WorldWideScience

Sample records for bridge design

  1. 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…

  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. 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.

  4. 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 ...

  5. 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 ...

  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. 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...

  8. 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,...

  9. 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...

  10. 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...

  11. 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...

  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. 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 ...

  14. 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

  15. 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...

  16. 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...

  17. 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...

  18. Field demonstration of new bridge approach slab designs and performance.

    Science.gov (United States)

    2014-06-01

    The Louisiana Department of Transportation and Development (DOTD) has initiated a major effort to minimize the bridge end bump problem associated : with differential settlement. As a result, a new design for the approach slab was proposed, which requ...

  19. Optimum design of concrete cable-stayed bridges

    Science.gov (United States)

    Martins, Alberto M. B.; Simões, Luís M. C.; Negrão, João H. J. O.

    2016-05-01

    The design of cable-stayed bridges involves a significant number of design variables and design objectives. The concrete cable-stayed bridge optimization is formulated here as a multi-objective optimization problem with objectives of minimum cost, minimum deflections and minimum stresses. A numerical method is developed to obtain the optimum design of such structures. This numerical method includes: structural analysis, sensitivity analysis and optimization. The structural analysis accounts for all the relevant effects (concrete time-dependent effects, construction stages and geometrical nonlinear effects). The structural response to changes in the design variables is achieved by a discrete direct sensitivity analysis procedure, and an entropy-based approach was used for structural optimization. The features and applicability of the proposed method are demonstrated by numerical examples concerning the optimization of a real-sized concrete cable-stayed bridge.

  20. Wind Resistant Design of Bridges in Japan Developments and Practices

    CERN Document Server

    Fujino, Yozo; Tanaka, Hiroshi

    2012-01-01

    For long-span bridges, wind action is a dominant factor in their safety and serviceability. A large number of long-span bridges have been built in Japan over the past 30 years, and tremendous amounts of research and technical development have been accomplished in wind resistant design. This book is a compilation of the results of active research and development. Wind resistant design standards generated in Japan are described in the first few chapters. Then comes information such as design wind speed, structural damping, wind tunnel tests, and analyses, which provide the basis of the design standards. Wind-induced vibrations and their control of girders, towers, cables, and other features are explained with examples of field measurements. Comprehensive listings of Japanese experience in vibration control are also presented. Because achieving particularly dynamic safety against wind is still not an easy task, these data and information will be valuable assets for the wind-engineering and bridge-engineering com...

  1. Bridging CALL & HCI: Input from Participatory Design

    Science.gov (United States)

    Cardenas-Claros, Monica S.; Gruba, Paul A.

    2010-01-01

    Participatory design (PD), or the collaboration between software engineers and end users throughout the design process, may help improve CALL design practices. In this case study, four ESL learners, a software designer, and a language teacher created and evaluated a series of paper prototypes concerning help options in computer-based second…

  2. 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...

  3. Research on Multidisciplinary Optimization Design of Bridge Crane

    Directory of Open Access Journals (Sweden)

    Tong Yifei

    2013-01-01

    Full Text Available Bridge crane is one of the most widely used cranes in our country, which is indispensable equipment for material conveying in the modern production. In this paper, the framework of multidisciplinary optimization for bridge crane is proposed. The presented research on crane multidisciplinary design technology for energy saving includes three levels, respectively: metal structures level, transmission design level, and electrical system design level. The shape optimal mathematical model of the crane is established for shape optimization design of metal structure level as well as size optimal mathematical model and topology optimal mathematical model of crane for topology optimization design of metal structure level is established. Finally, system-level multidisciplinary energy-saving optimization design of bridge crane is further carried out with energy-saving transmission design results feedback to energy-saving optimization design of metal structure. The optimization results show that structural optimization design can reduce total mass of crane greatly by using the finite element analysis and multidisciplinary optimization technology premised on the design requirements of cranes such as stiffness and strength; thus, energy-saving design can be achieved.

  4. Inclusive design: Bridging theory and practice

    NARCIS (Netherlands)

    Cremers, A.H.M.; Neerincx, M.A.; Jong, J.G.M. de

    2013-01-01

    Large groups in society lack the necessary skills to be sufficiently self-reliant and are in need of personal assistance. These groups could be supported by information and information technology (ICT), but only if this technology is designed to fit their (cognitive) abilities. Inclusive design

  5. Inclusive design: bridging theory and practice

    NARCIS (Netherlands)

    Mark Neerincx; Dr. Anita Cremers; Jacomien de Jong

    2013-01-01

    Large groups in society lack the necessary skills to be sufficiently self-reliant and are in need of personal assistance. These groups could be supported by information and information technology (ICT), but only if this technology is designed to fit their (cognitive) abilities. Inclusive design

  6. Design, analysis, and seismic performance of a hypothetical seismically isolated bridge on legacy highway.

    Science.gov (United States)

    2011-01-01

    The need to maintain the functionality of critical transportation lifelines after a large seismic event motivates the : strategy to design certain bridges for performance standards beyond the minimum required by bridge design codes. : To design a bri...

  7. Environmental comparison of a railway bridge with alternative designs

    DEFF Research Database (Denmark)

    Du, Guangli; Karoumi, Raid

    2012-01-01

    for quantifying and assessing the environmental impacts of the products through its whole life cycle. This paper presents a comparative case study between two alternative designs of Banafjäl Bridge: ballast track design and fixed slab track design. The methodology of LCA is utilized as a supporting tool....... The assessment considers the key environmental category of global warming potential from 'cradle to gate', which covers the material production and distribution process. The result shows that the fixed-slab design indicates a better environmental performance than the ballast track design....

  8. A bridge for accelerating materials by design

    Science.gov (United States)

    Sumpter, Bobby G.; Vasudevan, Rama K.; Potok, Thomas; Kalinin, Sergei V.

    2015-11-01

    Recent technical advances in the area of nanoscale imaging, spectroscopy and scattering/diffraction have led to unprecedented capabilities for investigating materials structural, dynamical and functional characteristics. In addition, recent advances in computational algorithms and computer capacities that are orders of magnitude larger/faster have enabled large-scale simulations of materials properties starting with nothing but the identity of the atomic species and the basic principles of quantum and statistical mechanics and thermodynamics. Along with these advances, an explosion of high-resolution data has emerged. This confluence of capabilities and rise of big data offer grand opportunities for advancing materials sciences but also introduce several challenges. In this perspective, we identify challenges impeding progress towards advancing materials by design (e.g., the design/discovery of materials with improved properties/performance), possible solutions and provide examples of scientific issues that can be addressed using a tightly integrated approach where theory and experiments are linked through big-deep data.

  9. Parametric test for the preliminary design of suspension bridges

    Science.gov (United States)

    Arruda, M. R. T.; Serafim, J. P. M.

    2017-06-01

    The preliminary design of suspension bridges is a very important step in the design of a structure, since this stage is the one that will lead to an efficient and economic structure. The models that are used nowadays are complex and sometimes hard to apply, leading to a lack of comprehension from the designing team. This work proposes a new simplified method for the preliminary design of cable suspension bridges that relate the stiffness of the deck truss with the stiffness of the cable, in which stresses are calculated. This relation is intended to know how much of the live load is absorbed by each of these elements and finally obtaining the pre-design values of each substructure. First simple parametric tests are executed using the proposed method and finite element method with geometrical non-linear analysis, in order to study its accuracy. Finally, a real case study is analysed using a known Portuguese suspension bridge, in which the proposed method is applied and compared with numerical solutions.

  10. Influence of the new LRFD seismic guidelines on the design of bridges in Virginia.

    Science.gov (United States)

    2004-01-01

    The Virginia Department of Transportation is currently using the AASHTO Standard Specifications for Highway Bridges, with some modifications, for its seismic highway bridge design. In April 2001, the Recommended LRFD Guidelines for the Seismic Design...

  11. Design criteria for portable timber bridge systems : static versus dynamic loads

    Science.gov (United States)

    John M. Franklin; S. E. Taylor; Paul A. Morgan; M. A. Ritter

    1999-01-01

    Design criteria are needed specifically for portable bridges to insure that they are safe and cost effective. This paper discusses different portable bridge categories and their general design criteria. Specific emphasis is given to quantifying the effects of dynamic live loads on portable bridge design. Results from static and dynamic load tests of two portable timber...

  12. 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

  13. 23 CFR 661.53 - What standards should be used for bridge design?

    Science.gov (United States)

    2010-04-01

    ... TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.53 What standards should be used for bridge design? (a) Replacement—A replacement structure must meet the current geometric, construction and... 23 Highways 1 2010-04-01 2010-04-01 false What standards should be used for bridge design? 661.53...

  14. Design and erection of the MUSEUM BRIDGE; Bijutsu no sekai eno yume no kakehashi. MUSEUM BRIDGE no sekkei seko

    Energy Technology Data Exchange (ETDEWEB)

    Ishihara, S.; Tsunekawa, M.; Umda, A.; Kishimoto, Y.; Yotsukura, Y.; Miitsu, K.; Okada, S.; Furukawa, M. [Kawasaki Heavy Industries, Ltd., Kobe (Japan)

    1998-12-20

    MUSEUM Projects for the religious corporation of Shinji-Shumeikai, at Shigaraki, Shiga prefecture. Fundamental design was by a project team led by the world-famous architect I.M. Pei. The museum is located in a prefectural park surrounded by forests. The design concept of the bridge aimed to connect Shangri-La (museum) to the real world. In order to satisfy this purpose, a cable-stayed bridge with external tendon was adopted as an original structure style, and details such as handrails, gratings, and gloss painting taken into consideration. The authors report the characteristics of the bridge and the sequence of erection. (author)

  15. Non-Flutter Design Principle for long Span Bridges

    DEFF Research Database (Denmark)

    Johansson, Jens; Andersen, Michael Styrk; Starch Øvre, Michele

    The case of flutter on a sharp edged flat plate section model, with a height-to-width ratio of 1:10, has been investigated at four different torsional-to-vertical frequency ratios equal to 0.71, 0.88, 1.19 and 2.10. At a torsional-to-vertical frequency ratio of approximately 1.1 the flutter wind...... velocity for a thin airfoil shows an asymptotical behavior. In traditional bridge design the torsional-to-vertical frequency ratio is increased to obtain higher flutter wind velocities. In the present study, we investigate, what we will label the non-flutter design principle, in which the torsional...... instability. The results are a first indication the non-flutter design principle could be applicable in future design of slender structures....

  16. Design and construction of the Natorigawa Bridge; Natorigawa kyoryo no sekkei/seko

    Energy Technology Data Exchange (ETDEWEB)

    Murai, Y.; Oba, M.; Omurata, Y. [JR East Japan Railway Co., Tokyo (Japan); Miyauchi, M.; Iwasaki, I. [Taisei Corp., Tokyo (Japan)

    1997-03-31

    The Natorigawa Bridge is reconstructed. Out of the reconstruction work, a report is made mainly on the design of the superstructure work of the PC panel-stayed bridge and the details of the work. In selecting bridge type, PC simple through beam bridge, steel trussed bridge, PC cable-stayed bridge, and PC panel-stayed bridge are compared, and a 2-span continuous PC panel-stayed bridge is adopted. Its appearance resembles that of the cable-stayed bridge, but the structure resembles a girder bridge. The appropriate span length is the intermediate range between those of the girder bridge and the cable-stayed bridge. Its trafficability is excellent with little deformation by the running of trains because the main beam, diagonal panel, and the main tower are connected rigidly to provide high rigidity of the entire bridge. PRC structure is employed in consideration of the restriction to beam height and economical efficiency. Analyses by a FEM model using two dimensional plane elements and by a few plane frame models as well as comparison of sectional force are performed for this bridge, and a proper plane model is selected. Substructure work, superstructure work and measurement work are described. 3 refs., 16 figs., 6 tabs.

  17. 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...

  18. Bridging the gap between building science and design studios

    Energy Technology Data Exchange (ETDEWEB)

    Papamichael, Konstantinos; Pal, Vineeta

    2002-02-06

    Design studios and building science courses have been conducted independent of each other, mainly due to a lack of tools that allow quick and easy consideration of building science criteria, such as comfort and energy requirements, during the design process. Existing tools are not user-friendly and their use requires significant effort in gaining familiarity with the input requirements, understanding the modeling assumptions and interpreting the output. This paper is about the Building Design Advisor (BDA), an evolving computer-based tool intended to bridge the gap between design studios and building science considerations by addressing the above-mentioned limitations of existing tools. BDA allows automatic preparation of input files to multiple simulation tools while the user is working in a CAD environment. BDA automatically activates the relevant simulation tools when the user selects performance parameters to be computed and provides the results in a graphical form, allowing comparison of multiple design options with respect to multiple performance criteria. The paper includes considerations for the use of the BDA in the design studio and ends with a description of the current development efforts and future plans.

  19. Comparative analysis of design codes for timber bridges in Canada, the United States, and Europe

    Science.gov (United States)

    James Wacker; James (Scott) Groenier

    2010-01-01

    The United States recently completed its transition from the allowable stress design code to the load and resistance factor design (LRFD) reliability-based code for the design of most highway bridges. For an international perspective on the LRFD-based bridge codes, a comparative analysis is presented: a study addressed national codes of the United States, Canada, and...

  20. Computational Design Tool for Bridge Hydrodynamic Loading in Inundated Flows of Midwest Rivers

    Science.gov (United States)

    2009-12-01

    The hydraulic forces experienced by an inundated bridge deck have great importance in the design of bridges. The proper estimation of loading exerted by the flow on the structure is important for design plans and is pertinent for evaluating its vulne...

  1. 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...

  2. Bridging from Goals to Tasks with Design Study Analysis Reports.

    Science.gov (United States)

    Lam, Heidi; Tory, Melanie; Munzner, Tamara

    2018-01-01

    Visualization researchers and practitioners engaged in generating or evaluating designs are faced with the difficult problem of transforming the questions asked and actions taken by target users from domain-specific language and context into more abstract forms. Existing abstract task classifications aim to provide support for this endeavour by providing a carefully delineated suite of actions. Our experience is that this bottom-up approach is part of the challenge: low-level actions are difficult to interpret without a higher-level context of analysis goals and the analysis process. To bridge this gap, we propose a framework based on analysis reports derived from open-coding 20 design study papers published at IEEE InfoVis 2009-2015, to build on the previous work of abstractions that collectively encompass a broad variety of domains. The framework is organized in two axes illustrated by nine analysis goals. It helps situate the analysis goals by placing each goal under axes of specificity (Explore, Describe, Explain, Confirm) and number of data populations (Single, Multiple). The single-population types are Discover Observation, Describe Observation, Identify Main Cause, and Collect Evidence. The multiple-population types are Compare Entities, Explain Differences, and Evaluate Hypothesis. Each analysis goal is scoped by an input and an output and is characterized by analysis steps reported in the design study papers. We provide examples of how we and others have used the framework in a top-down approach to abstracting domain problems: visualization designers or researchers first identify the analysis goals of each unit of analysis in an analysis stream, and then encode the individual steps using existing task classifications with the context of the goal, the level of specificity, and the number of populations involved in the analysis.

  3. Design of wireless synchronous structural monitoring system for large bridges

    Science.gov (United States)

    Liu, Zhiqiang; Liu, Wei; Li, Na; Yu, Yan; Mao, Xingquan; Yang, Zhitao

    2017-04-01

    Large bridges play a significant role in the development of both the urban traffic condition and the social economy. It is of high importance to monitor the operational bridges and to assess their security from the perspective of people's life and property safety. In this paper, a wireless bridge structure monitoring system was developed and DMTS synchronization algorithm (based on the one-way synchronization mechanism of the sender) which can meet the system requirement was proposed. Then the deck vibration test of a bridge in Xiamen was carried out. The study shows that the wireless sensing system has the advantage of high accuracy, and the feature of easy operation, good instantaneity, and low overhead costs, which has a good application prospect in the field of structure monitoring and condition assessment of the bridges.

  4. Next generation seismic fragility curves for California bridges incorporating the evolution in seismic design philosophy

    Science.gov (United States)

    Ramanathan, Karthik Narayan

    Quantitative and qualitative assessment of the seismic risk to highway bridges is crucial in pre-earthquake planning, and post-earthquake response of transportation systems. Such assessments provide valuable knowledge about a number of principal effects of earthquakes such as traffic disruption of the overall highway system, impact on the regions’ economy and post-earthquake response and recovery, and more recently serve as measures to quantify resilience. Unlike previous work, this study captures unique bridge design attributes specific to California bridge classes along with their evolution over three significant design eras, separated by the historic 1971 San Fernando and 1989 Loma Prieta earthquakes (these events affected changes in bridge seismic design philosophy). This research developed next-generation fragility curves for four multispan concrete bridge classes by synthesizing new knowledge and emerging modeling capabilities, and by closely coordinating new and ongoing national research initiatives with expertise from bridge designers. A multi-phase framework was developed for generating fragility curves, which provides decision makers with essential tools for emergency response, design, planning, policy support, and maximizing investments in bridge retrofit. This framework encompasses generational changes in bridge design and construction details. Parameterized high-fidelity three-dimensional nonlinear analytical models are developed for the portfolios of bridge classes within different design eras. These models incorporate a wide range of geometric and material uncertainties, and their responses are characterized under seismic loadings. Fragility curves were then developed considering the vulnerability of multiple components and thereby help to quantify the performance of highway bridge networks and to study the impact of seismic design principles on the performance within a bridge class. This not only leads to the development of fragility relations

  5. Frozen soil lateral resistance for the seismic design of highway bridge foundations : [summary].

    Science.gov (United States)

    2012-12-01

    With recent seismic activity and earthquakes in Alaska and throughout the Pacific Rim, seismic design is becoming an increasingly important public safety concern for : highway bridge designers. Hoping to generate knowledge that can improve the seismi...

  6. Continuous prestressed concrete girder bridges volume 1 : literature review and preliminary designs.

    Science.gov (United States)

    2012-06-01

    The Texas Department of Transportation (TxDOT) is currently designing typical highway bridge structures as simply supported using standard precast, pretensioned girders. TxDOT is interested in developing additional economical design alternatives for ...

  7. Using BIM to Improve the Design and Construction of Bridge Projects: A Case Study of a Long-span Steel-box Arch Bridge Project

    OpenAIRE

    Wenping Liu; Hongling Guo; Heng Li; Yan Li

    2014-01-01

    More and more mega-complex bridge projects are being or will be built worldwide. At the same time, the design and construction of such projects involve more and more challenges, e.g., complex structural designs, complicated construction environments, etc. This research study aims to apply BIM (Building Information Modelling) to bridge projects to improve the efficiency and effectiveness of design and construction. Through the analysis of the characteristics of bridge projects and relevant, as...

  8. Steel-soil composite bridge:an alternative design solution for short-span bridges towards sustainability

    OpenAIRE

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2017-01-01

    The construction sector is a major source of greenhouse gases. Under the increasingconcern in climate change and growing construction activities, the whole sector is challengedto shift focus toward sustainable solutions. The traditional procurement oftenprioritizes the technical and economic 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 ...

  9. Recent design methods for prestressed concrete cable stayed bridge; PC shachokyo no sekkei gijutsu no genjo

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, K. [Kajima Corp., Tokyo (Japan)

    1995-02-01

    The number of constructed prestressed concrete cable stayed bridges reached nearly 100 in Japan, and the technique has greatly developed. In this article, the current status of design techniques for prestressed concrete cable stayed bridges were introduced along with the examples of constructed bridges for the analysis method and the design method for each structure part while introducing the current examples of constructed bridges. Also, this kind of extra-dosed prestressed concrete bridge and prestressed concrete bridge with prestressed concrete stays were reported. Standards have been prepared including a chapter for the prestressed concrete cable stayed bridges in the Road Bridge Guideline document in February 1990. Load to be noticed as the characteristics peculiar to the prestressed concrete cable stayed bridges includes the shock due to live load, temperature change, and execution error of a tower. For example, 1/1000 of the total tower height is generally considered as the execution error of the tower. A diagonal member is manufactured at factories and in fields and has both advantages and disadvantages. The linear analysis of plane framework is general. Damping of and earthquakeproof designs against the wind and earthquake of the diagonal member were also provided. 11 refs., 17 figs., 2 tabs.

  10. Engineering design processes in seventh-grade classrooms: bridging the engineering education gap

    Science.gov (United States)

    English, Lyn D.; Hudson, Peter B.; Dawes, Les

    2012-10-01

    This paper reports on some findings from the first year of a three-year longitudinal study, in which seventh- to ninth-graders were introduced to engineering education. Specifically, the paper addresses students' responses to an initial design activity involving bridge construction, which was implemented at the end of seventh grade. This paper also addresses how students created their bridge designs and applied these in their bridge constructions; their reflections on their designs; their reflections on why the bridge failed to support increased weights during the testing process; and their suggestions on ways in which they would improve their bridge designs. The present findings include identification of six, increasingly sophisticated levels of illustrated bridge designs, with designs improving between the classroom and homework activities of two focus groups of students. Students' responses to the classroom activity revealed a number of iterative design processes, where the problem goals, including constraints, served as monitoring factors for students' generation of ideas, design thinking and construction of an effective bridge.

  11. Design, installation, and condition assessment of a concrete bridge deck constructed with ASTM A1035 CS no. 4 bars.

    Science.gov (United States)

    2017-06-01

    Recently developed corrosion-resistant reinforcing structural design guidelines were used to design, construct, and : assess a reinforced concrete bridge deck with high-strength ASTM A1035 CS steel bars. The bridge replacement is located : along the ...

  12. Maintenance and design of steel abutment piles in Iowa bridges.

    Science.gov (United States)

    2014-09-01

    Soil consolidation and erosion caused by roadway runoff have exposed the upper portions of steel piles at the abutments of : numerous bridges, leaving them susceptible to accelerated corrosion rates due to the abundance of moisture, oxygen, and : chl...

  13. New bridge design promises to lengthen service life : research spotlight.

    Science.gov (United States)

    2015-03-01

    In Michigans winter climate, the steel reinforcements in traditional boxbeam : bridges are susceptible to concrete cracking, deterioration and : corrosion. They are also difficult to inspect. To address these problems, : MDOT has partnered with Io...

  14. Soil Influence in Seismic Design of Bridges in Cuba

    OpenAIRE

    Dario Candebat Sánchez; Guillermo Godínez Melgares; Luis Felipe Caballero Cornier; Zulima Caridad Rivera Álvarez

    2017-01-01

    Soil geological conditions affect directly the seismic structural behavior of bridges. This work shows the importance of determining the site coefficient, a parameter used by Cuban seismic code for considering the influence of soil in the structural response. The research is based in the results obtained from the application of geophysical seismic refraction method. It is presented as an example a bridge located on Granma highway in Santiago de Cuba city, showing variations in lithology prese...

  15. Bridge Failure Due to Inadequate Design of Bed Protection

    Science.gov (United States)

    Gupta, Yogita; Kaur, Suneet; Dindorkar, Nitin

    2017-12-01

    The shallow foundation is generally provided on non-erodible strata or where scour depth is less. It is also preferable for low perennial flow or standing water condition. In the present case study shallow foundation is adopted for box type bridge. The total length of the bridge is 132.98 m, consisting of eight unit of RCC box. Each unit is composed of three cell box. The bottom slab of box unit is acted as raft foundation, founded 500 mm below ground level. River bed protection work is provided on both upstream and downstream side along the whole length of the bridge as it is founded above scour level. The bridge collapsed during the monsoon just after two years of service. The present paper explains the cause of failure. This study on failure of the bridge illustrates the importance of bridge inspection before and after monsoon period and importance of the timely maintenance. Standard specifications of Indian Road Congress for the river bed protection work are also included.

  16. Salt-bridge networks within globular and disordered proteins: characterizing trends for designable interactions.

    Science.gov (United States)

    Basu, Sankar; Mukharjee, Debasish

    2017-07-01

    There has been considerable debate about the contribution of salt bridges to the stabilization of protein folds, in spite of their participation in crucial protein functions. Salt bridges appear to contribute to the activity-stability trade-off within proteins by bringing high-entropy charged amino acids into close contacts during the course of their functions. The current study analyzes the modes of association of salt bridges (in terms of networks) within globular proteins and at protein-protein interfaces. While the most common and trivial type of salt bridge is the isolated salt bridge, bifurcated salt bridge appears to be a distinct salt-bridge motif having a special topology and geometry. Bifurcated salt bridges are found ubiquitously in proteins and interprotein complexes. Interesting and attractive examples presenting different modes of interaction are highlighted. Bifurcated salt bridges appear to function as molecular clips that are used to stitch together large surface contours at interacting protein interfaces. The present work also emphasizes the key role of salt-bridge-mediated interactions in the partial folding of proteins containing long stretches of disordered regions. Salt-bridge-mediated interactions seem to be pivotal to the promotion of "disorder-to-order" transitions in small disordered protein fragments and their stabilization upon binding. The results obtained in this work should help to guide efforts to elucidate the modus operandi of these partially disordered proteins, and to conceptualize how these proteins manage to maintain the required amount of disorder even in their bound forms. This work could also potentially facilitate explorations of geometrically specific designable salt bridges through the characterization of composite salt-bridge networks. Graphical abstract ᅟ.

  17. Bridging nanometer design-to-manufacturing gap: automated design rules correction and silicon verification

    Science.gov (United States)

    Karklin, Linard N.; Oren, Micha; Dudau, Dragos; Jordan, James D.

    2003-08-01

    Following Moore's Law semiconductor industry is going through a challenging transition from 180 nm to 130 nm manufacturing process geometries and rapidly approaching 90 nm geometries. The major challenges associated with the transition to nanometer design include: (1) Increasing design sizes and complexity (e.g. 300-400M transistors for FPGAs); (2) Increasing number of design rules (approaching 2000 for advanced 90 nm processes); (3) Increasing design cycle (4-9 months for ASICs); (4) Increasing design cost (advanced design flow cost $15M+). With the size and complexity of today's advanced ASICs and SoCs, the ability of designers to efficiently fix DRC errors is becoming a critical challenge impacting productivity and time-to-market. Designers need new EDA tools to process designs of very high complexity in shorter time. New tools should bridge design and process worlds by transparently providing designers with more detailed process (lithography) information. In this paper the authors will describe a method for manufacturing verification of automated design rule fixes. Many types of design rule violation are detected, automatically fixed, and verified by lithography simulation.

  18. Development of guidelines for incorporation of vertical ground motion effects in seismic design of highway bridges.

    Science.gov (United States)

    2008-05-01

    This study was undertaken with the objective of assessing the current provisions in SDC-2006 for incorporating : vertical effects of ground motions in seismic evaluation and design of ordinary highway bridges. A : comprehensive series of simulations ...

  19. Design and evaluation of a single-span bridge using ultra-high performance concrete.

    Science.gov (United States)

    2009-09-01

    "Research presented herein describes an application of a newly developed material called Ultra-High Performance Concrete (UHPC) to a : single-span bridge. The two primary objectives of this research were to develop a shear design procedure for possib...

  20. Design and construction guidelines for strengthening bridges using fiber reinforced polymers (FRP).

    Science.gov (United States)

    2014-09-01

    This research concerns the development of guidelines : for the design and use of externally-bonded FRP : strengthening systems on bridges in Michigan. Si : x representative international FRP-related guidelines : were analyzed and compared for applica...

  1. Field demonstration of new bridge approach slab designs and performance : [tech summary].

    Science.gov (United States)

    2014-06-01

    The Louisiana Department of Transportation and Development (DOTD) has launched a major e ort to solve : the bridge bump problem by changing the design of approach slabs where di erential settlement is expected. : The objective is to nd a fe...

  2. Design and evaluation of a single-span bridge using ultra-high performance concrete.

    Science.gov (United States)

    2009-09-01

    Research presented herein describes an application of a newly developed material called Ultra-High Performance Concrete (UHPC) to a : single-span bridge. The two primary objectives of this research were to develop a shear design procedure for possibl...

  3. Design procedure for Bridge Foundations Subject to Liquefaction-Induced Lateral Spreading

    Science.gov (United States)

    2017-04-01

    The response of piled bridge foundations to liquefaction-induced lateral soil deformation is an important design consideration in seismically active regions. Recent research and case history data suggest that three-dimensional deformation of the appr...

  4. Design of the New Arch Bridge at Mioveni

    Directory of Open Access Journals (Sweden)

    Alexandru Dima

    2014-07-01

    Full Text Available Road bridges with steel arches are used efficiently for medium and large spans. These solutions show advantages determined by the arches geometry, by the number and distributions of hangers and by the form and type of the arches bracing system.

  5. Designing for Anxiety Therapy, Bridging Clinical and Non-Clinical

    DEFF Research Database (Denmark)

    Bertelsen, Olav Wedege; Kramp, Gunnar

    2012-01-01

    In this position paper we discuss, in terms of the concept of boundary objects, how a mobile application, the MIKAT.app, bridge between clinical intervention in anxiety therapy, and life and coping strategies outside the clinic and across phases of being a person suffering from, or having suffered...

  6. Design principles of surfacings on orthotropic steel bridge decks

    NARCIS (Netherlands)

    Medani, T.O.

    2006-01-01

    This dissertation describes the research into surfacings of orthotropic steel bridge decks. The motive for this research is the frequently reported problems of this type of structures including cracking and rutting of surfacing materials and fatigue related cracks in the steel plate. An intensive

  7. Design and implementation of the ESL compact range underhung bridge crane

    Science.gov (United States)

    Shamansky, H. T.; Dominek, A. K.; Burnside, W. D.

    1987-01-01

    As the indoor compact range technology has continued to increase, the need to handle larger and heavier targets has also increased. This need for target lifting and handling prompted the feasibility study of the use of an underhung bridge crane to be installed in the ESL (ElectroScience Laboratory, Ohio State University) compact range. This report documents both the design of the underhung bridge crane that was installed and the implementation of the design in the actual installation of the crane.

