low-volume rural bridges.

    Science.gov (United States)

    2013-02-01

    The State of Kansas has approximately 25,464 bridges that are located on the state, county and : city roadway network. As the infrastructure in Kansas ages, bridges can become structurally : deficient or functionally obsolete. The Kansas Department o...

  18. Fatigue Testing of Dental Bridges on Selected Examples

    Directory of Open Access Journals (Sweden)

    Urban Dariusz

    2017-03-01

    Full Text Available The paper presents example tests of the functional quality of selected designs of dental bridges. These were: porcelain bridges on a metal base (cobalt based alloy, porcelain bridges on a zirconia base (zirconia ceramic – Zirkon Zahn, and full zirconia bridges (Zirkon Zahn. For the purpose of the study, durability of bridges in cyclic fatigue testing was adopted as a measure of their quality. The tests were carried out on a Zwick Roell Z010 universal testing machine. They consisted in cyclic loading and unloading of dental bridges mounted on gypsum models at a loading force of F= 400 [N] and a frequency of load of f= 1 [Hz]. Each bridge was subjected to a cycle of 7200 loads. The results show that there are no significant differences in the functional quality of the bridges.

  19. Integral bridge abutment-to-approach slab connection.

    Science.gov (United States)

    2008-06-01

    The Iowa Department of Transportation has long recognized that approach slab pavements of integral abutment bridges are prone to settlement and cracking, which manifests as the "bump at the end of the bridge". A commonly recommended solution is to in...

  20. Overload truck wheel load distribution on bridge decks.

    Science.gov (United States)

    2009-04-01

    There is a need to accurately analyze the load effects on bridge decks from permitted overload trucks on : Michigans roads. The AASHTO Standard Specifications for Highway Bridges, 17th edition, provides a : distribution width of live loads when re...

  1. Strain monitoring for horsetail falls and sylvan bridges

    Science.gov (United States)

    2002-05-01

    Fiber optic sensors were installed on two reinforced concrete bridges that had been strengthened with fiber reinforced polymer composites. The primary objective for one of the bridges was to provide strain data to verify a computer model for the brid...

  2. Multidisciplinary health monitoring of a steel bridge deck structure

    NARCIS (Netherlands)

    Pahlavan, P.L.; Pijpers, R.J.M.; Paulissen, J.H.; Hakkesteegt, H.C.; Jansen, T.H.

    2013-01-01

    Fatigue cracks in orthotropic bridge decks are an important cause for the necessary renovation of existing bridges. Parallel utilization of various technologies based on different physical sensing principles can potentially maximize the efficiency of structural health monitoring (SHM) systems for

  3. Implementation guidance for accelerated bridge construction in South Dakota

    Science.gov (United States)

    2017-09-01

    A study was conducted to investigate implementation of accelerated bridge construction (ABC) in South Dakota. Accelerated bridge construction is defined as construction practices that employ innovative techniques to reduce on-site construction time a...

  4. Accelerating bridge construction to minimize traffic disruption : research spotlight.

    Science.gov (United States)

    2013-12-01

    Since 2008, MDOT has been using accelerated bridge construction, which utilizes prefabricated components and structural placements, to minimize traffic disruptions during bridge replacement or rehabilitation. A recent project provided MDOT with a new...

  5. Development of risk models for Florida's bridge management system.

    Science.gov (United States)

    2013-06-01

    Florida Department of Transportation (FDOT) has been actively implementing the American Association of State Highway Transportation Officials (AASHTO) Pontis Bridge Management System (BMS), recently renamed AASHTOWare Bridge Management (BrM), to supp...

  6. Development of system reliability models for railway bridges.

    Science.gov (United States)

    2012-07-01

    Performance of the railway transportation network depends on the reliability of railway bridges, which can be affected by : various forms of deterioration and extreme environmental conditions. More than half of the railway bridges in US were : built ...

  7. Development of finite element models to predict dynamic bridge response.

    Science.gov (United States)

    1997-10-01

    Dynamic response has long been recognized as one of the significant factors affecting the service life and safety of bridge structures. Even though considerable research, both analytical and experimental, has been devoted to dynamic bridge behavior, ...

  8. Combined seismic plus live-load analysis of highway bridges.

    Science.gov (United States)

    2011-10-01

    "The combination of seismic and vehicle live loadings on bridges is an important design consideration. There are well-established design : provisions for how the individual loadings affect bridge response: structural components that carry vertical li...

  9. The need for conducting forensic analysis of decommissioned bridges.

    Science.gov (United States)

    2014-01-01

    A limiting factor in current bridge management programs is a lack of detailed knowledge of bridge deterioration : mechanisms and processes. The current state of the art is to predict future condition using statistical forecasting : models based upon ...

  10. Seismic vulnerability analysis of bridges in mountainous states.

    Science.gov (United States)

    2013-09-01

    Depending on the location, highway bridges can often support considerable amounts of traffic. Due to the limitations on current earthquake forecasting techniques, a normal amount of traffic will also typically remain on a bridge when an earthquake oc...

  11. Spalling solution of precast-prestressed bridge deck panels.

    Science.gov (United States)

    2010-10-01

    This research has examined spalling of several partial-depth precast prestressed concrete (PPC) bridge decks. It was recently obser : that some bridges with this panel system in the MoDOT inventory have experienced rusting of embedded steel reinforce...

  12. Shear capacity of in service prestressed concrete bridge girders.

    Science.gov (United States)

    2010-05-17

    The design of prestressed concrete bridge girders has changed significantly over the past several : decades. Specifically, the design procedure to calculate the shear capacity of bridge girders that : was used forty years ago is very different than t...

  13. Evaluation of the environmental impact of bridge deck runoff.

    Science.gov (United States)

    2012-12-01

    Bridges are located in very close proximity to receiving waters, and regulatory agencies often require specific stormwater : control measures for bridge deck runoff. While there is some information available on roadway runoff, few studies have : focu...

  14. Wheatstone bridge fed from a bilateral constant current source.

    Science.gov (United States)

    Velayudhan, C; Oommen, D

    1980-03-01

    A simple inexpensive scheme of an electronic amplifier for Wheatstone bridge application is presented. The bridge is excited from a bilateral constant current square wave source. The advantage of constant current drive is presented.

  15. Behavior and analysis of an integral abutment bridge.

    Science.gov (United States)

    2013-08-01

    As a result of abutment spalling on the integral abutment bridge over 400 South Street in Salt Lake City, Utah, the Utah Department of Transportation (UDOT) instigated research measures to better understand the behavior of integral abutment bridges. ...

  16. Soil-structure interaction studies for understanding the behavior of integral abutment bridges.

    Science.gov (United States)

    2012-03-01

    Integral Abutment Bridges (IAB) are bridges without any joints within the bridge deck or between the : superstructure and the abutments. An IAB provides many advantages during construction and maintenance of : a bridge. Soil-structure interactions at...

  17. Update of bridge design standards in Alabama for AASHTO LRFD seismic design requirements.

    Science.gov (United States)

    2013-11-01

    The Alabama Department of Transportation (ALDOT) has been required to update their bridge design to the LRFD Bridge Design Specifications. This transition has resulted in changes to the seismic design standards of bridges in the state. Multiple bridg...

  18. T-section glulam timber bridge modules : modeling and performance

    Science.gov (United States)

    Paul A. Morgan; Steven E. Taylor; Michael A. Ritter; John M. Franklin

    1999-01-01

    This paper describes the design, modeling, and testing of two portable timber bridges, each consisting of two noninterconnected longitudinal glued-laminated timber (glulam) deck panels 1.8 m (6 ft) wide. One bridge is 12.2 m (40 ft) long while the other bridge is 10.7 m (35 ft) long. The deck panels are fabricated in a unique double-tee cross section. The bridges...

  19. Dynamic wind effects on suspension and cable-stayed bridges

    Science.gov (United States)

    Larsen, Allan; Larose, Guy L.

    2015-01-01

    Cable supported bridges are flexible structures which may be excited into oscillations by the wind. The excitation forces acting on cable supported bridges are aerodynamic by nature, but are for a large part set into play by the underlying structural dynamics of the bridge structures. The paper discusses the various types of dynamic wind effects commonly encountered for suspension and cable-stayed bridges emphasizing the importance of the structural dynamics.

  20. Buckling Instability Behavior of Steel Bridge under Fire Hazard

    OpenAIRE

    Ying Wang; Muyu Liu

    2016-01-01

    Failure of buckling instability will most likely occur before the displacement reaches the allowable value of the code when a tanker burns under the steel bridge. This research focuses on critical buckling stress of bridge under fire hazard and a thermal analysis model of a steel bridge is established by FDS (Fire Dynamics Simulator). Thermal parameters of the steel are determined by the polynomial fitting method. Temperature field and elastic modulus of the bridge changing with time are calc...

  1. Impact of Underwater Explosions on Concrete Bridge Foundations

    Science.gov (United States)

    2016-06-01

    without rate dependence; (c) depiction of uniaxial compressive test; (d) stress- strain plot. Source: [38]. 3. Reinforced Concrete Modeling...UNDEX) with a bridge foundation modeled from an actual bridge was observed. Intermediate depths were the most damaging to the foundation when the bomb...bridge foundation modeled from an actual bridge was observed. Intermediate depths were the most damaging to the foundation when the bomb was detonated

  2. Vibration of railway bridges in the audible frequency range

    OpenAIRE

    Herron, David

    2009-01-01

    The noise level associated with a train travelling on a bridge is normally greater than that for a train travelling on plain track. It is sometimes the bridge noise that causes the highest levels of disturbance to people in the vicinity or triggers action underregulations such as the Environmental Noise Directive. Consequently, there is a need to study means of predicting noise levels from proposed bridges, noise controlmeasures for existing structures and principles of low-noise bridge desig...

  3. Fiber reinforced polymer composites for bridge structures

    Directory of Open Access Journals (Sweden)

    Alexandra CANTORIU

    2013-12-01

    Full Text Available Rapid advances in construction materials technology have led to the emergence of new materials with special properties, aiming at safety, economy and functionality of bridges structures. A class of structural materials which was originally developed many years ago, but recently caught the attention of engineers involved in the construction of bridges is fiber reinforced polymer composites. This paper provides an overview of fiber reinforced polymer composites used in bridge structures including types, properties, applications and future trends. The results of this study have revealed that this class of materials presents outstanding properties such as high specific strength, high fatigue and environmental resistance, lightweight, stiffness, magnetic transparency, highly cost-effective, and quick assembly, but in the same time high initial costs, lack of data on long-term field performance, low fire resistance. Fiber reinforced polymer composites were widely used in construction of different bridge structures such as: deck and tower, I-beams, tendons, cable stands and proved to be materials for future in this field.

  4. LPN/ADN Bridge Course. Instructor's Guide.

    Science.gov (United States)

    Barrett, Jan; And Others

    This curriculum guide has been constructed in order to bridge the skills gap between licensed practical nursing (LPN) programs and associate degree nursing (ADN) programs in Missouri. The curriculum was developed through a cooperative effort by persons from both sectors. The curriculum contains four major units, each consisting of several lessons,…

  5. Bridges with Trigonometry Equals Engineering Achievement

    Science.gov (United States)

    Gathing, Ahmed L.

    2011-01-01

    Exemplary and fun technology education classes in high schools are always welcome. The author introduces bridge building to his ninth graders and other students who comprise the Introduction to Engineering and Technology course within the first two months of the fall semester. In Georgia, Introduction to Engineering and Technology is the first of…

  6. The Librarian as Bridge-Builder

    Science.gov (United States)

    Fox, Kara; Horne, Laura M.; King, Tim; Seely, Sara; Walsh, Kathleen

    2008-01-01

    Libraries transform communities by providing well-organized information resources and services. Conversely, communities can also transform libraries if librarians appreciate the rich diversity of the communities' information needs, acting as bridges between communities as well as enabling and facilitating community-building. The roles of…

  7. Bridging the digital divide with mobile services

    CERN Document Server

    Yelton, Andromeda

    2013-01-01

    In this issue of Library Technology Reports, Andromeda Yelton shows how libraries can build on the breadth of this population to help bridge the digital divide and provide even greater access to information. Yelton breaks down the demographics of mobile internet users, provides examples of how different libraries are reaching out to these populations, and suggests what the future may hold for this trend.

  8. A model study of bridge hydraulics

    Science.gov (United States)

    2010-08-01

    Most flood studies in the United States use the Army Corps of Engineers HEC-RAS (Hydrologic Engineering : Centers River Analysis System) computer program. This study was carried out to compare results of HEC-RAS : bridge modeling with laboratory e...

  9. Acoustic emission health monitoring of steel bridges

    NARCIS (Netherlands)

    Pahlavan, P.L.; Paulissen, J.H.; Pijpers, R.J.M.; Hakkesteegt, H.C.; Jansen, T.H.

    2014-01-01

    Despite extensive developments in the field of Acoustic Emission (AE) for monitoring fatigue cracks in steel structures, the implementation of AE systems for large-scale bridges is hindered by limitations associated with instrumentation costs and signal processing complexities. This paper sheds

  10. Landslide stabilization measures for a bridge crossing

    Energy Technology Data Exchange (ETDEWEB)

    Prince, B.S.; Walter, D.J.; McRoberts, E.C. [AMEC Earth and Environmental Ltd., Edmonton, AB (Canada)

    2004-07-01

    A primary road was financed and constructed in 2003 by CNRL to provide access to its Horizon oil sands mine in northern Alberta. The road included a two lane, 50 metre high, 262 metre long bridge over the MacKay River near the town of Fort MacKay. The site of the bridge crossing was constrained by requirements that it bypass Aboriginal territory. The only available crossing site was near a river valley slope that had previously undergone deep-seated slope failure. The roadway design accounted for the possibility that future slope failures could occur at the bridge site. In response to safety concerns, the design assumed that valley slopes were in a near-failure state and remedial measures were taken to stabilize the slope. This paper discussed the specific geotechnical issues concerning the bridge abutments and the proposed methodology for dealing with them in a timely manner that would not affect the overall project schedule for the multi-billion dollar project. Risks were identified along with the requirements for long term monitoring. Back-analysis of the south valley slopes and an examination of weak clay materials in the north and south slopes indicated that slope stabilization measures would not be needed on the northern slope. However, a shear key and mechanically stabilized earth (MSE) wall was needed to stabilize the south valley slope. 3 refs., 1 tab., 7 figs.

  11. Thermal Bridge Effects in Window Grooves

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

    In this report thermal bridge effects in window grooves are analyzed. The analysis is performed using different thicknesses of the window groove insulation, to evaluate what the optimal solution is.All analysis in the report is performed using both 2- and 3-dimensional numerical analysis....

  12. The relevance of ''theory rich'' bridge assumptions

    NARCIS (Netherlands)

    Lindenberg, S

    1996-01-01

    Actor models are increasingly being used as a form of theory building in sociology because they can better represent the caul mechanisms that connect macro variables. However, actor models need additional assumptions, especially so-called bridge assumptions, for filling in the relatively empty

  13. Steel plate reinforcement of orthotropic bridge decks

    NARCIS (Netherlands)

    Teixeira de Freitas, S.