  8. FEATURES OF DESIGN OF TIED-ARCH BRIDGES WITH FLEXIBLE INCLINED SUSPENSION HANGERS

    Directory of Open Access Journals (Sweden)

    V. O. Samosvat

    2017-10-01

    Full Text Available Purpose. Investigation and analysis of the hanger arrangement and the structural stability of a Network arch bridge – a tied-arch bridge with inclined hangers that cross each other at least twice. It is also necessary to make a comparative analysis with other types of hanger arrangements. Methodology. The authors in their research investigated a large number of parameters to determine their influence in the force distribution in the arch. Eventually they determined optimal values for all parameters. These optimal values allowed developing a design guide that leads to optimal arch design. When solving this problem, the authors used three-dimensional finite element models and the objective was to determine the most suitable solution for a road bridge, with a span of 100 meters, consisting of two inclined steel arches, located on a road with two traffic lanes, subjected to medium traffic. The virtual prototype of the model is performed by finite element simulator Midas Civil. Findings. In this study, for the bridge deck, a concrete tie appears to be the best solution considering the structural behavior of network arches, but economic advantages caused by easier erection may lead to steel or a composite bridge deck as better alternatives. Design requirements and local conditions of each particular bridge project will decide the most economic deck design.Originality. To ensure passenger comfort and the stability and continuity of the track, deformations of bridges are constricted. A network arch is a stiff structure with small deflections and therefore suitable to comply with such demands even for high speed railway traffic.
A network arch bridge with a concrete tie usually saves more than half the steel required for tied arches with vertical hangers and concrete ties. Practical value. Following the study design advice given in this article leads to savings of about 60 % of structural steel compared with conventional tied arch bridges with

  9. Economic impact of multi-span, prestressed concrete girder bridges designed as simple span versus continuous span : final report.

    Science.gov (United States)

    2016-10-01

    The objective of this study was to determine the economic impact of designing pre-tensioned prestressed concrete beam (PPCB) : bridges utilizing the continuity developed in the bridge deck as opposed to the current Iowa Department of Transportation (...

  10. Economic impact of multi-span, prestressed concrete girder bridges designed as simple span versus continuous span : tech transfer summary.

    Science.gov (United States)

    2016-10-01

    The objective of this study was to determine the economic impact of : designing pre-tensioned prestressed concrete beam (PPCB) bridges : utilizing the continuity developed in the bridge deck as opposed to the : current Iowa Department of Transportati...

  11. Computational design of donor-bridge-acceptor systems exhibiting pronounced quantum interference effects.

    Science.gov (United States)

    Gorczak, Natalie; Renaud, Nicolas; Galan, Elena; Eelkema, Rienk; Siebbeles, Laurens D A; Grozema, Ferdinand C

    2016-03-07

    Quantum interference is a well-known phenomenon that dictates charge transport properties of single molecule junctions. However, reports on quantum interference in donor-bridge-acceptor molecules are scarce. This might be due to the difficulties in meeting the conditions for the presence of quantum interference in a donor-bridge-acceptor system. The electronic coupling between the donor, bridge, and acceptor moieties must be weak in order to ensure localised initial and final states for charge transfer. Yet, it must be strong enough to allow all bridge orbitals to mediate charge transfer. We present the computational route to the design of a donor-bridge-acceptor molecule that features the right balance between these contradicting requirements and exhibits pronounced interference effects.

  12. Protein thermal stability enhancement by designing salt bridges: a combined computational and experimental study.

    Directory of Open Access Journals (Sweden)

    Chi-Wen Lee

    Full Text Available Protein thermal stability is an important factor considered in medical and industrial applications. Many structural characteristics related to protein thermal stability have been elucidated, and increasing salt bridges is considered as one of the most efficient strategies to increase protein thermal stability. However, the accurate simulation of salt bridges remains difficult. In this study, a novel method for salt-bridge design was proposed based on the statistical analysis of 10,556 surface salt bridges on 6,493 X-ray protein structures. These salt bridges were first categorized based on pairing residues, secondary structure locations, and Cα-Cα distances. Pairing preferences generalized from statistical analysis were used to construct a salt-bridge pair index and utilized in a weighted electrostatic attraction model to find the effective pairings for designing salt bridges. The model was also coupled with B-factor, weighted contact number, relative solvent accessibility, and conservation prescreening to determine the residues appropriate for the thermal adaptive design of salt bridges. According to our method, eight putative salt-bridges were designed on a mesophilic β-glucosidase and 24 variants were constructed to verify the predictions. Six putative salt-bridges leaded to the increase of the enzyme thermal stability. A significant increase in melting temperature of 8.8, 4.8, 3.7, 1.3, 1.2, and 0.7°C of the putative salt-bridges N437K-D49, E96R-D28, E96K-D28, S440K-E70, T231K-D388, and Q277E-D282 was detected, respectively. Reversing the polarity of T231K-D388 to T231D-D388K resulted in a further increase in melting temperatures by 3.6°C, which may be caused by the transformation of an intra-subunit electrostatic interaction into an inter-subunit one depending on the local environment. The combination of the thermostable variants (N437K, E96R, T231D and D388K generated a melting temperature increase of 15.7°C. Thus, this study

  13. DESIGN AND APPLICABILITY OF STEEL AND STEEL-CONCRETE PLATE GIRDER BRIDGES WITH HYBRID SECTION

    Science.gov (United States)

    Nagai, Masatsugu; Miyashita, Takeshi; Liu, Cuiping; Inaba, Naofumi; Homma, Atsushi

    In Japan, steel and steel-concrete plate girder bridges with hybrid section, in which web plate has a relatively lower strength, have not been employed so far. From viewpoints of design method and economy, the background of situation is investigated. It is emphasized, on designing of this type of bridges and obtaining the competitiveness or superiority to conventional non-hybrid bridges, that shift of the design method from allowable stress design (ASD) method, which is conventional design method, to limit state design (LSD) method is necessary. On condition that LSD is employed, advantageous points over conventional non-hybrid girder is summarized. Shear strength of the hybrid girder is also studied, and evaluation of flexure, shear and flexure/shear interactive strength is proposed.

  14. DESIGN AND IMPLEMENTATION OF CAN / CAN, CAN 1 ETHERNET AND CAN/ATM BRIDGES

    Directory of Open Access Journals (Sweden)

    Hüseyin Ekiz

    1998-06-01

    Full Text Available The Controller Area Network (CAN is a high performance and highly reliable advanced serial cornmunication protocol which effıciently supports distributed real-time control systems at high speed, low cost, and a very high level data security. The CAN was originally developed as an automotive standard for a serial interface between electronic control units, but in a short time, it has become a desirable, cheap solution for networks in industrial environments. The fast growth of the CAN in industrial applications results some potential problems such as the size of the area that the devices, controlled by the CAN, are distributed and the communication between the CAN and the existing network systems (such as Ethernet or ATM. One of the solutions to these problems is to use bridges. However, the characteristics of the CAN creates problems, when CAN segments are connected by a bridge, since CAN frames do not contain any information related to destination address, source address, or LAN number that are used by traditional address-hased bridges for routing decisions. Thus, new bridges (suitable for the CAN protocol features must be designed to overcome the problems. The objective of this paper is not only to investigate the characteristics of bridged CAN systems and to give a bridge proposal to connect CAN segments, but also to design and implement bridges that connect the CAN and existing LAN s and provide communication between them.

  15. Design, fabrication and erection of Queen Mall Bridge; Queen mall kyo no sekkei seisaku kasetsu

    Energy Technology Data Exchange (ETDEWEB)

    Arai, M.; Ishii, A.; Shinohara, T. [Sumitomo Heavy Industries, Ltd., Tokyo (Japan)

    1997-12-20

    This paper describes design, fabrication and erection of Queen Mall Bridge, which is a new landmark in Minato-Mirai Yokohama. This bridge is two-span continuous cable stayed pedestrian bridge with a roof, and has a length 72.2 m, a width 18 m and a weight about 1,050 t. This bridge connects between the Queen`s Square and the second floor of Pacifico Yokohama. Achieving harmonious impression of the newly designed bridge in this area, glass roof was employed and all-weld method was applied to the in-site jointing of main girders and main tower in addition to the essential structural design. Since all-weld method was applied to the in-site jointing, highly accurate fabrication was considered during the in-site jointing. Due to the heavy traffic of the road below the bridge, the erection time was shortened under the severe erection conditions at night by large block method. Especially, accuracy control was considered for the whole shape management. Pre-assemble of all members was conducted just near the erection site, only 500 m away from the site, to shorten the construction time. 1 ref., 5 figs.

  16. Design and research on the first polish FRP composite road bridge

    Directory of Open Access Journals (Sweden)

    Siwowski Tomasz

    2015-12-01

    Full Text Available The main goal of the research project was to develop and demonstrate the first Polish FRP composite road bridge, starting from concept design and material research, and going thru manufacturing technique selection, detailed FEM analysis and structural testing of elements. The R&D project comprises also the proof test of the completed bridge as well as structural monitoring in exploitation period. The objective of the paper is the description of the bridge and its structural solutions, i.e. FRP box girders and lightweight concrete deck slab acting compositely. Further the FEM analysis of the girder and the bridge span made on design stage has been presented. The VARTM manufacturing technique was used for girders production. Its main steps have been also presented. Finally the research on the new FRP box girder with LRC slab (hybrid girder has been briefly showed. The full scale prototype girder with the total length of 22 m was tested to evaluate its carrying capacity, modes of failure, basic dynamic parameters as well as overall behaviour under ultimate static load. The FRP girder met the prescribed serviceability and safety criteria. The FEM model of the girder was validated against testing results and was further used for bridge design. Thanks to R&D project the first Polish FRP bridge is likely to be built late autumn 2015. The output of the research project gives a very promising future for the FRP composite bridge application. The research works showed in the paper have been partially financed by the Polish National Centre for Research and Development in the frame of the research project “ComBridge” (www.com-bridge.pl.

  17. Use of interactive graphics in bridge analysis and design.

    Science.gov (United States)

    1983-01-01

    This study evaluated the role of computer-aided design (CAD), including interactive graphics, in engineering design applications, especially in the design activities of the Virginia Department of Highways and Transportation. A review of the hardware ...

  18. Designing a second language bridging course for university students

    Directory of Open Access Journals (Sweden)

    Carol A. Puhl

    2013-02-01

    Full Text Available The increasing number of students, especially black students, enrolling at university and needing to study in a medium of instruction which is not their mother tongue has underlined the need for additional language preparation as one way to reduce the failure and dropout rate. A possible solution is a bridging course aimed at developing academic language competencies to enable students to cope with communicative demands of their chosen course. An effective bridging course must take into account the requirements of the chosen institution and course, the level of student competency already achieved, and the actual student needs. These needs are divided into three areas: cognitive, which includes communicative macro-language skills and problem-solving skills; affective which includes self-confidence, acceptance of responsibility, and motivation; and behavioural, which includes cross-cultural competencies. Issues include duration of the course, the extent to which the course catersfor special purposes, and the didactic strategies employed. Three further considerations are the influence on the course of sponsors from business and industry, the academic level of the course, and effective evaluation methods. Die toenemende aantal studente, vera/ swart studente, wat aan 'n universiteit registreer waar die onderrigmedium nie hul moedertaal is nie, noodsaak bykomende taalvoorbereiding in 'n poging om die druip- en uitsaksyfer te verminder. Een moontlike oplossing is 'n oorbruggingskursus wat gemik is op die ontwikkeling van akademiese taalvermoens om studente in staat te stel om die kommunikatiewe eise van hul gekose kursus die hoof te bied. 'n Effektiewe oorbruggingskursus moet die volgende faktore in ag nee m: die vereistes van die gekose inrigting en kursus, die vaardigheidsvlak wat die student a/reeds bereik het sowel as die werklike studentebehoeftes. Hierdie behoeftes word in drie kategoriee verdeel: kognitief - wat kommunikatiewe makro

  19. Design criteria for bi-stable behavior in a buckled multi-layered MEMS bridge

    Science.gov (United States)

    Michael, Aron; Kwok, Chee Yee

    2006-10-01

    In this paper, the bi-stability of a buckled multi-layered micro-bridge with elastically constrained boundary conditions is studied theoretically and experimentally. The residual moment due to non-symmetric distribution of residual stress in the layers of the micro-bridge is taken into consideration. The buckled shape model, which characterizes the initial buckled deflection, is employed in this study. A systematic method of designing bi-stable buckled micro-bridges has been developed and applied to multi-layered structures. The method is tested against ANSYS simulation and shown to be in excellent agreement. Two multi-layer micro-bridges have been fabricated: (i) 2.5 µm thick low stress SiO2/1 µm thick high compressive stress SiO2/2 µm thick SCS Si; (ii) 1 µm thick high compressive stress SiO2/2 µm thick SCS Si. The fabricated bridges are tested for bi-stability by thermal actuation and the results agree well with the analysis. The intrinsic bi-stable nature of a buckled micro-bridge can only be guaranteed as long as the residual moment is within a certain threshold value.

  20. Design rules for interfacial thermal conductance: Building better bridges

    Science.gov (United States)

    Polanco, Carlos A.; Rastgarkafshgarkolaei, Rouzbeh; Zhang, Jingjie; Le, Nam Q.; Norris, Pamela M.; Ghosh, Avik W.

    2017-05-01

    We study the thermal conductance across solid-solid interfaces as the composition of an intermediate matching layer is varied. In the absence of phonon-phonon interactions, an added layer can make the interfacial conductance increase or decrease depending on the interplay between (1) an increase in phonon transmission due to better bridging between the contacts and (2) a decrease in the number of available conduction channels that must conserve their momenta transverse to the interface. When phonon-phonon interactions are included, the added layer is seen to aid conductance when the decrease in resistances at the contact-layer boundaries compensate for the additional layer resistance. For the particular systems explored in this work, the maximum conductance happens when the layer mass is close to the geometric mean of the contact masses. The surprising result, usually associated with coherent antireflection coatings, follows from a monotonic increase in the boundary resistance with the interface mass ratio. This geometric mean condition readily extends to a compositionally graded interfacial layer with an exponentially varying mass that generates the thermal equivalent of a broadband impedance matching network.

  1. Using artificial neural networks in the design of orthotropic bridge decks

    Directory of Open Access Journals (Sweden)

    Ahmed Shamel Fahmy

    2016-12-01

    Full Text Available For orthotropic bridge decks a lot of progress has been made in the development of codes to aid in the design process, in addition to software tools for numerical analysis and design. However, professional software tools will not aid the designer in choosing a preliminary economic layout at the conceptual design stage. Designers would go through iterative, lengthy and expensive procedures to reach the best configuration. The present research provides a methodology to investigate the contingency of using artificial neural networks for conceptual design of orthotropic steel-deck bridge. A neural network model was trained with different combinations of dimensions, and eight types of safety checks were performed on all of them. The resulting network can predict whether the deck is safe or not. It is found that this approach for the selection of orthotropic deck dimensions is a better and cost-effective option compared with international codes or expert opinion.

  2. Feature of extradosed PC bridge and its design; Daihenshin keburu PC kyo no tokucho to sono sekkei

    Energy Technology Data Exchange (ETDEWEB)

    Komiya, M. [Japan Bridge and Structure Institute Inc., Tokyo (Japan)

    1997-03-31

    A PC bridge with the eccentricity of the external cable increased by protruding the deviated member to the outside of the beam for more effective use of the external cable is called a `PC bridge with tendons of large eccentricity.` The extradosed bridge of main beam/cable joint type is a PC bridge with the external cable arranged via a tower-shaped eccentric member provided at the intermediate support, and resembles morphologically a cable stayed bridge having a very low tower. There are two types of extradosed bridges, i.e. a type with concrete coated external cable (cable stayed slab bridge) and the other with non-coated external cable (external cable stayed bridge). Features, structural planning and designing of the general external cable stayed bridge are shown. The features are the possession of intermediate characteristics of those of the PC beam bridge and the PC cable stayed bridge from the viewpoints of structural property, workability, economic efficiency, and scenic property. Outline of the plan, selection of structural data, design of the external cable, and structural characteristics in the ultimate state are discussed. 19 refs., 18 figs., 15 tabs.

  3. Bridge-in-a-Backpack(TM) task 3.1: investigating soil - structure interaction - experimental design.

    Science.gov (United States)

    2015-07-01

    This report includes fulfillment of Task 3.1 of a multi-task contract to further enhance concrete filled FRP tubes, or : the Bridge in a Backpack. Task 3 is an investigation of soil-structure interaction for the FRP tubes. Task 3.1 is the : design of...

  4. Life cycle assessment of a railway bridge: comparison of two superstructure designs

    DEFF Research Database (Denmark)

    Du, Guangli; Karoumi, Raid

    2011-01-01

    database. Results show that the fixed-slab bridge option has a better environmental performance than the ballasted design due to the ease of maintenances. The initial material manufacture stage is responsible for the largest environmental burden, while the impacts from the construction machinery...

  5. Engineering Design Processes in Seventh-Grade Classrooms: Bridging the Engineering Education Gap

    Science.gov (United States)

    English, Lyn D.; Hudson, Peter B.; Dawes, Les

    2012-01-01

    This paper reports on some findings from the first year of a three-year longitudinal study, in which seventh- to ninth-graders were introduced to engineering education. Specifically, the paper addresses students' responses to an initial design activity involving bridge construction, which was implemented at the end of seventh grade. This paper…

  6. The Virtual Design Team: Designing Project Organizations as Engineers Design Bridges

    Directory of Open Access Journals (Sweden)

    Raymond E. Levitt

    2012-08-01

    Full Text Available This paper reports on a 20-year program of research intended to advance the theory and practice of organization design for projects from its current status as an art practiced by a handful of consultants worldwide, based on their intuition and tacit knowledge, to: (1 an “organizational engineering” craft, practiced by a new generation of organizational designers; and (2 an attractive and complementary platform for new modes of “virtual synthetic organization theory research.” The paper begins with a real-life scenario that provided the motivation for developing the Virtual Design Team (VDT, an agent-based project organizational simulation tool to help managers design the work processes and organization of project teams engaged in large, semi-routine but complex and fast-paced projects. The paper sets out the underlying philosophy, representation, reasoning, and validation of VDT, and it concludes with suggestions for future research on computational modeling for organization design to extend the frontiers of organizational micro-contingency theory and expand the range of applicability and usefulness of design tools for project organizations and supply-chain networks based on this theory.

  7. Effects of surface design on aerodynamic forces of iced bridge cables

    DEFF Research Database (Denmark)

    Koss, Holger

    2014-01-01

    °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 whether the design of bridge cable surface...

  8. Monogroove heat pipe design: Insulated liquid channel with bridging wick

    Science.gov (United States)

    Alario, J. P.; Brown, R. F.; Kosson, R. L.

    1985-05-01

    A screen mesh artery supported concentrically within the evaporator section of a heat pipe liquid channel retains liquid in the channel. Continued and uniform liquid feed to the heat pipe evaporation section (20) during periods of excessive heat transfer is assured. The overall design provides high evaporation and condensation film coefficients for the working fluid by means of the circumferential grooves in the walls of the vapor channel, while not interfering with the overall heat transport capability of the axial groove. The design has particular utility in zero-g environments.

  9. Landscape Design Dialogue. Bridging the gap between knowledge and action

    NARCIS (Netherlands)

    Jonge, de J.M.; Valk, van der A.J.J.

    2010-01-01

    Spatial planners and landscape architects do not excel in theory development. The authors, being a practicing landscape architect-planner and a planning scholar, explore new roads to a middle range theory of landscape design and planning. Building on theories-in-use in regional planning practice

  10. Get synchronized : Bridging the gap between design and volume production

    NARCIS (Netherlands)

    Smulders, F.E.H.M.

    2006-01-01

    The interface between Design and Manufacturing forms a locus of frequent interpersonal conflict. Misunderstandings, unwelcome surprises and planning problems are the rule rather than the exception. Within companies that deliver consumer goods in large quantities to the market this interface is also

  11. A Review of Multi-Criteria Decision-Making Methods Applied to the Sustainable Bridge Design

    Directory of Open Access Journals (Sweden)

    Vicent Penadés-Plà

    2016-12-01

    Full Text Available The construction of bridges has been necessary for societies since ancient times, when the communication between and within towns, cities or communities was established. Until recently, the economic factor has been the only one considered in the decision-making of any type of construction process for bridges. However, nowadays, the objective should not be just the construction of bridges, but of sustainable bridges. Economic, social and environmental factors, which form the three pillars of sustainability, have been recently added. These three factors usually have conflicting perspectives. The decision-making process allows the conversion of a judgment into a rational procedure to reach a compromise solution. The aim of this paper is to review different methods and sustainable criteria used for decision-making at each life-cycle phase of a bridge, from design to recycling or demolition. This paper examines 77 journal articles for which different methods have been used. The most used methods are briefly described. In addition, a statistical study was carried out on the Multiple Attribute Decision-making papers reviewed.

  12. Study Based on Bridge Health Monitoring System on Multihazard Load Combinations of Earthquake and Truck Loads for Bridge Design in the Southeast Coastal Areas of China

    Directory of Open Access Journals (Sweden)

    Dezhang Sun

    2015-01-01

    Full Text Available Similar to American LRFD Bridge Design Specifications, the current Chinese bridge design code is fully calibrated against gravity load and live load. Earthquake load is generally considered alone and has its own methodology, however, which is not covered in the code in a consistent probability-based fashion. Earthquake load and truck load are the main loads considered in the basis of bridge design in more than 70% of seismic areas in China. They are random processes, and their combination is the main subject of this paper. Seismic characteristics of southeast coastal areas of China are discussed and an earthquake probability curve is calculated through seismic risk analysis. Using measured truck load data from a Bridge Health Monitoring System, the multimodal characteristics of truck load are analyzed and a probability model for a time interval t is obtained by fitting results and reliability theory. Then, a methodology is presented to combine earthquake load and truck load on a probabilistic basis. To illustrate this method, truck load and earthquake load combinations are used. Results conceptually illustrate that truck load and earthquake load are not dominant in southeast coastal areas of China, but the effect of their combination is. This methodology quantitatively demonstrates that the design is controlled by truck load in most ranges; that is, truck load is more important to bridge design in the region.

  13. 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...

  14. High Frequency AC Inductor Analysis and Design for Dual Active Bridge (DAB) Converters

    DEFF Research Database (Denmark)

    Zhang, Zhe; Andersen, Michael A. E.

    2016-01-01

    The dual active bridge (DAB) converter is an isolated bidirectional dc-dc topology which is the most critical part for the power conversion systems such as solid-state transformers (SST). This paper focuses on analysis and design of high frequency ac inductors which are the power interfacing...... the core loss and the winding loss are almost equal is selected as the optimal one. The experimental results are presented to verify the validity of the analysis and design....

  15. The ReflecTable: Bridging the Gap between Theory and Practice in Design Education

    DEFF Research Database (Denmark)

    Hook, Jonathan; Hjermitslev, Thomas; Iversen, Ole Sejer

    The ReflecTable is a digital learning environment that explores how design games and video-led reflection might be combined to bridge the gap between the theoretical and practical components of design education. The concept seeks to leverage the qualities of exploratory design games and video...... and nine studies conducted during the course of its development. The studies suggest that the ReflecTable has the potential to support design students in understanding how theoretical concepts and methods relate to different design situations and their own evolving design practices....... to inspire design students to critically reflect upon the relationship between their evolving design practices and the theories and techniques they are taught in lectures, by allowing them to capture, review and reflect upon short videos of a design game. In this paper, we present the ReflecTable design...

  16. Classical and Modern Design Solutions in Conceptual Design of a Pedestrian Bridge over Vistula River in Cracow

    Science.gov (United States)

    Ryż, Karol; Pańtak, Marek

    2017-10-01

    In the paper the design concept of the steel pedestrian bridge over Vistula river in Cracow, Poland has been characterised. The footbridge was designed as a truss structure with steel pipes, Warren truss configuration, arched bottom chord and spans 15.5+120.0+15.5 m. Intensive tourist traffic around the Wawel Castle in Cracow, directed towards the historic Kazimierz district, Wawel Hill and the Old Town Market Place requires the creation of a bridge structure over the Vistula River that will meet both the communication and recreation functions. An additional aim was to design a structure which architectural form will not unduly and negatively interfere in the environment and will join the technical capabilities of the XXI century with the charm of nearby historic buildings.

  17. Analysis and Design of Half-Bridge Series Resonant Converter for Non-Contact Battery Charger

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang Gyun; Park, Jong Hu; Cho, Bo Hyung [Seoul National University (Korea); Seo, Dong Hyun [Samsung Electro-Mechanics (Korea); You, Jung Sik [Hyosung Heavy Industry (Korea)

    2000-04-01

    A non-contact battery charger for cellular phone is designed using half-bridge series resonant converter. This converter utilizes series resonance to reduce the undesirable effect of large leakage inductance of the detachable transformer and ZVS operation can reduce switching loss and switching noise. In this paper, analysis and design procedure of half-bridge series resonant converter with detachable transformer is presented. The input voltage is 85VAC-270VAC, and the output voltage and current is 4.1V and 800mA, respectively. Furthermore, a method of calculating the secondary current of the transformer to control the battery charging current in the constant current charging mode is proposed. The performance of the charger is verified through experiments. (author). 6 refs., 12 figs., 1 tab.

  18. Bridging operation and design. The encounter between practical and discipline-based knowledge in offshore platform design

    Energy Technology Data Exchange (ETDEWEB)

    Husemoen, Mette Suzanne

    1997-12-31

    This thesis investigates the relationship between operations and design and the design process, taking as case studies the two new platforms of Phillips Petroleum Company Norway on Ekofisk II, the Ekofisk 2/4 X drilling and wellhead platform and the Ekofisk 2/4 J processing and transportation platform. The emphasis has been on how to take into account operational experience in design. The two research questions are: (1) Are operations and design two communities-of-practice based on different kinds of knowledge?, and (2) What are the conditions for bridging knowledge in operations and design? From the theory reviewed and the field data presented the study concludes that physical closeness and integration of operations and design personnel, experience from the other community-of-practice, and mutual sympathy, trust, and respect, are important factors in bridging knowledge of the operations and design communities-of-practice and creating innovative solutions in design which transcend the existing knowledge in operations and design. 66 refs., 28 figs., 8 tabs.

  19. The effects of load history and design variables on performance limit states of circular bridge columns - volume 2 : experimental observations.

    Science.gov (United States)

    2015-01-01

    This report is the second of three volumes and presents detailed data and test summaries of the experimental portion of the work. In total : 30 large scale reinforced concrete bridge columns are reported in this volume. Recommendations for design and...

  20. Comparative design of the superstructure of timber bridges, using norm np 005 - 2003 and provisions of european standards

    Directory of Open Access Journals (Sweden)

    Chiotan Corina

    2015-12-01

    Full Text Available The norms and standards for design of timber bridges, as well as other structures built from this material, were obsolete, design standards that were used dated from 1978 to 1980. The introduction of European Standards has created a new legislative framework in the field of designing and building timber bridges. Currently the design of such constructions use Norm NP 005-2003 and SR EN 1995-1-1: 2004 Eurocode 5: Design of timber structures. Part 1-1: General. Common rules and rules for buildings, SR EN 1995-2: 2005 Eurocode 5: Design of timber structures. Part 2: Bridges, along with their national annexes. The aim of this paper is to analyze the design of the beams for timber bridges in parallel, using on one hand Norm NP 005 - 2003, and on the other hand provisions of European standards. The design requirements for both norms as well as the results of a case study for a structural element of a timber bridge will be presented.

  1. Analysis and Design of a Wireless Power Transfer System with Dual Active Bridges

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2017-10-01

    Full Text Available Nowadays, work on Wireless Power Transfer (WPT systems with dual active bridges is attracting great attention due to their low conduction losses, power regulation, load transformation and reactance compensation. However, in these studies limitations such as overall analysis, design and realization techniques of the system were not considered properly. To address the aforementioned issues, this paper presents a detailed analysis, design and realization of a Series-Series (SS WPT system with dual active bridges, which will improve the overall performance. Three independent Phase Angles (PAs have been analyzed and designed in this study, one PA on the primary side and the other two PAs on the secondary side. This Multiple Degrees of Phase Control (MDPC method can achieve additional reactance compensation, load transformation and output regulation simultaneously. To realize the proposed method in practice, key implementation techniques have been investigated in detail, including additional reactance estimation, mutual inductance estimation, phase detection and synchronization. The feasibility and effectiveness of the proposed system is verified through simulation and experimental results.

  2. Vibration mitigation of a bridge cable using a nonlinear energy sink: design and experiment

    Directory of Open Access Journals (Sweden)

    Weiss Mathieu

    2015-01-01

    Full Text Available This work deals with the design and experiment of a cubic nonlinear energy sink (NES for horizontal vibration mitigation of a bridge cable. Modal analysis of horizontal linear modes of the cable is experimentally performed using accelerometers and displacement sensors. A theoretical simplified 2-dof model of the coupled cable-NES system is used to analytically design the NES by mean of multi-time scale systems behaviours and detection its invariant manifold, equilibrium and singular points which stand for periodic and strongly modulated regimes, respectively. Numerical integration is used to confirm the efficiency of the designed NES for the system under step release excitation. Then, the prototype system is built using geometrical cubic nonlinearity as the potential of the NES. Efficiency of the prototype system for mitigation of horizontal vibrations of the cable under for step release and forced excitations is experimentally demonstrated.

  3. Biaxial Behavior of Ultra-High Performance Concrete and Untreated UHPC Waffle Slab Bridge Deck Design and Testing

    Science.gov (United States)

    D'Alessandro, Kacie Caple

    Ultra-high performance concrete (UHPC) was evaluated as a potential material for future bridge deck designs. Material characterization tests took place to identify potential challenges in mixing, placing, and curing UHPC. Biaxial testing was performed to evaluate behavior of UHPC in combined tension and compression stress states. A UHPC bridge deck was designed to perform similarly to a conventional concrete bridge deck, and a single unit bridge deck section was tested to evaluate the design methods used for untreated UHPC. Material tests identified challenges with placing UHPC. A specified compressive strength was determined for structural design using untreated UHPC, which was identified as a cost-effective alternative to steam treated UHPC. UHPC was tested in biaxial tension-compression stress states. A biaxial test method was developed for UHPC to directly apply tension and compression. The influence of both curing method and fiber orientation were evaluated. The failure envelope developed for untreated UHPC with random fiber orientation was suggested as a conservative estimate for future analysis of UHPC. Digital image correlation was also evaluated as a means to estimate surface strains of UHPC, and recommendations are provided to improve consistency in future tests using DIC methods. A preliminary bridge deck design was completed for untreated UHPC and using established material models. Prestressing steel was used as primary reinforcement in the transverse direction. Preliminary testing was used to evaluate three different placement scenarios, and results showed that fiber settling was a potential placement problem resulting in reduced tensile strength. The UHPC bridge deck was redesigned to incorporate preliminary test results, and two single unit bridge deck sections were tested to evaluate the incorporated design methods for both upside down and right-side up placement techniques. Test results showed that the applied design methods would be conservative

  4. Design and construction of Ogawa bridge; Ogawa bashi no sekkei to seko

    Energy Technology Data Exchange (ETDEWEB)

    Hori, T.; Chigira, F. [Kajima Corp., Tokyo (Japan); Sakao, H.

    1995-09-30

    Ogawa bridge 230m long by 15.5m wide has been planned on the national road No.401 at Katashina-mura in Gunma Prefecture. Structure mode is two spans continuous PC cable-stayed obliquely system, and a main tower is H type (height: 56m from the road surface) and is located at the center of the bridge alone. This place corresponding to the entrance of Oze famous national park, the main tower is designed so as to have bulge, imaging Mizubasho (lysichiton camtschatcense), from the middle part of the pier to the lower part of the main tower. Arrangement of the cables is designed as two faces of hung fun type and one side face is composed of 13 steel strands (dia. 15.2mm wire x 27 (partly 19); covered with PE tube) in front and rear respectively. A main girder is the box type PC block 2.3m height by 4m or 3m long, and 3m long one is for fastening with a cable. Centering on the main tower, the girder blocks are successively connected in front and rare alternatively and are fastened with cables in part. This overhanging connection work is carried out by two special movable conveyers `Wagens`. 26 figs., 2 tabs.

  5. Analysis and modelling composite timber-concrete systems: Design of bridge structure according to EN

    Directory of Open Access Journals (Sweden)

    Manojlović Dragan

    2016-01-01

    Full Text Available Timber-concrete composite structures are already applied more than 80 years in engineering practice, went trought the intuitive problem solution to the fully prefabricated hybride assemblies for dry building. The development path of timber-concrete composites was always followed by extensive theoretical and experimental research, whose results were successfully implemented in practice, i.e. on the market, but till presence didn't result in modern designer's code. In expectation of new European codes for timber-concrete composites, the objective of the paper is to provide a comprehensive review of available standards provisions and recent conclusions from literature. The key issues for practical design are highlighted and ilustrated on the example of glulam composite arch bridge structure with concrete deck, according the Eurocodes.

  6. Design and Characterization of a Peptide Mimotope of the HIV-1 gp120 Bridging Sheet

    Directory of Open Access Journals (Sweden)

    Guido Poli

    2012-05-01

    Full Text Available The Bridging Sheet domain of HIV-1 gp120 is highly conserved among the HIV-1 strains and allows HIV-1 binding to host cells via the HIV-1 coreceptors. Further, the bridging sheet domain is a major target to neutralize HIV-1 infection. We rationally designed four linear peptide epitopes that mimic the three-dimensional structure of bridging sheet by using molecular modeling. Chemically synthesized peptides BS3 and BS4 showed a fair degree of antigenicity when tested in ELISA with IgG purified from HIV+ broadly neutralizing sera while the production of synthetic peptides BS1 and BS2 failed due to their high degree of hydrophobicity. To overcome this limitation, we linked all four BS peptides to the COOH-terminus of GST protein to test both their antigenicity and immunogenicity. Only the BS1 peptide showed good antigenicity; however, no envelope specific antibodies were elicited upon mice immunization. Therefore we performed further analyses by linking BS1 peptide to the NH2-terminus of the E2 scaffold from the Geobacillus Stearothermophylus PDH complex. The E2-BS1 fusion peptide showed good antigenic results, however only one immunized rabbit elicited good antibody titers towards both the monomeric and oligomeric viral envelope glycoprotein (Env. In addition, moderate neutralizing antibodies response was elicited against two HIV-1 clade B and one clade C primary isolates. These preliminary data validate the peptide mimotope approach as a promising tool to obtain an effective HIV-1 vaccine.

  7. Abrasion-resistant concrete mix designs for precast bridge deck panels.

    Science.gov (United States)

    2010-08-01

    The report documents laboratory investigations undertaken to develop high performance concrete (HPC) for precast and pre-stressed bridge deck components that would reduce the life-cycle cost of bridges by improving the studded tire wear (abrasion) re...

  8. Design, construction, and field testing of an ultra high performance concrete pi-girder bridge.

    Science.gov (United States)

    2011-01-01

    The Jakway Park Bridge in Buchanan County, Iowa is the first bridge constructed with a new prestesssed girder system composed of : precast Ultra-High Performance Concrete (UHPC). These girders employ an integral deck to facilitate construction and ar...

  9. Comparison of design procedures and observed performance of bridges subjected to lateral spreading

    OpenAIRE

    Turner, Benjamin J; Brandenberg, Scott J.; Stewart, Jonathan P.

    2014-01-01

    Recently developed guidelines for analyzing deep foundations in liquefiable soils are compared with the performance of a highway bridge and adjacent railroad bridge that suffered damage during the 2010 Mw 7.2 El Mayor-Cucapah earthquake in Baja California, Mexico. A span of the pile-supported railroad bridge collapsed due to movement of a pier from lateral spreading. The highway bridge, supported on drilled shafts, suffered moderate structural damage but did not collapse. An overview of the s...

  10. Optimum Design of Multilayer Asphalt Surfacing Systems for Orthotropic Steel Deck Bridges

    NARCIS (Netherlands)

    Li, J.

    2015-01-01

    Orthotropic steel decks are widely utilized in long span bridges, movable bridges and shorter span road and rail bridges due to their favourable properties. These properties are low deadweight, large plastic reserves in case of overload and aesthetic advantages. Nowadays, more than 1000 orthotropic

  11. Asset Management Business Model for Design, Realization, and Maintenance of Fibre Reinforced Polymer Bridges

    Directory of Open Access Journals (Sweden)

    Rizal Sebastian

    2013-01-01

    Full Text Available This paper particularly addresses the market implementation of Fibre Reinforced Polymer (FRP for bridges. It presents the concept of demand and supply chain innovation as being investigated within two ongoing European collaborative research projects (FP7 titled Trans-IND and PANTURA. FRP has emerged as a real alternative structural material based on various sustainability considerations, among others the reduced life-cycle cost due to less maintenance needs, longer lifetime, and easiness to repair, replace, or recycle the components. The Trans-IND research project aims to develop and demonstrate new industrialized processes to use FRP for civil infrastructure projects at a large scale. In order to be cost effective, a new value-chain strategy for the design, realization, and maintenance of FRP bridges is required to replace the fragmented supply chain and the one-off approach to a construction project. This paper focuses on the development of new business models based on asset management strategy, which covers the entire demand and supply chains. Research on new business models is supported by the insight into the market and regulatory frameworks in different EU countries. This is based on field surveys across the EU that have been carried out as a part of the Trans-IND and PANTURA collaborative research projects.

  12. Design of Riprap Stone Around Bridge Piers Using Empirical and Neural Network Method

    Directory of Open Access Journals (Sweden)

    Mojtaba Karimaee Tabarestani

    2015-06-01

    Full Text Available An attempt was made to develop a method for sizing stable riprap around bridge piers based on a huge amount of experimental data, which is available in the literature. All available experimental data for circular as well as round-nose-and-tail rectangular piers were collected. The data for rectangular piers, with different aspect ratios, aligned with the flow or skewed at different angles to the flow, were used in this analysis. In addition, new experiments were also conducted for larger pier width to riprap size ratio, which was not available in the literature. Based on at least 190 experimental data, the effect of important parameters on riprap stability were studied which showed that the effective pier width is the most effective parameter on riprap stability. In addition, an empirical equation was developed by multiple regression analysis to estimate the stable riprap stone size around bridge piers. The ratio of predicted to experiment riprap size value for all experimental data is larger than one with an average value of 1.75, which is less than many other empirical equations. Finally, in order to achieve a higher accuracy for riprap design, the artificial neural network (ANN method based on utilizing non-dimensional parameters was deployed. The results showed that the ANN model provides around a 7% improved prediction for riprap size compared to the conventional regression formula.

  13. Design and Implementation of Half-Bridge LLC Resonant Converter by FHA Technique

    Directory of Open Access Journals (Sweden)

    Navid Salehi

    2015-07-01

    Full Text Available Although in existence for many years, only recently has the LLC resonant converters, in particular in its half-bridge implementation, gained in the popularity it certainly deserve. The advantages such as high efficiency, low level of EMI emissions, and its ability to achieve high power density are such features that suited for power supply demand of many modern applications such as ATX PCs and flat panel TVs. One of the major difficulties in concern with designing such converter is complex model and non-linear equations that cannot be easily used into a design procedure. So in this paper, design is based on the assumption that input-to-output power transfer is essentially due to the fundamental Fourier series components of currents and voltages. This technique known as First Harmonic Approximation (FHA and is a proper method to obtain the voltage gain through solving the equivalent ac circuit of the resonant tank. The design simulated by Pspice and finally the experimental results show design procedure base on FHA technique.

  14. Novel Wien Bridge Oscillator Design Using Functional Block Structure with Current Conveyors

    Directory of Open Access Journals (Sweden)

    Pavel Brandstetter

    2012-01-01

    Full Text Available The purpose of this paper is to generally present possibilities of the current conveyor use in the well-known active electronic circuits. Current conveyors are able to substitute all known active elements. This claim is supported by the fact, that four basic functional block structures can be realized by use of current conveyors - voltage-controlled voltage source, voltage-controlled current source, current-controlled current source and current-controlled voltage source. The paper presents particular example of use of functional block structure with current conveyors in Wien bridge oscillator, where it successfully substitutes operational amplifier on the place of active element. Both theoretical formulae and design description are given. Finally, OrCAD PSpice simulation results are presented.

  15. An investigation of aspects of design of resin-bonded bridges in general dental practice and hospital services.

    Science.gov (United States)

    Patsiatzi, Eleni; Grey, Nick J A

    2004-07-01

    To assess the design of resin-bonded bridges (RBBs) by dentists, the quality of information provided to a dental laboratory, and aid identification of best practice. A retrospective case series study of slips for RBB construction, sent by hospital and general dental practitioners to a dental laboratory based in a postgraduate dental institute in Scotland, UK. 384 forms were reviewed. For single-tooth replacements, 40% of designs for upper anterior bridges and 46% for lower posterior bridges were fixed-fixed (F-F) when a cantilever design was a better option. Thirty-six (9.3%) of RBB designs involved double abutting. On the laboratory forms, fewer than five (1%) cases included instructions about the thickness of the metal framework and in 48% there was no reference to the extension of the metal framework. For single-tooth replacements, a relatively high percentage of dentists prescribed a fixed-fixed design for RBBs, despite the evidence advocating the use of a cantilever design. A significant number of dentists used double abutments. The information provided to the laboratory for the construction of resin-bonded bridges was often insufficient.

  16. Computational Protein Engineering: Bridging the Gap between Rational Design and Laboratory Evolution

    Directory of Open Access Journals (Sweden)

    Shina Caroline Lynn Kamerlin

    2012-09-01

    Full Text Available Enzymes are tremendously proficient catalysts, which can be used as extracellular catalysts for a whole host of processes, from chemical synthesis to the generation of novel biofuels. For them to be more amenable to the needs of biotechnology, however, it is often necessary to be able to manipulate their physico-chemical properties in an efficient and streamlined manner, and, ideally, to be able to train them to catalyze completely new reactions. Recent years have seen an explosion of interest in different approaches to achieve this, both in the laboratory, and in silico. There remains, however, a gap between current approaches to computational enzyme design, which have primarily focused on the early stages of the design process, and laboratory evolution, which is an extremely powerful tool for enzyme redesign, but will always be limited by the vastness of sequence space combined with the low frequency for desirable mutations. This review discusses different approaches towards computational enzyme design and demonstrates how combining newly developed screening approaches that can rapidly predict potential mutation “hotspots” with approaches that can quantitatively and reliably dissect the catalytic step can bridge the gap that currently exists between computational enzyme design and laboratory evolution studies.

  17. Bridging the Design Gap: Towards an intuitive Design Tool (CD ROM)

    NARCIS (Netherlands)

    Wendrich, Robert E.; Tragter, Hendrik; Kokkeler, Frans; van Houten, Frederikus J.A.M.

    2009-01-01

    A main task of industrial designers is the shaping and transformations of ideas or fuzzy notions into abstract or materialized equivalents. These sketches, models or other representations can be described as the sum of form and shape aspects, aesthetics, intuitive qualities as well as technical and

  18. Bridging the Gap: A Manual Primer into Design Computing in the Context of Basic Design Education

    Science.gov (United States)

    Uysal, V. Safak; Topaloglu, Fulden

    2017-01-01

    Design education is in need of a wider restructuring to accommodate new developments and paradigmatic shifts brought forth by the information age, all of which capitalise a move towards complexity theory, systems science and digital technologies. The intention of this article is to approach one particular aspect of this need: that is, how basic…

  19. A BASIC STUDY OF EVALUATION STRUCTURE TO VISUAL DESIGN OF NEO-FUNCTIONALISM BRIDGES

    Science.gov (United States)

    Matsui, Teppei; Sasaki, Yoh

    This research's final goal is to clarify how people focus on the external appearance of neo-functionalism bridges which are characterized by their distinguishing morphological features, and also determine whether people evaluate these bridges and how they do it. As a first step, the research focuses on the Through-type Arch Bridge and attempts to make clear the evaluation structure by means of an experimental psychology approach. Upon this, the dynamic image will be defined by the vitality flow and motion impression that characterize this kind of bridge. The sensibility evaluation experiment is carried out by using CG that reflects the changes of related feature shapes. Thus, the relationship between the assortments of the bridge's morphological characteristic and its impression are analyzed by using Rough Set Theory. As a result, it was possible to find out a variety of evaluation trends related to the intellectual background of the bridge observer and also establish the distinct characteristics of various evaluation trends.

  20. Topological design of all-ceramic dental bridges for enhancing fracture resistance.

    Science.gov (United States)

    Zhang, Zhongpu; Chen, Junning; Li, Eric; Li, Wei; Swain, Michael; Li, Qing

    2016-06-01

    Layered all-ceramic systems have been increasingly adopted in major dental prostheses. However, ceramics are inherently brittle, and they often subject to premature failure under high occlusion forces especially in the posterior region. This study aimed to develop mechanically sound novel topological designs for all-ceramic dental bridges by minimizing the fracture incidence under given loading conditions. A bi-directional evolutionary structural optimization (BESO) technique is implemented within the extended finite element method (XFEM) framework. Extended finite element method allows modeling crack initiation and propagation inside all-ceramic restoration systems. Following this, BESO searches the optimum distribution of two different ceramic materials, namely porcelain and zirconia, for minimizing fracture incidence. A performance index, as per a ratio of peak tensile stress to material strength, is used as a design objective. In this study, the novel XFEM based BESO topology optimization significantly improved structural strength by minimizing performance index for suppressing fracture incidence in the structures. As expected, the fracture resistance and factor of safety of fixed partial dentures structure increased upon redistributing zirconia and porcelain in the optimal topological configuration. Dental CAD/CAM systems and the emerging 3D printing technology were commercially available to facilitate implementation of such a computational design, exhibiting considerable potential for clinical application in the future. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  1. Structural Behavior and Design of Barrier-Overhang Connection in Concrete Bridge Superstructures Using AASHTO LRFD Method

    Directory of Open Access Journals (Sweden)

    Byungik Chang

    2012-01-01

    Full Text Available The U.S. Departments of Transportation adopted the AASHTO LRFD Bridge Design Specifications during the year 2007, which is mandated by AASHTO and FHWA. The application of LRFD specification initiated numerous research works in this field. This investigation addresses the LRFD and Standard design methodologies of concrete deck slab, deck overhang, barrier and combined barrier-bridge overhang. The purpose of this study is to propose a simplified manual design approach for the barrier-deck overhang in concrete bridges. For concrete deck slab overhang and barrier, application of National Cooperative Highway Research Program crash test is reviewed. The failure mechanism, design philosophy and load cases including extreme event limit states for barrier and overhang are discussed. The overhang design for the combined effect of bending moment and axial tension is probably the most important part of the design process. The overhang might be a critical design point of the deck with significantly higher amount of reinforcement. The design process becomes complicated due to combined force effect, LRFD crash test level requirement and the existence of several load combinations. Using this program, different LRFD load combinations are plotted together with the interaction diagram and the design is validated.

  2. Seismic behaviour of cable-stayed bridges : design, analysis and seismic devices

    OpenAIRE

    Cámara Casado, Alfredo

    2011-01-01

    The social and economical importance of long-span bridges is extremely large; cablestayed bridges currently span distances ranging from 200 to even more than 1000 m, representing key points along infrastructure networks and requiring an outstanding knowledge of their seismic response. The objective of the study is three-fold; (i) to discern how project decisions affect the seismic behaviour of cable-stayed bridges;(ii) to shed light on appropriate analysis strategies in order to address th...

  3. Mix design for improved strength and freeze-thaw durability of pervious concrete fill in Pearl-Chain Bridges

    DEFF Research Database (Denmark)

    Lund, Mia Schou Møller; Kevern, John T.; Schaefer, Vernon R.

    2017-01-01

    , fibers, and by internal curing using lightweight aggregate to best possibly meet the requirements for a fill material in Pearl-Chain Bridges. The 28-day compressive strength, splitting tensile strength, shear strength, permeability, and freeze-thaw durability were determined and compared for eight...... density, and thus the easiest to place. The addition of a high-range water reducing admixture and lightweight sand (expanded shale) for internal curing improved the 28-day compressive strength and splitting tensile strength. The coarse aggregate gradation had a large influence on permeability; however......Pearl-Chain Bridges are an innovative precast arch bridge technology which can utilize pervious concrete as fill material. The present study investigates how the mix design of the pervious concrete fill can be influenced by use of an air-entraining admixture, a high-range water reducing admixture...

  4. Mix design for improved strength and freeze-thaw durability of pervious concrete fill in Pearl-Chain Bridges

    DEFF Research Database (Denmark)

    Lund, Mia Schou Møller; Kevern, John T.; Schaefer, Vernon R.

    2017-01-01

    Pearl-Chain Bridges are an innovative precast arch bridge technology which can utilize pervious concrete as fill material. The present study investigates how the mix design of the pervious concrete fill can be influenced by use of an air-entraining admixture, a high-range water reducing admixture......, fibers, and by internal curing using lightweight aggregate to best possibly meet the requirements for a fill material in Pearl-Chain Bridges. The 28-day compressive strength, splitting tensile strength, shear strength, permeability, and freeze-thaw durability were determined and compared for eight...... different mixture proportions using two different sizes of granite coarse aggregate and at two different water-to-cement ratios. The specimens had an average void content of 24-28 %. Specimens containing air entraining and high-range water reducing admixtures were most workable, as determined by fresh...

  5. Field demonstration of new bridge approach slab designs and performance : [research project capsule].

    Science.gov (United States)

    2008-10-01

    A normal bridge approach slab in Louisiana is a reinforced concrete slab. It connects : the bridge deck to the adjacent paved roadway. Its intended functions are: : 1. To span the void that may develop below the slab due to soil erosion or : embankme...

  6. Differential mode EMI filter design for ultra high efficiency partial parallel isolated full-bridge boost converter

    DEFF Research Database (Denmark)

    Makda, Ishtiyaq Ahmed; Nymand, M.

    2013-01-01

    This paper presents a practical method to design a Differential Mode EMI filter for fuel cell powered isolated full bridge dc-dc boost converter. As the input voltage of such converter is inherently low with very high dc and ripple currents and since the EMI limits also does not change for such a......This paper presents a practical method to design a Differential Mode EMI filter for fuel cell powered isolated full bridge dc-dc boost converter. As the input voltage of such converter is inherently low with very high dc and ripple currents and since the EMI limits also does not change...... for such application, it calls for a carefully optimized EMI filter which is designed and implemented in this work. Moreover, the negative input impedance of the regulated converter is extremely low; well-designed filter damping branch is also included. Differential mode noise is analyzed analytically for a 3KW/400V...

  7. 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

  8. Design of pedestrian truss bridge with Sengon-Rubber laminated veneer lumber

    Science.gov (United States)

    Herbudiman, B.; Pranata, Y. A.; Pangestu, L.

    2017-12-01

    Timber bridges are one of the bridge that has long been used, but nowadays, large dimension of sawn timber has limited supply and also it is not environmental-friendly. Laminated veneer lumber (LVL) is a engineered wood that becomes one of the promising alternative, because it is made from lower quality wood that processed to be used as a more quality one. The bridge planned to be a pedestrian truss bridge with length of 9 m, width of 3 m, height of 2.5 m, and using bolt and steel plate as its connection system. Mechanical properties of LVL obtained directly from laboratory test result. Bridge modeling and planning for wood construction refers to SNI 7973:2013, while the loading refers to SNI 1725:2016. Based on the modelling and calculation, the dimension of truss frame and girder beam which are 9 cm x 9 cm and 9 cm x 18 cm have adequate strengths and satisfy deflection requirement.

  9. Bridging the Design-Science Gap with Tools: Science Learning and Design Behaviors in a Simulated Environment for Engineering Design

    Science.gov (United States)

    Chao, Jie; Xie, Charles; Nourian, Saeid; Chen, Guanhua; Bailey, Siobhan; Goldstein, Molly H.; Purzer, Senay; Adams, Robin S.; Tutwiler, M. Shane

    2017-01-01

    Many pedagogical innovations aim to integrate engineering design and science learning. However, students frequently show little attempt or have difficulties in connecting their design projects with the underlying science. Drawing upon the Cultural-Historical Activity Theory, we argue that the design tools available in a learning environment…

  10. Patterns of HCI design and HCI design of patterns bridging HCI design and model-driven software engineering

    CERN Document Server

    Seffah, Ahmed

    2015-01-01

    As interactive systems are quickly becoming integral to our everyday lives, this book investigates how we can make these systems, from desktop and mobile apps to more wearable and immersive applications, more usable and maintainable by using HCI design patterns. It also examines how we can facilitate the reuse of design practices in the development lifecycle of multi-devices, multi-platforms and multi-contexts user interfaces. Effective design tools are provided for combining HCI design patterns and User Interface (UI) driven engineering to enhance design whilst differentiating between UI

  11. Soft-switching PWM full-bridge converters topologies, control, and design

    CERN Document Server

    Ruan, Xinbo

    2014-01-01

    Soft-switching PWM full-bridge converters have been widely used in medium-to-high power dc-dc conversions for topological simplicity, easy control and high efficiency. Early works on soft-switching PWM full-bridge converter by many researchers included various topologies and modulation strategies.  However, these works were scattered, and the relationship among these topologies and modulation strategies had not been revealed. This book intends to describe systematically the soft-switching techniques for pulse-width modulation (PWM) full-bridge converters, including the topologies, control and

  12. Design Optimization and Structural Performance Evaluation of Plate Girder Bridge Constructed Using a Turn-Over Process

    Science.gov (United States)

    Eom, Gi-Ha; Kim, Sung Jae; Lee, Tae-Hee; Kim, Jang-Ho Jay

    2017-01-01

    A recent trend in bridge construction has been the optimization of the cost-to-performance ratio. The most effective way to optimize the cost-to-performance ratio is to maximize the efficiency of the superstructure. Currently, many bridge engineers and designers favor two- or three- girder plate superstructures, due to their cost advantages. However, research on the performance enhancements of the I-type girder in two- or three- girder plate bridges is lacking. One of the most important performance improvement technologies for the I-type girder is the “preflex” method. In the preflex method, the specimen is inverted during the construction process to apply prestressed cambering to the specimen by using self-weight. However, a problem with the preflex construction method is difficulty with inverting the girder/plate system during the concrete curing process. Therefore, a new inverting system called Turn-Over (TO) wheel was proposed. Using TO wheels, wider variations to the I-type girder design can be achieved. Using this TO construction method, various cross sectional designs of girder plate systems can be considered due to its easiness in inverting the girder/plate system. In this study, the location of concrete confinement sections between the steel I-beams and concrete plates was varied in an I-girder cross-sectional design. Design parameters included effective height, flange thickness, flange width, confining concrete section width, etc. From this study, the optimum cross-sectional design of the I-girder/concrete plate system was achieved. Then, a single 20 m TO girder/plate system and two 20 m TO girder bridges were constructed and tested to evaluate their performance. From the test, failure behavior, load carrying capacity, crack pattern, etc., are obtained. The results are discussed in detail in this paper. PMID:28772644

  13. Design Optimization and Structural Performance Evaluation of Plate Girder Bridge Constructed Using a Turn-Over Process

    Directory of Open Access Journals (Sweden)

    Gi-Ha Eom

    2017-03-01

    Full Text Available A recent trend in bridge construction has been the optimization of the cost-to-performance ratio. The most effective way to optimize the cost-to-performance ratio is to maximize the efficiency of the superstructure. Currently, many bridge engineers and designers favor two- or three- girder plate superstructures, due to their cost advantages. However, research on the performance enhancements of the I-type girder in two- or three- girder plate bridges is lacking. One of the most important performance improvement technologies for the I-type girder is the “preflex” method. In the preflex method, the specimen is inverted during the construction process to apply prestressed cambering to the specimen by using self-weight. However, a problem with the preflex construction method is difficulty with inverting the girder/plate system during the concrete curing process. Therefore, a new inverting system called Turn-Over (TO wheel was proposed. Using TO wheels, wider variations to the I-type girder design can be achieved. Using this TO construction method, various cross sectional designs of girder plate systems can be considered due to its easiness in inverting the girder/plate system. In this study, the location of concrete confinement sections between the steel I-beams and concrete plates was varied in an I-girder cross-sectional design. Design parameters included effective height, flange thickness, flange width, confining concrete section width, etc. From this study, the optimum cross-sectional design of the I-girder/concrete plate system was achieved. Then, a single 20 m TO girder/plate system and two 20 m TO girder bridges were constructed and tested to evaluate their performance. From the test, failure behavior, load carrying capacity, crack pattern, etc., are obtained. The results are discussed in detail in this paper.

  14. Design Optimization and Structural Performance Evaluation of Plate Girder Bridge Constructed Using a Turn-Over Process.

    Science.gov (United States)

    Eom, Gi-Ha; Kim, Sung Jae; Lee, Tae-Hee; Kim, Jang-Ho Jay

    2017-03-13

    A recent trend in bridge construction has been the optimization of the cost-to-performance ratio. The most effective way to optimize the cost-to-performance ratio is to maximize the efficiency of the superstructure. Currently, many bridge engineers and designers favor two- or three- girder plate superstructures, due to their cost advantages. However, research on the performance enhancements of the I-type girder in two- or three- girder plate bridges is lacking. One of the most important performance improvement technologies for the I-type girder is the "preflex" method. In the preflex method, the specimen is inverted during the construction process to apply prestressed cambering to the specimen by using self-weight. However, a problem with the preflex construction method is difficulty with inverting the girder/plate system during the concrete curing process. Therefore, a new inverting system called Turn-Over (TO) wheel was proposed. Using TO wheels, wider variations to the I-type girder design can be achieved. Using this TO construction method, various cross sectional designs of girder plate systems can be considered due to its easiness in inverting the girder/plate system. In this study, the location of concrete confinement sections between the steel I-beams and concrete plates was varied in an I-girder cross-sectional design. Design parameters included effective height, flange thickness, flange width, confining concrete section width, etc. From this study, the optimum cross-sectional design of the I-girder/concrete plate system was achieved. Then, a single 20 m TO girder/plate system and two 20 m TO girder bridges were constructed and tested to evaluate their performance. From the test, failure behavior, load carrying capacity, crack pattern, etc., are obtained. The results are discussed in detail in this paper.