    2012-01-01

    The PhD research is focused on the reinforcement of fatigue cracked orthotropic steel bridge decks (OBD) by adding a second steel plate to the existing deck. The main idea is to stiffen the existing deck plate, which will reduce the stresses at the fatigue sensitive details and extend the fatigue

  14. Use of wood in buildings and bridges

    Science.gov (United States)

    Russell C. Moody; Anton TenWolde

    1999-01-01

    In North America, most housing and commercial structures built prior to the 20th century used wood as the major structural material. The abundant wood resource formed the basic structure for most houses, commercial buildings, bridges, and utility poles. Today, houses and many light commercial and industrial buildings are made using modern wood structural materials....

  15. Post-earthquake bridge inspection guidelines.

    Science.gov (United States)

    2010-10-01

    This report presents a course of action that can be used by New York States Department of Transportation : (NYSDOT) to respond to an earthquake that may have damaged bridges, so that the highway system can be : assessed for safety and functionalit...

  16. 5 MS 124-06 Bridge

    African Journals Online (AJOL)

    Damary

    2006-11-01

    Nov 1, 2006 ... A. Bridge, RN, MSc, W. Kipp, MD, MPH, PhD, Professor, Department of Public Health Sciences, K. Raine, PhD, RD,. Director and .... avocados and green vegetables. The lack of yellow fruits in the diets of the children could be attributed to the rainy season (September-November), when fruits such as ...

  17. Building Bridges, Robots, and High Expectations

    Science.gov (United States)

    Bennie, Fiona; Corbett, Charlotte; Palo, Angela

    2015-01-01

    This article describes an after-school program at the Horace Mann School for the Deaf (HMS), the oldest public day school for deaf students in the United States, where almost half of the student body imagined and created bridge and robotic machines. The Deaf Robotics Engineering and Math Team, or the DREAM Team club, included HMS students in…

  18. Studying the Bridge-Type Parametric Scatterer

    Science.gov (United States)

    Babanov, N. Yu.; Klyuev, A. V.; Lartsov, S. V.; Samarin, V. P.

    2017-10-01

    We study a parametric scatterer representing a quadripole of four bridge-type parametric circuits with antennas connected to the circuit arms and tuned to the pump signal and its half-wave subharmonic on the basis of simulation and full-scale experiments in the frequency range near 800 MHz.

  19. Summer Bridge's Effects on College Student Success

    Science.gov (United States)

    Bir, Beth; Myrick, Mondrail

    2015-01-01

    This study considered whether participation in a rigorous, intense summer bridge program had a significant effect on the academic success of African-American male and female students in developmental education, compared to nonparticipants, at a four-year Historically Black University in terms of retention, progression, and graduation from…

  20. Neighborhood Bridges: A Subversive Act of Storytelling

    Science.gov (United States)

    DeMark, Sharon

    2004-01-01

    In this article, the author describes Neighborhood Bridges, The Children's Theatre Company's (CTC) critical literacy program that gives young people from the most impoverished and troubled neighborhoods in Minneapolis the courage and power to speak their minds both orally and through the written word in such a daunting setting. The 2003-04 school…

  1. The mechanics of ship impacts against bridges

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Zhang, Shengming

    1998-01-01

    a glancing blow between the ship and the bridge structure. This model is based on rigid body mechanics and well suited for inclusion in a probabilistic analysis procedure. Finally, some empirical expressions are presented which relate the energy absorbed by crushing of ship structures to the maximum impact...

  2. Bridge over troubled water: Guidance crosses | Amundson ...

    African Journals Online (AJOL)

    This article is based on a keynote presentation at an international conference where the focus was cross-over career guidance. Simon and Garfunkel's popular song, "Bridge over troubled water", was used as a metaphor for exploring the cross-over theme. Some of the concepts under consideration included the working ...

  3. A literature survey on industrialized bridge construction.

    Science.gov (United States)

    1972-01-01

    The purpose of this survey was to aid the writer in understanding and retaining material in preparation for a project on the industrialization of bridge construction. However, it was believed that the results of the survey would be informative to oth...

  4. Accelerating Bridge Construction to Reduce Congestion

    Science.gov (United States)

    2011-05-01

    The magnitude of the "residual" displacements at the end of an earthquake can affect the amount of time needed to restore a bridge to service. It may be possible to reduce these displacements (and downtimes) by introducing prestressing forces into br...

  5. Short Course on Seismic Design of Bridges

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 8. Short Course on Seismic Design of Bridges. Information and Announcements Volume 9 Issue 8 August 2004 pp 88-88. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/009/08/0088-0088 ...

  6. Repair methods for prestressed girder bridges.

    Science.gov (United States)

    2009-04-30

    It is common practice that aging and structurally damaged prestressed concrete bridge members are taken out of service and replaced. : This, however, is not an efficient use of materials and resources since the member can often be repaired in situ. T...

  7. Traffic load effects in prestrssed concrete bridges

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.; Allaix, D.L.; Courage, W.M.G.

    2007-01-01

    The traffic load effect of a two-span prestressed concrete bridge with two traffic lanes is analyzed in this paper. The design value of the result-ing bending moment in some prescribed sections is estimated by means of a Monte Carlo simulation. The model for the vehicular loads is derived from a set

  8. Active aerodynamic stabilisation of long suspension bridges

    DEFF Research Database (Denmark)

    Nissen, Henrik Ditlev; Sørensen, Paul Haase; Jannerup, Ole Erik

    2004-01-01

    use of control analysis and design techniques, a linear model of the structural and aerodynamic motion around equilibriun is developed. The model is validated through comparison with finite element calculations and wind tunnel experimental data on the Great Belt East Bridge in Denmark. The developed...

  9. Journaling: A Bridge between School and Home

    Science.gov (United States)

    McGough, Julie

    2013-01-01

    This article describes how first-grade students create meaningful communication with families and help build the student-teacher-parent relationship through journaling. Journals are a useful tool to bridge school and home. A journal can communicate learning goals, develop scientific vocabulary, and create dialogue through oral and written…

  10. Construction Technology of Long Span Bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    2000-01-01

    A large variety of construction methods are used during construction of major bridges, and in many cases the final structural system must be chosen with due respect to the construction process. Today the preferred construction methods are: the free-cantilever method, the launching method...

  11. AFM plough YBCO micro bridges: substrate effects

    CSIR Research Space (South Africa)

    Elkaseh, A

    2009-04-01

    Full Text Available AFM nanolithography was used as a novel cutting technique to define micro-size YBCO superconducting constrictions. Researchers studied the substrate effects on MgO and STO substrates and showed that the observed Shapiro steps from the bridges on STO...

  12. Circuit bridging of components by smoke

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T.J.; Nowlen, S.P.; Anderson, D.J. [Sandia National Labs., Albuquerque, NM (United States)

    1996-10-01

    Smoke can adversely affect digital electronics; in the short term, it can lead to circuit bridging and in the long term to corrosion of metal parts. This report is a summary of the work to date and component-level tests by Sandia National Laboratories for the Nuclear Regulatory Commission to determine the impact of smoke on digital instrumentation and control equipment. The component tests focused on short-term effects such as circuit bridging in typical components and the factors that can influence how much the smoke will affect them. These factors include the component technology and packaging, physical board protection, and environmental conditions such as the amount of smoke, temperature of burn, and humidity level. The likelihood of circuit bridging was tested by measuring leakage currents and converting those currents to resistance in ohms. Hermetically sealed ceramic packages were more resistant to smoke than plastic packages. Coating the boards with an acrylic spray provided some protection against circuit bridging. The smoke generation factors that affect the resistance the most are humidity, fuel level, and burn temperature. The use of CO{sub 2} as a fire suppressant, the presence of galvanic metal, and the presence of PVC did not significantly affect the outcome of these results.

  13. Parent Power: Build the Bridge to Success

    Science.gov (United States)

    US Department of Education, 2010

    2010-01-01

    President Obama has a cradle-to-career plan to reform the nation's schools. He also is calling on parents to take responsibility for their child's success. His vision includes the belief that all children can and will succeed, and that parents are the bridge to this success. Parents, guardians and caregivers can help children by connecting with…

  14. Switches and Bridges - Comparison and Contrast

    OpenAIRE

    Marian M. Pope

    2017-01-01

    This paper presents a comparison and contrast of switches and bridges. The paper discusses the Open Systems Interconnection (OSI) model for the layers used by the devices. The intelligence and specific functions of each device are also mentioned. The paper also presents the location of each device in a network

  15. Bridge Hopping on Conducting Polymers in Solution

    OpenAIRE

    Hone, Daniel W.; Orland, Henri

    2000-01-01

    Configurational fluctuations of conducting polymers in solution can bring into proximity monomers which are distant from each other along the backbone. Electrons can hop between these monomers across the "bridges" so formed. We show how this can lead to (i) a collapse transition for metallic polymers, and (ii) to the observed dramatic efficiency of acceptor molecules for quenching fluorescence in semiconducting polymers.

  16. Perspective: Bridging the Special Education Divide.

    Science.gov (United States)

    Andrews, Jack E.; Carnine, Douglas W.; Coutinho, Martha J.; Edgar, Eugene B.; Forness, Steven R.; Fuchs, Lynn S.; Jordan, Dixie; Kauffman, James M.; Patton, James M.; Paul, James; Rosell, Jon; Rueda, Robert; Schiller, Ellen; Skrtic, Thomas M.; Wong, James

    2000-01-01

    This article explores different viewpoints on special education reform, including conceptualizations of disability, the purpose of special education, beliefs about the expected outcomes of special education, and understanding of the current state of knowledge. How these different views can be bridged by focusing on early detection and prevention…

  17. Comprehensive bridge deck deterioration mapping of nine bridges by nondestructive evaluation technologies.

    Science.gov (United States)

    2011-01-01

    The primary objective of this research was to demonstrate the benefits of NDT technologies for effectively detecting : and characterizing deterioration in bridge decks. In particular, the objectives were to demonstrate the capabilities of : ground-pe...

  18. Railroad Bridges in Louisiana, Geographic NAD83, FEMA (1997) [railroad_bridges_FEMA_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is is a point dataset for the locations and attributes of 32 Louisiana railroad bridges. The attributes include city (nearest?), county (sic), routefrom (city),...

  19. Performance Assessment of Bridges Using GPS: The Juarez Bridge in Culiacan, Mexico

    Science.gov (United States)

    Vazquez, G. E.; Gaxiola-Camacho, J. R.; Trejo, M.; Echagaray, J.; Guzman, G. M.

    2015-12-01

    Performance assessment of bridges has become very important during recent years. Bridges around the world are aging, leading to the incorporation of efficient, reliable, and economic evaluation procedures. These techniques must assess properly the performance of bridges under several loading conditions in a real manner, representing the physics of the problem. Among several approaches, Global Positioning System (GPS) can be intelligently used for the performance evaluation of bridges. We focused on GPS, since it naturally produces position estimates as compared to seismic instruments that record either velocity or acceleration, and thus require an integration. There are several reasons that make the Juarez Bridge a case of study for evaluation: it is approximately 45 years old, it is a reinforced concrete structure, it connects two significant zones of the city, and its spans is closely to 200 meters long. In addition, thousands of vehicles and pedestrians use the Juarez Bridge every day, which make feasible the GPS performance assessment. Hence, in order to produce optimal position estimates, GPS data were collected during two consecutive hours at three different periods of the day for a whole week (Monday through Sunday), to represent three critical limit states of the bridge (mid-span and end-spans). GPS data were processed using the GAMIT/GLOBK software, considering 1-second sampling rate, 15-degree cutoff angle, ionosphere-free double-differenced (DD) carrier phase method, and precise final orbits disseminated by IGS (International GNSS Service). The displacements obtained from the above discussed procedure are compared with allowable values documented in bridge construction manuals. Reliability theory was used to evaluate the probability of failure of the bridge for the three periods of the day. In addition, a conclusion was made about the most risky day of the week for the use of the Juarez Bridge. It is expected that the results from the proposed research

  20. Bridge pier scour in cohesive soil: a review

    Indian Academy of Sciences (India)

    Bridge failure due to local scour has stimulated the enthusiasm of many researchers to study the causes of scouring and to predict the ultimate scour depth at bridge foundation. A brief review of the state of artwork of investigation conducted on local scour at bridge pier in cohesive bed material is presented. Scour process ...

  1. Reduction of Impact Noise of Trams on a Major Bridge

    NARCIS (Netherlands)

    Dittrich, M.G.; Bosshaart, C.; Wessels, P.W.

    2015-01-01

    As part of a recent renovation of the Erasmus bridge in Rotterdam, improvements were made to reduce impact noise caused by trams passing a series of rai! joints. The bridge inciudes several different sections inciuding a bascule bridge and is in an inner city tocation with new adjacent apartment

  2. Renovation techniques for fatigue cracked orthotropic steel bridge decks

    NARCIS (Netherlands)

    de Jong, F.B.P.

    2007-01-01

    This dissertation presents the research into renovation techniques for orthotropic steel bridge decks. These techniques are needed to solve fatigue problems in the decks of these bridges, as several fatigue cracks have been detected in the deck structure of these bridges the last decade. A

  3. Railing systems for use on timber deck bridges

    Science.gov (United States)

    Ronald K. Faller; Michael A. Ritter; Barry T. Rosson; Sheila R. Duwadi

    1999-01-01

    Bridge railing systems in the United States have historically been designed based on static load criteria given in the AASHTO Standard Specifications for Highway Bridges. In the past decade, full-scale vehicle crash testing has been recognized as a more appropriate and reliable method of evaluating bridge railing acceptability. In 1989. AASHTO published the Guide...

  4. HealthBridge : Information and Communication Technologies for ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    HealthBridge : Information and Communication Technologies for Data Collection and Management. Formerly called PATH Canada, HealthBridge has been working since 1982 with partners in Asia, Africa and the Americas to improve the health of vulnerable populations. HealthBridge staff are currently located in Canada, ...

  5. Monitoring bridge scour using fiber optic sensors : [tech summary].

    Science.gov (United States)

    2015-04-01

    It is well known that scour is one of the major causes of bridge failures. In the last 30 years, more than 1,000 bridges collapsed in : the US and about 60% of the failures are related to the scour of bridges foundations. Due to the difficulty in ...

  6. Future Trends in Reliability-Based Bridge Management

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Future bridge management systems will be based on simple stochastic models predicting the residual strength of structural elements. The current deterministic management systems are not effective in optimizing e.g. the life cycle cost of a bridge or a system of bridges. A number of important facto...

  7. Morphology of human myocardial bridges and association with ...

    African Journals Online (AJOL)

    Background: The functional significance of myocardial bridging remains controversial. The bridge morphology and structure of the tunneled vessels may modify its ultimate clinical effects. Objective: To describe the morphological characteristics of myocardial bridges and their influence on coronary histology. Design: A ...

  8. Seismic Performance of Multi-Span RC Railway Bridges

    DEFF Research Database (Denmark)

    Georgakis, Christos; Barrau, Xavier

    2008-01-01

    Presently, there is no clear method for determining the optimal railway bridge design for a particular ground type and expected seismic intensity. Four main types of RC bridge dominate the current multi-span railway bridge design trends – the Simply Supported Beam, Continuous Box-Girder (CBG), CB...

  9. Improving the Dynamics of Suspension Bridges using Active Control Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Improving the dynamics of suspension bridge using active control is discussed in this paper. The main dynamic problem with long suspension bridges is the aeroelastic phenomenon called flutter. Flutter oscillations of a bridge girder is a stability problem and the oscillations are perpendicular...

  10. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Temporary crown and bridge resin. 872.3770 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3770 Temporary crown and bridge resin. (a) Identification. A temporary crown and bridge resin is a device composed of a material, such as...

  11. reliability assessment of stringers spacings in bridges as function

    African Journals Online (AJOL)

    user

    This presentation accounts for established functions of stringer spacing of major Nigerian woods when used as bridge decks. It entails stochastic evaluation of bridge wood decks with absolute regards to the spacing of supporting stringers. A timber bridge deck is modelled on timber stringers in accordance with current.

  12. Post-Earthquake Traffic Capacity of Modern Bridges in California

    Science.gov (United States)

    2010-03-01

    Evaluation of the capacity of a bridge to carry self-weight and traffic loads after an earthquake is essential for a : safe and timely re-opening of the bridge. In California, modern highway bridges designed using the Caltrans : Seismic Design Criter...

  13. 33 CFR 401.51 - Signaling approach to a bridge.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Signaling approach to a bridge... approach to a bridge. (a) Unless a vessel's approach has been recognized by a flashing signal, the master shall signal the vessel's presence to the bridge operator by VHF radio when it comes abreast of any of...

  14. Shear and Moment Capacity of the Ruytenschildt Bridge

    NARCIS (Netherlands)

    Lantsoght, E.O.L.; van der Veen, C.; de Boer, A

    2016-01-01

    In August 2014, the Ruytenschildt Bridge, a reinforced concrete solid slab bridge, in Friesland, the Netherlands was tested until failure. One of the goals of the experiment is to analyze the failure mode of the slab bridge under a tandem of 4 wheel loads and to compare the capacity of the full

  15. 29 CFR 1917.124 - Dockboards (car and bridge plates).

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Dockboards (car and bridge plates). 1917.124 Section 1917..., DEPARTMENT OF LABOR (CONTINUED) MARINE TERMINALS Terminal Facilities § 1917.124 Dockboards (car and bridge... and across openings. (b) (c) Dockboards (car and bridge plates). (1) Dockboards shall be strong enough...

  16. 49 CFR 236.387 - Movable bridge locking.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Movable bridge locking. 236.387 Section 236.387 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.387 Movable bridge locking. Movable bridge locking shall be tested at least once a...

  17. Live Load Testing of Historic Covered Timber Bridges

    Science.gov (United States)

    Travis Hosteng; James Wacker; Brent Phares

    2013-01-01

    The National Historic Covered Bridge Preservation Program (NHCBP), sponsored by the Federal Highway Administration (FHWA), is intended to preserve covered timber bridge structures nationwide. Today, less than 700 covered timber bridges still exist in the United States and of those many are closed to vehicular traffic. Furthermore, a large percentage of the remaining...

  18. Evaluation of fleet management techniques for timber highway bridges

    Science.gov (United States)

    Brent M. Phares; Travis K. Hosteng; Justin Dahlberg; Michael A. Ritter

    2011-01-01

    The general condition of the nation's bridges presents a complex management issue when considering cost, safety, and time. Consequently, the management of those bridges can become an overwhelming task. The need for a management system that is specific to rural systems may help to improve the management of this significant number of bridges. Although individual...

  19. Evaluation of cracking of the US 331 bridge deck.

    Science.gov (United States)

    2010-08-01

    The focus of this report is a three-span, continuous, skewed bridge that was constructed in the : summer of 2003 as the northbound roadway bridge on US 331 in Montgomery County, : Alabama. This bridge deck exhibited extensive transverse and horizonta...

  20. Advanced Bridge Capacity and Structural Integrity Assessment Methodology

    Science.gov (United States)

    2013-03-01

    bridges , including reinforced concrete bridges with continuous girders across a support and prestressed structures. Identifying the class of...assessment of reinforced concrete bridges by making improved estimates of the level of longitudinal and shear reinforcement. The pro- posed assessment...Figure 7. AASHTO HS20-44 Truck (Precast/ Prestressed Concrete Institute 2003). ......................... 11 Figure 8. California Permit Truck (Caltrans

  1. Ambient Response Analysis of the Great Belt Bridge

    DEFF Research Database (Denmark)

    Brincker, Rune; Frandsen, J. B.; Andersen, P.

    2000-01-01

    In this paper an ambient response analysis of the Great Belt Bridge is presented. The Great Belt Bridge is one of the largest suspension bridges in the world, and the analysis was carried out in order to investigate the possibilities of estimating reliable damping values from the ambient response...

  2. 23 CFR 650.807 - Bridges requiring a USCG permit.

    Science.gov (United States)

    2010-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS Navigational Clearances for Bridges § 650.807 Bridges requiring a USCG... accommodation of floating construction equipment of any type that is not required for navigation channel... appropriate level by FHWA for structural concepts, hydraulics, and navigational clearances prior to submission...

  3. Analysis of Bridge Player Profiles According to Their Intelligence Areas

    Science.gov (United States)

    Bilir, Fatma Pervin; Sirin, Yeliz

    2017-01-01

    The aim of this study is to figure out profiles of bridge players and analyzing them according to their intelligence areas. The sample of the study is consist of 100 volunteers out of 200 bridge players who have attended "Çukurova open double bridge championship" in Adana, Turkey at February 2016. Data have been collected via…

  4. Bridge pier scour in cohesive soil: a review

    Indian Academy of Sciences (India)

    Y Sonia Devi

    life and financial losses. As bridge scour is responsible for. 60% of river bridge failure, U.S. Federal Highway. Administration (FHWA) considers this as an important engineering concern [2]. The Scholarie Creek bridge failure that killed 10 people in New York in 1987 prompted enhanced sponsored research of about $11 ...

  5. Strengthening of rural bridges using rapid-installation FRP technology : route 63 bridge no. H356, Phelps County.

    Science.gov (United States)

    2009-10-01

    This report presents the use of externally bonded fiber reinforced polymers (FRP) laminates for the flexural strengthening of a : concrete bridge. The bridge selected for this project is a two-span simply supported reinforced concrete slab with no tr...

  6. Correlation of shear design between AASHTO LRFD bridge design specifications and AASHTO Guide Specifications for the LRFD Seismic Bridge Design.

    Science.gov (United States)

    2017-01-05

    This report presents the analytical study of the shear capacity of reinforced concrete columns using both the AASHTO LRFD Bridge Design Specifications and the AASHTO Guide Specifications for the LRFD Seismic Bridge Design. The study investigates vari...

  7. Development and validation of deterioration models for concrete bridge decks - phase 1 : artificial intelligence models and bridge management system.

    Science.gov (United States)

    2013-06-01

    This research documents the development and evaluation of artificial neural network (ANN) models to predict the condition ratings of concrete highway bridge decks in Michigan. Historical condition assessments chronicled in the national bridge invento...

  8. Field performance of timber bridges. 13, Mohawk Canal stress-laminated bridge

    Science.gov (United States)

    P. D. Hilbrich Lee; X. Lauderdale

    The Mohawk Canal bridge was constructed in August 1994, just outside Roll, Arizona. It is a simple-span, double-lane, stress-laminated deck superstructure, approximately 6.4 m (21 ft) long and 10.4 m (34 ft) wide and constructed with Combination 16F-V3 Douglas Fir glued-laminated timber beam laminations. The performance of the bridge was monitored continuously for 2...

  9. A Hierarchical Analysis of Bridge Decision Makers ... The Role of New Technology Adoption in the Timber Bridge Market: Special Project

    Science.gov (United States)

    Robert L. Smith; Robert J. Bush; Daniel L. Schmoldt

    1995-01-01

    Bridge design engineers and local highway officials make bridge replacement decisions across the United States. The Analytical Hierarchy Process was used to characterize the bridge material selection decision of these individuals. State Department of Transportation engineers, private consulting engineers, and local highway officials were personally interviewed in...

  10. Electrical characteristics of semiconductor bridge initiator-automobile airbag igniters

    Science.gov (United States)

    Liu, Mingfang; Yu, Lin; Han, Xia

    2017-07-01

    To study the ignition characteristics of semiconductor bridges (SCB) for automobile airbag igniters, a model was proposed to compute the electrical characteristics of SCB based on the structural characteristics, resistance properties, and the working process of the bridge. Numerical simulation was conducted to analyze the voltage and current trends at two ends of bridges with various geometric dimensions and those with identical geometric dimensions and oxide layers of different thicknesses. Voltage-current curves for bridges of three different dimensions were obtained through numerical simulation. Bridges of larger geometric dimensions were found to require higher voltage to reach the melting point, which means higher energy input is required.

  11. Analysis of using porous asphalt on the surfaces of bridges

    Directory of Open Access Journals (Sweden)

    Ryszard Chmielewski

    2016-09-01

    Full Text Available The article concerns the analysis of the use of modern technology while paving the road bridges. It shall assess the possibility of using porous asphalt paving of road bridges. Based on the results of laboratory tests of selected porous asphalt, such as: determination of free space in the mixture of mineral-asphalt, runoff of the binder, sensitivity to water and frost, the loss of grains in the mixture, the design of porous asphalt mixture has been completed.[b]Keywords[/b]: construction of bridges, road bridges pavements, porous asphalt, dehydration of the bridges

  12. Wind Tunnel Experiments with Active Control of Bridge Section Model

    DEFF Research Database (Denmark)

    Hansen, Henriette I.; Thoft-Christensen, Palle

    This paper describes results of wind tunnel experiments with a bridge section model where movable flaps are integrated in the bridge girder so each flap is the streamlined part of the edge of the girder. This active control flap system is patented by COWIconsult and may be used to increase...... the flutter wind velocity for future ultra-long span suspension bridges. The purpose of the wind tunnel experiments is to investigate the principle to use this active flap control system. The bridge section model used in the experiments is therefore not a model of a specific bridge but it is realistic...

  13. Seismic Passive Control of Cable-Stayed Bridges

    Directory of Open Access Journals (Sweden)

    Hosam-Eddin M. Ali

    1995-01-01

    Full Text Available A three-dimensional modeling procedure is proposed for cable-stayed bridges with rubber, steel, and lead energy dissipation devices. The passive control technique is investigated by considering the response of bridge models with and without energy dissipation devices. The impact of various design parameters on the seismic response of current and future bridge designs is studied. Appropriate locations and properties of the passive devices can achieve better performance for cable-stayed bridges by balancing the significant reduction in earthquake-induced forces against tolerable displacements. Proper design of passive systems can help provide solutions for retro-fitting some existing bridges.

  14. Dynamic Vehicle Impact for Safety Assessment of Bridges

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Enevoldsen, I.

    of the numerical modal parameters of the bridge are known, Only irregularities from imperfect expansion joints have been modelled as bumps at the entrance to the bridge. The results are obtained from a simulation study for different passage situations of the two heavy vehicles. Further, consequences for the safety......In this paper the dynamic amplification of vehicle load at minor highway bridges is considered for safety assessment of the load carrying capacity of bridges. The considered case is the most critical for bridges, i.e. the simultaneous passage of two heavy trucks. A short description...

  15. A Review of Indirect Bridge Monitoring Using Passing Vehicles

    Directory of Open Access Journals (Sweden)

    Abdollah Malekjafarian

    2015-01-01

    Full Text Available Indirect bridge monitoring methods, using the responses measured from vehicles passing over bridges, are under development for about a decade. A major advantage of these methods is that they use sensors mounted on the vehicle, no sensors or data acquisition system needs to be installed on the bridge. Most of the proposed methods are based on the identification of dynamic characteristics of the bridge from responses measured on the vehicle, such as natural frequency, mode shapes, and damping. In addition, some of the methods seek to directly detect bridge damage based on the interaction between the vehicle and bridge. This paper presents a critical review of indirect methods for bridge monitoring and provides discussion and recommendations on the challenges to be overcome for successful implementation in practice.

  16. Evaluating the life cycle environmental impact of short span bridges

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2016-01-01

    impact of the construction sector. Life cycle assessment (LCA) is a systematic method for assessing the environmental impact of products and systems, but its application in bridges is scarce. In Swede, most of the bridges are short spans and the type of concrete slab-frame bridge (CFB) accounts...... for a large share. Soil steel composite bridge (SSCB) is a functional equivalent solution for CFB. In order to mitigate the environmental burdens of short span bridges, this paper performed a comparative LCA study between these two types of bridge. The results indicate that the initial material consumption......Bridge infrastructure consumes large amount of energy and raw materials, leading to considerable environmental burdens. The traditional infrastructure construction prioritizes its technical and economic viability. In recent years, the society devotes an ever-increased attention to the environmental...

  17. Polymeric salt bridges for conducting electric current in microfluidic devices

    Science.gov (United States)

    Shepodd, Timothy J [Livermore, CA; Tichenor, Mark S [San Diego, CA; Artau, Alexander [Humacao, PR

    2009-11-17

    A "cast-in-place" monolithic microporous polymer salt bridge for conducting electrical current in microfluidic devices, and methods for manufacture thereof is disclosed. Polymeric salt bridges are formed in place in capillaries or microchannels. Formulations are prepared with monomer, suitable cross-linkers, solvent, and a thermal or radiation responsive initiator. The formulation is placed in a desired location and then suitable radiation such as UV light is used to polymerize the salt bridge within a desired structural location. Embodiments are provided wherein the polymeric salt bridges have sufficient porosity to allow ionic migration without bulk flow of solvents therethrough. The salt bridges form barriers that seal against fluid pressures in excess of 5000 pounds per square inch. The salt bridges can be formulated for carriage of suitable amperage at a desired voltage, and thus microfluidic devices using such salt bridges can be specifically constructed to meet selected analytical requirements.

  18. Evaluating the life cycle environmental impact of short span bridges

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2016-01-01

    Bridge infrastructure consumes large amount of energy and raw materials, leading to considerable environmental burdens. The traditional infrastructure construction prioritizes its technical and economic viability. In recent years, the society devotes an ever-increased attention to the environmental...... impact of the construction sector. Life cycle assessment (LCA) is a systematic method for assessing the environmental impact of products and systems, but its application in bridges is scarce. In Swede, most of the bridges are short spans and the type of concrete slab-frame bridge (CFB) accounts...... for a large share. Soil steel composite bridge (SSCB) is a functional equivalent solution for CFB. In order to mitigate the environmental burdens of short span bridges, this paper performed a comparative LCA study between these two types of bridge. The results indicate that the initial material consumption...

  19. The feasibility of castable ceramic material in dental bridge construction.

    Science.gov (United States)

    Lin, T H; Chung, K H; Chan, C C

    1992-11-01

    This study was to investigate the feasibility of dental bridges constructed with castable ceramic material (Dicor). A dental bridge model was designed similar to the clinical situation. The marginal fit of Dicor crown and a three-unit bridge was evaluated and no statistically significant differences in marginal openings between Dicor crowns and bridges were determined except the mesial and distal end surfaces of the bridge works. The fracture strengths of different thicknesses of Dicor test bars were measured with a three-point bending technique in a jig mounted in a universal testing machine. The results revealed that the bridge design with the thickest (6mm) connector and the shortest (8 mm) width of the pontic had the highest fracture resistance. In addition, pores with size up to 50 microns were disclosed in the fractured interface. The optimal design of Dicor bridge is determined according to the results of this study along with the clinical trial.

  20. Structural behaviour and design criteria of under-deck cable-stayed bridges and combined cable-stayed bridges. Part 1: Single-span bridges

    National Research Council Canada - National Science Library

    Ruiz-Teran, A. M; Aparicio, A. C

    2008-01-01

    .... Both bridge types offer many advantages over conventional schemes in several aspects, such as structural efficiency, enhanced construction possibilities, and both economic and aesthetical considerations...