  15. A New Local Flap Nipple Reconstruction Technique Using Dermal Bridge and Preoperatively Designed Tattoo

    Science.gov (United States)

    Iwahira, Yoshiko

    2017-01-01

    Background: Nipple–areolar reconstruction is the final step in breast reconstruction. Reconstruction using local flaps and tattooing is useful in cases of bilateral reconstruction, a small nipple–areolar complex (NAC) as the donor site, and avoiding disturbance of the normal side and other body parts. However, this method can cause projection loss and color fading of the nipple. Moreover, the breast mound is reconstructed with an implant. Methods: We performed nipple–areolar reconstruction of 90 nipples using clover-designed flaps oriented at 120 degrees and tattooing after breast silicone implantation in 64 women. The tattoo was designed before flap operation and stained darker. Following donor site closure, a dermal flap was made as a bridge for nipple support. The nipple space was separated by the dermal flap from the breast mound and was filled with subcutaneous tissue. The size of the reconstructed nipple projection was measured postoperatively and 1 year later. The projection maintenance rate was calculated. Results: The heights of the nipple projection were 11.3 ± 1.8 mm (95% confidence interval [CI]: 10.9–11.7) just after the operation and 6.09 ± 2.4 mm (95% CI: 5.6–6.6) 1 year later. The actual range of nipple projection between these 2 heights was 5.2 ± 2.4 mm (95% CI: 4.7–5.7). The maintenance rate of the reconstructed nipple projection after 12 months was 54.1 ± 20.9 (95% CI: 49.7–58.5). The nipple color was maintained for over a year. Conclusions: Our nipple–areolar reconstruction technique could maintain the projection and color of the reconstructed nipple for a long period. Good outcomes were obtained in this implant-based breast reconstruction. PMID:28507843

  16. Design and Evaluation of Scour for Bridges Using HEC-18 : technical brief.

    Science.gov (United States)

    2017-07-01

    This project developed a new approach for evaluating erosive scour at New Jersey bridges over non-tidal waterways. The main deliverable was the Scour Evaluation Model (SEM), which offers new analysis procedures, while still retaining the applicable p...

  17. Thermal behavior of IDOT integral abutment bridges and proposed design modifications.

    Science.gov (United States)

    2013-05-01

    The Illinois Department of Transportation (IDOT) has increasingly constructed integral abutment bridges (IABs) : over the past few decades, similar to those in many other states. Because the length and skew limitations : currently employed by IDOT ha...

  18. Anchorage Zone Design for Pretensioned Precast Bulb-T Bridge Girders in Virginia

    OpenAIRE

    E.D. Crispino; Cousins, Thomas E.; Roberts-Wollmann, Carin L.

    2009-01-01

    Precast/prestressed concrete girders are commonly used in bridge construction in the United States. The application and diffusion of the prestress force in a pretensioned girder cause a vertical tension force to develop near the end of the beam. Field surveys of the beam ends of pretensioned bridge girders indicate that many of the precast bulb-T (PCBT) beams used in Virginia develop cracks within the anchorage zone region. The lengths and widths of these cracks range from acceptable to poor ...

  19. 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....

  20. Design and rationale of the HCC BRIDGE study in China: a longitudinal, multicenter cohort trial in hepatocellular carcinoma

    OpenAIRE

    Qiao You-Lin; Orsini Lucinda S; Therneau Terry; Chen Minshan

    2011-01-01

    Abstract Background More than 50% of the worldwide cases of hepatocellular carcinoma occur in China, and this malignancy currently represents the country's second leading cause of cancer death in cities and the leading cause in rural areas. Despite recent advances in the control and management of hepatocellular carcinoma within China, this disease remains a major health care issue. The global HCC BRIDGE study, designed to assess patterns of hepatocellular carcinoma therapy use and associated ...

  1. Experimental design for the evaluation of high-T(sub c) superconductive thermal bridges in a sensor satellite

    Science.gov (United States)

    Scott, Elaine P.; Lee, Kasey M.

    1994-01-01

    Infrared sensor satellites, which consist of cryogenic infrared sensor detectors, electrical instrumentation, and data acquisition systems, are used to monitor the conditions of the earth's upper atmosphere in order to evaluate its present and future changes. Currently, the electrical connections (instrumentation), which act as thermal bridges between the cryogenic infrared sensor and the significantly warmer data acquisition unit of the sensor satellite system, constitute a significant portion of the heat load on the cryogen. As a part of extending the mission life of the sensor satellite system, the researchers at the National Aeronautics and Space Administration's Langley Research Center (NASA-LaRC) are evaluating the effectiveness of replacing the currently used manganin wires with high-temperature superconductive (HTS) materials as the electrical connections (thermal bridges). In conjunction with the study being conducted at NASA-LaRC, the proposed research is to design a space experiment to determine the thermal savings on a cryogenic subsystem when manganin leads are replaced by HTS leads printed onto a substrate with a low thermal conductivity, and to determine the thermal conductivities of HTS materials. The experiment is designed to compare manganin wires with two different types of superconductors on substrates by determining the heat loss by the thermal bridges and providing temperature measurements for the estimation of thermal conductivity. A conductive mathematical model has been developed and used as a key tool in the design process and subsequent analysis.

  2. Construction and Design of Post-Tensioned Pearl-Chain Bridges using SL-Technology

    DEFF Research Database (Denmark)

    Halding, Philip Skov

    2016-01-01

    Pre‐fabricated closed‐spandrel concrete arch bridges have existed for more than 50 years. Pearl‐Chain (PC) Bridges are a new award‐winning state‐of‐the‐art segmental concrete arch bridge concept invented by professor Kristian Hertz. A PC‐Arch can consist of a number of pre‐tensioned low‐weight SL......‐Decks. One SL‐Deck is a combination of light aggregate concrete, and regular concrete. Curved post‐tensioning ducts are cast into the elements, and several SL‐Decks are post‐tensioned together in an arch shape to become a PC‐Arch. A PC‐Bridge is built by erecting a number of adjacent PC‐Arches and applying....... The case showed that the pre‐compression in the arch from pre‐stressing, rise/to span ratio, and layer thickness of the filling as expected had influence on the capacity and could be altered to meet the capacity demands of a specific project. For an unevenly loaded bridge, in general, the lowest capacity...

  3. Experimental evaluation of the buckling phenomena in the new joint design for upper deck structure of a bridge

    Directory of Open Access Journals (Sweden)

    Solazzi L.

    2010-06-01

    Full Text Available This paper is concerned with the experimental mechanical analysis of a new design of a joint for a main components of a upper deck of a road bridge. These components are subject to the compression state stress induced by the weight and the load acting on the road. Each upper deck of a bridge (positioned on each side of the bridge is composed by four tubular structures that must be joint each together. The joint must to take in to account many aspects, for example that the length of each component is not the same (because, obviously, there is a mechanical tolerance. This phenomena induce different compression stress on each component and so is very important non only the critical buckling load but also the post buckling behaviour of the structure. It is very important that if a single tubular structure reaches the critical load of instability, it still has load capacity . This is to avoid that, in the case where a column reaches the instability, the entire load acting on a column increase the load on the remaining three. For this purpose many different geometrical solutions have been designed (elaborated by fem analyses and successively tested experimentally. This work reports the main experimental results on the best joint solution and how this increase the load capacity and the displacement respect to the solution without this flange.

  4. Analytical model and design of spoke-type permanent-magnet machines accounting for saturation and nonlinearity of magnetic bridges

    Science.gov (United States)

    Liang, Peixin; Chai, Feng; Bi, Yunlong; Pei, Yulong; Cheng, Shukang

    2016-11-01

    Based on subdomain model, this paper presents an analytical method for predicting the no-load magnetic field distribution, back-EMF and torque in general spoke-type motors with magnetic bridges. Taking into account the saturation and nonlinearity of magnetic material, the magnetic bridges are equivalent to fan-shaped saturation regions. For getting standard boundary conditions, a lumped parameter magnetic circuit model and iterative method are employed to calculate the permeability. The final field domain is divided into five types of simple subdomains. Based on the method of separation of variables, the analytical expression of each subdomain is derived. The analytical results of the magnetic field distribution, Back-EMF and torque are verified by finite element method, which confirms the validity of the proposed model for facilitating the motor design and optimization.

  5. Development of LRFD design procedures for bridge piles in Iowa : field testing of steel H-piles in clay, sand, and mixed soils and data analysis (volume II).

    Science.gov (United States)

    2011-09-01

    In response to the mandate on Load and Resistance Factor Design (LRFD) implementations by the Federal Highway Administration : (FHWA) on all new bridge projects initiated after October 1, 2007, the Iowa Highway Research Board (IHRB) sponsored these r...

  6. Synthesis and evaluation of lightweight concrete research relevant to the AASHTO LRFD bridge design specifications : potential revisions for definition and mechanical properties.

    Science.gov (United States)

    2012-11-01

    Much of the fundamental basis for the current lightweight concrete provisions in the AASHTO LRFD Bridge : Design Specifications is based on research of lightweight concrete (LWC) from the 1960s. The LWC that was : part of this research used tradition...

  7. Synthesis and evaluation of lightweight concrete research relevant to the AASHTO LRFD bridge design specifications : identification of articles for further evaluation and potential revision.

    Science.gov (United States)

    2012-11-01

    Much of the fundamental basis for the current lightweight concrete provisions in the AASHTO LRFD Bridge : Design Specifications is based on research of lightweight concrete (LWC) from the 1960s. The LWC that was : part of this research used tradition...

  8. Investigation of flange failures in falsework cap and sill beams : recommendations for the design of beams and posts in bridge falsework.

    Science.gov (United States)

    2008-12-01

    Recent field observations in bridge falsework identified potential deficiencies in the design of falsework resulting in : localized bending in sill and cap beam flanges and lateral buckling in other beams. Possible limits states associated with : the...

  9. Computational design of donor-bridge-acceptor systems exhibiting pronounced quantum interference effects

    NARCIS (Netherlands)

    Gorczak-Vos, N.; Renaud, N.; Galán García, E.; Eelkema, R.; Siebbeles, L.D.A.; Grozema, F.C.

    2016-01-01

    Quantum interference is a well-known phenomenon that dictates charge transport properties of single molecule junctions. However, reports on quantum interference in donor-bridge-acceptor molecules are scarce. This might be due to the difficulties in meeting the conditions for the presence of

  10. Computational design of donor-bridge-acceptor systems exhibiting pronounced quantum interference effects

    NARCIS (Netherlands)

    Gorczak, N.; Renaud, N.; Galan, E.; Eelkema, R.; Siebbeles, L.D.A.; Grozema, F.C.

    2016-01-01

    Quantum interference is a well-known phenomenon that dictates charge transport properties of single molecule junctions. However, reports on quantum interference in donor-bridge-acceptor molecules are scarce. This might be due to the difficulties in meeting the conditions for the presence of quantum

  11. Asset management business model for design, realization, and maintenance of fibre reinforced polymer bridges

    NARCIS (Netherlands)

    Sebastian, R.

    2013-01-01

    This paper particularly addresses the market implementation of Fibre Reinforced Polymer (FRP) for bridges. It presents the concept of demand and supply chain innovation as being investigated within two ongoing European collaborative research projects (FP7) titled Trans-IND and PANTURA. FRP has

  12. Design of bridge crane girder strain acquisition system based on virtual instrument

    Directory of Open Access Journals (Sweden)

    Wenxue LIU

    Full Text Available Girder is an important part of the bridge crane, which is also the main force element. In order to prevent accidents, it is necessary to collect the bridge crane girder stress data to analyse the fatigue life. This paper constructs a bridge crane girder strain acquisition system. The hardware system consists of sensors, connectors, data acquisition cards, wireless data transmission groups, POE power and host computer. The software system consists of NI MAX to interface with the computer's NI hardware and software resources,and LabVIEW programming to display and storage the girder strain data. Through this system, positions and working days strain data acquisition for the 50/10 t bridge crane girder gets the key positions strain data. The results show that the girder strain data acquisition system runs stably, channel signals of acquisition task transmit accurately, and the terminal data stores competely, meeting the detection requirements, which provides an important data support for the subsequent fatigue analysis and accurate remaining service life prediction of the crane girder.

  13. Anchorage zone design for pretensioned precast bulb-T bridge girders in Virginia.

    Science.gov (United States)

    2009-01-01

    Precast/prestressed concrete girders are commonly used in bridge construction in the United States. The application and diffusion of the prestress force in a pretensioned girder cause a vertical tension force to develop near the end of the beam. Fiel...

  14. Environmentally Friendly Solution to Ground Hazards in Design of Bridges in Earthquake Prone Areas Using Timber Piles

    Science.gov (United States)

    Sadeghi, H.

    2015-12-01

    Bridges are major elements of infrastructure in all societies. Their safety and continued serviceability guaranties the transportation and emergency access in urban and rural areas. However, these important structures are subject to earthquake induced damages in structure and foundations. The basic approach to the proper support of foundations are a) distribution of imposed loads to foundation in a way they can resist those loads without excessive settlement and failure; b) modification of foundation ground with various available methods; and c) combination of "a" and "b". The engineers has to face the task of designing the foundations meeting all safely and serviceability criteria but sometimes when there are numerous environmental and financial constrains, the use of some traditional methods become inevitable. This paper explains the application of timber piles to improve ground resistance to liquefaction and to secure the abutments of short to medium length bridges in an earthquake/liquefaction prone area in Bohol Island, Philippines. The limitations of using the common ground improvement methods (i.e., injection, dynamic compaction) because of either environmental or financial concerns along with the abundance of timber in the area made the engineers to use a network of timber piles behind the backwalls of the bridge abutments. The suggested timber pile network is simulated by numerical methods and its safety is examined. The results show that the compaction caused by driving of the piles and bearing capacity provided by timbers reduce the settlement and lateral movements due to service and earthquake induced loads.

  15. Design and construction of a cable-stayed composite girder bridge with precast RC-slabs; Purekyasuto shohan gosei keta shachokoyo no sekkei to seko

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, K. [Tokyo Metropolitan Univ. (Japan). Faculty of Technology; Shimura, T.; Tachibana, Y.; Echigo, S. [Kawada Industries Inc., Tokyo (Japan)

    1995-09-20

    A report on design and execution of cable-stayed composite girder bridge with precast RC-slabs constructed first in Japan though in small scale was described. This bridge adopted steel slabs relatively low in slab height for main slab and with two boxes slab section, and was designed at an aim of being more economic and shorter in its working term in comparison with steel girder slab type, on a base of the design in a region allowable with the existing design standards. This bridge is mainly in accordance with the regulation on continuous bridge in the prescription of road bridge, and is designed for normal RC-girder selecting between girder supports to direction normal to bridge axis as usual without using specially strong concrete to the girder. And, in order to fill with the regulation on allowable tensile stress on considering effects of creep and drying shrinkage, a method adding prestress to the slabs was adopted. Furthermore, a loop-like overlap joint for cable joint for the precast girders, expansion concrete for joint portion to compose the girder with the steel slab and so forth were adopted. 12 refs., 22 figs., 5 tabs.

  16. Design of a customised bridging mandibular prosthesis for complex reconstruction: a pilot study.

    Science.gov (United States)

    Tarsitano, A; Battaglia, S; Sandi, A; Marchetti, C

    2017-06-01

    The gold standard for mandibular reconstruction is universally recognised and consists of the replacement of the bony part of the mandible with a bony microvascular free flap supported by a reconstructive plate. Although this procedure is feasible and reproducible in most patients, at times poor oncological prognosis or poor performance status force surgeons to consider other reconstructive solutions. In these cases, the main alternative in reconstructing a mandibular defect is represented by bridging plates combined with soft tissue flaps. However, repairing a mandibular defect with a reconstructive plate only can lead to a series of diverse complications. The most frequent complications reported are rupture and oral exposure of the plate. In this paper, we describe a new method for mandibular reconstruction using a customised bridging mandibular prosthesis (CBMP) without bone free flap. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale, Rome, Italy.

  17. Optimized Design and Testing of a Prototype Military Bridge System for Rapid In-Theater Construction

    Science.gov (United States)

    2006-11-01

    MLC 30 were applied to the system with multiple load cases for each axle, truck, and track loading. The load cases were applied sequentially to...flexural failure due to concrete crushing along the center of slab span. The failure was identified with center span cracking and associated concrete...Layer Prefabricated FRP Grids for Rapid Bridge Deck Construction: Case Study. ASCE Journal of Composites for Construction, 10, 201-121. Berg, A. C

  18. Assessment of vehicular live load and load factors for design of short-span bridges according to the new Egyptian Code

    Directory of Open Access Journals (Sweden)

    Hatem M. Seliem

    2015-04-01

    The study shows that concrete box-girders designed according to ECP-201:2012 and ECP-201:2003 using the ultimate limit state method yield almost the same demand. Despite the increase in the VLL of ECP-201:2012, and consequently the live load forces, concrete I-shaped girder bridges will be subjected to less total factored internal forces in comparison to ECP-201:2003 This is attributed to the interaction between the live to dead loads ratio and the load combinations. Design of composite steel plate girder bridges according to ECP-201:2012 using the allowable stress design method yields over designed sections.

  19. Control and design of full-bridge three-level converter for renewable energy sources

    DEFF Research Database (Denmark)

    Yao, Zhilei; Xu, Jing; Guerrero, Josep M.

    2015-01-01

    Output voltage of renewable energy sources, such as fuel cell and PV cell, is often low and varies widely with load and environmental conditions. Therefore, the high step-up DC-DC converter is needed between renewable energy sources and the grid-connected inverter. However, voltage stress...... of rectifier diodes is high and filter is large in traditional voltage-source converters in a wide input-voltage range. In order to solve the aforementioned problems, a full-bridge (FB) three-level (TL) converter is proposed. It can operate at both two-level and three-level modes, so it is suitable for wide...

  20. 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...

  1. Design, fabrication, erection of Yuge-Ohashi bridge; Yuge ohashi no sekkei seisaku kasetsu

    Energy Technology Data Exchange (ETDEWEB)

    Nagamine, T.; Konishi, T.; Sasaki, K.; Miyakawa, T. [Sumitomo Heavy Industries, Ltd., Tokyo (Japan)

    1995-12-20

    Introduced herein is the construction of Yuge-Ohashi Bridge, a 325-meter long three-span cable-stayed structure. Each tower is provided with deflectors to prevent galloping vibration that the bridge may experience after completion. Because it was afraid that the towers during the erection process would experience at the base sections a bend that would be greater than their withstand strength, vibration dampers TMDs (Tuned Mass Dampers) were installed. To enable the spars to withstand strong wind after completion, wing-type flaps were arranged on their sides. To damp vibration during the spar cantilever erection process, TMDs of the cantilever type were provided capable of responding to the vertical direction vibration, for which weights were caused to travel along the arms for tuning. To prevent the top-stage cables from rain caused vibration, U-shape grooves were provided. To prevent the intermediate-stage cables from rain caused vibration, high-attenuation rubber dampers were installed. A side span spar and a tower were installed en bloc by FC (Floating Crane) boats, and the central span spar was installed by cantilever erection. Thanks to the fuzzy control-aided accuracy management system, cable adjustment was efficiently accomplished and the accuracy fell within the target value range. 4 refs., 5 figs.

  2. Design and construction of coal unloading bridge at Hekinan thermal power plant. Hekinan karyoku hatsudensho yotan sanbashi no sekkei to seko

    Energy Technology Data Exchange (ETDEWEB)

    Kanetani, Y.; Tamaki, K.; Nishio, Y. (Chubu Electric Power Co. Inc., Nagoya, (Japan))

    1990-05-30

    A coal firing power plant (700,000kW {times} 3) is under construction at Hekinan City in Aichi Prefecture, Japan. A report is made on the design and construction work of the coal unloading bridge which is nearly completed. About 4.65 million tons of coal/year is expected to be landed mostly from ocean-going ships, but the bridge is so designed as to serve as a combination berth for ocean-going ships and coastwise vessels because a small quantity of coal is landed from coasting vessels as well. Outlines of the scale and layout of the landing bridge, anchorage, and facilities on the bridge are introduced. In connection with the design conditions, conditions of ship, meteorological and hydrographic conditions, submarine geography, geological conditions, design seismic intensity, design load, etc. are explained. As to the outline of structure, description is made on the selection of structural type, determination of optimum block length, height of the bridge top, structural analysis, outline of structure and corrosion resistance. As regards the outline of the work, number of works, work flow, result of processes, rapid construction, and the arrangement of heavy machines are described. Subjects concerning pile driving work and superstructure work are also reported. 13 figs., 10 tabs.

  3. 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.

  4. An Optimization Algorithm for the Design of an Irregularly-Shaped Bridge Based on the Orthogonal Test and Analytic Hierarchy Process

    Directory of Open Access Journals (Sweden)

    Hanbing Liu

    2016-11-01

    Full Text Available Irregularly-shaped bridges are usually adopted to connect the main bridge and ramps in urban overpasses, which are under significant flexion-torsion coupling effects and in complicated stress states. In irregular-shaped bridge design, the parameters such as ramp radius, bifurcation diaphragm stiffness, box girder height, and supporting condition could affect structural performance in different manners. In this paper, the influence of various parameters on three indices, including maximum stress, the stress variation coefficient, and the fundamental frequency of torsional vibration, is investigated and analyzed based on orthogonal test method. Through orthogonal analysis, the major influence parameters and corresponding optimal values for these indices are achieved. Combining with the analytic hierarchy process (AHP, the hierarchical structure model of the multi-indices orthogonal test is established and a comprehensive weight analysis method is proposed to reflect the parameter influence on overall mechanical properties of an irregularly-shaped bridge. Influence order and optimal values of parameters for overall mechanical properties are determined based on the weight of factors and levels calculated by the comprehensive weight analysis method. The results indicate that the comprehensive weight analysis method is superior to the overall balance method, which verifies the effectiveness and accuracy of the comprehensive weight analysis in the parameter optimization of the multi-indices orthogonal test for an irregularly-shaped bridge. Optimal parameters obtained in this paper can provide reference and guidance for parameter control in irregularly-shaped bridge design.

  5. 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...

  6. 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 ...

  7. Educational Game Design. Bridging the gab between computer based learning and experimental learning environments

    DEFF Research Database (Denmark)

    Andersen, Kristine

    2007-01-01

    Considering the rapidly growing amount of digital educational materials only few of them bridge the gab between experimental learning environments and computer based learning environments (Gardner, 1991). Observations from two cases in primary school and lower secondary school in the subject...... of home economics shows that problems in computer based learning occurs when the basis of the learning process changes from being hands-on experimental with the subject to being experienced through or with a computer. Some of the central problems in home economics are to force abstraction from...... with a prototype of a MOO storyline. The aim of the MOO storyline is to challenge the potential of dialogue, user involvement, and learning responsibility and to use the children?s natural curiosity and motivation for game playing, especially when digital games involves other children. The paper proposes a model...

  8. Bridging the Gap between Experts in Designing Multimedia-Based Instructional Media for Learning

    Science.gov (United States)

    Razak, Rafiza Abdul

    2013-01-01

    The research identified and explored the cognitive knowledge among the instructional multimedia design and development experts comprising of multimedia designer, graphic designer, subject-matter expert and instructional designer. A critical need exists for a solid understanding of the factors that influence team decision making and performance in…

  9. Evaluation of Bridges Subjected to Military Loading and Dynamic Hydraulic Effects: Review of Design Regulations, Selection Criteria, and Inspection Procedures for Bridge Railing Systems

    Science.gov (United States)

    2011-08-01

    Concrete continuous o Steel o Steel continuous o Prestressed concrete o Prestressed concrete continuous o Wood or Timber o Masonry ERDC/GSL TR-11...tested concrete parapet. ................................................................................................. 57 Table 18. Crash Tested F...Shape Concrete Barrier. .................................................................................. 75 Table 19. Crash tested timber bridge

  10. Common-mode noise analysis, modeling and filter design for a phase-shifted full-bridge forward converter

    DEFF Research Database (Denmark)

    Makda, Ishtiyaq Ahmed; Nymand, Morten

    2015-01-01

    This paper presents the common-mode noise analysis and modeling of a phase-shifted full-bridge forward converter. The common-mode noise source due to a transformer inter-winding capacitance is considered for the case of study. The generated common-mode noise voltage-source in a converter is analy......This paper presents the common-mode noise analysis and modeling of a phase-shifted full-bridge forward converter. The common-mode noise source due to a transformer inter-winding capacitance is considered for the case of study. The generated common-mode noise voltage-source in a converter...... is analytically determined, which then leads to a common-mode noise modeling of a phase-shifted converter. Using a proposed model, common-mode noise-current harmonics are calculated and a fully analytical filter design procedure is presented to comply with the CISPR-11 standard. Finally, a prototype phase-shifted...... forward converter is built to verify the theoretical analysis. This study shows that the primary-to-secondary transformer winding capacitance creates a very significant amount of common-mode noise current in a phase-shifted forward converter....

  11. Analytical model and design of spoke-type permanent-magnet machines accounting for saturation and nonlinearity of magnetic bridges

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Peixin; Chai, Feng [State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001 (China); Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China); Bi, Yunlong [Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China); Pei, Yulong, E-mail: peiyulong1@163.com [Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China); Cheng, Shukang [State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001 (China); Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2016-11-01

    Based on subdomain model, this paper presents an analytical method for predicting the no-load magnetic field distribution, back-EMF and torque in general spoke-type motors with magnetic bridges. Taking into account the saturation and nonlinearity of magnetic material, the magnetic bridges are equivalent to fan-shaped saturation regions. For getting standard boundary conditions, a lumped parameter magnetic circuit model and iterative method are employed to calculate the permeability. The final field domain is divided into five types of simple subdomains. Based on the method of separation of variables, the analytical expression of each subdomain is derived. The analytical results of the magnetic field distribution, Back-EMF and torque are verified by finite element method, which confirms the validity of the proposed model for facilitating the motor design and optimization. - Highlights: • The no-load magnetic field of poke-type motors is firstly calculated by analytical method. • The magnetic circuit model and iterative method are employed to calculate the permeability. • The analytical expression of each subdomain is derived.. • The proposed method can effectively reduce the predesign stages duration.

  12. 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, ...

  13. Load and resistance factor design of bridge foundations accounting for pile group-soil interaction.

    Science.gov (United States)

    2015-11-01

    Pile group foundations are used in most foundation solutions for transportation structures. Rigorous and reliable pile design methods are : required to produce designs whose level of safety (probability of failure) is known. By utilizing recently dev...

  14. Trialogues : A framework for bridging the gap between people research and design

    NARCIS (Netherlands)

    Postma, C.E.; Lauche, K.; Stappers, P.J.

    2009-01-01

    In design research literature, several tools and techniques have been developed that support design teams in establishing creative understandings of people and their contexts of product use, e.g. [1] [2] [3]. Many of these approaches suggest that designers simply adopt the role of people researcher.

  15. Analysis and design of bridge structure for a micro Fabry-Perot cavity

    Science.gov (United States)

    Li, Yuanyuan; Meng, Qinghua; Chen, Sihai; Dong, Yuming

    2016-03-01

    Abstract—This paper describes a MEMS-based tunable Fabry-Perot filter that can be directly integrated on a detector. The Fabry-Perot filter consists of two parallel mirrors and lets the light with particular wavelength pass through. The wavelength depends on the gap between the mirrors. The gap of the micromechanical Fabry-Perot filter can be changed by applying a voltage to the mirrors, an electrostatic force inducing an attraction between the substrate and the top mirror. Based on the comprehensive analysis of the working principle of the micro F-P cavity filter, the optimum tuning scheme of micro F-P cavity filter is established. A simulation of the mechanical behavior was performed based on finite elements, using ANSYS software. We finally establish the L-arm type cantilever to support cavity structure, the micro-bridge can achieve a considerable range of tuning; relatively high fill factor, filter light leakage is avoided; the high abilityto keep parallel can achieve high precision filtering effect; structural stability, it can resist the residual stress of manufacture. This MEMS F-P tunable filter can be a potential application in spectroscopic sensing and optical communication system.

  16. Design of an improved RCD buffer circuit for full bridge circuit

    Science.gov (United States)

    Yang, Wenyan; Wei, Xueye; Du, Yongbo; Hu, Liang; Zhang, Liwei; Zhang, Ou

    2017-05-01

    In the full bridge inverter circuit, when the switch tube suddenly opened or closed, the inductor current changes rapidly. Due to the existence of parasitic inductance of the main circuit. Therefore, the surge voltage between drain and source of the switch tube can be generated, which will have an impact on the switch and the output voltage. In order to ab sorb the surge voltage. An improve RCD buffer circuit is proposed in the paper. The peak energy will be absorbed through the buffer capacitor of the circuit. The part energy feedback to the power supply, another part release through the resistor in the form of heat, and the circuit can absorb the voltage spikes. This paper analyzes the process of the improved RCD snubber circuit, According to the specific parameters of the main circuit, a reasonable formula for calculating the resistance capacitance is given. A simulation model will be modulated in Multisim, which compared the waveform of tube voltage and the output waveform of the circuit without snubber circuit with the improved RCD snubber circuit. By comparing and analyzing, it is proved that the improved buffer circuit can absorb surge voltage. Finally, experiments are demonstrated to validate that the correctness of the RC formula and the improved RCD snubber circuit.

  17. Enterprise Command, Control, and Design: Bridging C2 Practice and CT Research

    Science.gov (United States)

    2007-01-01

    military units, task forces and coalitions, govern- ment agencies, unions, guilds, sports teams, churches, families, and even social movements...classroom curricula and pedagogy to incorporate the princi- ples and tools associated with enterprise design as a rational, inte- grated design

  18. User Studies and Systems Design: Bridging the Gap (SIGs USE, HCI).

    Science.gov (United States)

    Robins, David

    2000-01-01

    Presents an abstract for a planned session on the need to coordinate user studies and information retrieval system design research. Topics include human-based research and system-based research; children's information use; usability and cartographic information systems; and ethnomethodology and system design. Panelists included: Nick Belkin, Dania…

  19. 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...

  20. Bridging the Gap Between Actors and Digital tools in a Furnishing Design Process

    DEFF Research Database (Denmark)

    Brink Rasmussen, Mai; Nielsen, Anne Nørkjær

    ) and Virtual Reality (VR) can be implemented in various phases of the building project. The implementation of BIM is expected to support the designers and improve the collaboration among multiple actors, but the social aspects related to the use of BIM in the design process needs further investigation......The high level of complexity in today’s building design requires a high level of interdisciplinary collaboration, which historically is an uncommon working method in the building industry. To support the interdisciplinary collaboration, new digital tools such as Building Information Models (BIM...