  1. Rhetoric of Youth, or Bridges to Nowhere

    Directory of Open Access Journals (Sweden)

    Thomas Harrison

    2014-05-01

    Full Text Available Architectonically speaking, there comes a stage in life that looks like a house. Everything appears already built up, all filled with kids and furniture, functionally disposed in interconnected spaces. The age of adulthood. Childhood instead is a playground, with apparatuses for swinging and climbing and an open court to serve their somewhat anarchic whims. What leads to the adult house is a road, which most people embark on in their twenties, as they decide what to do with their lives. But before one finds this road one needs to pass a bridge: the architectonics of youth, which, as I understand it in this paper, entails a passage between two distinct terrains, each more distinct than the passage between them: childhood and adulthood. Youth is not the road to the house of adulthood, which is discovered later; youth is a bridge, taking us to a place from which many roads start. Committing to an adult project means choosing one of them.

  2. Epoxy coated reinforcement in bridge decks

    Science.gov (United States)

    Wills, J.

    A review was conducted of methods relating to the use of epoxy coated reinforcing bars for bridge decks and their potential for use in the United Kingdom. A survey of work carried out in the USA was carried out and the analysis used in a preliminary cost study. The options of having either a hot rolled asphalt surfacing or a permanently exposed concrete wearing surface were considered. It was concluded that epoxy coating of the top steel in addition to current waterproofing practice would provide, at relatively little extra cost, additional assurance that the reinforcement would be adequately protected throughout the life of a bridge. Current design rules do not permit decks with permanently exposed concrete wearing surface without waterproofing. Epoxy coating may afford a means of introducing such decks but before a positive recommendation to delete waterproofing can be made further studies would have to be undertaken.

  3. Ether bridge formation in loline alkaloid biosynthesis

    Science.gov (United States)

    Pan, Juan; Bhardwaj, Minakshi; Faulkner, Jerome R.; Nagabhyru, Padmaja; Charlton, Nikki D.; Higashi, Richard M.; Miller, Anne-Frances; Young, Carolyn A.; Grossman, Robert B.; Schardl, Christopher L.

    2014-01-01

    Lolines are potent insecticidal agents produced by endophytic fungi of cool-season grasses. These alkaloids are composed of a pyrrolizidine ring system and an uncommon ether bridge linking carbons 2 and 7. Previous results indicated that 1-aminopyrrolizidine was a pathway intermediate. We used RNA interference to knock down expression of lolO, resulting in the accumulation of a novel alkaloid identified as exo-1-acetamidopyrrolizidine based on high-resolution MS and NMR. Genomes of endophytes differing in alkaloid profiles were sequenced, revealing that those with mutated lolO accumulated exo-1-acetamidopyrrolizidine but no lolines. Heterologous expression of wild-type lolO complemented a lolO mutant, resulting in the production of N-acetylnorloline. These results indicated that the non-heme iron oxygenase, LolO, is required for ether bridge formation, probably through oxidation of exo-1-acetamidopyrrolizidine. PMID:24374065

  4. Precision bridge circuit using a temperature sensor

    Science.gov (United States)

    Mount, Bruce E. (Inventor)

    1992-01-01

    A precision bridge measurement circuit connected to a current source providing a linear output voltage versus resistance change of a variable resistance (resistance temperature transducer) including a voltage follower in one branch of the bridge so that the zero setting of the transducer resistance does not depend upon the current source or upon an excitation voltage. The zero setting depends only on the precision and stability of the three resistances. By connecting the output of an instrumentation amplifier to a feedback resistor and then to the output of the voltage follower, minor nonlinearities in the resistance-vs-temperature output of a resistance-temperature transducer, such as a platinum temperature sensor, may be corrected. Sensors which have nonlinearity opposite in polarity to platinum, such as nickel-iron sensors, may be linearized by inserting an inverting amplifier into the feedback loop.

  5. Online Bridge Crack Monitoring with Smart Film

    Directory of Open Access Journals (Sweden)

    Benniu Zhang

    2013-01-01

    Full Text Available Smart film crack monitoring method, which can be used for detecting initiation, length, width, shape, location, and propagation of cracks on real bridges, is proposed. Firstly, the fabrication of the smart film is developed. Then the feasibility of the method is analyzed and verified by the mechanical sensing character of the smart film under the two conditions of normal strain and crack initiation. Meanwhile, the coupling interference between parallel enameled wires of the smart film is discussed, and then low-frequency detecting signal and the custom communication protocol are used to decrease interference. On this basis, crack monitoring system with smart film is designed, where the collected crack data is sent to the remote monitoring center and the cracks are simulated and recurred. Finally, the monitoring system is applied to six bridges, and the effects are discussed.

  6. Fatigue-Prone Details in Steel Bridges

    Directory of Open Access Journals (Sweden)

    Mohsen Heshmati

    2012-11-01

    Full Text Available This paper reviews the results of a comprehensive investigation including more than 100 fatigue damage cases, reported for steel and composite bridges. The damage cases are categorized according to types of detail. The mechanisms behind fatigue damage in each category are identified and studied. It was found that more than 90% of all reported damage cases are of deformation-induced type and generated by some kind of unintentional or otherwise overlooked interaction between different load-carrying members or systems in the bridge. Poor detailing, with unstiffened gaps and abrupt changes in stiffness at the connections between different members were also found to contribute to fatigue cracking in many details.

  7. Existing bridge evaluation using deficiency point method

    Directory of Open Access Journals (Sweden)

    Vičan Josef

    2016-01-01

    Full Text Available In the transforming EU countries, transportation infrastructure has a prominent position in advancing industry and society. Recent developments show, that attention should be moved from the design of new structures towards the repair and reconstruction of existing ones to ensure and increase their satisfactory structural reliability and durability. The problem is very urgent because many construction projects, especially transport infrastructure, in most European countries are more than 50-60 years old and require rehabilitations based on objective evaluations. Therefore, the paper presents methodology of existing bridge evaluation based on reliability concept using Deficiency Point Method. The methodology was prepared from the viewpoint to determine the priority order for existing bridge rehabilitation.

  8. Reversed Currents in Charged Liquid Bridges

    Directory of Open Access Journals (Sweden)

    Klaus Morawetz

    2017-05-01

    Full Text Available The velocity profile in a water bridge is reanalyzed. Assuming hypothetically that the bulk charge has a radial distribution, a surface potential is formed that is analogous to the Zeta potential. The Navier–Stokes equation is solved, neglecting the convective term; then, analytically and for special field and potential ranges, a sign change of the total mass flow is reported caused by the radial charge distribution.

  9. COMPRESSIVE MEMBRANE ACTION in BRIDGE DECK SLABS

    OpenAIRE

    JACKSON, PAUL AUSTIN

    1989-01-01

    Merged with duplicate record 10026.1/654 on 27.02.2017 by CS (TIS) An elastic analysis of restrained slab strips shows that membrane action enhances serviceability behaviour. However, the enhancement is not as great as for strength and serviceability is critical when membrane action is considered in design. A relatively simple form of non-linear finite element analysis is developed which is able to model bridge deck behaviour allowing for membrane action. This reduces som...

  10. Phosphonates and Stannoxanes: Building Bridges Between Main ...

    Indian Academy of Sciences (India)

    Table of contents. Phosphonates and Stannoxanes: Building Bridges Between Main Group and Transition Metal Chemistry · Slide 2 · Organostannoxanes and Organophosphonates · Slide 4 · Slide 5 · Slide 6 · Slide 7 · Slide 8 · Slide 9 · Slide 10 · Slide 11 · Slide 12 · Slide 13 · Slide 14 · Slide 15 · Slide 16 · Slide 17 · Slide 18.

  11. RESEARCH OF BRIDGE STRUCTURE VIBRATION CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    V.P. Babak

    2005-02-01

    Full Text Available  Bridge structure test results with using different types of dynamic force have been considered. It has been shown, that the developed technique of registering and processing vibration signals allows obtaining thin spectrum structure. The analysis of its change that is defined by the type of structure loading applied has been carried out. Key parameters of the vibration signals registered have been defined.

  12. Madison Milton Design Build Bridge Construction

    OpenAIRE

    Johnson, Murray

    2013-01-01

    The design build team will provide an overview of the Madison Milton Ohio River Bridge Project construction. There will be a brief discussion of the design-build process. Specific discussions of the retrofits to the existing caissons and piers that allowed for the existing substructure to be reused as well as discussions of the truss design, erection, span lifts, and sliding will be provided.

  13. Upstand Finite Element Analysis of Slab Bridges

    OpenAIRE

    O'Brien, Eugene J.; Keogh, D.L.

    1998-01-01

    For slab bridge decks with wide transverse edge cantilevers, the plane grillage analogy is shown to be an inaccurate method of linear elastic analysis due to variations in the vertical position of the neutral axis. The upstand grillage analogy is also shown to give inaccurate results, this time due to inappropriate modelling of in-plane distortions. An alternative method, known as upstand finite element analysis, is proposed which is sufficiently simple to be used on an everyday basis in the ...

  14. Cybersecurity and Privacy - bridging the gap

    DEFF Research Database (Denmark)

    . Policies, frameworks, strategies, laws, tools, techniques, and technologies – all of these are tightly interwoven when it comes to security and privacy. This book is another attempt to bridge the gap between the industry and academia. The book addresses the views from academia and industry on the subject....... Technical topics discussed in the book include: Cybersecurity Encryption Privacy policy Trust Security and Internet of Things Botnets Data risks Cloud-based Services Visualization...

  15. Bridging Experience With Eptifibatide After Stent Implantation.

    Science.gov (United States)

    Barra, Megan E; Fanikos, John; Gerhard-Herman, Marie D; Bhatt, Deepak L

    2016-09-01

    Patients who have undergone intracoronary stent implantation often require surgery within the first year after the procedure. Planned or emergent surgical intervention requires interruption of antiplatelet therapy and is associated with an increased risk of stent thrombosis. Eptifibatide, an intravenous glycoprotein IIb/IIIa inhibitor (GPIIb/IIIa), can be considered for antiplatelet bridging of high-risk patients in the periprocedural period. The aim of this report is to describe the management of antiplatelet therapy and outcomes of patients who were bridged with eptifibatide perioperatively within 1 year of intracoronary stent implantation. We performed a retrospective analysis of patients identified through the hospital's computer system consecutively from January 1, 2011 to December 31, 2014. We included 18 patients who were bridged from an oral P2Y12-receptor antagonist with eptifibatide before surgery. Outcome measures were the incidence of thromboembolic events or stent thrombosis within 30 days of surgery and death within 90 days of hospital discharge. Safety measures were the incidence of thrombolysis in myocardial infarction major, minor, or minimal bleeding. Of the 18 patients assessed, no patients experienced thromboembolic events or stent thrombosis. There was one major bleeding event and one minimal bleeding event postoperatively. Antiplatelet therapy management was highly variable in the perioperative period with 72.2% receiving the recommended GPIIb/IIIa loading dose, 50% of patients not continuing aspirin throughout the surgery, 27.8% of patients stopping antiplatelet therapy less than 5 days before surgery, and 50% not receiving a loading dose of an oral P2Y12-receptor antagonist postoperatively. Within a limited sample size, bridging with an intravenous GPIIb/IIIa inhibitor appeared feasible. Further study is needed on the optimal strategy to manage patients with recent stenting who need surgical procedures.

  16. Structural Repair Of Prestressed Concrete Bridge Beams

    OpenAIRE

    Pekyer, Bülent

    2010-01-01

    Each year a lot of prestressed concrete beams are damaged by overwheight vehicles and environmental effects. There are numerous repair techniques proposed by entrepreneurial and academic institutions which restore prestressed concrete girder flexural strength and save both material and economic resources. This document focuses on the practical application of prestressed concrete bridge girder repair methods. In this document, repair methods are presented for three prototype prestressed concre...

  17. Characterization of stormwater runoff from bridges in North Carolina and the effects of bridge deck runoff on receiving streams

    Science.gov (United States)

    Wagner, Chad R.; Fitzgerald, Sharon A.; Sherrell, Roy D.; Harned, Douglas A.; Staub, Erik L.; Pointer, Brian H.; Wehmeyer, Loren L.

    2011-01-01

    In 2008, the North Carolina General Assembly passed House Bill 2436 that required the North Carolina Department of Transportation (NCDOT) to study the water-quality effects of bridges on receiving streams. In response, the NCDOT and the U.S. Geological Survey (USGS) collaborated on a study to provide information necessary to address the requirements of the Bill. To better understand the effects of stormwater runoff from bridges on receiving streams, the following tasks were performed: (1) characterize stormwater runoff quality and quantity from a representative selection of bridges in North Carolina; (2) measure stream water quality upstream from selected bridges to compare bridge deck stormwater concentrations and loads to stream constituent concentrations and loads; and (3) determine if the chemistry of bed sediments upstream and downstream from selected bridges differs substantially based on presence or absence of a best management practice for bridge runoff.

  18. Behaviour of several fatigue prone bridge details

    Science.gov (United States)

    Kubiš, Petr; Ryjáček, Pavel

    2017-09-01

    Three fatigue welded bridge joints analysed in this work are the alternative details of the bottom flange connection. This construction detail is mainly used for the erection connection for steel and composite bridges. If applied in the place, where live load is significant, the fatigue becomes the main design criterion. The detail category is thus very important factor. The aim of this paper is to analyse the possibilities of the improving the behaviour of this detail, by various methods. First solution is to modify the shape of the cope hole to the elliptic shape. Second option is to use the “Olemutz” fully welded detail. This detail is often used in bridge designing despite there is no exact information about the fatigue category, and doubts of the performance exists. “Olemutz” is a long web plate slit that is filled by the double bevel weld after the execution of the bottom flange weld. The last detail is the elliptic cope hole filled by the plate-cap welded into an empty hole. The geometry is the same, as in the first case. The conclusion of the numerical analysis and the pilot fatigue experiments is discussed with several practical recommendations for designing.

  19. Forward, backward, and weighted stochastic bridges

    Science.gov (United States)

    Drummond, Peter D.

    2017-10-01

    We define stochastic bridges as conditional distributions of stochastic paths that leave a specified point in phase-space in the past and arrive at another one in the future. These can be defined relative to either forward or backward stochastic differential equations and with the inclusion of arbitrary path-dependent weights. The underlying stochastic equations are not the same except in linear cases. Accordingly, we generalize the theory of stochastic bridges to include time-reversed and weighted stochastic processes. We show that the resulting stochastic bridges are identical, whether derived from a forward or a backward time stochastic process. A numerical algorithm is obtained to sample these distributions. This technique, which uses partial stochastic equations, is robust and easily implemented. Examples are given, and comparisons are made to previous work. In stochastic equations without a gradient drift, our results confirm an earlier conjecture, while generalizing this to cases with path-dependent weights. An example of a two-dimensional stochastic equation with no potential solution is analyzed and numerically solved. We show how this method can treat unexpectedly large excursions occurring during a tunneling or escape event, in which a system escapes from one quasistable point to arrive at another one at a later time.

  20. Optimal construction of army ant living bridges.

    Science.gov (United States)

    Graham, Jason M; Kao, Albert B; Wilhelm, Dylana A; Garnier, Simon

    2017-12-21

    Integrating the costs and benefits of collective behaviors is a fundamental challenge to understanding the evolution of group living. These costs and benefits can rarely be quantified simultaneously due to the complexity of the interactions within the group, or even compared to each other because of the absence of common metrics between them. The construction of 'living bridges' by New World army ants - which they use to shorten their foraging trails - is a unique example of a collective behavior where costs and benefits have been experimentally measured and related to each other. As a result, it is possible to make quantitative predictions about when and how the behavior will be observed. In this paper, we extend a previous mathematical model of these costs and benefits to much broader domain of applicability. Specifically, we exhibit a procedure for analyzing the optimal formation, and final configuration, of army ant living bridges given a means to express the geometrical configuration of foraging path obstructions. Using this procedure, we provide experimentally testable predictions of the final bridge position, as well as the optimal formation process for certain cases, for a wide range of scenarios, which more closely resemble common terrain obstacles that ants encounter in nature. As such, our framework offers a rare benchmark for determining the evolutionary pressures governing the evolution of a naturally occurring collective animal behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Measuring the stress-bridging law of a heterogeneous material

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C. (Cheng)

    2002-01-01

    In this investigation, fracture experiments on a high explosive material (PBX 9501) were conducted using the digital image correlation technique. From the experimental measurement, we are able to determine quantitatively the stress-bridging law (or decohesion law), which characterizes the relationship between the bridging stress and the opening displacement cross the bridging zone. The plastic bonded HMX (PBX) high explosives are composed of the energetic crystal (HMX) and a polymeric binder. Previous experimental observations showed that the fracture process in the sugar mock, a simulant of the PBX 9501 high explosive, is very different from that in brittle solids, even though the high explosive material PBX 9501 is quite brittle under tension. A close examination of the fracture surface revealed that before crack initiation and propagation, a very large damage region is developed ahead of the crack tip. Since such a damage region is very narrow, it can be modeled as a stress bridging zone. Due to the presence of the sizable bridging zone, conventional fracture mechanics is no longer applicable. Stress bridging has to be considered explicitly in order to understand of fracture processes in the PBX 9501 high explosive and the sugar mock. The model, which explicitly incorporates stress-bridging mechanism, is shown in Fig.1. In describing the model, one would need the following quantities, bridging zone length R, bridging stress {sigma}(x{sub 1}), bridging-zone opening displacement {sigma}(x{sub 1}), and the critical stress, {sigma}{sub C}, at which bridging zone starts to develop. Among these quantities, the key element for the bridging model is the relationship between the bridging stress {sigma} and the opening displacement cross the bridging zone {sigma}, i.e., {sigma}({delta}), or the stress-bridging law that can only be determined through experimental measurement. In this study, fracture experiments on PBX 9501 high explosive using the digital image correlation

  2. The Internet Inter-Orb Protocol Security Bridge

    Directory of Open Access Journals (Sweden)

    Pawel Slowikowski

    1999-01-01

    Full Text Available In this paper, we present a security bridge for the Internet protocol of interoperability amongst CORBA objects and the Internet inter-ORB Protocol (IIOP. The bridge helps in making accessible objects in the Internet and makes possible the access control to them. The bridge was realized in the popular request broker the Visigenic's VisiBroker under Windows 95/NT and Solaris 2.X operating systems. We describe two ways of locating the bridge in the request broker. The first means uses one name domain of broker and is not transparent for client. The second one uses two name domains and provides objects protection on the level of the Naming Service and is transparent lor the client. We also describe the variant ofthe second means with using GateKeeper server to support IIOP tunneling within HTTP. We emphasize the importance of a firewall, cooperating with a bridge. which is required for the purpose of providing object protection. The paper presents an original conception of security managing, basing on the ideas of users, groups and resources defined using the standard terms of CORBA, IIOP and TCP/IP, that allows to control positively and negatively the access to classes (interfaces, objects and also to their individual methods. This conception was effectively implemented in a functioning bridge. Further chapters describe the foundations and some details of the bridge implementation sueli as the use ofthe Interface Repository, cache memory application, thread synchronization and the way of synchronization of the configuration applet with the bridge's objects. We discuss the influence of these solutions on the efficiency ofthe bridge and its source code portability. We also present the general structure of the component objects ofthe bridge with a scheme. ln the next part we characterize the implementation foundations ofthe bridge manager, realized as an applet in Java, with the stress on the possibility of the bridge configuration through the

  3. Improving Bridging from Informatics Practice to Theory.

    Science.gov (United States)

    Lehmann, C U; Gundlapalli, A V

    2015-01-01

    In 1962, Methods of Information in Medicine ( MIM ) began to publish papers on the methodology and scientific fundamentals of organizing, representing, and analyzing data, information, and knowledge in biomedicine and health care. Considered a companion journal, Applied Clinical Informatics ( ACI ) was launched in 2009 with a mission to establish a platform that allows sharing of knowledge between clinical medicine and health IT specialists as well as to bridge gaps between visionary design and successful and pragmatic deployment of clinical information systems. Both journals are official journals of the International Medical Informatics Association. As a follow-up to prior work, we set out to explore congruencies and interdependencies in publications of ACI and MIM. The objectives were to describe the major topics discussed in articles published in ACI in 2014 and to determine if there was evidence that theory in 2014 MIM publications was informed by practice described in ACI publications in any year. We also set out to describe lessons learned in the context of bridging informatics practice and theory and offer opinions on how ACI editorial policies could evolve to foster and improve such bridging. We conducted a retrospective observational study and reviewed all articles published in ACI during the calendar year 2014 (Volume 5) for their main theme, conclusions, and key words. We then reviewed the citations of all MIM papers from 2014 to determine if there were references to ACI articles from any year. Lessons learned in the context of bridging informatics practice and theory and opinions on ACI editorial policies were developed by consensus among the two authors. A total of 70 articles were published in ACI in 2014. Clinical decision support, clinical documentation, usability, Meaningful Use, health information exchange, patient portals, and clinical research informatics emerged as major themes. Only one MIM article from 2014 cited an ACI article. There

  4. Longest cable-stayed bridge TATARA; Longest shachokyo Tatara Ohashi

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, K. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

    1998-06-15

    The world`s longest cable-stayed bridge Tatara having a central span of 890 m had the both ends closed in August 1997, linking Namakuchi Island and Omishima Island. Final finishing work is continuing for opening of the West Seto Expressway in the spring of 1999. A cable-stayed bridge supports the bridge girders by perpendicular components of tensile force of cables stayed obliquely. On the other hand, there is a concern that the girders may have axial compression force generated due to horizontal components of the force from the cable tensile force, which can cause buckling of the girders. Therefore, in order to suspend the girders efficiently by increasing the perpendicular components of the cable force, and moreover to suppress the axial compression force on the girders, it is more advantageous to make bridge towers high, hence the towers of this bridge are highest among the bridges on the Shimanami Ocean Road. This bridge whose long girders are stayed with 21-stage multi cables presented a problem in designing the buckling in steel girders near the towers due to the horizontal components of the force generated by the bridge. Discussions were given, therefore, by using load withstanding force experiments using a whole bridge model of 1/50 scale, buckling experiments on full-size reinforcing plate models, and load withstanding force analysis using a tower model. A number of other technical discussions were repeated, by which the world`s longest cable-stayed bridge was completed. 9 figs., 1 tab.

  5. Field Tests and Simulation of Lion-Head River Bridge

    Directory of Open Access Journals (Sweden)

    Yao-Min Fang

    2007-01-01

    Full Text Available Lion-Head River Bridge is a twin bridge in parallel position. The east-bounded was designed and constructed as a traditional prestress concrete box girder bridge with pot bearings; and the west-bounded was installed with seismic isolation devices of lead rubber bearings. The behavior of the isolated bridge is compared with that of the traditional bridge through several field tests including the ambient vibration test, the force vibration test induced by shakers, the free vibration test induced by a push and fast release system, and the truck test. The bridges suffered from various extents of damage due to the Chi-Chi and the Chi-I earthquakes of great strength during the construction and had been retrofitted. The damage was reflected by the change of the bridges' natural frequencies obtained from the ambient vibration tests. The models of the two bridges are simulated by the finite element method based on the original design drawings. Soil-structure interaction was also scrutinized in this study. The simulation was then modified based on the results from the field tests. Dynamic parameters of bridges are identified and compared with those from theoretical simulation. The efficiency is also verified to be better for an isolated bridge.

  6. Bridges analysis, design, structural health monitoring, and rehabilitation

    CERN Document Server

    Bakht, Baidar

    2015-01-01

    This book offers a valuable guide for practicing bridge engineers and graduate students in structural engineering; its main purpose is to present the latest concepts in bridge engineering in fairly easy-to-follow terms. The book provides details of easy-to-use computer programs for: ·      Analysing slab-on-girder bridges for live load distribution. ·      Analysing slab and other solid bridge components for live load distribution. ·      Analysing and designing concrete deck slab overhangs of girder bridges under vehicular loads. ·      Determining the failure loads of concrete deck slabs of girder bridges under concentrated wheel loads. In addition, the book includes extensive chapters dealing with the design of wood bridges and soil-steel bridges. Further, a unique chapter on structural health monitoring (SHM) will help bridge engineers determine the actual load carrying capacities of bridges, as opposed to their perceived analytical capacities. The chapter addressing structures...

  7. A cloud-based information repository for bridge monitoring applications

    Science.gov (United States)

    Jeong, Seongwoon; Zhang, Yilan; Hou, Rui; Lynch, Jerome P.; Sohn, Hoon; Law, Kincho H.

    2016-04-01

    This paper describes an information repository to support bridge monitoring applications on a cloud computing platform. Bridge monitoring, with instrumentation of sensors in particular, collects significant amount of data. In addition to sensor data, a wide variety of information such as bridge geometry, analysis model and sensor description need to be stored. Data management plays an important role to facilitate data utilization and data sharing. While bridge information modeling (BrIM) technologies and standards have been proposed and they provide a means to enable integration and facilitate interoperability, current BrIM standards support mostly the information about bridge geometry. In this study, we extend the BrIM schema to include analysis models and sensor information. Specifically, using the OpenBrIM standards as the base, we draw on CSI Bridge, a commercial software widely used for bridge analysis and design, and SensorML, a standard schema for sensor definition, to define the data entities necessary for bridge monitoring applications. NoSQL database systems are employed for data repository. Cloud service infrastructure is deployed to enhance scalability, flexibility and accessibility of the data management system. The data model and systems are tested using the bridge model and the sensor data collected at the Telegraph Road Bridge, Monroe, Michigan.

  8. Bridge scour countermeasure assessments at select bridges in the United States, 2014–16

    Science.gov (United States)

    Dudunake, Taylor J.; Huizinga, Richard J.; Fosness, Ryan L.

    2017-05-23

    In 2009, the Federal Highway Administration published Hydraulic Engineering Circular No. 23 (HEC-23) to provide specific design and implementation guidelines for bridge scour and stream instability countermeasures. However, the effectiveness of countermeasures implemented over the past decade following those guidelines has not been evaluated. Therefore, in 2013, the U.S. Geological Survey, in cooperation with the Federal Highway Administration, began a study to assess the current condition of bridge-scour countermeasures at selected sites to evaluate their effectiveness. Bridge-scour countermeasures were assessed during 2014-2016. Site assessments included reviewing countermeasure design plans, summarizing the peak and daily streamflow history, and assessments at each site. Each site survey included a photo log summary, field form, and topographic and bathymetric geospatial data and metadata. This report documents the study area and site-selection criteria, explains the survey methods used to evaluate the condition of countermeasures, and presents the complete documentation for each countermeasure assessment.

  9. A peroxide-bridged imidazole dimer formed from a photochromic naphthalene-bridged imidazole dimer.

    Science.gov (United States)

    Hatano, Sayaka; Abe, Jiro

    2012-04-28

    2,4,5-Triphenylimidazole (lophine) is known as the first chemiluminescence substrate, and its oxidized derivative, the 2,4,5-triphenylimidazolyl radical, corresponds to the coloured species in the photochromic reaction of hexaarylbiimidazole (HABI). We report the first direct observation of the O(2) adduct of the imidazolyl radical that forms the end-on peroxide-bridged imidazole dimer. The ring-opening reaction of the peroxide-bridged imidazole dimer leading to the formation of an N-benzoylbenzamidine derivative supports the presence of the 4,5-epidioxide of lophine as a reaction intermediate of its chemiluminescence. This journal is © the Owner Societies 2012

  10. Investigation of Aerodynamic Interference of Double Deck Bridges

    Energy Technology Data Exchange (ETDEWEB)

    Sitek, M. A. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division. Transportation Research and Analysis Computing Center (TRACC); Bojanowski, C. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division. Transportation Research and Analysis Computing Center (TRACC); Lottes, S. A. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division. Transportation Research and Analysis Computing Center (TRACC)

    2016-05-01

    Construction of a twin bridge can be a cost effective and minimally disruptive way to increase capacity when an existing bridge is not near the end of its service life. With ever growing vehicular traffic, when demand approaches the capacity of many existing roads and bridges. Remodeling a structure with an insufficient number of lanes can be a good solution in case of smaller and less busy bridges. Closing down or reducing traffic on crossings of greater importance for the construction period, however, can result in major delays and revenue loss for commerce and transportation as well as increasing the traffic load on alternate route bridges. Multiple-deck bridges may be the answer to this issue. A parallel deck can be built next to the existing one, without reducing the flow. Additionally, a new bridge can be designed as a twin or multi-deck structure. Several such structures have been built throughout the United States, among them: - The New NY Bridge Project - the Tappan Zee Hudson River Crossing, - SR-182 Columbia River Bridge, - The Thaddeus Kosciusko Bridge (I-87), - The Allegheny River Bridge, Pennsylvania, which carries I76, - Fred Hartman Bridge, TX, see Figure 1.2. With a growing number of double deck bridges, additional, more detailed, studies on the interaction of such bridge pairs in windy conditions appears appropriate. Aerodynamic interference effects should be examined to assure the aerodynamic stability of both bridges. There are many studies on aerodynamic response of single deck bridges, but the literature on double-deck structures is not extensive. The experimental results from wind tunnels are still limited in number, as a parametric study is required, they can be very time consuming. Literature review shows that some investigation of the effects of gap-width and angle of wind incidence has been done. Most of the CFD computational studies that have been done were limited to 2D simulations. Therefore, it is desirable to investigate twin decks

  11. Wireless Smart Sensor Network System Using SmartBridge Sensor Nodes for Structural Health Monitoring of Existing Concrete Bridges

    Science.gov (United States)

    Gaviña, J. R.; Uy, F. A.; Carreon, J. D.

    2017-06-01

    There are over 8000 bridges in the Philippines today according to the Department of Public Works and Highways (DPWH). Currently, visual inspection is the most common practice in monitoring the structural integrity of bridges. However, visual inspections have proven to be insufficient in determining the actual health or condition of a bridge. Structural Health Monitoring (SHM) aims to give, in real-time, a diagnosis of the actual condition of the bridge. In this study, SmartBridge Sensor Nodes were installed on an existing concrete bridge with American Association of State Highway and Transportation Officials (AASHTO) Type IV Girders to gather vibration of the elements of the bridge. Also, standards on the effective installation of SmartBridge Sensor Nodes, such as location and orientation was determined. Acceleration readings from the sensor were then uploaded to a server, wherein they are monitored against certain thresholds, from which, the health of the bridge will be derived. Final output will be a portal or webpage wherein the information, health, and acceleration readings of the bridge will be available for viewing. With levels of access set for different types of users, the main users will have access to download data and reports. Data transmission and webpage access are available online, making the SHM system wireless.