  1. Bridging the Gap between Actors and Digital tools in a Furnishing Design Process

    DEFF Research Database (Denmark)

    Rasmussen, Mai; Gade, Anne Nørkjær; Jensen, Rasmus Lund

    2017-01-01

    ) and Virtual Reality (VR) can be implemented in various phases of the building project. The implementation of BIM is expected to support the designers and improve the collaboration among multiple actors, but the social aspects related to the use of BIM in the design process needs further investigation......The high level of complexity in today’s building design requires a high level of interdisciplinary collaboration, which historically is an uncommon working method in the building industry. To support the interdisciplinary collaboration, new digital tools such as Building Information Models (BIM...

  2. Bridging the Gap between Actors and Digital tools in a Knotworking Design Process

    DEFF Research Database (Denmark)

    Rasmussen, Mai; Gade, Anne Nørkjær; Jensen, Rasmus Lund

    ) and Virtual Reality (VR) have been developed to be implemented in various phases of the building project. The implementation of BIM is expected to support the designers and improve the collaboration among multiple actors, but the social aspects related to the use of BIM in the design process needs further......The high level of complexity in today’s building design requires a high level of inter-disciplinary collaboration, which historically is an uncommon working method in the building industry. To support the inter-disciplinary collaboration, new digital tools such as Building Information Models (BIM...

  3. Seismic analysis and design of bridge abutments considering sliding and rotation

    Science.gov (United States)

    1997-09-15

    Current displacement based seismic design of gravity retaining walls utilizes a sliding block idealization, and considers only a translation mode of deformation. Authors update and extend the coupled equations of motion that appear in the literature....

  4. Bridging the gap: theory-based design of a microsurgical skills course for ophthalmology residents.

    Science.gov (United States)

    Koukkoulli, Antigoni; Chandra, Aman; Sheth, Hithen; Okhravi, Narciss; Verma, Seema; Sullivan, Paul; Ezra, Daniel G

    2015-01-01

    Although theory-based schemes for course design are widely used in educational settings, making use of cognitive theory in the design of surgical skills courses in ophthalmology is rare. The primary aim of this study is to describe the application of instructional design, an established theory-based approach in course design, to the development of a surgical skills course for ophthalmology residents. The secondary aim of this study is to assess the educational effect of this theory-based course. A 1-day skills course was designed according to Gagné׳s events of instruction model, which was employed as a template for the instructional sequence of learning steps. Skills acquisition following the implementation of the model was measured with precourse and postcourse assessments. Moorfields Eye Hospital organized the 1-day annual intermediate surgical skills course, which was hosted at the Royal College of Ophthalmologists' microsurgical skills laboratory. A total of 20 ophthalmology residents of Moorfields Eye Hospital participated in the study. A 1-day surgical skills course was formulated according to the instructional design principles outlined. The 4 objectives of the course (corneal suturing, corneal gluing, intravitreal injections, and eyelid suturing) were addressed in a parallel fashion as to allow for multiple objectives to be processed simultaneously, in the context of the instructional design sequence. Assessments demonstrated significant improvement in skills acquisition for the 4 course objectives. Instructional design is a valuable tool for planning effective surgical training courses as it is portable, allowing its application to a wide variety of outcomes and settings, and its terminology is simple and understandable to those working in clinical education. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  5. Load and Resistance Factor Design of Bridge Foundations Accounting for Pile Group–Soil Interaction

    OpenAIRE

    Han, Fei; Lim, Jeehee; Salgado, Rodrigo; Prezzi, Monica; Zaheer, Mir

    2015-01-01

    Pile group foundations are used in most foundation solutions for transportation structures. Rigorous and reliable pile design methods are required to produce designs whose level of safety (probability of failure) is known. By utilizing recently developed, advanced, two-surface plasticity constitutive models, rigorous finite element analyses are conducted. These analyses are for axially loaded single piles and pile groups with several pile-to-pile distances in various group configurations inst...

  6. Bridging the Gap between Eco-Design and the Human Thinking System

    Directory of Open Access Journals (Sweden)

    Mona Komeijani

    2016-03-01

    Full Text Available Technological progress has enabled widespread adoption and use of consumer electronics, changing how global society lives and works. This progress has come with immense environmental cost, including extraction of scarce materials, consumption of fossil fuels, and growing e-waste challenges. Eco-design has emerged as a promising approach to reduce the environmental footprint of electronics by integrating sustainability-oriented decisions early in the product realization process. However, most approaches focus on the product itself, not on the consumer who ultimately decides how to purchase, use, maintain, and dispose of the device. This article presents a new framework to guide designers in developing products with features that encourage consumers to use them in an environmentally sustainable manner. The Sustainable Behavior Design (SBD framework links common design concepts (ergonomic, emotional, preventative, and interaction design with core aspects of the human thinking system to create features to make users aware of their behavior and decisions (reflective thinking or result in sustainable behaviors even when users are unaware (automatic thinking. The SBD framework is demonstrated using a case study on a smartphone, a high demand product. The reimagined smartphone design integrates solutions addressing both automatic and reflective thinking systems, potentially reducing life cycle impacts by almost 30%.

  7. Comparison of infrastructure designs for quay wall and small bridges in concrete, steel, wood and composites with regard to the co2-emission and the life cycle analysis

    NARCIS (Netherlands)

    Van Heel, D.D.; Maas, T.; De Gijt, J.G.; Said, M.

    2011-01-01

    This paper describes quay wall and bridge designs in different materials, which are compared with regard the the CO2-emission and the Life Cycle Analysis (LCA). For this study the requirements and boundary conditions from the Euromax Terminal quay wall, in the Port of Rotterdam, have been used. The

  8. Practical cable tension adjustment based upon the satisfaction concept of bridge designers; Sekkeisha no manzokudo wo koryo shita fuzzy cable choryoku choseiho

    Energy Technology Data Exchange (ETDEWEB)

    Kaneyoshi, M.; Tanaka, H. [Hitachi Zosen, Tokyo (Japan)] Furuta, H. [Kansai Univ., Osaka (Japan)

    1998-07-21

    Cable tension adjustment of bridge beam of cable stayed bridge and so forth that uses cable as a structural element is classified into (1) pre-stress adjustment of cable at design level, (2) slim adjustment required at erection level. The former deals with the structurally high dimensional statically indeterminate structures like cable-stayed bridges and is a process for carrying out economical design by making the stress resultant of main girder small due to the introduction of appropriate pre-stress stress on this cable. The later is the process of getting rid off the errors caused in cable tension and camber of girder and tower regarding various errors such as design, fabrication and erection errors. The authors developed analysis method using fuzzy regression analysis and this has been applied in number of practical bridges. In this research, much more practical method is developed where the aspire of designer can be introduced easily by applying the satisfaction concept. By using this, pre-stress adjustment and shim adjustment of cable can be possible in a practical way. 9 refs., 7 figs., 8 tabs.

  9. Intersection how enterprise design bridges the gap between business, technology, and people

    CERN Document Server

    Guenther, Milan

    2012-01-01

    Many organizations struggle with the dynamics and the complexity of today''s social ecosystems that connect everyone and everything, everywhere and all the time. Facing challenges at the intersection of business models, technical developments, and human needs, modern enterprises must overcome the siloed thinking and isolated efforts of the past, and instead address their relationships to people holistically. In Intersection, Milan Guenther introduces a Strategic Design approach that aligns the overarching efforts of Branding, Enterprise Architecture, and Experience Design, and sets them on a

  10. Universal Design for Learning as a Bridge to Inclusion: A Qualitative Report of Student Voices

    Science.gov (United States)

    Katz, Jennifer; Sokal, Laura

    2016-01-01

    Innovations in pedagogy are, at their core, aimed at improving the educational experiences and outcomes of learners. Being as many countries are embracing a philosophy of inclusive education, designers of educational reform must be mindful of the effects of any proposed innovations on the experiences and outcomes of a broad range of diverse…

  11. Cybersecurity Protection: Design Science Research toward an Intercloud Transparent Bridge Architecture (ITCOBRA)

    Science.gov (United States)

    Wilson, Joe M.

    2013-01-01

    This dissertation uses design science research and engineering to develop a cloud-based simulator for modeling next-generation cybersecurity protection frameworks in the United States. The claim is made that an agile and neutral framework extending throughout the cyber-threat plane is needed for critical infrastructure protection (CIP). This…

  12. Design of a cable stayed composite bridge using a probabilistic FE analysis

    NARCIS (Netherlands)

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

    1999-01-01

    Within the use of alternative methods of probabilistic analysis and coming up computers with more CPU-power, today it Is possible within a design office, to analyse structures in a probabilistic way. After a pilot Implementation of some alternative methods in an existing FE-code, some structures are

  13. Bridging the gap: The design of bank loan contracts and distance

    NARCIS (Netherlands)

    Hollander, Stephan; Verriest, A.J.M.

    How do the distance constraints faced by lenders in acquiring borrower information affect the design of bank loan contracts? Theoretical studies posit that greater information asymmetry leads to the allocation of stronger ex ante decision rights to the lender (the uninformed party). Consistent with

  14. Effects of Thinking Style on Design Strategies: Using Bridge Construction Simulation Programs

    Science.gov (United States)

    Sun, Chuen-Tsai; Wang, Dai-Yi; Chang, Yu-Yeh

    2013-01-01

    Computer simulation users can freely control operational factors and simulation results, repeat processes, make changes, and learn from simulation environment feedback. The focus of this paper is on simulation-based design tools and their effects on student learning processes in a group of 101 Taiwanese senior high school students. Participants…

  15. Cybersecurity Protection: Design Science Research toward an Intercloud Transparent Bridge Architecture (ICTOBRA)

    Science.gov (United States)

    Wilson, Joe M.

    2013-01-01

    This dissertation uses design science research and engineering to develop a cloud-based simulator for modeling next-generation cybersecurity protection frameworks in the United States. The claim is made that an agile and neutral framework extending throughout the cyber-threat plane is needed for critical infrastructure protection (CIP). This…

  16. Bridging design and behavioral research with variance-based structural equation modeling

    NARCIS (Netherlands)

    Henseler, Jörg

    2017-01-01

    Advertising research is a scientific discipline that studies artifacts (e.g., various forms of marketing communication) as well as natural phenomena (e.g., consumer behavior). Empirical advertising research therefore requires methods that can model design constructs as well as behavioral constructs,

  17. Development of wave and surge atlas for the design and protection of coastal bridges in south Louisiana : [tech summary].

    Science.gov (United States)

    2015-02-01

    The failures of highway bridges on the Gulf Coast seen in the aftermath of Hurricane Katrina in 2005 were unprecedented. : In the past four decades, wind waves accompanied by high surges from hurricanes have damaged a number of coastal : bridges alon...

  18. Designing Alternatives: Design Thinking as a Mediating Learning Strategy to Bridge Science and the Humanities for Leadership Learning

    Science.gov (United States)

    Clegorne, Nicholas A.; Mastrogiovanni, Jason M. M.

    2015-01-01

    Drawing on the work of educational anti-consumerists such as David F. Noble (2002) as well as design theory (Cross, 2006; Dorst, 2011; Farrell & Hooker, 2013) and adaptive leadership (Heifetz, Grashow, & Linsky, 2009), these authors frame the complex interactions involving teaching and learning along a spectrum bracketed by training on one…

  19. Bridging Theory and Practice: Developing Guidelines to Facilitate the Design of Computer-based Learning Environments

    Directory of Open Access Journals (Sweden)

    Lisa D. Young

    2003-10-01

    Full Text Available Abstract. The design of computer-based learning environments has undergone a paradigm shift; moving students away from instruction that was considered to promote technical rationality grounded in objectivism, to the application of computers to create cognitive tools utilized in constructivist environments. The goal of the resulting computer-based learning environment design principles is to have students learn with technology, rather than from technology. This paper reviews the general constructivist theory that has guided the development of these environments, and offers suggestions for the adaptation of modest, generic guidelines, not mandated principles, that can be flexibly applied and allow for the expression of true constructivist ideals in online learning environments.

  20. Bridging the “Front Stage” and “Back Stage” in Service System Design

    OpenAIRE

    Glushko, Robert J.; Tabas, Lindsay

    2007-01-01

    Service management and design has thus far primarily focused on the interactions between employees and customers. This perspective holds that the quality of the “service experience” is determined by the customer during this final “service encounter” that takes place in the “front stage.” This emphasis discounts the contribution of the activities in the “back stage” of the service value chain where materials or information needed by the front stage are processed. However, the vast increase in ...

  1. Activity-Based Design as a Way to Bridge Artifacts, Professions, and Theories

    DEFF Research Database (Denmark)

    Brynskov, Martin

    2007-01-01

    This paper will focus on the challenges in designing pervasive computing technology for children’s play, taking into account current trends in popular culture. In search of theoretical support for this work I have been exploring an activity-based approach called ‘habitats’ to describe the conditi......, informational, and pragmatic – together with the ability to describe their relations are a useful platform for practitioners and theorists who are forced to span a heterogeneous mash-up of technologies, theories, and professions....

  2. Modelling and design of planar Hall effect bridge sensors for low-frequency applications

    DEFF Research Database (Denmark)

    Persson, Åsa; Bejhed, R.S.; Østerberg, Frederik Westergaard

    2013-01-01

    process for optimizing a PHEB to a particular set of requirements on the bandwidth, detectivity, compliance voltage and amplified signal-to-noise ratio. By applying this design process, the size, sensitivity, resistance, bias current and power consumption of the PHEB can be estimated. The model indicates...... and moderate noise figure. In this work, the applicability of such PHEB sensors to different areas is investigated. An analytical model is constructed to estimate the performance of an arbitrary PHEB sensor geometry in terms of, e.g., sensitivity and detectivity. The model is valid for an ideal case, e...

  3. 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.

  4. Design and construction of the Daini-Chikumagawa bridge; Dai ni Chikumagawa kyoryo no sekkei to seko

    Energy Technology Data Exchange (ETDEWEB)

    Inaba, N.; Takasusuki, K.; Hirasawa, T.; Kanamori, M.

    1996-01-30

    The Daini-Chikumagawa bridge, having spans of 134m {times} 2 which is the largest in Japan as the concrete railroad, is a prestressed concrete (PC) oblique cable-stayed bridge building on the Hokuriku Shinkansen express line which is constructing towards Nagano Olympic (Feb.1998). Regarding adoption of the oblique cable-stayed bridge for the railroad bridge, there are very few examples on a global scale and in Japan besides this bridge there is only one example (Omoto bridge (Iwate pref.), span = 85m). One H type tower (H = 65m from the surface of bridge) is erected at the center of the Chikuma river and then main girders are built at the front and rear of this tower. These main girders, being separated into 5m {times} 24 blocks per one side excepting surroundings of the tower, are fabricated as a three room box type PC block (total width 12.8m; height 3.0m) each on the river beach near the spot. These blocks are jointed from the tower side by the overhanging work using the constructing vehicles and are fixed with oblique materials (cables; two face hanging system) at intervals of 10m. 4 refs., 16 figs., 5 tabs.

  5. Categories, Boundaries, and Bridges: The Social Geography of Schooling and the Need for New Institutional Designs

    Directory of Open Access Journals (Sweden)

    Hal A. Lawson

    2016-09-01

    Full Text Available As unprecedented child and family migration patterns continue, neighborhoods, hamlets, towns, cities, states/provinces, and entire nations are impacted. These impacts are especially profound when migrants’ first language is not the host nation’s dominant one; when they relocate in communities already challenged by poverty, social exclusion, and social isolation; and when educator-controlled, standardized, stand-alone schools continue to focus exclusively on teacher-directed, academic learning during the school day. Under these circumstances, standardized schools struggle to achieve desirable results, making it clear that relations between schools and their host locales are consequential for everyone. Using the United States as a case example, this introductory analysis provides an appreciative framework for the new designs presented in this Special Issue of Education Sciences.

  6. 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...

  7. Comparison of using different bridge prosthetic designs for partial defect restoration through mathematical modeling.

    Science.gov (United States)

    Styranivska, Oksana; Kliuchkovska, Nataliia; Mykyyevych, Nataliya

    2017-01-01

    To analyze the stress-strain states of bone and abutment teeth during the use of different prosthetic designs of fixed partial dentures with the use of relevant mathematical modeling principles. The use of Comsol Multiphysics 3.5 (Comsol AB, Sweden) software during the mathematical modeling of stress-strain states provided numerical data for analytical interpretation in three different clinical scenarios with fixed dentures and different abutment teeth and demountable prosthetic denture with the saddle-shaped intermediate part. Microsoft Excel Software (Microsoft Office 2017) helped to evaluate absolute mistakes of stress and strain parameters of each abutment tooth during three modeled scenarios and normal condition and to summarize data into the forms of tables. In comparison with the fixed prosthetic denture supported by the canine, first premolar, and third molar, stresses at the same abutment teeth with the use of demountable denture with the saddle-shaped intermediate part decreased: at the mesial abutment tooth by 2.8 times, at distal crown by 6.1 times, and at the intermediate part by 11.1 times, respectively, the deformation level decreased by 3.1, 1.9, and 1.4 times at each area. The methods of mathematical modeling proved that complications during the use of fixed partial dentures based on the overload effect of the abutment teeth and caused by the deformation process inside the intermediate section of prosthetic construction.

  8. 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.

  9. Ontology Design Patterns: Bridging the Gap Between Local Semantic Use Cases and Large-Scale, Long-Term Data Integration

    Science.gov (United States)

    Shepherd, Adam; Arko, Robert; Krisnadhi, Adila; Hitzler, Pascal; Janowicz, Krzysztof; Chandler, Cyndy; Narock, Tom; Cheatham, Michelle; Schildhauer, Mark; Jones, Matt; Raymond, Lisa; Mickle, Audrey; Finin, Tim; Fils, Doug; Carbotte, Suzanne; Lehnert, Kerstin

    2015-04-01

    Integrating datasets for new use cases is one of the common drivers for adopting semantic web technologies. Even though linked data principles enables this type of activity over time, the task of reconciling new ontological commitments for newer use cases can be daunting. This situation was faced by the Biological and Chemical Oceanography Data Management Office (BCO-DMO) as it sought to integrate its existing linked data with other data repositories to address newer scientific use cases as a partner in the GeoLink Project. To achieve a successful integration with other GeoLink partners, BCO-DMO's metadata would need to be described using the new ontologies developed by the GeoLink partners - a situation that could impact semantic inferencing, pre-existing software and external users of BCO-DMO's linked data. This presentation describes the process of how GeoLink is bridging the gap between local, pre-existing ontologies to achieve scientific metadata integration for all its partners through the use of ontology design patterns. GeoLink, an NSF EarthCube Building Block, brings together experts from the geosciences, computer science, and library science in an effort to improve discovery and reuse of data and knowledge. Its participating repositories include content from field expeditions, laboratory analyses, journal publications, conference presentations, theses/reports, and funding awards that span scientific studies from marine geology to marine ecology and biogeochemistry to paleoclimatology. GeoLink's outcomes include a set of reusable ontology design patterns (ODPs) that describe core geoscience concepts, a network of Linked Data published by participating repositories using those ODPs, and tools to facilitate discovery of related content in multiple repositories.

  10. The effects of load history and design variables on performance limit states of circular bridge columns - volume 3 : analysis methods.

    Science.gov (United States)

    2015-01-01

    This report is the third of three volumes and presents the numerical portion of the research project on the impacts of loading history on : the behavior of reinforced concrete bridge columns. Two independent finite element methods were utilized to ac...

  11. A precast concrete bridge bent designed to re-center after an earthquake : research report, October 2008.

    Science.gov (United States)

    2008-10-01

    In this study the post-earthquake residual displacements of reinforced concrete bridge bents were investigated. The system had mild steel that was intended to dissipate energy and an unbonded, post-tensioned tendon that was supposed to remain elastic...

  12. A precast concrete bridge bent designed to re-center after an earthquake : draft research report, August 2008.

    Science.gov (United States)

    2008-08-01

    In this study the post-earthquake residual displacements of reinforced concrete bridge bents were investigated. The system had mild steel that was intended to dissipate energy and an unbonded, post-tensioned tendon that was supposed to remain elastic...

  13. An integrated damping and strengthening strategy for performance-based seismic design and retrofit for highway bridges.

    Science.gov (United States)

    2009-05-01

    In this study, a damping-enhanced strengthening (DES) strategy was introduced to retrofit bridge structures for multiple : performance objectives. The main objectives of this study are (1) to numerically demonstrate the effectiveness of the anchoring...

  14. Evaluation of design methods to determine scour depths for bridge structures : LTRC research project capsule 08-3ST.

    Science.gov (United States)

    2009-04-01

    Scour, an engineering term for erosion, is : the result of the erosive action of flowing : water excavating and carrying away : material from the bed and banks of : streams and from around the piers and : abutments of bridges. For analysis : purposes...

  15. 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...

  16. Experimental evaluation and design of unfilled and concrete-filled FRP composite piles, task 2 - FRP composite pile driving at the Richmond-Dresden bridge over the Kennebec River.

    Science.gov (United States)

    2014-01-01

    The overall goal of this project is the experimental evaluation and design of unfilled and concrete-filled FRP : composite piles for load-bearing in bridges. This report covers Task 2, FRP Composite Pile Driving at the : Richmond-Dresden Bridge over ...

  17. 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...

  18. The Building Bridges Project: Involving Older Adults in the Design of a Communication Technology to Support Peer-to-Peer Social Engagement

    Science.gov (United States)

    Wherton, Joseph; Prendergast, David

    There are a variety of factors that can lead to social isolation and loneliness in old age, including decline in physical and mental health, as well as change to social environment. The Building Bridges project explores how communication technology can help older adults remain socially connected. This paper will first provide an overview of a prototype communication system designed to support peer-to-peer group interaction. A description of the user-centered design process will be provided to demonstrate the importance of involving older adults at the earliest stages. The implications for designing new technology for older adults are discussed.

  19. 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)....

  20. 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.

  1. 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.

  2. 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.

  3. 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...

  4. Designing the Bridge: Perceptions and Use of Downscaled Climate Data by Climate Modelers and Resource Managers in Hawaii

    Science.gov (United States)

    Keener, V. W.; Brewington, L.; Jaspers, K.

    2016-12-01

    To build an effective bridge from the climate modeling community to natural resource managers, we assessed the existing landscape to see where different groups diverge in their perceptions of climate data and needs. An understanding of a given community's shared knowledge and differences can help design more actionable science. Resource managers in Hawaii are eager to have future climate projections at spatial scales relevant to the islands. National initiatives to downscale climate data often exclude US insular regions, so researchers in Hawaii have generated regional dynamically and statistically downscaled projections. Projections of precipitation diverge, however, leading to difficulties in communication and use. Recently, a two day workshop was held with scientists and managers to evaluate available models and determine a set of best practices for moving forward with decision-relevant downscaling in Hawaii. To seed the discussion, the Pacific Regional Integrated Sciences and Assessments (RISA) program conducted a pre-workshop survey (N=65) of climate modelers and freshwater, ecosystem, and wildfire managers working in Hawaii. Scientists reported spending less than half of their time on operational research, although the majority was eager to partner with managers on specific projects. Resource managers had varying levels of familiarity with downscaled climate projections, but reported needing more information about uncertainty for decision making, and were less interested in the technical model details. There were large differences between groups of managers, with 41.7% of freshwater managers reporting that they used climate projections regularly, while a majority of ecosystem and wildfire managers reported having "no familiarity". Scientists and managers rated which spatial and temporal scales were most relevant to decision making. Finally, when asked to compare how confident they were in projections of specific climate variables between the dynamical and

  5. 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,…

  6. 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...

  7. 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....

  8. A designed 5-fluorouracil-based bridged silsesquioxane as an autonomous acid-triggered drug-delivery system.

    Science.gov (United States)

    Giret, Simon; Théron, Christophe; Gallud, Audrey; Maynadier, Marie; Gary-Bobo, Magali; Garcia, Marcel; Wong Chi Man, Michel; Carcel, Carole

    2013-09-16

    Two new prodrugs, bearing two and three 5-fluorouracil (5-FU) units, respectively, have been synthesized and were shown to efficiently treat human breast cancer cells. In addition to 5-FU, they were intended to form complexes through H-bonds to an organo-bridged silane prior to hydrolysis-condensation through sol-gel processes to construct acid-responsive bridged silsesquioxanes (BS). Whereas 5-FU itself and the prodrug bearing two 5-FU units completely leached out from the corresponding materials, the prodrug bearing three 5-FU units was successfully maintained in the resulting BS. Solid-state NMR ((29) Si and (13) C) spectroscopy show that the organic fragments of the organo-bridged silane are retained in the hybrid through covalent bonding and the (1) H NMR spectroscopic analysis provides evidence for the hydrogen-bonding interactions between the prodrug bearing three 5-FU units and the triazine-based hybrid matrix. The complex in the BS is not affected under neutral medium and operates under acidic conditions even under pH as high as 5 to deliver the drug as demonstrated by HPLC analysis and confirmed by FTIR and (13) C NMR spectroscopic studies. Such functional BS are promising materials as carriers to avoid the side effects of the anticancer drug 5-FU thanks to a controlled and targeted drug delivery. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Analysis, Design, Modeling, and Control of an Interleaved-Boost Full-Bridge Three-Port Converter for Hybrid Renewable Energy Systems

    DEFF Research Database (Denmark)

    Mira Albert, Maria del Carmen; Zhang, Zhe; Knott, Arnold

    2017-01-01

    This paper presents the design, modeling, and control of an isolated dc-dc three-port converter (TPC) based on an interleaved-boost full-bridge converter with pulsewidth modulation (PWM) and phase-shift control for hybrid renewable energy systems. In the proposed topology, the switches are driven...... by phase-shifted PWM signals, where both phase angle and duty cycle are the controlled variables. The power flow between the two inputs is controlled through the duty cycle, whereas the output voltage can be regulated effectively through the phase shift. The primary-side MOSFETs can achieve zero...

  10. Design optimization of a high-power transformer for three-phase dual active bridge DC-DC converter for MVDC grids

    OpenAIRE

    Lee, Youngsil; Vakil, Gaurang; Feldman, Ralph; Goodman, Andrew; Wheeler, Patrick

    2016-01-01

    High-power DC-DC converter will be one of the essential technologies for the future DC grids. Especially, a three-phase dual-active bridge DC-DC (3DAB) Converter is highly suitable for high-power DC systems. Key component within this converter is the high power transformer operated at a medium frequency (MF) range. The design and optimization of this key component is presented in this paper. The transformer provides galvanic isolation from low voltage level to medium level or high voltage lev...

  11. 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...

  12. 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

  13. 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...

  14. 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,...

  15. 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...

  16. 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

  17. 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.

  18. 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…

  19. 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 ...

  20. 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...

  1. 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...

  2. 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...

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. 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.

  8. 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...

  9. Rational design, synthesis, and biological evaluation of lactam-bridged gramicidin A analogues: discovery of a low-hemolytic antibacterial peptide.

    Science.gov (United States)

    Mao, Ji; Kuranaga, Takefumi; Hamamoto, Hiroshi; Sekimizu, Kazuhisa; Inoue, Masayuki

    2015-03-01

    A linear peptide, gramicidin A (GA), folds into a β(6.3) -helix, functions as an ion channel in the cell membrane, and exerts antibacterial activity. Herein we describe the rational design, synthesis, and biological evaluation of lactam-bridged GA analogues. The GA analogue with a 27-membered macrolactam was found to adopt a stable β(6.3) -helical conformation and exhibits higher ion-exchange activity than GA. Furthermore, this GA analogue retains the potent antibiotic activity of GA, but its hemolytic activity and toxicity toward mammalian cells are significantly lower than those of GA. This study thus dissociates the antibacterial and hemolytic/cytotoxic activities of GA, and charts a rational path forward for the development of new ion-channel-based antibiotics. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Isolated Full Bridge Boost DC-DC Converter Designed for Bidirectional Operation of Fuel Cells/Electrolyzer Cells in Grid-Tie Applications

    DEFF Research Database (Denmark)

    Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    Energy production from renewable energy sources is continuously varying, for this reason energy storage is becoming more and more important as the percentage of green energy increases. Newly developed fuel cells can operate in reverse mode as electrolyzer cells; therefore, they are becoming...... an attractive technology for energy storage grid-tie applications. In this application dc-dc converter optimization is very challenging due to the large voltage range that the converter is expected to operate. Moreover, the fuel-electrolyzer cell side of the converter is characterized by low voltage and high...... current. Dc-dc converter efficiency plays a fundamental role in the overall system efficiency since processed energy is always flowing through the converter; for this reason, loss analysis and optimization are a key component of the converter design. The paper presents an isolated full bridge boost dc...

  11. Inspection method of cable-stayed bridge using magnetic flux leakage detection: principle, sensor design, and signal processing

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Fengyu; Wang, Xingsong [Southeast University, Nanjing (China); Wu, Hongtao [Nanjing University of Aeronautics and Astronautics, Nanjing (China)

    2012-03-15

    A nondestructive testing technique based on magnetic flux leakage is presented to inspect automatically the stay cables with large diameters of a cable-stayed bridge. Using the proposed inspection method, an online nondestructive testing (NDT) modular sensor is developed. The wreath-like sensor is composed of several sensor units that embrace the cable at equal angles. Each sensor unit consists of two permanent magnets and a hall sensor to detect the magnetic flux density. The modular sensor can be installed conveniently on cables with various diameters by increasing the number of sensor units and adjusting the relative distances between adjacent sensor units. Results of the experiments performed on a man-made cable with faults prove that the proposed sensor can inspect the status signals of the inner wires of the cables. To filter the interfering signals, three processing algorithms are discussed, including the moving average method, improved detrending algorithm, and signal processing based on a digital filter. Results show that the developed NDT sensor carried by a cable inspection robot can move along the cable and monitor the state of the stay cables.

  12. A perspective on bridging scales and design of models using low-dimensional manifolds and data-driven model inference

    KAUST Repository

    Tegner, Jesper

    2016-10-04

    Systems in nature capable of collective behaviour are nonlinear, operating across several scales. Yet our ability to account for their collective dynamics differs in physics, chemistry and biology. Here, we briefly review the similarities and differences between mathematical modelling of adaptive living systems versus physico-chemical systems. We find that physics-based chemistry modelling and computational neuroscience have a shared interest in developing techniques for model reductions aiming at the identification of a reduced subsystem or slow manifold, capturing the effective dynamics. By contrast, as relations and kinetics between biological molecules are less characterized, current quantitative analysis under the umbrella of bioinformatics focuses on signal extraction, correlation, regression and machine-learning analysis. We argue that model reduction analysis and the ensuing identification of manifolds bridges physics and biology. Furthermore, modelling living systems presents deep challenges as how to reconcile rich molecular data with inherent modelling uncertainties (formalism, variables selection and model parameters). We anticipate a new generative data-driven modelling paradigm constrained by identified governing principles extracted from low-dimensional manifold analysis. The rise of a new generation of models will ultimately connect biology to quantitative mechanistic descriptions, thereby setting the stage for investigating the character of the model language and principles driving living systems.

  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. 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...

  15. 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...

  16. 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...

  17. 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...

  18. Development of wave and surge atlases for the design and protection of coastal bridges in South Louisiana.

    Science.gov (United States)

    2011-05-01

    The objectives of this proposed research are to: 1. Develop a 100-year design. a. maximum water surface elevation and associated wave height, b. maximum wave height and associated water elevation atlases for South Louisiana coastal waters. 2. Obtain ...

  19. Optimal Design of a Push-Pull-Forward Half-Bridge (PPFHB) Bidirectional DC–DC Converter With Variable Input Voltage

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2012-01-01

    This paper presents a low-cost bidirectional isolated dc–dc converte, derived from dual-active-bridge converter for the power sources with variable output voltage like supercapacitors. The proposed converter consists of push-pull-forward circuit half-bridge circuit (PPFHB) and a high-frequency tr......This paper presents a low-cost bidirectional isolated dc–dc converte, derived from dual-active-bridge converter for the power sources with variable output voltage like supercapacitors. The proposed converter consists of push-pull-forward circuit half-bridge circuit (PPFHB) and a high...

  20. Impact of cross-tie design on the in-plane stiffness and local mode formation of cable networks on cable-stayed bridges

    Science.gov (United States)

    Ahmad, Javaid; Cheng, Shaohong; Ghrib, Faouzi

    2016-02-01

    Suppressing unfavorable stay cable vibrations using cross-ties is becoming more popular on cable-stayed bridges though the mechanics of the formed cable network is yet fully understood. In practice, the main task in designing cross-ties or cable networks is to choose the cross-tie installation location, stiffness and number based on the main cable properties in the network. To have a more comprehensive picture of how to choose these design parameters to achieve higher in-plane network stiffness while minimizing the number of excited local modes, it is imperative to examine dynamic behavior of cable networks with general configurations. In the current study, an analytical model of a general cable network consisting of multiple main cables interconnected by multiple lines of transverse flexible cross-ties will be developed. A new term, defined as the local mode cluster, will be introduced to assess the severity of local mode excitation. Criteria for identifying the presence of local mode cluster will be proposed. A parametric study will be conducted to evaluate the impact of cross-tie installation location, stiffness and number on the network modal response. Results obtained from the present study will provide deeper insight into the selection of these system parameters to achieve the combined benefits of increasing network in-plane stiffness and minimizing the excitation of local modes.

  1. Development of wave and surge atlas for the design and protection of coastal bridges in South Louisiana - phase 2.

    Science.gov (United States)

    2016-09-01

    This report summarizes the work performed by INTERA Incorporated (INTERA), for the Louisiana Department of Transportation and Development (DOTD) on Phase 2 of LTRC project No. 10-4ST, Development of Wave and Surge Atlas for the Design Protection o...

  2. Bridging the Field Trip Gap: Integrating Web-Based Video as a Teaching and Learning Partner in Interior Design Education

    Science.gov (United States)

    Roehl, Amy

    2013-01-01

    This study utilizes web-based video as a strategy to transfer knowledge about the interior design industry in a format that interests the current generation of students. The model of instruction developed is based upon online video as an engaging, economical, and time-saving alternative to a field trip, guest speaker, or video teleconference.…

  3. 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.

  4. 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

  5. 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....

  6. Design, construction and load testing of the Pat Daly road bridge in Washington County, MO, with internal glass fiber reinforced polymers reinforcement.

    Science.gov (United States)

    2013-01-01

    The overarching goal of this project is to deploy and assess an innovative corrosion-free bridge construction technology for long-term : performance of new and existing bridges. The research objective of this project is to conduct a comprehensive stu...

  7. Design, construction and load testing of the Pat Daly Bridge in Washington County, MO, with internal glass fiber reinforced polymers reinforcement.

    Science.gov (United States)

    2013-01-01

    The overarching goal of this project is to deploy and assess an innovative corrosion-free bridge construction technology for long-term : performance of new and existing bridges. The research objective of this project is to conduct a comprehensive stu...

  8. Three Dimensional Analysis of the Final Design of Pier Extensions and West Guide Wall to Mitigate Local Scour Risk at the BNSF Railroad Bridge Downstream of the Prado Dam Supplemental Report

    Energy Technology Data Exchange (ETDEWEB)

    Lottes, S. A. [Argonne National Lab. (ANL), Argonne, IL (United States); Sinha, N. [Argonne National Lab. (ANL), Argonne, IL (United States); Bojanowski, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Kerenyi, K. [Turner-Fairbank Highway Research Center, McLean, VA (United States); Sharp, Jeremy [U.S. Army Corps of Engineers, Vicksburg, MI (United States), Coastal and Hydraulics Lab

    2016-06-01

    This report is a supplement to a previous report [ref] covering optimization of wedge shaped pier extensions to streamline large bluff body piers as a local scour countermeasure for the Burlington Northern and Santa Fe (BNSF) Railroad Bridge over the Santa Ana River downstream of Prado Dam in Riverside County, CA. The optimized design was tested in a 1/30 scale physical model at U.S. Army Engineer Research and Development Center (ERDC) in Vicksburg, MS, and the optimized design was used as the base for the construction design. Constructability issues having to do with both materials and site conditions including access underneath the BNSF bridge yielded a construction design that required making the pier extensions wider and either moving the western curve of the west guide wall upstream or changing its geometry.

  9. 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...

  10. 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...

  11. 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...

  12. Bridging the language gap: a co-designed quality improvement project to engage professional interpreters for women during labour.

    Science.gov (United States)

    Yelland, Jane; Biro, Mary Anne; Dawson, Wendy; Riggs, Elisha; Vanpraag, Dannielle; Wigg, Karen; Antonopoulos, John; Morgans, Jenny; Szwarc, Jo; East, Chris; Brown, Stephanie

    2017-10-01

    Objective The aim of the study was to improve the engagement of professional interpreters for women during labour. Methods The quality improvement initiative was co-designed by a multidisciplinary group at one Melbourne hospital and implemented in the birth suite using the plan-do-study-act framework. The initiative of offering women an interpreter early in labour was modified over cycles of implementation and scaled up based on feedback from midwives and language services data. Results The engagement of interpreters for women identified as requiring one increased from 28% (21/74) at baseline to 62% (45/72) at the 9th month of implementation. Conclusion Improving interpreter use in high-intensity hospital birth suites is possible with supportive leadership, multidisciplinary co-design and within a framework of quality improvement cycles of change. What is known about the topic? Despite Australian healthcare standards and policies stipulating the use of accredited interpreters where needed, studies indicate that services fall well short of meeting these during critical stages of childbirth. What does the paper add? Collaborative approaches to quality improvement in hospitals can significantly improve the engagement of interpreters to facilitate communication between health professionals and women with low English proficiency. What are the implications for practice? This language services initiative has potential for replication in services committed to improving effective communication between health professionals and patients.

  13. 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...

  14. 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...

  15. Bridging the ';knowing and doing gap' in disaster risk reduction using design and design thinking; Ideation of concepts to improve hazard preparedness and response

    Science.gov (United States)

    van Manen, S. M.

    2013-12-01

    The central goal of disaster risk reduction (DRR) is to reduce the impact and cost of natural hazards, in human, environmental and economic terms. There are numerous approaches that aim to achieve this but recent studies have shown a substantial gap between risk reduction actions taken at national and local levels. The traditional media of the scientist: education, outreach and increasingly community involvement, have been shown to raise levels of awareness and understanding but generate little change in terms of people's actions. This can be attributed to the differences in hazard perception and the relative weight placed on various aspects by scientists, authorities and communities as a result of non-hazard related factors. Therefore DRR, particularly when placed in its social, environmental and economic contexts, is an excellent example of what is termed a ';wicked problem': a problem that is difficult to formulate, where data to base decisions on are incomplete, the stakeholders are many and they hold contradicting views and the consequences of actions on the wider system are unclear. Although both science and design are geared towards problem solving, design, in drawing equally on art and engineering skills, does so in a fundamentally different but complementary way. Neither design nor science will solve the wicked problem that is DRR, but scientists, engineers and designers can improve the current state of disaster risk reduction by tackling aspects of underlying risk factors. This work will present concepts aimed at engaging people in novel and innovative ways with scientific results, with a specific focus on improving hazard preparedness and tangible, rather than abstract, ways of communicating hazard levels. Key considerations include the need to graft onto existing behaviours or innovate on existing products to simplify implementation, the possibility to co-create and connect through design and balancing desirability with technical and economical

  16. 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...

  17. Comportamiento estructural y criterios de diseño de los puentes extradosados: visión general y estado del arte Structural behavior and design criteria of extradosed bridges: general insight and state of the art

    Directory of Open Access Journals (Sweden)

    José Benjumea

    2010-01-01

    Full Text Available Durante los últimos 10 años, los puentes extradosados se han convertido en una solución estructural atractiva alrededor del mundo, gracias a los buenos resultados obtenidos con las primeras realizaciones en Japón. Esta nueva tipología, reconocida generalmente como una solución intermedia entre los puentes atirantados y los de pretensado de viga cajón construidos por voladizos sucesivos, se ha convertido en una opción interesante. Por consiguiente, dado el interés que hoy en día existe alrededor de este tipo de puente, en este trabajo se presenta el contexto histórico que describe su origen, y se exponen la influencia de los principales elementos estructurales en el comportamiento del puente, y los criterios de diseño que han sido propuestos por investigadores en el tema. De esta manera, se espera ofrecer una visión general de la concepción y el comportamiento estructural de los puentes extradosados para que sea considerada una alternativa más de tipología estructural de puentes en nuestro medio.Over the past 10 years, Extradosed bridges have become an attractive structural type around the world, due to the good results obtained with the first bridges constructed in Japan. This new typology, generally recognized as an intermediate solution between cable stayed bridges and cantilever constructed prestressed box-girder bridges, because these take advantages of design and constructions methods of the other two typologies, has become an interesting option. Therefore, given the interest that exist about this type of bridge, in this paper the historical context that describes its origin, the influence of the principal structural elements and the design criteria proposed by researchers are presented. In this way it is expected to offer a general insight into the design conception and structural behavior of Extradosed Bridges, so that they may be considered as an alternative structure for bridges in the Americas.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  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. 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 ...

  5. Bridging worlds

    DEFF Research Database (Denmark)

    Rose, Jeremy; Memon, Saifullah Hassan

    2012-01-01

    This paper reports a case study where Soft Systems Methodology (SSM) was used to help automate a largely manual administrative (examination) information system in a Pakistani university. Various design suggestions for information system improvements, both administrative and IT-supported were made...... analysis tools into the design process. The research extends SSM in information system development (ISD) - from a single situational analysis to a comparative process and can be adapted as a pattern for practitioners with similar automation needs....... (and implemented) through comparison with another university in Denmark which is well supported by computer systems. An action design research approach with an interpretative epistemology/ontology was adopted. Though the single comparison experience is difficult to generalise, we conclude that SSM...

  6. 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.

  7. 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.

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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.

  14. 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....

  15. 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...

  16. 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.

  17. 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.

  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. Annex 3: BRIDGESIM, a simulation tool for the system design of bridge heating for ice prevention with solar heat stored in a seasonal ground duct store

    Energy Technology Data Exchange (ETDEWEB)

    Pahud, D.

    2006-12-15

    This is the Annex 3 of the annual report 2006 of the Serso project. This appendix provides details on the BRIDGESIM simulation tool for the simulation of a bridge heating system that uses heat stored in summer in a long-term diffusive borehole store to ensure an ice-free surface on a road bridge in winter. The operation of the control system which controls the heating system is described. The simulation tool is described and the various input parameters are discussed, as is the parametrisation of the tool itself. These parameters include not only timescales but also data on the borehole heat exchangers, data on the buried heating pipes in the road surface, thermal conductivity of the circulating heat-transfer fluid, ground parameters, intermediate water tank parameters and many other related data. The running of the simulation and output data are also described. Outputs are also presented in graphical form.

  20. 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

  1. Shear capacity of in service pre-stressed 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 those...

  2. Study of the time-dependent clear water scour around circular bridge piers

    Directory of Open Access Journals (Sweden)

    Aksoy Aysegul Ozgenc

    2017-03-01

    Full Text Available The local scour around bridge piers influences their stabilities and plays a key role in the bridge failures. The estimation of the maximum possible scour depth around bridge piers is an important step in the design of the bridge pier foundations. In this study, the temporal evolution of local scour depths as well as the equilibrium scour depths were analyzed.

  3. 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

  4. 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...

  5. 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...

  6. 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....

  7. 49 CFR 237.131 - Design.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Design. 237.131 Section 237.131 Transportation... TRANSPORTATION BRIDGE SAFETY STANDARDS Repair and Modification of Bridges § 237.131 Design. Each repair or... component of a bridge shall be designed by a railroad bridge engineer. The design shall specify the manner...

  8. 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...

  9. [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.

  10. 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....

  11. 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 ...

  12. 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

  13. Fatigue classification of welded joints in orthotropic steel bridge decks

    NARCIS (Netherlands)

    Kolstein, M.H.

    2007-01-01

    This dissertation presents the research into fatigue classifications of welded joints in orthotropic steel bridge decks. These classifications are needed to calculate the fatigue life of these joints and should be included in the design codes. For years bridge design was mainly based on static

  14. 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.

  15. 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.

  16. 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...

  17. 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....

  18. 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....

  19. Bridging the Gap between User Experience Research and Design in Industry: An Analysis of Two Common Communication Tools--Personas and Scenarios

    Science.gov (United States)

    Putnam, Cynthia

    2010-01-01

    User experience (UX) research in the design of technology products utilizes human-centered design (HCD) methods to summarize and explain pertinent information about end users to designers. However, UX researchers cannot effectively communicate the needs and goals of users if designers do not find UX research (a) easy to integrate into design…

  20. 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.

  1. Plans for crash-tested bridge railings for longitudinal wood decks

    Science.gov (United States)

    M. A. Ritter; R. K. Faller; P. D. Hilbrich Lee; B. T. Rosson; S. R. Duwadi

    1995-01-01

    In the past decade, bridge railing design criteria have moved away from static-load design and have focused on full-scale crash testing as a more appropriate and reliable means of evaluating bridge railings. The five bridge railing plans presented reflect the results of a cooperative research project between the Midwest Roadside Safety Facility, University of Nebraska...

  2. 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.

  3. Dynamic response for structural health monitoring of the Penang (I) cable-stayed bridge

    Science.gov (United States)

    Mohammed, M. I.; Sulaeman, E.; Mustapha, F.

    2017-03-01

    The paper discusses the dynamic response of the Penang (I) cable stayed bridge structure under various moving load representing typical traffic load of the bridge. The bridge has a total span of 440 m excluding the transition bridge that assumed to be not connected structurally to the main bridge structure. The bridge that links the fast growing Pinang Island and the Malaysian Mainland Peninsula has been known to be fully utilized which leads to the construction of Penang (II) bridge and now the third one. Due to highly traffic use of the bridge that may lead to reduction of the bridge design life, the dynamic response of the bridge becomes important to predict critical part of the bridge structure elements including the main girder and the 144 stay cables. The present study reveals that, due to flexible nature of the cable stayed bridge, the moving load that interacts with the natural dynamic characteristics of the bridge, gives significant stress increment compare to proportional static load especially when the moving load is un-symmetric. For this reason, several classes of typical vehicle passing the bridge with various vehicle speeds are investigated to demonstrate their effect on the bridge displacement, internal forces and stresses. The results can be used for further fatigue assessment of the bridge.

  4. Theoretical and field experimental evaluation of skewed modular slab bridges : [research summary].

    Science.gov (United States)

    2012-12-01

    Adjacent precast, prestressed concrete multi-beam bridges have become more : prevalent due to their rapid construction time and cost effectiveness. Over the : years, various adjustments and refinements have been made to the design of : these bridges ...

  5. 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

  6. Feasibility of fiber reinforced composite materials used in highway bridge superstructures

    OpenAIRE

    Lin, Shih-Yung

    1988-01-01

    Composite materials are considered here as structural materials of highway bridge superstructures. Bridge deck designs can be done according to AASHTO1 specification and elastic design concepts. In order to evaluate the feasibility of composites as structural materials of highway bridge superstructures, composite materials are compared not only to composite materials themselves but also to the most popular bridge structural materials, which are reinforced concrete and struc...

  7. 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.

  8. 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...

  9. 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)

  10. 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...

  11. 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...

  12. Three Dimensional Analysis of Pier Extension and Guide Wall Design Alternatives to Mitigate Local Scour Risk at the BNSF Railroad Bridge Downstream of the Prado Dam

    Energy Technology Data Exchange (ETDEWEB)

    Lottes, S. A. [Argonne National Lab. (ANL), Argonne, IL (United States); Bojanowski, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Sinha, N. [Argonne National Lab. (ANL), Argonne, IL (United States); Kerenyi, K [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-03-01

    The primary objectives of the computational fluid dynamics (CFD) analysis are (1) to verify that the design concept of using wedge shaped pier extensions to divert flow around piers as a scour counter measure has the intended effect on the flow, (2) to refine the design of the length and orientation of the pier extensions within the channel and (3) to optimize the guide walls that will protect a set of outer piers and the abutments on each side of the channel. The original proposed design is shown in Figure 1.3. The results of this effort are the recommended designs that are judged to be the best designs based on results from the set of test cases run combined with engineering judgment. The refined designs from the CFD analysis are expected to be tested in a limited set of physical model experiments to verify that they work well.

  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. 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.

  15. 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.

  16. Toward Better Understanding of Turbulence Effects on Bridge Aerodynamics

    Directory of Open Access Journals (Sweden)

    Shuyang Cao

    2017-12-01

    Full Text Available With the trend of variable cross-sections for long-span bridges from truss-stiffened to quasi-streamlined, and then to multiple-box cross-section geometries, the importance of aeroelastic performance is becoming increasingly significant in wind-resistant design. This article shows that there is clearly insufficient qualitative as well as quantitative understanding of turbulence effects on bridge aerodynamics, particularly the mechanisms behind them. Although turbulence might help the stabilization of long-span bridges, and is thus not a conclusive parameter in wind-resistant design, turbulence effects on the aerodynamic and aeroelastic behaviors of a bridge need to be better understood because interaction between a bridge and turbulence always exists. This article also briefly introduces a newly developed multiple-fan wind tunnel that is designed to control turbulence to assist the study of turbulence effects.

  17. Computer modeling of road bridge for simulation moving load

    Directory of Open Access Journals (Sweden)

    Miličić Ilija M.

    2016-01-01

    Full Text Available In this paper is shown computational modelling one span road structures truss bridge with the roadway on the upper belt of. Calculation models were treated as planar and spatial girders made up of 1D finite elements with applications for CAA: Tower and Bridge Designer 2016 (2nd Edition. The conducted computer simulations results are obtained for each comparison of the impact of moving load according to the recommendations of the two standards SRPS and AASHATO. Therefore, it is a variant of the bridge structure modeling application that provides Bridge Designer 2016 (2nd Edition identical modeled in an environment of Tower. As important information for the selection of a computer applications point out that the application Bridge Designer 2016 (2nd Edition we arent unable to treat the impacts moving load model under national standard - V600. .

  18. 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.

  19. 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...

  20. 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

  1. 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...

  2. 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, ...

  3. 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

  4. 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

  5. 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...

  6. Analysis and Experimental on Aircraft Insulation Thermal Bridge Effect

    Directory of Open Access Journals (Sweden)

    XIA Tian

    2017-06-01

    Full Text Available Two kinds of typical aircraft insulation structures were designed for the heat bridge in the metal ribs of aircraft insulation structures. In order to study the influence of heat bridge effect on thermal insulation performance, each configuration was analyzed by the transient heat transfer FEA, check point temperature was obtained in the hot surface temperature of 100 ℃, 200 ℃, 300 ℃, 424 ℃ respectively, and the validity of FEA was proved by insulation performance experiment. The result showed that the thermal bridge has a great influence to the insulation performance of insulation structure, and the thermal bridge influence should be considered adequately when the insulation structure designed. Additionally, the blocking method for thermal bridge is also put forward.

  7. Long term monitoring of carbon composite strands in the Penobscot-Narrows bridge.

    Science.gov (United States)

    2015-06-01

    The Penobscot-Narrows Bridge was constructed between May 2003 and December 2006. The bridge is a cable-stayed design with twin pylons and a 2,120-foot span. This cable-stayed bridge features a cradle stay system that : allows for each cable strand in...

  8. Fatigue of bridges with a horizontal rotation axle under random wind load

    NARCIS (Netherlands)

    Maljaars, J.; Steenbergen, R.D.J.M.

    2012-01-01

    The operating mechanisms of movable bridges are subjected to various types of fluctuating loads which may induce fatigue damage. Wind load acting on the bridge deck - when the bridge is open - is one of the important load types. A wind load model is proposed that can be used in the fatigue design

  9. A review of long-span suspension bridges: a case of Akashi-Kaikyo ...

    African Journals Online (AJOL)

    These bridges contain remarkable features of novel bridge construction technology, such as poly-aramid fibre pilot rope, prefabricated parallel wire strands and air injected cables. Earthquake resistance has often been an important design and construction parameter. Keywords: long-span suspension bridges, poly-ararnid ...

  10. 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...

  11. 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...

  12. Analysis and design of a parallel-connected single active bridge DC-DC converter for high-power wind farm applications

    DEFF Research Database (Denmark)

    Park, Kiwoo; Chen, Zhe

    2013-01-01

    ripples without increasing switching losses or device stresses. Analysis of both the input and output current characteristics and design aspects of the transformer, the filter inductor, and the input and output filter capacitors will be presented. Considering the high maintenance cost and fault tolerant...

  13. 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)....

  14. 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. ...

  15. Developments and Prospects of Long-Span High-Speed Railway Bridge Technologies in China

    Directory of Open Access Journals (Sweden)

    Shunquan Qin

    2017-12-01

    Full Text Available With the rapid developments of the high-speed railway in China, a great number of long-span bridges have been constructed in order to cross rivers and gorges. At present, the longest main span of a constructed high-speed railway bridge is only 630 m. The main span of Hutong Yangtze River Bridge and of Wufengshan Yangtze River Bridge, which are under construction, will be much longer, at 1092 m each. In order to overcome the technical issues that originate from the extremely large dead loading and the relatively small structural stiffness of long-span high-speed railway bridges, many new technologies in bridge construction, design, materials, and so forth have been developed. This paper carefully reviews progress in the construction technologies of multi-function combined bridges in China, including combined highway and railway bridges and multi-track railway bridges. Innovations and practices regarding new types of bridge and composite bridge structures, such as bridges with three cable planes and three main trusses, inclined main trusses, slab-truss composite sections, and steel-concrete composite sections, are introduced. In addition, investigations into high-performance materials and integral fabrication and erection techniques for long-span railway bridges are summarized. At the end of the paper, prospects for the future development of long-span high-speed railway bridges are provided.

  16. 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.

  17. Shaking Table Tests of Curved Bridge considering Bearing Friction Sliding Isolation

    Directory of Open Access Journals (Sweden)

    Lei Yan

    2016-01-01

    Full Text Available Specific to severe damage to curved bridges in earthquakes caused by the excessive force of the fixed bearings and piers, a new seismic design method on curved bridges considering bearing friction sliding isolation is proposed in this paper. Seismic model bridge and isolation model bridge with similarity ratio of 1/20 were made and the shaking table comparison test was conducted. The experimental results show that the isolation model curved bridge suffered less seismic damage than the seismic model curved bridge. The fundamental frequencies of the seismic model bridge and isolation model bridge decreased and the damping ratio increased with the increase of seismic intensity. Compared with seismic curved bridge, the maximum reduction rates of peak acceleration along the radial and tangential directions on the top of pier of the isolation model curved bridge were 47.3% and 55.5%, respectively, and the maximum reduction rate of the peak strain on the bottom of pier of the isolation model curved bridge was 43.4%. For the isolation model curved bridge, the maximum reduction rate of peak acceleration on the top of pier was 24.6% compared with that on the bottom of pier. The study results can provide experimental basis for the seismic design of curved bridges.

  18. 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.

  19. Bridging the Generational Culture Gap in Youth Civic Engagement through Social Media: Lessons Learnt from Young Designers in Three Civic Organisations

    OpenAIRE

    Mainsah, Henry; Brandtzæg, Petter Bae; Følstad, Asbjørn

    2016-01-01

    Youth civic identities and social media practices are changing rapidly, and civic organisations are struggling to exploit the potential of social media to reach youth. One major challenge concerns the generational culture gap between the networked culture of today’s youth and the top–down culture characteristic of many civic organisations. This study presents lessons learnt from three cases where young designers (22–26 years) were engaged to develop social media concepts for civic organisatio...

  20. Seismic Performance of Self-Consolidating Concrete Bridge Columns

    Science.gov (United States)

    2017-09-01

    The high amount of confining lateral steel required by seismic design provisions for rectangular bridge columns can cause steel congestion. The high amount of confining steel may hinder the placement of conventional concrete (CC). Self-consolidating ...

  1. Self-Consolidating Concrete for Prestressed Bridge Girders

    Science.gov (United States)

    2017-07-01

    This document reports the findings of a research project designed to better understand material and structural performance of prestressed bridge girders made with Self-Consolidating Concrete (SCC) from Wisconsin. SCC has high potential to be used for...

  2. 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.

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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…

  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. Numerical analysis of dynamic response of vehicle–bridge coupled system on long-span continuous girder bridge

    Directory of Open Access Journals (Sweden)

    Lipeng An

    2016-07-01

    Full Text Available To systematically study the vehicle–bridge coupled dynamic response and its change rule with different parameters, a vehicle model with seven degrees of freedom was built and the total potential energy of vehicle space vibration system was deduced. Considering the stimulation of road roughness, the dynamic response equation of vehicle–bridge coupled system was established in accordance with the elastic system principle of total potential energy with stationary value and the “set-in-right-position” rule. On the basis of the self-compiled Fortran program and bridge engineering, the dynamic response of long-span continuous girder bridge under vehicle load was studied. This study also included the calculation of vehicle impact coefficient, evaluation of vibration comfort, and analysis of dynamic response parameters. Results show the impact coefficient changes with lane number and is larger than the value calculated by the “general code for design of highway bridges and culverts (China”. The Dieckmann index of bridge vibration is also related to lane number, and the vibration comfort evaluation is good in normal conditions. The relevant conclusions from parametric analyses have practical significance to dynamic design and daily operation of long-span continuous girder bridges in expressways. Safety and comfort are expected to improve significantly with further control of the vibration of vehicle–bridge system.

  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. Blueprint and First Experiences Bridging Hardware Virtualization and Global Grids for Advanced Scientific Computing: Designing and Building a Global Edge Services Framework (ESF) for OSG, EGEE, and LCG

    CERN Document Server

    Rana, A S; Vaniachine, A; Wurthwein, F; Foster, I; Sotomayor, B; Freeman, T

    2006-01-01

    We report on first experiences with building and operating an edge services framework (ESF) based on Xen virtual machines instantiated via the workspace service in Globus toolkit, and developed as a joint project between EGEE, LCG, and OSG. Many computing facilities are architected with their compute and storage clusters behind firewalls. Edge services (ES) are instantiated on a small set of gateways to provide access to these clusters via standard grid interfaces. Experience on EGEE, LCG, and OSG has shown that at least two issues are of critical importance when designing an infrastructure in support of ES. The first concerns ES configuration. It is impractical to assume that each virtual organization (VO) using a facility will employ the same ES configuration, or that different configurations will coexist easily. Even within a VO, it should be possible to run different versions of the same ES simultaneously. The second issue concerns resource allocation: it is essential that an ESF be able to effectively gu...

  14. 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.

  15. Ambient Modal Testing of the Vestvej Bridge using Random Decrement

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Brincker, Rune; Rytter, A.

    concerning application of vibration based inspection of bridges. The data analysis process of ambient vribration testing of bridges has traditionally been based on auto and cross spectral densities estimated using an FFT algorithm. In the pre-analysis state the spectral densities are all averaged to obtain......This paper presents an ambient vibration study of the Vestvej Bridge. The bridge is a typically Danish two-span concrete bridge which crosses a highway. The purpose of the study is to perform a pre-investigation of the dynamic behavior to obtain information for the design of a demonstration project...... the averaged spectral densities(ASD). From the ASD the eigenfrequencies of the structure can be identified. This information can be used in the main analysis, where alle modal parameters are extracted from the spectral densities. Due to long cabling and low response levels (small ambient loads) the response...