  12. Geometry dependence of the magnetization reversal process in bridged dots

    Energy Technology Data Exchange (ETDEWEB)

    Escobar, R.A. [Departamento de Física, CEDENNA, Universidad de Santiago de Chile, USACH, Av. Ecuador 3493, Santiago (Chile); Lage, E. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 02139 Cambridge, MA (United States); D’Albuquerque e Castro, J. [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, RJ 21945-970 (Brazil); Altbir, D., E-mail: dora.altbir@usach.cl [Departamento de Física, CEDENNA, Universidad de Santiago de Chile, USACH, Av. Ecuador 3493, Santiago (Chile); Ross, C.A. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 02139 Cambridge, MA (United States)

    2017-06-15

    Based on Monte Carlo numerical simulations: results for the magnetization reversal process in thin circular Ni dots connected by a bridge are presented. The dependence of the process on both the width of the bridge and the orientation of the applied magnetic field has been investigated. It was found that when the applied magnetic field is set parallel to the bridge, the hysteresis curves are weakly dependent on the width of the bridge, being rather close to that of a single dot of the same diameter. On the other hand, when the magnetic field is applied perpendicularly to the bridge, a significant reduction in the coercivity of the system is obtained, even in the case of narrower bridges.

  13. Measurements of bridges' vibration characteristics using a mobile phone

    Directory of Open Access Journals (Sweden)

    Z. M. C. Pravia

    Full Text Available ABSTRACTThis research presents an alternative way to perform a bridge inspection, which considers the dynamics parameters from the structure. It shows an experimental phase with use of a mobile phone to extract the accelerations answers from two concrete bridges, from those records is feasible to obtain natural frequencies using the Fast Fourier Transform (FFT.Numerical models with uses finite element model (FEM allow to determine the natural frequencies from the two concrete bridges and compare with the experimental phase of each one. The final results shows it's possible to use mobiles phones to extract vibration answers from concrete bridges and define the structural behavior of bridges from natural frequencies, this procedure could be used to evaluate bridges with lower costs.

  14. Extension of POA based on Fiber Element to Girder Bridge

    Science.gov (United States)

    Li, Zhenxin; Qiang, Shizhong

    2010-05-01

    Because of its main advantage of simplicity, practicality, lower computational cost and relative good results Pushover analysis (POA) has become an effective analytical tool during the last decade for the seismic assessment of buildings. But such work on bridges has been very limited. Hence, the aim of this study is to adapt POA for nonlinear seismic analysis of girder bridges, and investigate its applicability in the case of an existing river-spanning approach bridge. To three different types bridge models the nonlinear POA, which adopts fiber model nonlinear beam-column element based on flexibility approach, with return period about 2500 years is carried out. It can be concluded that POA is applicable for bridges, with some shortcomings associated with the method in general, even when it is applied for buildings. Finally the applicable selection for monitoring point and lateral load pattern is suggested according to dynamic characteristic of girder bridges.

  15. THE MODERN DECISIONS ABOUT CONSTRUCTIONS OF BRIDGE FLOOR

    Directory of Open Access Journals (Sweden)

    I. D. Sakharova

    2010-03-01

    Full Text Available The paper is dealt with the changes introduced into the code of regulations «Bridges and pipes» developed as alternative to SNiP 2.05.03-84* related to the bridge floor of bridge structures: the possibility of refusing sidewalks, the change in road and sidewalk cross falls, the building of road pavement structures with the placement of asphalt concrete coating over waterproofing, and the drainage system construction.

  16. Some Investigations Performed for the Bridge Over Jiu at Aninoasa

    Directory of Open Access Journals (Sweden)

    Răcănel Ionuţ Radu

    2012-12-01

    Full Text Available The carrying structure of the bridge over the Jiu River at Aninoasa consists in two parallel concrete arches with variable height of the cross section, sustaining a concrete deck through vertical concrete hangers. In the time period passed since the bridge was erected, some structural elements shown damages. In order to establish the technical state of the bridge, a technical appraisement was performed and according to this, the most exposed elements to the risk of failure are the hangers.

  17. International Contribution to the Highway Agency's Bridge Related Research

    DEFF Research Database (Denmark)

    Nowak, A. S.; Thoft-Christensen, Palle

    The objective of this paper is to summarize recent contributions of international experts to the research program sponsored by the Highways Agency. An efficient management of existing bridges requires methodology for an accurate evaluation of the actual loads and load carrying capacity and predic...... of reliability models for analysis of bridges subjected to corrosion and fatigue, and reliability-based optimization of maintenance strategies for bridges....

  18. Dynamic characteristics of old railway steel bridges in Egypt

    Directory of Open Access Journals (Sweden)

    Hassan Maha M.

    2017-01-01

    Full Text Available Dynamic response of existing railway bridges is influenced by many factors including structural properties, railway traffic speed, and train-to-bridge frequency. Excessive vibrations cause passengers’ discomfort, rail elements deterioration, higher derailment risks, fatigue deformation problems, stress amplification, and eventually high maintenance costs. In such cases, applied remedies include limiting traffic speed or changing bridge mass or stiffness. Traffic induced vibrations can also be mitigated by enhancing structural damping through application of Tuned Mass Dampers. Egypt has one of the oldest railway transportation network with several steel bridges crossing the Nile River, in addition to several canals. In a running project, dynamic properties of selective bridges on the Egyptian railway networks infrastructures are investigated through extensive field testing. The considered bridges cover a wide range of structural properties including simply-supported and continuous bridges, spans ranging between 40 to 90 m, single and double track lines, and open timber bridges. Field tests results are studied; hence, key factors affecting bridge dynamic characteristics are discussed and highlighted. Moreover, results are compared with those extracted from finite element analyses. The project aims at evaluating the possibility of excessive vibration problems while considering different values of train velocities. In the current study, focus is given to two example bridges. Field and numerical results are exhibited and discussed. Eventually, possibility of excessive vibration problems are determined considering different values of train velocities. It was observed that available formulas in current design codes do not capture warping and torsional modes that present fundamental modes for truss bridges. In addition, existing railway bridges do not satisfy serviceability limit states when considering high speed trains.

  19. Global Bridges: building an international network for tobacco dependence treatment

    Directory of Open Access Journals (Sweden)

    Katie Kemper

    2016-03-01

    Full Text Available Global Bridges, hosted at Mayo Clinic, is the most diverse international network of healthcare professionals dedicated to tobacco dependence treatment. Global Bridges works with grantees and partners in all six WHO regions to educate healthcare providers on evidence-based treatment and advocate for effective tobacco policy. This session will describe accomplishments and lessons learned in the Global Bridges program over nearly six years, and opportunities to better integrate cessation support into comprehensive tobacco control.

  20. SOLUTION FOR AN EQUIPMENT OF RAILWAY BRIDGE MONITORING

    Directory of Open Access Journals (Sweden)

    Liviu Mihai SIMA

    2009-11-01

    Full Text Available This paper presents a solution for the railway bridges monitoring based on the use of already existing equipments in the railway installations and some new equipments based on photo-elements, as well. This kind of equipments can function in continue and discontinuous regime, means of them tracking down if the bridge piles suffered movements by different reasons. This aspect can put in danger the safety of the circulation on that bridge.

  1. Common pathologies in RC bridge structures: a statistical analysis

    OpenAIRE

    Santos, J.; Nunes, C.; Fernandes, C.; Varum, H.

    2007-01-01

    One of the main tasks in bridge engineering is to maintain the existing bridge stock according to current and predicted traffic and safety requirements. Bridges deterioration commonly occurs due to a wide variety of pathological factors, with origin in, for example: unexpected traffic loads, vehicle impacts, environmental factors, earth movements, chloride attack, carbonation effect, lack of maintenance, de-icing salts, degradation of the drainage systems, pavement quality. Consid...

  2. Hysteretic Behavior of Prestressed Concrete Bridge Pier with Fiber Model

    OpenAIRE

    Hui-li, Wang; Guang-qi, Feng; Si-feng, Qin

    2014-01-01

    The hysteretic behavior and seismic characteristics of the prestressed concrete bridge pier were researched. The effects of the prestressed tendon ratio, the longitudinal reinforcement ratio, and the stirrup reinforcement ratio on the hysteretic behavior and seismic characteristics of the prestressed concrete bridge pier have been obtained with the fiber model analysis method. The analysis show some results about the prestressed concrete bridge pier. Firstly, greater prestressed tendon ratio ...

  3. Some aspects of technical models within bridge management system

    Directory of Open Access Journals (Sweden)

    Grković Slobodan

    2015-01-01

    Full Text Available Bridge Management System (BMS represents a rational and systematic approach to organizing and conducting of all activities related to bridge maintenance. Main goal of BMS is helping the bridge owner to make an optimal decision with respect to bridge maintenance budget, whether it is dedicated to one bridge or to group of bridges, by securing that the decision is made on the basis of Life-Cycle Cost (LCC estimates. The structure of BMS is based on condition rating and Bridge Database (BD, Deterioration model (DM, Cost Model for evaluation of costs and Optimization Model for choosing the most rational maintenance strategy. Relationship between bridge condition rating and DM with maintenance costs within BMS is very important. Predictions regarding future intensity and rate of bridge deterioration depends on multitude of factors and it is a consequence of several simultaneous actions and deterioration processes (DP which need to be included into DMs. DMs are mostly based on modeling of physical and chemical actions and processes or they are based on statistical analysis of large number of data regarding the condition of existing bridges, or on artificial intelligence models, etc. Stochastic models based on Markov processes are applied within more advanced contemporary BMS. Due to social and economic circumstances and lack of financial resources over the last two decades in Republic of Serbia bridge maintenance was neglected and creation of BD was discontinued. The paper deliberates some aspects of technical models within BMS, with DMs being pointed out, development of BD within bridge maintenance in Republic of Serbia and it gives an overview of sophisticated BMS and current advances in this field.

  4. Running Safety of Trains under Vessel-Bridge Collision

    Directory of Open Access Journals (Sweden)

    Yongle Li

    2015-01-01

    Full Text Available To optimize the sensor placement of the health monitoring system, the dynamic behavior of the train-bridge system subjected to vessel-collision should be studied in detail firstly. This study thus focuses on the characteristics of a train-bridge system under vessel-bridge collision. The process of the vessel-bridge collision is simulated numerically with a reliable finite element model (FEM. The dynamic responses of a single car and a train crossing a cable-stayed bridge are calculated. It is shown that the collision causes significant increase of the train’s lateral acceleration, lateral wheelset force, wheel unloading rate, and derailment coefficient. The effect of the collision on the train’s vertical acceleration is much smaller. In addition, parametric studies with various train’s positions, ship tonnage, and train speed are performed. If the train is closer to the vessel-bridge collision position or the ship tonnage is larger, the train will be more dangerous. There is a relatively high probability of running danger at a low speed, resulting from longer stay of the train on the bridge. The train’s position, the ship tonnage, and the train speed must be considered when determining the most adverse conditions for the trains running on bridges under vessel-bridge collision.

  5. Determination Method of Bridge Rotation Angle Response Using MEMS IMU.

    Science.gov (United States)

    Sekiya, Hidehiko; Kinomoto, Takeshi; Miki, Chitoshi

    2016-11-09

    To implement steel bridge maintenance, especially that related to fatigue damage, it is important to monitor bridge deformations under traffic conditions. Bridges deform and rotate differently under traffic load conditions because their structures differ in terms of length and flexibility. Such monitoring enables the identification of the cause of stress concentrations that cause fatigue damage and the proposal of appropriate countermeasures. However, although bridge deformation monitoring requires observations of bridge angle response as well as the bridge displacement response, measuring the rotation angle response of a bridge subject to traffic loads is difficult. Theoretically, the rotation angle response can be calculated by integrating the angular velocity, but for field measurements of actual in-service bridges, estimating the necessary boundary conditions would be difficult due to traffic-induced vibration. To solve the problem, this paper proposes a method for determining the rotation angle response of an in-service bridge from its angular velocity, as measured by a inertial measurement unit (IMU). To verify our proposed method, field measurements were conducted using nine micro-electrical mechanical systems (MEMS) IMUs and two contact displacement gauges. The results showed that our proposed method provided high accuracy when compared to the reference responses calculated by the contact displacement gauges.

  6. Myocardial bridge: is the risk of perforation increased?

    National Research Council Canada - National Science Library

    Li, Weimin; Li, Yue; Sheng, Li; Gong, Yongtai

    2008-01-01

    ...; however, coronary perforation caused by stent implantation has been reported. The present report describes two myocardial bridge cases with severe coronary rupture soon after stent implantation...

  7. Strengthening of a railway bridge with NSMR and CFRP tubes

    DEFF Research Database (Denmark)

    Täljsten, Björn; Bennitz, Anders; Danielsson, Georg

    2008-01-01

    flexural strength of the slab transverse to the tracks. NSMR bars are positioned in the concrete cover on the underside of the bridge, while the new system is inserted in holes drilled through the bridge, in the cross direction and located in the upper part of the bridge slab. In connection......Strengthening of structures with CFRP is today considered an accepted method to upgrade concrete structures. In this paper two different CFRP strengthening systems are combined to give extended service life to a Swedish double-trough-double-track railway bridge, constructed in concrete with a 10...

  8. Study on safety level of RC beam bridges under earthquake

    Science.gov (United States)

    Zhao, Jun; Lin, Junqi; Liu, Jinlong; Li, Jia

    2017-08-01

    This study considers uncertainties in material strengths and the modeling which have important effects on structural resistance force based on reliability theory. After analyzing the destruction mechanism of a RC bridge, structural functions and the reliability were given, then the safety level of the piers of a reinforced concrete continuous girder bridge with stochastic structural parameters against earthquake was analyzed. Using response surface method to calculate the failure probabilities of bridge piers under high-level earthquake, their seismic reliability for different damage states within the design reference period were calculated applying two-stage design, which describes seismic safety level of the built bridges to some extent.

  9. Evaluation of a bridge using simplified element modeling

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, C.R. [Los Alamos National Lab., NM (United States); Duffey, T.A. [New Mexico Highlands Univ., Las Vegas, NM (United States)

    1995-02-01

    An experimental-numerical comparison of the forced and ambient vibrations Of a multi-span composite plate-girder bridge was performed. The bridge was modeled using a finite element program at three levels of complexity, including a simple 250 DOF model that utilizes a single beam element to represent the entire bridge cross section. Difficulties encountered in the development of the simple model are discussed. The dynamic properties predicted by the simple model were consistent with these measured on the bridge and computed using more detailed finite element models.

  10. OnWien Bridge Oscillators as Modified Multi-vibrators

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2014-01-01

    A tutorial introduction to electrical oscilla- tors. Investigating Wien bridge oscillators as modified multi-vibrators. Introducing chaotic behavior into a Wien bridge oscillator by means of adding a simple nonlinear cir- cuit as a load of one of the amplifier input terminals......A tutorial introduction to electrical oscilla- tors. Investigating Wien bridge oscillators as modified multi-vibrators. Introducing chaotic behavior into a Wien bridge oscillator by means of adding a simple nonlinear cir- cuit as a load of one of the amplifier input terminals...