  16. Ambient Modal Testing of the Vestvej Bridge using Random Decrement

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Brincker, Rune; Rytter, A.

    1998-01-01

    concerning application of vibration based inspection of bridges. The data analysis process of ambient vribration testing of bridges has traditionally been based on auto and cross spectral densities estimated using an FFT algorithm. In the pre-analysis state the spectral densities are all averaged to obtain......This paper presents an ambient vibration study of the Vestvej Bridge. The bridge is a typically Danish two-span concrete bridge which crosses a highway. The purpose of the study is to perform a pre-investigation of the dynamic behavior to obtain information for the design of a demonstration project...... the averaged spectral densities(ASD). From the ASD the eigenfrequencies of the structure can be identified. This information can be used in the main analysis, where alle modal parameters are extracted from the spectral densities. Due to long cabling and low response levels (small ambient loads) the response...

  17. 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.

  18. Design of novel antimicrobial peptide dimer analogues with enhanced antimicrobial activity in vitro and in vivo by intermolecular triazole bridge strategy.

    Science.gov (United States)

    Liu, Beijun; Huang, Haifeng; Yang, Zhibin; Liu, Beiyin; Gou, Sanhu; Zhong, Chao; Han, Xiufeng; Zhang, Yun; Ni, Jingman; Wang, Rui

    2017-02-01

    Currently, antimicrobial peptides have attracted considerable attention because of their broad-sprectum activity and low prognostic to induce antibiotic resistance. In our study, for the first time, a series of side-chain hybrid dimer peptides J-AA (Anoplin-Anoplin), J-RR (RW-RW), and J-AR (Anoplin-RW) based on the wasp peptide Anoplin and the arginine- and tryptophan-rich hexapeptide RW were designed and synthesized by click chemistry, with the intent to improve the antimicrobial efficacy of peptides against bacterial pathogens. The results showed that all dimer analogues exhibited up to a 4-16 fold increase in antimicrobial activity compared to the parental peptides against bacterial strains. Furthermore, the antimicrobial activity was confirmed by time-killing kinetics assay with two strains which showed that these dimer analogues at 1, 2×MIC were rapidly bactericidal and reduced the initial inoculum significantly during the first 2-6h. Notably, dimer peptides showed synergy and additivity effects when used in combination with conventional antibiotics rifampin or penicillin respectively against the multidrug-resistant strains. In the Escherichia coli-infected mouse model, all of hybrid dimer analogues had significantly lower degree of bacterial load than the untreated control group when injected once i.p. at 5mg/kg. In addition, the infected mice by methicillin-resistant (MRSA) strain could be effectively treated with J-RR. All of dimer analogues had membrane-active action mode. And the membrane-dependent mode of action signifies that peptides functions freely and without regard to conventional resistant mechanisms. Circular dichroism analyses of all dimer analogues showed a general predominance of α-helix conformation in 50% trifluoroethanol (TFE). Additionally, the acute toxicities study indicated that J-RR or J-AR did not show the signs of toxicity when adult mice exposed to concentration up to 120mg/kg. The 50% lethal dose (LD50) of J-AA was 53.6mg/kg. In

  19. On the road to metallic nanoparticles by rational design: bridging the gap between atomic-level theoretical modeling and reality by total scattering experiments.

    Science.gov (United States)

    Prasai, Binay; Wilson, A R; Wiley, B J; Ren, Y; Petkov, Valeri

    2015-11-14

    The extent to which current theoretical modeling alone can reveal real-world metallic nanoparticles (NPs) at the atomic level was scrutinized and demonstrated to be insufficient and how it can be improved by using a pragmatic approach involving straightforward experiments is shown. In particular, 4 to 6 nm in size silica supported Au(100-x)Pd(x) (x = 30, 46 and 58) explored for catalytic applications is characterized structurally by total scattering experiments including high-energy synchrotron X-ray diffraction (XRD) coupled to atomic pair distribution function (PDF) analysis. Atomic-level models for the NPs are built by molecular dynamics simulations based on the archetypal for current theoretical modeling Sutton-Chen (SC) method. Models are matched against independent experimental data and are demonstrated to be inaccurate unless their theoretical foundation, i.e. the SC method, is supplemented with basic yet crucial information on the length and strength of metal-to-metal bonds and, when necessary, structural disorder in the actual NPs studied. An atomic PDF-based approach for accessing such information and implementing it in theoretical modeling is put forward. For completeness, the approach is concisely demonstrated on 15 nm in size water-dispersed Au particles explored for bio-medical applications and 16 nm in size hexane-dispersed Fe48Pd52 particles explored for magnetic applications as well. It is argued that when "tuned up" against experiments relevant to metals and alloys confined to nanoscale dimensions, such as total scattering coupled to atomic PDF analysis, rather than by mere intuition and/or against data for the respective solids, atomic-level theoretical modeling can provide a sound understanding of the synthesis-structure-property relationships in real-world metallic NPs. Ultimately this can help advance nanoscience and technology a step closer to producing metallic NPs by rational design.

  20. A Bridge to Active Learning: A Summer Bridge Program Helps Students Maximize Their Active-Learning Experiences and the Active-Learning Experiences of Others

    Science.gov (United States)

    Cooper, Katelyn M.; Ashley, Michael; Brownell, Sara E.

    2017-01-01

    National calls to improve student academic success in college have sparked the development of bridge programs designed to help students transition from high school to college. We designed a 2-week Summer Bridge program that taught introductory biology content in an active-learning way. Through a set of exploratory interviews, we unexpectedly…

  1. Building bridges between doctors and patients: the design and pilot evaluation of a training session in argumentation for chronic pain experts.

    Science.gov (United States)

    Zanini, Claudia; Sarzi-Puttini, Piercarlo; Atzeni, Fabiola; Di Franco, Manuela; Rubinelli, Sara

    2015-05-19

    Shared decision-making requires doctors to be competent in exchanging views with patients to identify the appropriate course of action. In this paper we focus on the potential of a course in argumentation as a promising way to empower doctors in presenting their viewpoints and addressing those of patients. Argumentation is the communication process in which the speaker, through the use of reasons, aims to convince the interlocutor of the acceptability of a viewpoint. The value of argumentation skills for doctors has been addressed in the literature. Yet, there is no research on what a course on argumentation might look like. In this paper, we present the content and format of a training session in argumentation for doctors and discuss some insights gained from a pilot study that examined doctors' perceived strengths and limitations vis-à-vis this training. The training session (eight hours) combined different aspects from prominent theories of argumentation and was designed to strengthen doctors' argumentative discussion skills. A convenient, self-selected sample of 17 doctors who were experts in the field of chronic pain participated in the training and evaluated it via a feedback form and semi-structured interviews. The participants found that the training session gave a structure to types of communication they use to interact with their patients, and taught them techniques that can increase their effectiveness. Moreover, it provided tools to help address some of the challenges of modern doctor-patient interactions, including dealing with patients' unrealistic expectations and medically inaccurate beliefs, and reaching agreement when there are differences of opinion. This study enriches the research in the field of medical education. In line with the findings of studies that explore the value of argumentation in different fields, argumentative discussion skills can be applied by doctors to express their views and to account for the views of patients without

  2. Bridging the gap between pragmatic intervention design and theory: using behavioural science tools to modify an existing quality improvement programme to implement "Sepsis Six".

    Science.gov (United States)

    Steinmo, Siri H; Michie, Susan; Fuller, Christopher; Stanley, Sarah; Stapleton, Caitriona; Stone, Sheldon P

    2016-02-03

    Sepsis has a mortality rate of 40 %, which can be halved if the evidence-based "Sepsis Six" care bundle is implemented within 1 h. UK audit shows low implementation rates. Interventions to improve this have had minimal effects. Quality improvement programmes could be further developed by using theoretical frameworks (Theoretical Domains Framework (TDF)) to modify existing interventions by identifying influences on clinical behaviour and selecting appropriate content. The aim of this study was to illustrate using this process to modify an intervention designed using plan-do-study-act (P-D-S-A) cycles that had achieved partial success in improving Sepsis Six implementation in one hospital. Factors influencing implementation were investigated using the TDF to analyse interviews with 34 health professionals. The nursing team who developed and facilitated the intervention used the data to select modifications using the Behaviour Change Technique (BCT) Taxonomy (v1) and the APEASE criteria: affordability, practicability, effectiveness, acceptability, safety and equity. Five themes were identified as influencing implementation and guided intervention modification. These were:(1) "knowing what to do and why" (TDF domains knowledge, social/professional role and identity); (2) "risks and benefits" (beliefs about consequences), e.g. fear of harming patients through fluid overload acting as a barrier to implementation versus belief in the bundle's effectiveness acting as a lever to implementation; (3) "working together" (social influences, social/professional role and identity), e.g. team collaboration acting as a lever versus doctor/nurse conflict acting as a barrier; (4) "empowerment and support" (beliefs about capabilities, social/professional role and identity, behavioural regulation, social influences), e.g. involving staff in intervention development acting as a lever versus lack of confidence to challenge colleagues' decisions not to implement acting as a barrier; (5

  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-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...

  4. 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...

  5. Impact Coefficient Analysis of Long-Span Railway Cable-Stayed Bridge Based on Coupled Vehicle-Bridge Vibration

    Directory of Open Access Journals (Sweden)

    Yongle Li

    2015-01-01

    Full Text Available Compared with medium and small span bridges, very limited attention has been paid on the research of the impact coefficient of long-span railway bridges. To estimate the impact effects of long-span railway bridges subjected to moving vehicles, a real long-span railway cable-stayed bridge is regarded as the research object in this study, and a coupled model of vehicle-bridge system is established. The track irregularities are taken as the system excitation and the dynamic responses of the vehicle-bridge system are calculated. The impact effects on main girder, stayed cable, bearings, and bridge tower are discussed at various vehicle speeds. The results show that different components of the long-span railway cable-stayed bridge have different impact coefficients. Even for each part, the impact coefficient is also different at different local positions. It reveals that the impact coefficients in the actual situation may have significant differences with the related code clauses in the present design codes.

  6. Research achievements in under-deck and combined cable-stayed bridges

    OpenAIRE

    Ruiz-Teran, Ana M.; Aparicio, Angel C.

    2010-01-01

    Under-deck cable-stayed bridges and combined cable-stayed bridges constitute two innovative bridge types that have been designed and built on only a few occasions over the last thirty years by outstanding structural engineers, such as Leonhardt, Schlaich, Menn, Virlogeux, Manterola, and Cremer. In these bridge types, the stay cables have unconventional layouts: below the deck, in the case of under-deck cable-stayed bridges, and above and below the deck, in the case of combined cable-stayed br...

  7. A study on seismic behavior of pile foundations of bridge abutment on liquefiable ground through shaking table tests

    Science.gov (United States)

    Nakata, Mitsuhiko; Tanimoto, Shunsuke; Ishida, Shuichi; Ohsumi, Michio; Hoshikuma, Jun-ichi

    2017-10-01

    There is risk of bridge foundations to be damaged by liquefaction-induced lateral spreading of ground. Once bridge foundations have been damaged, it takes a lot of time for restoration. Therefore, it is important to assess the seismic behavior of the foundations on liquefiable ground appropriately. In this study, shaking table tests of models on a scale of 1/10 were conducted at the large scale shaking table in Public Works Research Institute, Japan, to investigate the seismic behavior of pile-supported bridge abutment on liquefiable ground. The shaking table tests were conducted for three types of model. Two are models of existing bridge which was built without design for liquefaction and the other is a model of bridge which was designed based on the current Japanese design specifications for highway bridges. As a result, the bending strains of piles of the abutment which were designed based on the current design specifications were less than those of the existing bridge.

  8. 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...

  9. Multiobjective Optimal Control of Longitudinal Seismic Response of a Multitower Cable-Stayed Bridge

    Directory of Open Access Journals (Sweden)

    Geng Fangfang

    2016-01-01

    Full Text Available The dynamic behavior of a multitower cable-stayed bridge with the application of partially longitudinal constraint system using viscous fluid dampers under real earthquake ground motions is presented. The study is based on the dynamic finite element model of the Jiashao Bridge, a six-tower cable-stayed bridge in China. The prime aim of the study is to investigate the effectiveness of viscous fluid dampers on the longitudinal seismic responses of the bridge and put forth a multiobjective optimization design method to determine the optimized parameters of the viscous fluid dampers. The results of the investigations show that the control objective of the multitower cable-stayed bridge with the partially longitudinal constraint system is to yield maximum reductions in the base forces of bridge towers longitudinally restricted with the bridge deck, with slight increases in the base forces of bridge towers longitudinally unrestricted with the bridge deck. To this end, a multiobjective optimization design method that uses a nondominating sort genetic algorithm II (NSGA-II is used to optimize parameters of the viscous fluid dampers. The effectiveness of the proposed optimization design method is demonstrated for the multitower cable-stayed bridge with the partially longitudinal constraint system, which reveals that a design engineer can choose a set of proper parameters of the viscous fluid dampers from Pareto optimal fronts that can satisfy the desired performance requirements.

  10. Wind Tunnel Measurements for Flutter of a Long-Afterbody Bridge Deck.

    Science.gov (United States)

    Chen, Zeng-Shun; Zhang, Cheng; Wang, Xu; Ma, Cun-Ming

    2017-02-09

    Bridges are an important component of transportation. Flutter is a self-excited, large amplitude vibration, which may lead to collapse of bridges. It must be understood and avoided. This paper takes the Jianghai Channel Bridge, which is a significant part of the Hong Kong-Zhuhai-Macao Bridge, as an example to investigate the flutter of the bridge deck. Firstly, aerodynamic force models for flutter of bridges were introduced. Then, wind tunnel tests of the bridge deck during the construction and the operation stages, under different wind attack angles and wind velocities, were carried out using a high frequency base balance (HFBB) system and laser displacement sensors. From the tests, the static aerodynamic forces and flutter derivatives of the bridge deck were observed. Correspondingly, the critical flutter wind speeds of the bridge deck were determined based on the derivatives, and they are compared with the directly measured flutter speeds. Results show that the observed derivatives are reasonable and applicable. Furthermore, the critical wind speeds in the operation stage is smaller than those in the construction stage. Besides, the flutter instabilities of the bridge in the construction and the operation stages are good. This study helps guarantee the design and the construction of the Jianghai Channel Bridge, and advances the understanding of flutter of long afterbody bridge decks.

  11. 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...

  12. The Performance Evaluation of Concrete Filled Steel Tubular Arch Bridge

    OpenAIRE

    Ma Wei-long

    2015-01-01

    In this paper, the system assessment theory of he concrete filled steel tubular arch bridge which is based on the theory of the reliability of system reliability is researched through the finite element analysis software ANSYS. Because the concrete filled steel tube arch bridge has the characteristics, such as the components numerous, complex forces, unable to list the of the explicit limit state equation, so use the probability design module of ANSYS (PDS) technology for the perf...

  13. Concepts and new perspectives for long span bridges

    Directory of Open Access Journals (Sweden)

    Brancaleoni Fabio

    2016-07-01

    Full Text Available A discussion of the dominant factors affecting the behaviour of long span cable supported bridges is the subject of this paper. The main issue is the evolution of properties and response of the bridge with the size of the structure, represented by the critical parameter of span length, showing how this affects the conceptual design. After a review of the present state of the art, perspectives for future developments are discussed.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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 ...

  19. 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.

  20. 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...

  1. Error Sources in Proccessing LIDAR Based Bridge Inspection

    Science.gov (United States)

    Bian, H.; Chen, S. E.; Liu, W.

    2017-09-01

    Bridge inspection is a critical task in infrastructure management and is facing unprecedented challenges after a series of bridge failures. The prevailing visual inspection was insufficient in providing reliable and quantitative bridge information although a systematic quality management framework was built to ensure visual bridge inspection data quality to minimize errors during the inspection process. The LiDAR based remote sensing is recommended as an effective tool in overcoming some of the disadvantages of visual inspection. In order to evaluate the potential of applying this technology in bridge inspection, some of the error sources in LiDAR based bridge inspection are analysed. The scanning angle variance in field data collection and the different algorithm design in scanning data processing are the found factors that will introduce errors into inspection results. Besides studying the errors sources, advanced considerations should be placed on improving the inspection data quality, and statistical analysis might be employed to evaluate inspection operation process that contains a series of uncertain factors in the future. Overall, the development of a reliable bridge inspection system requires not only the improvement of data processing algorithms, but also systematic considerations to mitigate possible errors in the entire inspection workflow. If LiDAR or some other technology can be accepted as a supplement for visual inspection, the current quality management framework will be modified or redesigned, and this would be as urgent as the refine of inspection techniques.

  2. ERROR SOURCES IN PROCCESSING LIDAR BASED BRIDGE INSPECTION

    Directory of Open Access Journals (Sweden)

    H. Bian

    2017-09-01

    Full Text Available Bridge inspection is a critical task in infrastructure management and is facing unprecedented challenges after a series of bridge failures. The prevailing visual inspection was insufficient in providing reliable and quantitative bridge information although a systematic quality management framework was built to ensure visual bridge inspection data quality to minimize errors during the inspection process. The LiDAR based remote sensing is recommended as an effective tool in overcoming some of the disadvantages of visual inspection. In order to evaluate the potential of applying this technology in bridge inspection, some of the error sources in LiDAR based bridge inspection are analysed. The scanning angle variance in field data collection and the different algorithm design in scanning data processing are the found factors that will introduce errors into inspection results. Besides studying the errors sources, advanced considerations should be placed on improving the inspection data quality, and statistical analysis might be employed to evaluate inspection operation process that contains a series of uncertain factors in the future. Overall, the development of a reliable bridge inspection system requires not only the improvement of data processing algorithms, but also systematic considerations to mitigate possible errors in the entire inspection workflow. If LiDAR or some other technology can be accepted as a supplement for visual inspection, the current quality management framework will be modified or redesigned, and this would be as urgent as the refine of inspection techniques.

  3. Damage identification in highway bridges using distribution factors

    Science.gov (United States)

    Gangone, Michael V.; Whelan, Matthew J.

    2017-04-01

    The U.S. infrastructure system is well behind the needs of the 21st century and in dire need of improvements. The American Society of Civil Engineers (ASCE) graded America's Infrastructure as a "D+" in its recent 2013 Report Card. Bridges are a major component of the infrastructure system and were awarded a "C+". Nearly 25 percent of the nation's bridges are categorized as deficient by the Federal Highway Administration (FWHA). Most bridges were designed with an expected service life of roughly 50 years and today the average age of a bridge is 42 years. Finding alternative methods of condition assessment which captures the true performance of the bridge is of high importance. This paper discusses the monitoring of two multi-girder/stringer bridges at different ages of service life. Normal strain measurements were used to calculate the load distribution factor at the midspan of the bridge under controlled loading conditions. Controlled progressive damage was implemented to one of the superstructures to determine if the damage could be detected using the distribution factor. An uncertainty analysis, based on the accuracy and precision of the normal strain measurement, was undertaken to determine how effective it is to use the distribution factor measurement as a damage indicator. The analysis indicates that this load testing parameter may be an effective measure for detecting damage.

  4. IMPLEMENTATION OF DIAGNOSIS AND REPAIR OF BRIDGE STRUCTURES

    Directory of Open Access Journals (Sweden)

    Yushkov Vladimir Sergeevich

    2016-06-01

    Full Text Available Insufficiency and delays of maintenance of the technical state of bridges is greatly related to work labour input, absence of adequate mechanical means and automation of the process of inspection of structures. The authors considered domestic and foreign Machinery which repair bridge structures and are used to conduct surveys, tests and special repairs on different levels, both above and below the vehicle position. The design of a machine with the main operational characteristics is presented. The defects detected during the inspection of bridges are enumerated. In the conditions of deterioration of the bridges of different structures and responding the requirements to reduce the risk level of engineering structures’ operation there is a demand in renewing the population of machines for investigation of the technical condition of automobile bridge, because of special vehicles deterioration, there is no staff of specialists who are able to solve the problems of maintenance and increasing the reliability of bridge structures to the required extend. Also the main principles of control and inspection of bridge structures include the requirements to technical equipment for measurements and testing equipment.

  5. A Simple and Universal Resistive-Bridge Sensors Interface

    Directory of Open Access Journals (Sweden)

    Sergey Y. YURISH

    2011-02-01

    Full Text Available Resistive-bridge sensors are widely used in various sensor systems. There are many sensor signal conditioners from different manufacturers for such sensing elements. However, no one existing on the modern market integrated converter for resistive bridge sensors can work with both: resistive-bridge sensing elements and resistive-to-frequency and -duty-cycle converters’ outputs. A proposed and described in the article universal interface for resistive-bridge sensing elements and bridge-output-to-frequency and/or duty cycle converters based on the designed Universal Sensors and Transducers Interface (USTI integrated. It is based on a simple, cost effective three-point measuring technique and does not require any additional active components. The USTI IC is realized in a standard CMOS technology. The active supply current at operating voltage +4.5 V and clock frequency 20 MHz is not more than 9.5 mA This paper reports experimental results with a strain gauges bridge emulator and differential pressure resistive bridge sensor SX30GD2.

  6. Estimation of Curvature Changes for Steel-Concrete Composite Bridge Using Fiber Bragg Grating Sensors

    Directory of Open Access Journals (Sweden)

    Donghoon Kang

    2013-01-01

    Full Text Available This study is focused on the verification of the key idea of a newly developed steel-concrete composite bridge. The key idea of the proposed bridge is to reduce the design moment by applying vertical prestressing force to steel girders, so that a moment distribution of a continuous span bridge is formed in a simple span bridge. For the verification of the key technology, curvature changes of the bridge should be monitored sequentially at every construction stage. A pair of multiplexed FBG sensor arrays is proposed in order to measure curvature changes in this study. They are embedded in a full-scale test bridge and measured local strains, which are finally converted to curvatures. From the result of curvature changes, it is successfully ensured that the key idea of the proposed bridge, expected theoretically, is viable.

  7. 3 long bridges of dream were realized Opening of West Seto Motorway; Yume no 3 kakyo ga jitsugen/nishiseto jidoshado haitsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-06-10

    Onomichi-Imabari route/Setouchi Simanami Thruway, which adorned the finish of Honshu-Shikoku projects was completed on 1st, May. With this completion, 3 long bridges of dream were completely realized, following to Kojima-Sakaide (1988) and Kobe-Naruto (1998). This time, 5 bridges of this Motorway, the world's longest cable stayed bridge Tatara Long Bridge, world's first 3 continuous suspension bridge Kurushima Strait No.1{approx}No.3 bridge and New Onomichi Long Bridge, were opened. 10 bridges including 5 bridges (In-noshima Long Bridge, Ikeguchi Bridge, Omishima Bridge, Hakata/Oshima Long Bridge and Oshima Long Bridge) already under service connect 9 islands between Onomichi, Hiroshima Prefecture and Imabari, Ehime Prefecture, with a route 59 km long. Characteristic design was adopted for each bridge to demonstrate world's highest bridge erection technology of Japan. In a series of concrete construction to support superstructure of these bridges, underwater non-segregation type concrete with low hydration heat cement mainly for foundation and substructure, and high fluidity concrete for dense reinforcement layout were adopted. (translated by NEDO)

  8. 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...

  9. 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...

  10. 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...

  11. 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 ...

  12. 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...

  13. 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.

  14. 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...

  15. 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.

  16. 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.

  17. 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.

  18. Bridges Expansion Joints

    National Research Council Canada - National Science Library

    Sergey W. Kozlachkow

    2012-01-01

    .... 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...

  19. Criteria for assessment of bridge aesthetic and visual quality

    Science.gov (United States)

    Rozentale, I.; Paeglitis, A.

    2017-10-01

    The bridge designers should find an ideal balance between structure, economy, buildability, aesthetics, durability and harmony with industrial or natural landscape. During the last years, the society has adopted documents providing procedures for evaluation of the impact of the structural appearance on surrounding landscape. The European Landscape Convention defines the landscape as an area perceived by people, whose character is the result of the action and interaction of natural and/or human factors. The Convention indicates the methods for clear and objective assessment of the landscape’s visual qualities. The esthetical qualities of bridge structures, appearance and attraction should satisfy not only the technicians - engineers and architects, but mostly the surrounding population. Each of these groups has a different perception of esthetical qualities of structure. Many authors have used different methods and criteria for assessment of bridge aesthetics. The aim of this paper is to provide an overview of the bridge aesthetic and visual quality assessment methods and criteria.

  20. Bridge SHM system based on fiber optical sensing technology

    Science.gov (United States)

    Li, Sheng; Fan, Dian; Fu, Jiang-hua; Huang, Xing; Jiang, De-sheng

    2015-09-01

    The latest progress of our lab in recent 10 years on the area of bridge structural health monitoring (SHM) based on optical fiber sensing technology is introduced. Firstly, in the part of sensing technology, optical fiber force test-ring, optical fiber vibration sensor, optical fiber smart cable, optical fiber prestressing loss monitoring method and optical fiber continuous curve mode inspection system are developed, which not only rich the sensor types, but also provides new monitoring means that are needed for the bridge health monitoring system. Secondly, in the optical fiber sensing network and computer system platform, the monitoring system architecture model is designed to effectively meet the integration scale and effect requirement of engineering application, especially the bridge expert system proposed integration of sensing information and informatization manual inspection to realize the mode of multi index intelligence and practical monitoring, diagnosis and evaluation. Finally, the Jingyue bridge monitoring system as the representative, the research on the technology of engineering applications are given.

  1. Reserves in load capacity assessment of existing bridges

    Science.gov (United States)

    Žitný, Jan; Ryjáček, Pavel

    2017-09-01

    High percentage of all railway bridges in the Czech Republic is made of structural steel. Majority of these bridges is designed according to historical codes and according to the deterioration, they have to be assessed if they satisfy the needs of modern railway traffic. The load capacity assessment of existing bridges according to Eurocodes is however often too conservative and especially, braking and acceleration forces cause huge problems to structural elements of the bridge superstructure. The aim of this paper is to review the different approaches for the determination of braking and acceleration forces. Both, current and historical theoretical models and in-situ measurements are considered. The research of several local European state norms superior to Eurocode for assessment of existing railway bridges shows the big diversity of used local approaches and the conservativeness of Eurocode. This paper should also work as an overview for designers dealing with load capacity assessment, revealing the reserves for existing bridges. Based on these different approaches, theoretical models and data obtained from the measurements, the method for determination of braking and acceleration forces on the basis of real traffic data should be proposed.

  2. Behavior of FRP Link Slabs in Jointless Bridge Decks

    Directory of Open Access Journals (Sweden)

    Aziz Saber

    2012-01-01

    Full Text Available The paper investigated the use of fiberglass-reinforced plastic (FRP grid for reinforcement in link slabs for jointless bridge decks. The design concept of link slab was examined based on the ductility of the fiberglass-reinforced plastic grid to accommodate bridge deck deformations. The implementation of hybrid simulation assisted in combining the experimental results and the theoretical work. The numerical analyses and the experimental work investigated the behavior of the link slab and confirmed its feasibility. The results indicated that the technique would allow simultaneous achievement of structural need, lower flexural stiffness of the link slab approaching the behavior of a hinge, and sustainability need of the link slab. The outcome of the study supports the contention that jointless concrete bridge decks may be designed and constructed with fiberglass-reinforced plastic grid link slabs. This concept would also provide a solution to a number of deterioration problems associated with bridge deck joints and can be used during new construction of bridge decks. The federal highway administration provided funds to Louisiana Department of Transportation through the innovative bridge research and development program to implement the use of FRP grid as link slab.

  3. Study on seismic behaviour of integral concrete bridges with different skew angles through fragility curves

    Directory of Open Access Journals (Sweden)

    Mahmoud Reza ُُShiravand

    2017-12-01

    Full Text Available Bridges are key elements in urban transportation system and should be designed to sustain earthquake induced damages to be utilized after earthquake. Extensive damages during last earthquakes highlighted the importance of seismic assessment and damage estimation of bridges. Skewness is one of the primary parameters effects on seismic behavior of bridges. Skew bridges are defined as bridges with skew angle piers and abutments. In these bridges, the piers have some degrees of skewness due to construction restrictions, such as those caused by crossing a waterway, railway line or road. This paper aims to investigate seismic behavior of skew concrete bridges using damage criteria and estimate probability of piers damage with fragility curves. To this end, three types of concrete bridges with two, three and four spans and varying skew angles of 00 ,100, 200 and 300 are modeled with finite element software. Seismic responses of bridge piers under 10 earthquake ground motion records are calculated using incremental dynamic analysis. Following, damage criteria proposed by Mackie and Stojadinovic are used to define damage limits of bridge piers in four damage states of slight, moderate, extensive and complete and bridge fragility curves are developed. The results show that increasing skew angles increases the probability of damage occurrence, particularly in extensive and complete damage states.

  4. Real-time seismic monitoring of the integrated cape girardeau bridge array and recorded earthquake response

    Science.gov (United States)

    Celebi, M.

    2006-01-01

    This paper introduces the state of the art, real-time and broad-band seismic monitoring network implemented for the 1206 m [3956 ft] long, cable-stayed Bill Emerson Memorial Bridge in Cape Girardeau (MO), a new Mississippi River crossing, approximately 80 km from the epicentral region of the 1811-1812 New Madrid earthquakes. The bridge was designed for a strong earthquake (magnitude 7.5 or greater) during the design life of the bridge. The monitoring network comprises a total of 84 channels of accelerometers deployed on the superstructure, pier foundations and at surface and downhole free-field arrays of the bridge. The paper also presents the high quality response data obtained from the network. Such data is aimed to be used by the owner, researchers and engineers to assess the performance of the bridge, to check design parameters, including the comparison of dynamic characteristics with actual response, and to better design future similar bridges. Preliminary analyses of ambient and low amplitude small earthquake data reveal specific response characteristics of the bridge and the free-field. There is evidence of coherent tower, cable, deck interaction that sometimes results in amplified ambient motions. Motions at the lowest tri-axial downhole accelerometers on both MO and IL sides are practically free from any feedback from the bridge. Motions at the mid-level and surface downhole accelerometers are influenced significantly by feedback due to amplified ambient motions of the bridge. Copyright ASCE 2006.