  11. Structural condition assessment of the bridge in Ostrava

    Directory of Open Access Journals (Sweden)

    Čech Jindřich

    2017-01-01

    Full Text Available This paper deals with the comparison of results of dynamic test and numerical modelling of a road bridge across the Dr. Kudela street in the street Rudná in Ostrava. The bridge is a reinforced concrete structure, made of post-tensioned KA-beams. On the bridge were verified material properties. Calculation model to validate the static and dynamic behavior of structures was created. On the bridge were measured dynamic properties (frequency, mode shapes and attenuation during excitation construction by hydraulic vibration exciter. Article will focus on comparing the results of the calculation of dynamic structures and properties measured on real structure upon excitation.

  12. Assessment of concrete bridge decks with alkali silica reactions

    DEFF Research Database (Denmark)

    Eriksen, Kirsten; Jansson, Jacob; Geiker, Mette Rica

    2008-01-01

    , Bagsværd, Denmark to provide information on the damage condition as well as the residual reactivity of the concrete. The Danish Road Directory’s guidelines for inspection and assessment of alkali silica damaged bridges will be briefly presented, and proposed modifications will be describe......Based on investigations of concrete from an approximately 40 years old bridge a procedure to support the management of maintenance and repair of alkali silica damaged bridges is proposed. Combined petrography and accelerated expansion testing were undertaken on cores from the Bridge at Skovdiget...

  13. Commutation Processes in Multiresonant ZVS Bridge Converter

    Directory of Open Access Journals (Sweden)

    Miroslaw Luft

    2008-01-01

    Full Text Available The analysis of the multiresonant ZVS DC/DC bridge converter is presented. The control system of the converter is basedon the method of frequency control at the constant time of transistor turn-off with a phase shift. The operation of the circuit is givenand the operating range of the converter is defined where ZVS switching operation is assured. Control characteristics are given andthe converter’s efficiency is defined. The circuit’s operation is analysed on the basis of results of the converter simulation tests using Simplorer programme.

  14. Bridging knowledge capital with tourism destination stakeholders

    DEFF Research Database (Denmark)

    Wejrum, Lone Møller; Madsen, Jan Halberg; d'Ambrosio, Luigi

    2015-01-01

    process for the bachelor students at the IHM programme is according to the Problem Based Learning (PBL) principles to ensure the students’ motivation. Thus the students are participating in finding and defining the challenges and problems for the destination combining their theoretical knowledge...... individual interviews, focus group discussions and ethnographic observations. Findings/recommendations: - This is a conceptual paper that focuses on investigating the cooperation between hospitality knowledge institutions and destination stakeholders focusing on the specific case of the Italian destination...... Campi Flegrei. The ambition of this paper is to give a contribution to destination management and development theories and to explore the outcome of bridging knowledge institutions with destination stakeholders....

  15. Comparison of Temperature Loadings of Bridge Girders

    Directory of Open Access Journals (Sweden)

    J. Římal

    2008-01-01

    Full Text Available This paper compares the effect of temperature changes on the superstructure of bridges, above all the effect of non-uniform temperature. Loadings according to standards ESN 73 6203, ENV 1991-1-5 and DIN 1072 are compared here. The paper shows a short summary of temperature loading according to each standard and shows the comparison of bending moments arisen from these temperature loadings on superstructure made from continuous girder from a steel-concrete box girder with a composite concrete slab. With respect to a variety of design processes, the comparison is made without any coefficient of loading, combination or material. 

  16. Switchbacks and the Bridge to Nowhere

    OpenAIRE

    Susskind, Leonard; Zhao, Ying

    2014-01-01

    This paper is in three parts: Part 1 explains the relevance of Einstein-Rosen bridges for one-sided black holes. Like their two-sided counterparts, one-sided black holes are connected to ERBs whose growth tracks the increasing complexity of the quantum state. Quantitative solutions for one-sided ERBs are presented in the appendix. Part 2 calls attention to the work of Nielsen and collaborators on the geometry of quantum complexity. This geometric formulation of complexity provides a valuable ...

  17. Influence of Icing on Bridge Cable Aerodynamics

    DEFF Research Database (Denmark)

    Koss, Holger; Frej Henningsen, Jesper; Olsen, Idar

    2013-01-01

    °C may lead to large amplitude vibrations of bridge cables under wind action. For the prediction of aerodynamic instability quasi-steady models have been developed estimating the cable response magnitude based on structural properties and aerodynamic force coefficients for drag, lift and torsion....... The determination of these force coefficients require a proper simulation of the ice layer occurring under the specific climatic conditions, favouring real ice accretion over simplified artificial reproduction. The work presented in this paper was performed to study the influence of ice accretion on the aerodynamic...

  18. Prestressed concrete cable-stayed bridge; PC shachokyo `Tajiri sky bridge` no seko

    Energy Technology Data Exchange (ETDEWEB)

    Kaida, Y.; Tsujino, F. [Osaka Prefectural Government Office, Osaka (Japan); Yamamoto, T.; Hishiki, Y.; Saito, K.

    1995-01-30

    The outline on the execution of PC cable-stayed bridge `Tajiri Sky Bridge` which was built at the opposite coast of Kansai International Airport was reported. This bridge is a double-sided suspension PC cable-stayed bridge with a tower height of 93.6 m having a main beam which is 26.3 m wide, featuring H-type main tower with one side beam, a smooth main beam structure, the leg top part with a large section, etc. A large-capacity factory manufacturing type non-grout cable with a pull strength of 1,900 ton class was adopted for the diagonal bracing. The leg top part is in a massive concrete structure so that, for avoiding the crack of cement due to temperature, a low heat build-up furnace cement was adopted, the water reducing agent was used, pre-cooling and side-clamping PC steel material were adopted and moderate pre-stress was introduced. In the execution of the connection part of the main beam, for preventing the deflection fluctuation due to the change of the main beam/main tower/diagonal bracing due to temperature and vibration due to wind, the earth anchor was used to tentatively fix the extended part. During execution, the wind velocity was strong reaching 25 m/s, which did not produce any problems. 1 ref., 24 figs., 3 tabs.

  19. Building water bridges in air: Electrohydrodynamics of the floating water bridge

    NARCIS (Netherlands)

    Gomez Marin, Alvaro; Lohse, Detlef

    2010-01-01

    The interaction of electrical fields and liquids can lead to a phenomenon that defies intuition. Some famous examples can be found in electrohydrodynamics as Taylor cones, whipping jets, or noncoalescing drops. A less famous example is the floating water bridge: a slender thread of water held

  20. This Bridge Called My Leadership: An Essay on Black Women as Bridge Leaders in Education

    Science.gov (United States)

    Horsford, Sonya Douglass

    2012-01-01

    The purpose of this essay is to contextualize the existing research literature on leadership for diversity, equity, and social justice in education with "bridge leadership" as historically practiced by Black women leaders in the USA. Its primary aim is to demonstrate how the intersection of race and gender as experienced by the Black…

  1. The Bridge and the Troll Underneath: Summer Bridge Programs and Degree Completion

    Science.gov (United States)

    Douglas, Daniel; Attewell, Paul

    2014-01-01

    College graduation rates in the United States are low in both real and relative terms. This has left all stakeholders looking for novel solutions while perhaps ignoring extant but underused programs. This article examines the effect of "summer bridge" programs, which have students enroll in coursework prior to beginning their first full…

  2. Dialkylenecarbonate-Bridged Polysilsesquioxanes. Hybrid Organic Sol-Gels with a Thermally Labile Bridging Group

    Energy Technology Data Exchange (ETDEWEB)

    Loy, D.A.; Beach, J.V.; Baugher, B.M.; Assink, R.A.; Shea, K.J.; Tran, J.; Small, J.H.

    1999-04-21

    In this paper, we introduce a new approach for altering the properties of bridged polysilsesquioxane xerogels using post-processing modification of the polymeric network. The bridging organic group contains latent functionalities that can be liberated thermally, photochemically, or by chemical means after the gel has been processed to a xerogel. These modifications can produce changes in density, volubility, porosity, and or chemical properties of the material. Since every monomer possesses two latent functional groups, the technique allows for the introduction of high levels of functionality in hybrid organic-inorganic materials. Dialkylenecarbonate-bridged polysilsesquioxane gels were prepared by the sol-gel polymerization of bis(triethoxysilylpropyl)carbonate (1) and bis(triethoxysilylisobutyl)-carbonate (2). Thermal treatment of the resulting non-porous xerogels and aerogels at 300-350 C resulted in quantitative decarboxylation of the dialkylenecarbonate bridging groups to give new hydroxyalkyl and olefinic substituted polysilsesquioxane monolithic xerogels and aerogels that can not be directly prepared through direct sol-gel polymerization of organotrialkoxysilanes.

  3. Precast concrete elements for accelerated bridge construction : laboratory testing of precast substructure components, Boone County bridge.

    Science.gov (United States)

    2009-01-01

    Vol. 1-1: In July 2006, construction began on an accelerated bridge project in Boone County, Iowa that was composed of precast substructure : elements and an innovative, precast deck panel system. The superstructure system consisted of full-depth dec...

  4. Bridging environmental mixtures and toxic effects.

    Science.gov (United States)

    Allan, Sarah E; Smith, Brian W; Tanguay, Robert L; Anderson, Kim A

    2012-12-01

    Biological Response Indicator Devices Gauging Environmental Stressors (BRIDGES) is a bioanalytical tool that combines passive sampling with the embryonic zebrafish developmental toxicity bioassay to provide a quantitative measure of the toxicity of bioavailable complex mixtures. Passive sampling devices (PSDs), which sequester and concentrate bioavailable organic contaminants from the environment, were deployed in the Willamette and Columbia Rivers within and outside of the Portland Harbor Superfund site in Portland, OR, USA. Six sampling events were conducted in the summer and fall of 2009 and 2010. Passive sampling device extracts were analyzed for polycyclic aromatic hydrocarbon (PAH) compounds and screened for 1,201 chemicals of concern using deconvolution-reporting software. The developmental toxicity of the extracts was analyzed using the embryonic zebrafish bioassay. The BRIDGES tool provided site-specific, temporally resolved information about environmental contaminant mixtures and their toxicity. Multivariate modeling approaches were applied to paired chemical and toxic effects data sets to help unravel chemistry-toxicity associations. Modeling elucidated spatial and temporal trends in PAH concentrations and the toxicity of the samples and identified a subset of PAH analytes that were the most highly correlated with observed toxicity. Although the present study highlights the complexity of discerning specific bioactive compounds in complex mixtures, it demonstrates methods for associating toxic effects with chemical characteristics of environmental samples. Copyright © 2012 SETAC.

  5. A review of bridge scour monitoring techniques

    Directory of Open Access Journals (Sweden)

    L.J. Prendergast

    2014-04-01

    Full Text Available The high profile failure of the Malahide Viaduct in Dublin, Ireland, which is a part of the EU TEN-T network of critical transport links, was caused by foundation scour. Scour is a common soil-structure interaction problem. In light of current changes in climate, increasing frequency of flooding, coupled with the increasing magnitude of these flood events, will lead to a higher risk of bridge failure. Monitoring scour is of paramount importance to ensure the continued safe operation of the aging bridge asset network. Most monitoring regimes are based on expensive underwater instrumentation that can often be subjected to damage during times of flooding, when scour risk is at its highest. This paper presents a critical review of existing scour monitoring equipments and methodologies with a particular focus on those using the dynamic response of the structure to indicate the existence and severity of the scour phenomenon affecting the structure. A sensitivity study on a recently developed monitoring method is also undertaken.

  6. Spacetime-bridge solutions in vacuum gravity

    Science.gov (United States)

    Sengupta, Sandipan

    2017-11-01

    Vacuum spacetime solutions, which are representations of a bridgelike geometry, are constructed as purely geometric sources of curvature in gravity theory. These configurations satisfy the first-order equations of motion everywhere. Each of them consists of two identical sheets of asymptotically flat geometry, connected by a region of finite extension where the tetrad is noninvertible. The solutions can be classified into nonstatic and static spacetimes. The first class represents a single causal universe equipped (locally) with a timelike coordinate everywhere. The latter, on the other hand, could be interpreted as a sum of two self-contained universes which are causally disconnected. These geometries, even though they have different metrical dimensions in the regions within and away from the bridge, are regular. This is reflected through the associated gauge-covariant fields, which are continuous across the hypersurfaces connecting the invertible and noninvertible phases of the tetrad and are finite everywhere. These vacuum bridge solutions have no analogue in the Einsteinian theory of gravity.

  7. Bridging physics and biology teaching through modeling

    Science.gov (United States)

    Hoskinson, Anne-Marie; Couch, Brian A.; Zwickl, Benjamin M.; Hinko, Kathleen A.; Caballero, Marcos D.

    2014-05-01

    As the frontiers of biology become increasingly interdisciplinary, the physics education community has engaged in ongoing efforts to make physics classes more relevant to life science majors. These efforts are complicated by the many apparent differences between these fields, including the types of systems that each studies, the behavior of those systems, the kinds of measurements that each makes, and the role of mathematics in each field. Nonetheless, physics and biology are both sciences that rely on observations and measurements to construct models of the natural world. In this article, we propose that efforts to bridge the teaching of these two disciplines must emphasize shared scientific practices, particularly scientific modeling. We define modeling using language common to both disciplines and highlight how an understanding of the modeling process can help reconcile apparent differences between the teaching of physics and biology. We elaborate on how models can be used for explanatory, predictive, and functional purposes and present common models from each discipline demonstrating key modeling principles. By framing interdisciplinary teaching in the context of modeling, we aim to bridge physics and biology teaching and to equip students with modeling competencies applicable in any scientific discipline.

  8. Bridge Condition Assessment based on Vibration Responses of Passenger Vehicle

    Science.gov (United States)

    Miyamoto, Ayaho; Yabe, Akito

    2011-07-01

    In this paper, we propose a new method of assessing the condition of existing short- and medium-span reinforced/prestressed concrete bridges based on vibration monitoring data obtained from a public bus. This paper not only describes details of a prototype monitoring system that uses information technology and sensors capable of providing more accurate knowledge of bridge performance than conventional ways but also shows a few specific examples of bridge condition assessment based on vehicle vibrations measured by using an in-service public bus equipped with vibration measurement instrumentation. This paper also describes a sensitivity analysis of deteriorating bridges based on simulation of the acceleration response of buses conducted by the "substructure method" employing a finite element model to verify the above bridge performance results. The main conclusions obtained in this study can be summarized as follows: (1) Because the vibration responses of passenger vehicles, such as buses, have a good linear relationship with the vibration responses of the target bridges, the proposed system can be used as a practical monitoring system for bridge condition assessment. (2) The results of sensitivity analysis performed by the substructure method show that bus vibration responses are useful for evaluating target bridge performance. (3) The proposed method was applied to a network of real bridges in a local area to evaluate its effectiveness. The results indicate that the proposed method can be used to prioritize the repair/strengthening works of existing bridges based on various vibration information in order to help bridge administrators establish rational maintenance strategies.

  9. Bridge Condition Assessment based on Vibration Responses of Passenger Vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Ayaho [Graduate School of Science and Engineering, Yamaguchi University, Ube (Japan); Yabe, Akito, E-mail: miya818@yamaguchi-u.ac.jp, E-mail: nagai@kke.co.jp [Seismic Engineering Department, KOZO KEIKAKU Engineering Inc. Tokyo (Japan)

    2011-07-19

    In this paper, we propose a new method of assessing the condition of existing short- and medium-span reinforced/prestressed concrete bridges based on vibration monitoring data obtained from a public bus. This paper not only describes details of a prototype monitoring system that uses information technology and sensors capable of providing more accurate knowledge of bridge performance than conventional ways but also shows a few specific examples of bridge condition assessment based on vehicle vibrations measured by using an in-service public bus equipped with vibration measurement instrumentation. This paper also describes a sensitivity analysis of deteriorating bridges based on simulation of the acceleration response of buses conducted by the 'substructure method' employing a finite element model to verify the above bridge performance results. The main conclusions obtained in this study can be summarized as follows: (1) Because the vibration responses of passenger vehicles, such as buses, have a good linear relationship with the vibration responses of the target bridges, the proposed system can be used as a practical monitoring system for bridge condition assessment. (2) The results of sensitivity analysis performed by the substructure method show that bus vibration responses are useful for evaluating target bridge performance. (3) The proposed method was applied to a network of real bridges in a local area to evaluate its effectiveness. The results indicate that the proposed method can be used to prioritize the repair/strengthening works of existing bridges based on various vibration information in order to help bridge administrators establish rational maintenance strategies.

  10. Finite element modeling approach and performance evaluation of fiber reinforced polymer sandwich bridge panels : final report.

    Science.gov (United States)

    2009-08-01

    In the United States, about 27% of the bridges are classified as structurally deficient or functionally obsolete. : Bridge owners are continually investigating methods to effectively retrofit existing bridges, or to economically replace : them with n...

  11. Laboratory testing and finite element modeling of precast bridge deck panel transverse connections.

    Science.gov (United States)

    2010-08-06

    Precast bridge deck panels are increasingly used to reduce construction times and associated traffic delays as part of many DOTs push for accelerated bridge construction. They allow a bridge deck to be built or replaced in days instead of months. ...

  12. Finite element modeling approach and performance evaluation of fiber reinforced polymer sandwich bridge panels : summary.

    Science.gov (United States)

    2009-08-01

    In the United States, about 27% of the bridges are classified as structurally deficient or functionally obsolete. Bridge owners are continually investigating methods to effectively retrofit existing bridges, or to economically replace them with new o...

  13. Earthquake fragility assessment of curved and skewed bridges in Mountain West region : research brief.

    Science.gov (United States)

    2016-09-01

    the ISSUE : the RESEARCH : Earthquake Fragility : Assessment of Curved : and Skewed Bridges in : Mountain West Region : Reinforced concrete bridges with both skew and curvature are common in areas with complex terrains. : These bridges are irregular ...

  14. Earthquake fragility assessment of curved and skewed bridges in Mountain West region.

    Science.gov (United States)

    2016-09-01

    Reinforced concrete (RC) bridges with both skew and curvature are common in areas with : complex terrains. Skewed and/or curved bridges were found in existing studies to exhibit more : complicated seismic performance than straight bridges, however th...

  15. A sensor network system for the health monitoring of the Parkview bridge deck.

    Science.gov (United States)

    2010-01-31

    Bridges are a critical component of the transportation infrastructure. There are approximately 600,000 bridges in : the United State according to the Federal Highway Administration. Four billion vehicles traverse these bridges daily. : Regular inspec...

  16. Polyurethane foam infill for fiber-reinforced polymer (FRP) bridge deck panels.

    Science.gov (United States)

    2014-05-01

    Although still in their infancy, fiber-reinforced polymer (FRP) bridges have shown great promise in eliminating corrosion : concerns and meeting (or exceeding) FHWAs goal of 100-year life spans for bridges. While FRP bridges are cost-effective in ...

  17. 77 FR 21436 - Safety Zone, East River, Brooklyn Bridge Scaffolding Repair, Brooklyn, NY

    Science.gov (United States)

    2012-04-10

    ... that a crane barge struck the scaffolding under the eastern span of the Brooklyn Bridge. As a result of... bridge, from the centerline of the bridge to the tower on the Brooklyn side. The safety zone will...

  18. Implementation of sustainable and green design and construction practices for bridges.

    Science.gov (United States)

    2012-12-01

    The focus of this research is to develop a framework for more sustainable design and construction : processes for new bridges, and sustainable maintenance practices for existing bridges. The framework : includes a green rating system for bridges. The...

  19. Research on evaluation and standardization of accelerated bridge construction techniques, part II.

    Science.gov (United States)

    2015-09-01

    The Michigan Department of Transportation (MDOT) uses Accelerated bridge construction : (ABC) to reduce delays and minimize construction impacts. MDOT contracted and completed : several bridges using prefabricated bridge elements and systems (PBES). ...

  20. Research on evaluation and standardization of accelerated bridge construction techniques, part I.

    Science.gov (United States)

    2015-09-01

    The Michigan Department of Transportation (MDOT) uses Accelerated bridge construction : (ABC) to reduce delays and minimize construction impacts. MDOT contracted and completed : several bridges using prefabricated bridge elements and systems (PBES). ...

  1. Thermal gradients in Southwestern United States and the effect on bridge bearing loads : final report.

    Science.gov (United States)

    2017-05-01

    Thermal gradients became a component of bridge design after soffit cracking in prestressed concrete bridges was attributed to nonlinear temperature distribution through the depth of the bridge. While the effect of thermal gradient on stress distribut...

  2. Structural identification of a real-world shear-critical prestressed concrete highway bridge.

    Science.gov (United States)

    2012-08-01

    A typical span of the Little River overflow bridge located in McCurtain County, Oklahoma, a shear-critical prestressed concrete bridge identified by the Oklahoma Department of Transportation (ODOT) Bridge Division, is studied using a multidisciplinar...

  3. The Effect of Deck Width Addition Toward Stability of Cable Stayed Bridge: Case Study of Siak Sri Indrapura Bridge, Riau

    Directory of Open Access Journals (Sweden)

    Supriyadi Bambang

    2017-01-01

    Full Text Available An aeroelastic interaction always take places in long-span bridge, i.e. the dynamic relationship between wind forces (aerodynamic and bridge structural motion (dynamics. Wind forces may lead to serviceability and safety problems, and may even cause instability of the whole bridge structure due to the flexibility nature of long span bridge structures.The slimer girder plate will make the structure more unstable as can be seen from the occurrence of lateral deformation. This paper presents the results analysis of cable stayed bridge that has total span of 640 m, two planes configuration of harp-typed hanger cable, the A shape pylons span along 320 m (main span,and side span of 160m. Structural analysis was conducted to determine the optimum ratio between width and spans of cable stayed bridge. The bridge was modeled with various width of 7 to 22 m. Structural modelling was conducted using SAP2000 software to analyze the structural stability of cable stayed bridge under wind load at speed of 35 m/s.The influence of wind loads to the cable stayed bridge stability can be seen based on the bridge deck deformation at the Y-axis (U2, in which for the width of the bridge deck of 7 m, 8 m, 9 m and 10 m, the deformation of U2 are 0.26 m; 0.17 m; 0.12 m and 0.10 m, respectively. Meanwhile, for bridge’s width of 11-22 m, the value of U2 axis deformation is relatively constant between 0.08 m to 0.07 m. This finding suggests that the ratio between width and length of bridge greatly affect the stability of the cable stayed bridge. Cable-stayed bridge, especially for concrete bridge, with two plain system having optimum ratio of width and length show no sign of an aerodynamic instability when fulfills the requirements of B ≥ L / 3.

  4. Experimental Investigation of Aerodynamic Instability of Iced Bridge Cable Sections

    DEFF Research Database (Denmark)

    Koss, Holger; Lund, Mia Schou Møller

    2013-01-01

    of bridge cables under wind action. This paper describes the experimental simulation of ice accretion on a real bridge cable sheet HDPE tube segment (diameter 160mm) and its effect on the aerodynamic load. Furthermore, aerodynamic instability will be estimated with quasi-steady theory using the determined...

  5. Modal analysis of cable-stayed UHPC bridge

    Directory of Open Access Journals (Sweden)

    Tej Petr

    2017-01-01

    Full Text Available This paper deals with the dynamic analysis of cable-stayed UHPC bridge over the Vltava river near town Melnik in Czech Republic, Europe. Bridge serves for pedestrians and cyclists. This work aims to familiarize the reader with dynamic calculations carried out and the results obtained, describing the dynamic properties of proposed bridge. The construction of bridge is designed as a cable-stayed structure with prestressed bridge deck consisting of prefabricated UHPC panels and reversed “V” shaped steel pylon with height of approximately 40 meters. The deck is anchored using 24 steel hangers in one row in a steel pylon - 17 ropes in the main span and 7 cables on the other side. Range of the main span is 99.18 meters and the secondary span is 31.9 m. Deck width is 4.5 meters with 3.0 meters passing space. The bridge is designed for the possibility of passage of vehicles weighting up to 3.5 tonnes. Deck panels are made of UHPC with reinforcement. At the edge of the bridge on the side of the shorter span the bridge deck is firmly connected with abutment and on the other deck it is stored using a pair of sliding bearings.

  6. ArtsBridge America: Bringing the Arts Back to School

    Science.gov (United States)

    Brouillette, Liane R.; Burns, Maureen A.

    2005-01-01

    This article examines the origin of ArtsBridge America, a K-12 school/university arts education partnership. It also summarizes findings from a research study on the effect that ArtsBridge participation had on a sample of university arts students. The study indicated that the transition from student to teaching artist required transformation of…

  7. Properties of Sn-Ag proximity effect bridges

    Energy Technology Data Exchange (ETDEWEB)

    Fan Hongchang; Yu Zheng

    1983-09-01

    We have measured the I-V characteristics, I/sub c/(t) and T/sub c/ of Sn-Ag proximity effect bridges, obtaining some interesting results. We have also analyzed and tried to explain the results in terms of phenomenological theories, believing that microbridge theories of Skocpol, Beasley and Tinkham (SBT) also apply to our proximity effect bridges.

  8. Integral abutment bridge for Louisiana's soft and stiff soils.

    Science.gov (United States)

    2016-03-01

    Integral abutment bridges (IABs) have been designed and constructed in a few US states in the past few : decades. The initial purpose of building such bridges was to eliminate the expansion joints and resolve the : joint-induced problems. Although IA...

  9. Societal aspects of bridge management and safety in the Netherlands

    NARCIS (Netherlands)

    Klatter, H.E.; Vrouwenvelder, A.C.W.M.; Noortwijk, J.M. van

    2006-01-01

    The main reason for the existence of civil infrastructures is public interest. Therefore, various societal aspects should drive an infrastructure program. Civil infrastructures are long-lived as-sets. Bridges and other structures are designed for lifetimes of 50 to 100 years. A bridge can last much

  10. Probabilistic FE analysis of a cable stayed composite bridge

    NARCIS (Netherlands)

    Boer, A. de; Waarts, P.H.

    1999-01-01

    This paper describes the design of a new cable stayed composite bridge near Kampen in the Netherlands. In the design process, the safety of bridges is insured by means of partial safety factors for both strength and load parameters. As a result it is generally accepted that the structure as a whole

  11. On Reliability Based Optimal Design of Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In recent years important progress has been made in assessment of the lifetime behaviour of concrete bridges. Due to the large uncertainties related to the loading and the deterioration of such bridges, an assessment based on stochastic modelling of the significant parameters seems to be only rel...

  12. User manual for veteran's glass city skyway bridge monitoring system.

    Science.gov (United States)

    2017-02-01

    Douglas Nims 0000-0001-7663-397X : Victor Hunt 0000-0002-1590-3291 : Arthur Helmicki 0000-0002-7759-5482 : The Veterans Glass City Skyway Bridge is a large cable stayed bridge in Toledo, Ohio owned and : operated by the Ohio Department of Transpor...

  13. Linking bonding and bridging ownership social capital in private firms

    NARCIS (Netherlands)

    Ilse A. Matser; Roberto H. Flören; Lorraine M. Uhlaner; Marta M. Berent-Braun

    2015-01-01

    This study examines the relationship between bonding and bridging ownership social capital (OSC) for a random sample of 679 privately held small and medium-sized firms. Results confirm the positive effects of bonding OSC (quality of relationships and shared vision) on bridging OSC (network

  14. Comparative durability of timber bridges in the USA

    Science.gov (United States)

    James P. Wacker; Brian K. Brashaw

    2017-01-01

    As engineers begin to utilize life-cycle-cost design approaches for timber bridges, there is a necessity for more reliable data about their durability and expected service life. This paper summarizes a comprehensive effort to assess the current condition of more than one hundred timber highway bridge superstructures throughout the United States. This national study was...

  15. Structural Task Analysis--The Bridge Between Selection and Training.

    Science.gov (United States)

    Dees, James W.

    A procedure for using Guilford's structure of the intellect as the theoretical basis for a task analysis model is presented. It is reasoned that such a model would furnish a bridge between task analysis and test selection, and also a bridge between test selection and test validation. Such a mechanism might answer some fo the EEOC criticisms of…

  16. Fragility curves for bridges under differential support motions

    DEFF Research Database (Denmark)

    Konakli, Katerina

    2012-01-01

    This paper employs the notion of fragility to investigate the seismic vulnerability of bridges subjected to spatially varying support motions. Fragility curves are developed for four highway bridges in California with vastly different structural characteristics. The input in this analysis consists...

  17. Study of behavior of hanging bridges type Pony

    Directory of Open Access Journals (Sweden)

    Caori Patricia Takeuchi Tam

    2004-01-01

    Full Text Available In the country there is a great quantity of hanging bridges type pony. This article presents the methodology and the results obtained in a study of the behavior of this type of bridges for the construction and the service loads. Besides, the behavior of the lateral stability of these models.

  18. Developing green bridge rating system using Simos’ procedure

    Directory of Open Access Journals (Sweden)

    Mohamed Marzouk

    2014-08-01

    Full Text Available Sustainable development principles have been implemented in various sectors including construction. Proper development and operation of infrastructure projects, such as bridges and highways, can contribute significantly to the mission of sustainable development. In this respect, there is little existing work on appropriate methods to assess the sustainability performance of bridge projects. This paper introduces a key-list of gathered important criteria that affect the sustainability of bridge projects. Various construction industry standards have been reviewed in order to decide the criteria that influence sustainability of bridge projects. The initial list of criteria has been identified by unstructured interviews. Then, structured interviews and questionnaire survey have been conducted to identify the final list that is deemed important in rating green bridges. Various construction industry standards have been reviewed to decide on the criteria that influence sustainability of bridge projects. Final criteria results from this paper are used to develop a green bridge rating system to achieve sustainable development. Degree of importance and weights of these criteria are determined using Simos’ procedure. Five classes of bridges are proposed to judge their status with respect to sustainability, with these being Non-Green, Certified, Green, total Green, and Evergreen.

  19. structural reliability of the nigerian grown abura timber bridge beam

    African Journals Online (AJOL)

    ENGR. J. I. AGUWA

    2013-07-02

    Jul 2, 2013 ... developed and used for reliability analysis of the Nigerian grown Abura timber bridge beam so designed, to ascertain its ... for timber bridge beams at depth of 400mm, breadth of 150mm and span of 5000mm under the ultimate limit state ..... of a Glue-Jointed Roof Truss" J.Eng.& Appl Sci,. Vol 17, Number 1, ...

  20. Assessment of the Reliability of Concrete Slab Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Jensen, F. M.; Middleton, C. R.

    This paper is based on research performed for the Highways Agency, London, UK under the project DPU/9/44 "Revision of Bridge Assessment Rules Based on Whole Life Performance: Concrete Bridges". It contains details of a methodology which can be used to generate Whole Life (WL) reliability profiles....