  5. Venture Creation Programs: Bridging Entrepreneurship Education and Technology Transfer

    Science.gov (United States)

    Lackéus, Martin; Williams Middleton, Karen

    2015-01-01

    Purpose: The purpose of this paper is to explore how university-based entrepreneurship programs, incorporating real-life venture creation into educational design and delivery, can bridge the gap between entrepreneurship education and technology transfer within the university environment. Design/methodology/approach: Based on a literature review…

  6. 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.

  7. 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.

  8. 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....

  9. Design

    DEFF Research Database (Denmark)

    Volf, Mette

    This publication is unique in its demystification and operationalization of the complex and elusive nature of the design process. The publication portrays the designer’s daily work and the creative process, which the designer is a part of. Apart from displaying the designer’s work methods...... and design parameters, the publication shows examples from renowned Danish design firms. Through these examples the reader gets an insight into the designer’s reality....

  10. 78 FR 37969 - Safety Zone; South Park Bridge Construction, Lower Duwamish Waterway, Seattle, WA

    Science.gov (United States)

    2013-06-25

    ...The Coast Guard is establishing a temporary safety zone in the lower Duwamish Waterway around the South Park Bridge in Seattle, Washington for the re-construction of the bridge. The safety zone is necessary to ensure the safety of the maritime public and workers involved in the bridge construction. The safety zone will prohibit any person or vessel from entering or remaining in the safety zone unless authorized by the Captain of the Port or his Designated Representative.

  11. A statistical model of operational impacts on the framework of the bridge crane

    Science.gov (United States)

    Antsev, V. Yu; Tolokonnikov, A. S.; Gorynin, A. D.; Reutov, A. A.

    2017-02-01

    The technical regulations of the Customs Union demands implementation of the risk analysis of the bridge cranes operation at their design stage. The statistical model has been developed for performance of random calculations of risks, allowing us to model possible operational influences on the bridge crane metal structure in their various combination. The statistical model is practically actualized in the software product automated calculation of risks of failure occurrence of bridge cranes.

  12. Study on the Pure Torsion Performance of I-Type Steel-Concrete Composite Bridge with Double Girders

    Science.gov (United States)

    Liu, H. C.; Wan, S.; Liu, Q. J.

    2017-11-01

    At present, the study of the torsion performance of the steel-concrete composite bridge with open sections are usually simplified to study the torsion performance of single-girder steel-concrete composite bridge added the influence of transverse vehicle distribution. Due to the existence of transverse connections between the bridge girders, the overall torsion performance of double-girder composite bridge is different from that of single-girder composite bridge. Therefore, it is necessary to study the effect of different forms of the connections on the torsional properties of the double-girder composite bridge through experiments. In this paper, three double-girder steel-concrete composite model bridges are designed to study the effect of different forms of transverse connections and the effect of different shapes of steel webs on torsional properties of composite bridges.

  13. 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...

  14. 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...

  15. 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]....

  16. 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.

  17. 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...

  18. Numerical investigation into thermal load responses of steel railway bridge

    Science.gov (United States)

    Saravana Raja Mohan, K.; Sreemathy, J. R.; Saravanan, U.

    2017-07-01

    Bridge design requires consideration of the effects produced by temperature variations and the resultant thermal gradients in the structure. Temperature fluctuation leads to expansion and contraction of bridges and these movements are taken care by providing expansion joints and bearings. Free movements of a member can be restrained by imposing certain boundary condition but at the same time considerable allowances should be made for the stresses resulting from this restrained condition since the additional deformations and stresses produced may affect the ultimate and serviceability limit states of the structure. If the reaction force generated by the restraints is very large, then its omission can lead to unsafe design. The principal objective of this research is to study the effects of temperature variation on stresses and deflection in a steel railway bridge. A numerical model, based on finite element analysis is presented for evaluating the thermal performance of the bridge. The selected bridge is analyzed and the temperature field distribution and the corresponding thermal stresses and strains are calculated using the finite element software ABAQUS. A thorough understanding of the thermal load responses of a structure will result in safer and dependable design practices.

  19. Double-composite rectangular truss bridge and its joint analysis

    Directory of Open Access Journals (Sweden)

    Yongjian Liu

    2015-08-01

    Full Text Available This paper describes a novel composite tubular truss bridge with concrete slab and concrete-filled rectangular chords. With concrete slab plus truss system and joints reinforced with concrete and Perfobond Leiste rib, double composite truss bridge proved to be a fairly suitable solution in negative moment area. Perfobond Leiste shear connector (PBL is widely implemented in the composite structure for its outstanding fatigue resistance. In this pilot bridge, Perfobond Leister ribs (PBR were installed in the truss girder's joints, which played double roles as shear connector and stiffener. An erection method and overall bridge structural analysis were then presented. Typical joints in the pilot bridge were selected to analyze the effect of PBR. Investigation of the effect of PBR in concrete-filled tubular joints was elaborated. Comparison has revealed that concrete-filled tubular joints with PBR have much higher constraint capability than joints without PBR. For rectangular tubular truss, the punching shear force of the concrete filled joint with PBR is approximately 43% larger than that of the joint without PBR. Fatigue performance of the joint installed with PBR was improved, which was found through analysis of the stress concentration factor of joint. The PBR installed in the joints mitigated the stress concentration factor in the chord face. Therefore, the advantages of this new type of bridge are demonstrated, including the convenience of construction using rectangular truss, innovative concept of structural design and better global and local performances.

  20. Procurement of Beams in Multiple D&B Bridge Projects

    Directory of Open Access Journals (Sweden)

    CT. Ramanathan

    2010-06-01

    Full Text Available Selected infrastructure development projects are being implemented by Design and Build (D&B pocurement system in Sabah (East Malaysia by the Public Works Department (PWD. In the first phase 45 bridge replacement projects were awarded in 5 packages. These simultaneous multiple Bridge projects are for the development of the backward areas and hence their timely completion is utmost important. Procurement and production of bridge beams have been the critical element of construction in these rural areas and no researches has been reported on various aspects of procurement of the bridge beams in multiple D&B projects. The aspects of procurement researched in this work include the determination of a common beam element for the ease of procurement and the optimization of the construction methodology, the finalization and purchasing plate dimensions to suite the manufacturer's production range, the delivery of materials, the planning and monitoring of fabrication, the preparation and assembly, and the erection and launching of beams. The beams are optimized using element optimization techniques. The most important problems in fabricating steel girders were in planning and scheduling of materials for the fabrication and the fabrication process. Findings in all the aspects of production of steel girders are highlighted through a case study of six long span bridges at various locations in Sabah. Solutions drawn from lessons learnt which minimize wastages, and aids in timely completion of beams in multiple bridge construction are discussed.

  1. Special heavy plates and steel solutions for bridge building

    Science.gov (United States)

    Lehnert, Tobias

    2017-09-01

    In many European countries infrastructure, -road as well as railway infrastructure-, needs intensive investments to follow the growing demands of mobility and goods traffic. Steel or steel composite bridges offer in this context viable and very sustainable solutions. Due to its unlimited recyclability steel can in general be seen as the ideal material for such sustainable constructions, but especially when designers or fabricators exploit the nowadays available possibilities of steel industry very cost-efficient and remarkable constructions are realizable. This paper will highlight some of these newest developments in heavy plates for bridge building. For example, for small span railway bridges the so-called thick plate trough bridges have proven to be a favourable concept. Very heavy plates with single plate weights up to 42 t allow building these bridges very efficiently out of one or very few single plates. Another interesting development is the so-called longitudinally profiled plates which allow a varying plate thickness along the actual loading profile. As last point the rising entry of higher strength steels in bridge building will be discussed and it will be shown why thermomechanically rolled plates are the ideal solution for these demands.

  2. 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....

  3. Structural and mechanical characterisation of bridging veins: A review.

    Science.gov (United States)

    Famaey, Nele; Ying Cui, Zhao; Umuhire Musigazi, Grace; Ivens, Jan; Depreitere, Bart; Verbeken, Erik; Vander Sloten, Jos

    2015-01-01

    Bridging veins drain the venous blood from the cerebral cortex into the superior sagittal sinus (SSS) and doing so they bridge the subdural space. Despite their importance in head impact biomechanics, little is known about their properties with respect to histology, morphology and mechanical behaviour. Knowledge of these characteristics is essential for creating a biofidelic finite element model to study the biomechanics of head impact, ultimately leading to the improved design of protective devices by setting up tolerance criteria. This paper presents a comprehensive review of the state-of-the-art knowledge on bridging veins. Tolerance criteria to prevent head injury through impact have been set by a number of research groups, either directly through impact experiments or by means of finite element (FE) simulations. Current state-of-the-art FE head models still lack a biofidelic representation of the bridging veins. To achieve this, a thorough insight into their nature and behaviour is required. Therefore, an overview of the general morphology and histology is provided here, showing the clearly heterogeneous nature of the bridging vein complex, with its three different layers and distinct morphological and histological changes at the region of outflow into the superior sagittal sinus. Apart from a complex morphology, bridging veins also exhibit complex mechanical behaviour, being nonlinear, viscoelastic and prone to damage. Existing material models capable of capturing these properties, as well as methods for experimental characterisation, are discussed. Future work required in bridging vein research is firstly to achieve consensus on aspects regarding morphology and histology, especially in the outflow cuff segment. Secondly, the advised material models need to be populated with realistic parameters through biaxial mechanical experiments adapted to the dimensions of the bridging vein samples. Finally, updating the existing finite element head models with these

  4. Distal tibiofibular bone-bridging in transtibial amputation.

    Science.gov (United States)

    Pinzur, Michael S; Beck, Jennifer; Himes, Ryan; Callaci, John

    2008-12-01

    The creation of a bone bridge between the residual tibia and fibula is a controversial surgical technique used in the performance of transtibial amputation. Twenty consecutive patients who underwent a unilateral transtibial amputation, as a consequence of traumatic injury, had distal tibiofibular bone-bridging performed by a single surgeon. Eight completed the Prosthesis Evaluation Questionnaire (PEQ), a validated outcomes instrument designed to measure patient self-reported health-related quality of life after a lower-extremity amputation. Their responses were compared with those of a previously reported control group of nondiabetic patients who had undergone transtibial amputation with the use of a traditional technique and with those of a previously reported consecutive group of Brazilian patients, including twelve who were diabetic, who had undergone a similar bone-bridge procedure. The scores in the American bone-bridge group were similar to those in the control group and not as good as those in the Brazilian bone-bridge group. The American bone-bridge and control groups scored lower in the Social Burden, Ambulation, Frustration, Sounds, Utility, and Well-Being domains of the PEQ. While many experts in the care of amputees believe that the distal tibiofibular bone-bridge technique improves patient functional outcomes, our small group of patients treated with this procedure did not appear to have better outcomes than a group of patients treated successfully with a standard surgical technique. More information is needed before the bone-bridge technique can be recommended as an important component of standard transtibial amputation surgery.

  5. 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...

  6. 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...

  7. 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...

  8. 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 ...

  9. 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)

  10. 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.

  11. Comparative Research of Extra-large-span Cable-stayed Bridge with Steel Truss Girder and Steel Box Girder

    Directory of Open Access Journals (Sweden)

    Tan Manjiang

    2015-01-01

    Full Text Available To research structural performance of extra-large-span cable-stayed bridge under different section forms, with the engineering background of a 800m main-span cable-stayed bridge with steel truss girder, the cable-stayed bridge with steel box girder is designed according to the current bridge regulations when two bridges are designed in an ultimate state of the carrying capacity, so the maximum stress and minimum stress of the stress envelope diagram are substantially the same. A comprehensive comparison is given to two types of bridge on the aspect of static force, natural vibration frequency, stability, economic performance and so on. Analysis results provide future reference for the large-span cable-stayed bridge to select between the steel truss girder and the steel box girder.

  12. Study on the structural characteristics of extradosed concrete bridges; Ekusutoradozudo kyo no kozo tokusei ni kansuru ichikosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Oka, Y. [Japan Highway Public Corp., Tokyo (Japan); Kasuga, A. [Sumitomo Construction Co. Ltd., Tokyo (Japan); Yamazaki, J. [Nihon Univ., Tokyo (Japan). Coll. of Science and Engineering

    1997-03-31

    Parameters are analyzed to provide data for deciding, in the planning and designing stages, whether a cable stayed bridge or an extradosed bridge should be adopted. Comparative investigation of the vibration properties of both types of bridges is also referred to. The result of the study on the structural properties of the cable stayed road bridge and the extradosed road bridge is introduced. Based on the concept of the extradosed bridge, designers are now able to select without restraint the after load sharing rate of the diagonal members. Parameter analysis of a diagonal member reinforced 3-span continuous beam is performed. By introducing indices showing the load sharing rate of the diagonal member, the cable stayed bridge can be distinguished logically from the extradosed bridge in designing. It is found important that the height of the main tower is set to approximately 10% the length of the center span for the construction of the extradosed bridge. The vibration properties of the cable stayed bridge and the extradosed bridge of the same scale are compared. 7 refs., 18 figs., 6 tabs.

  13. Static and Dynamic Mechanical Properties of Long-Span Cable-Stayed Bridges Using CFRP Cables

    Directory of Open Access Journals (Sweden)

    Mei Kuihua

    2017-01-01

    Full Text Available The elastic modulus and deadweight of carbon fiber-reinforced polymer (CFRP cables are different from those of steel cables. Thus, the static and dynamic behaviors of cable-stayed bridges using CFRP cables are different from those of cable-stayed bridges using steel cables. The static and dynamic performances of the two kinds of bridges with a span of 1000 m were studied using the numerical method. The effects of geometric nonlinear factors on static performance of the two kinds of cable-stayed bridges were analyzed. The live load effects and temperature effects of the two cable-stayed bridges were also analyzed. The influences of design parameters, including different structural systems, the numbers of auxiliary piers, and the space arrangement types of cable, on the dynamic performance of the cable-stayed bridge using CFRP cables were also studied. Results demonstrate that sag effect of the CFRP cable is much smaller than that of steel cable. The temperature effects of CFRP cable-stayed bridge are less than those of steel cable-stayed bridge. The vertical bending natural vibration frequency of the CFRP cable-stayed bridge is generally lower than that of steel cable-stayed bridge, whereas the torsional natural vibration frequency of the former is higher than that of the latter.

  14. Cable-stayed PC bridge with inclined main tower. Hachinohe port island bridge; Keisha shuto to yusuru 2 keikan renzoku PC shachokyo. Hachinoheko port island renrakykyo (kasho)

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, A. [Hachinohe Institute of Technology, Aomori (Japan)

    1994-09-15

    The design and construction of the inclined main bridge, which is being constructed at the mouth of the Hachinohe Harbor (in Japan), are outlined in this paper. This connecting bridge has an overall length of 265.56 m, and consists of the main bridge member of asymmetric 2 cable-stayed PC bridge and the 3 cable-stayed PC box member bridge. An asymmetric design was employed for the main bridge frame to ensure the access space for small ships passing between bridge girders, easy maintenance and service, improved economy, and excellent view. The main tower is a single-pillar reinforced concrete structure with an inclination of 15{degree} and 47 m in height. Forty-eight diagonal cables are arranged so that 12 cable trains are connected to the main tower on the right and left sides respectively, and the back-stay cable structure is used for each upper 3 cable trains to improve safety against the earthquake. The main beam is made by a prestressed concrete structure with inverse trapezoidal 3-chamber frame section. This structure is superior in increasing the safety against wind. Steel tube sheet-pile well is selected for the bridge pier base, and debris layer is selected as a support layer for the base. For the construction of the lower bridge section, sand conversion through predrilling of rubble-mound and debris layer was executed. The underwater non-separative concrete and embedded type frame are used around the bridge piers and its surrounding. For the construction of the upper bridge section, steel frames are used inside the main tower to ensure the construction precision. 7 figs.

  15. The Status and Prospect of Research into Protective Structures of Bridge Piers against Rockfall Impact

    Science.gov (United States)

    Gao, Liang; Zhang, Shan; Zhang, Junfa; Wu, Xiangnan

    2017-06-01

    Rockfall impact on bridge piers threats severely the mountain bridge structures of lifeline engineering. Intended for mountain bridge pier protection against rockfall impact, the paper conducted comprehensive reviews on the research status of impact effects, anti-collision structure, impact response to rockfall, and protective design at home and abroad, and proposed a new-type protective structure against rockfall impact. In addition, the paper carried out deep studies on such key scientific issues as impact effect calculation, protective materials against rockfall impact, damage mechanism of protective units, and parameter optimization on the system of protective structures against rockfall impact as well, aiming to strength disaster prevention of mountain bridge structures.

  16. Economical bridge solutions based on innovative composite dowels and integrated abutments ecobridge

    CERN Document Server

    Băncilă, Radu

    2015-01-01

    This book is an outcome of the research project “ECOBRIDGE – Demonstration of ECOnomical BRIDGE solutions based on innovative composite dowels and integrated abutments – RFCS – CT 2010-00024”, which has been co-funded by the Research Fund for Coal and Steel (R.F.C.S.) of the European Community. The main topics of the book are the following: design of integral bridges, innovative composite dowels for the shear transmission, construction of bridges, structural analysis of bridges and monitoring. The book joins the technical experience and the contributions of the involved research partners. The technical content of all the papers is present-day in the field of the design, construction and monitoring of innovative composite bridges. The efficient design and construction improve and consolidate the market position of steel construction and steel producing industry. In addition, the advanced forms of construction are contributing to savings in material and energy consumption for the structure during prod...

  17. 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. 

  18. Technical research and development of long-spanned bridges; Chodai kyoryo no gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, F.; Yamanaka, M.; Ogawa, K.; Mizukami, Y.; Kano, J.; Watanabe, K. [Kawasaki Heavy Industries, Ltd., Kobe (Japan)

    1996-10-15

    Outlined herein is technical development of long-spanned bridges represented by suspension and cable-stayed bridges. The design of long-spanned bridges requires theoretical analysis of flexibility in which balance after they are deformed by load is taken into consideration. The matrix finite displacement analysis program is developed for optimizing cable-stayed bridge designs and determining suspension bridge shapes as the new major functions. The analysis program, named KASTAN, is also developed for stress analysis of the structure details. A wind tunnel for structure designs is installed to analyze resistance to wind. A number of experiments have been carried out by the tunnel for the designs of segment, main tower and overall bridge models. The means of controlling wind-caused vibration include hydraulic dampers, mass dampers, and combination of high damping rubber and spacer. Cable-stayed bridges are highly flexible, their types being selected by tower height and shape, span ratio and shape of the main beam, and cable position. These bridges constructed by the company include the S-shaped ones whose main beams are supported by cables suspended by two towers of different height, and the others with H-shape towers of high columns which are connected to each other by horizontal beams. 11 refs., 15 figs.

  19. Photophysical and redox properties of dinuclear Ru and Os polypyridyl complexes with incorporated photostable spiropyran bridge

    NARCIS (Netherlands)

    Jukes, R.T.F.; Bozic, B.; Belser, P.; De Cola, L.; Hartl, F.

    2009-01-01

    Aimed at creating a true photoswitchable energy transfer system, four dinuclear complexes containing ruthenium(II) and osmium(II) metal centers bridged by spiropyran-type linkers were designed and investigated. The bridge in its closed spiropyran form was shown to be a good insulator for energy

  20. Linking Flood-Related Damage to Bridges and Stream Geomorphic Conditions in Vermont

    Science.gov (United States)

    Anderson, I.; Dewoolkar, M.; Rizzo, D.; Huston, D.

    2014-12-01

    Bridge scour design predicts the depth of erosion given conditions of the streambed, geometry and flow. The depth of the scour hole is calculated empirically, while the width is assumed to be a percentage of the estimated depth. In Vermont, bridge damage resulting from the 2011 Tropical Storm Irene showed high numbers of stream widening and outflanking at bridges rather than vertical scour holes. The outflanking of bridges is not represented in current bridge scour design, where riprap is typically recommended to prevent horizontal stream migration. This study evaluates whether stream geomorphic information can be used to determine conditions that resulted in outflanking. Post flood inspection photographs are reviewed to identify cases of outflanking, and data from the National Bridge Inventory (NBI) and the Vermont Agency of Natural Resources' (VTANR) Rapid Geomorphic Assessment (RGA) are used to determine the specific site and stream characteristics at the bridges. When applicable, bridge design plans and HEC-RAS modeling are used to compare scour depth calculations to evidence of damage from site photographs. Geomorphic assessments are used to determine if there are site differences that resulted in outflanking rather than traditional vertical scour. The damage from outflanking erosion can be quantified and modeled similar to the process of calculating scour depths, aiding in the prediction of outflanking, and improving the ability to design against it.

  1. MASH TL-3 crash testing and evaluation of the TxDOT T631 Bridge Rail.

    Science.gov (United States)

    2016-07-01

    The Texas Type T631 bridge rail was developed as a low-cost, flexible bridge rail system for TL-2 : applications. Many of the features used for the system tested at MwRSF for TL-3 were incorporated into the : design developed for this project for MAS...

  2. Crash test and evaluation of the TxDOT T631 bridge rail.

    Science.gov (United States)

    2014-01-01

    In August 2010, Midwest Roadside Safety Facility (MwRSF) developed and crash tested a low-cost, energy-absorbing bridge rail for the Manual for Assessing Safety Hardware (MASH) TL-3 applications. This low-cost bridge rail was designed to be compatibl...

  3. Live-load distribution on glued-laminated timber girder bridges : final report : conclusions and recommendations

    Science.gov (United States)

    Fouad Fanous; Jeremy May; Terry Wipf; Michael Ritter

    2011-01-01

    Increased use of timber bridges in the U.S. transportation system has required additional research to improve the current design methodology of these bridges. For this reason, the U.S. Forest Service, Forest Products Laboratory (FPL), and the Federal Highway Administration have supported several research programs to attain the objective listed above. This report is a...

  4. Balanced Cantilever Girder Bridge Over the Danube-Black Sea Channel

    Directory of Open Access Journals (Sweden)

    Giordano Aldo

    2013-12-01

    Full Text Available This paper describes the design and construction of a “balanced cantilever girder” bridge over the Danube-Black Sea channel, characterized by a central span of 155m with two symmetrical side spans of 77.5m. The total length of the bridge, including portions of the abutments support, is 312.0m.

  5. Service life assessment of timber highway bridges in USA climate zones

    Science.gov (United States)

    James P. Wacker; Brian K. Brashaw; Thomas G. Williamson; P. David Jones; Matthew S. Smith; Travis K. Hosteng; David L. Strahl; Lola E. Coombe; V.J. Gopu

    2014-01-01

    As engineers begin to estimate life-cycle costs and sustainable design approaches for timber bridges, there is a need 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...

  6. Monolithic Concrete vs Precast Concrete for the Construction of Bridge by Th Cantilever Method

    Directory of Open Access Journals (Sweden)

    Morlova Dumitru Daniel

    2015-07-01

    Full Text Available In the article "Monolithic Concrete vs Precast Concrete for the Construction of Bridges by the Cantilever Method", there are approached a number of issues that come out in the design and execution of prestressed concrete bridge structures using the cantilever method.

  7. A new multiconstraint method for determining the optimal cable stresses in cable-stayed bridges.

    Science.gov (United States)

    Asgari, B; Osman, S A; Adnan, A

    2014-01-01

    Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM). The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method.

  8. A New Multiconstraint Method for Determining the Optimal Cable Stresses in Cable-Stayed Bridges

    Directory of Open Access Journals (Sweden)

    B. Asgari

    2014-01-01

    Full Text Available Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM. The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method.

  9. 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

  10. Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Pettiway, Keon

    2017-01-01

    by designers, planners, etc. (staging from above) and mobile subjects (staging from below). A research agenda for studying situated practices of mobility and mobilities design is outlined in three directions: foci of studies, methods and approaches, and epistemologies and frames of thinking. Jensen begins......In this chapter, Ole B. Jensen takes a situational approach to mobilities to examine how ordinary life activities are structured by technology and design. Using “staging mobilities” as a theoretical approach, Jensen considers mobilities as overlapping, actions, interactions and decisions...... with a brief description of how movement is studied within social sciences after the “mobilities turn” versus the idea of physical movement in transport geography and engineering. He then explains how “mobilities design” was derived from connections between traffic and architecture. Jensen concludes...

  11. 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...

  12. Design

    DEFF Research Database (Denmark)

    Volf, Mette

    Design - proces & metode iBog®  er enestående i sit fokus på afmystificering og operationalisering af designprocessens flygtige og komplekse karakter. Udgivelsen går bag om designerens daglige arbejde og giver et indblik i den kreative skabelsesproces, som designeren er en del af. Udover et bredt...... indblik i designerens arbejdsmetoder og designparametre giver Design - proces & metode en række eksempler fra anerkendte designvirksomheder, der gør det muligt at komme helt tæt på designerens virkelighed....

  13. CONSTRUCTION THE BRIDGE PIER AS PARAMETRIC OBJECT USING AUTODESK REVIT

    Directory of Open Access Journals (Sweden)

    K. I. Hladka

    2017-08-01

    Full Text Available Purpose. The work is aimed to solve the following tasks: 1 to investigate the possibilities of Autodesk Revit to create parametric objects; 2 to create an information model of the bridge pier with the possibility of changing the model size without changing geometry of the object; 3 to trace the complexity and feasibility of using parametric models when designing the elements of bridges. Methodology. The studies were carried out using spatial modeling in the Autodesk Revit system. The ratio of the parameters of the object was set, the relationship between individual geometric elements was determined and the changes that were made to the model with the change of the specified parameters were checked. Findings. Support model of two types has been created: for railway bridges and for road bridges. Both types of models change the dimensions and the number of constituent elements in accordance with the entered parameters. The performed work confirms the possibility of creating information parametric models of complex form and the expediency of using them in the design of bridges and not only. Originality. Creation of information models is a modern and relevant topic. But both in the literature and in Internet resources, parametrization is considered on the example of simple objects. The model proposed in the article consists of several dependent geometric bodies; therefore, it opens the topic of objects parameterization more fully and in detail, in comparison with the existing sources. As for the creation of parametric models of the bridge elements - such information is not found in the literature, that is, it is proposed for the first time. Practical value. Parametrization of spatial models allows significantly to accelerate and simplify the process of designing any objects due to the use of typical parametric models in many projects. Especially it concerns the design of bridges, since the standard elements for them, such as support or span are not

  14. Design

    Science.gov (United States)

    Buchanan, Richard; Cross, Nigel; Durling, David; Nelson, Harold; Owen, Charles; Valtonen, Anna; Boling, Elizabeth; Gibbons, Andrew; Visscher-Voerman, Irene

    2013-01-01

    Scholars representing the field of design were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Richard Buchanan, Nigel Cross, David Durling, Harold Nelson, Charles Owen, and Anna Valtonen. Scholars…

  15. Professional Rhetorics: Bridging the Gap between Writing, Speaking, & Digital Media

    Science.gov (United States)

    Hodgson, Justin

    2009-01-01

    This article presents the syllabus for the course "Professional Rhetorics: Bridging the Gap Between Writing, Speaking, & Digital Media." The course is designed to help students develop into effective rhetors for today's professional environments, and it will do so by exploring numerous rhetorical strategies associated with oral,…

  16. Evacuation of mixed populations from trains on bridges

    DEFF Research Database (Denmark)

    Kindler, C.; Sørensen, J.G.; Dederichs, A.S.

    2012-01-01

    An understanding of human evacuation dynamics and performance are important when designing complex buildings such as bridges and when applying performance-based codes in order to reduce the risk of exposing occupants to critical conditions in case of fire. The majority of previous studies deal...

  17. Engineering and introduction of de novo disulphide bridges in ...

    Indian Academy of Sciences (India)

    In this study, Disulphide by Design software, homology modelling and moleculardynamics simulations were used to select appropriate amino acid pairs for the introduction of disulphide bridge toimprove protein thermostability. The thermostability of the wild-type and three selected mutant enzymes wereevaluated by half-life ...

  18. Environmental Impact Optimization of Reinforced Concrete Slab Frame Bridges

    DEFF Research Database (Denmark)

    Yavari, Majid Solat; Du, Guangli; Pacoste, Costin

    2017-01-01

    yet of a higher concrete class, while cost optimization by considering extra constructability factors provided thicker sections and easier to construct design. This dissimilarity in the results highlights the importance of combining environmental impact (and its associated environmental cost......) and investment cost to find more material-efficient, economical, sustainable and time-effective bridge solutions....

  19. AHP-VIKOR Bridge Structural System Selection in Urban Areas Tehran: Interchanges Case Study

    Directory of Open Access Journals (Sweden)

    Ali Akbar Ramezanianpour

    2016-10-01

    Full Text Available The selection of “Structural system” is one of the most important factors in any bridge and infrastructure design. Designers perform the structural calculations for the project determines the priorities as well as design and performance criteria. Further analysis of the structural selection problem and the identification of the bridge desirable capabilities, triggered the consideration of analytic hierarchy process (AHP as a possible basis for the decision making. The methodology uses the VIKOR to evaluate the alternatives according to the decision criteria and determine the solution. The methodology was developed by a group of bridge designers involved in design and management of urban infrastructure projects and demonstrated using a Steel Girder bridge in an urban area as an optimum alternative.

  20. Safety Identifying of Integral Abutment Bridges under Seismic and Thermal Loads

    Science.gov (United States)

    Easazadeh Far, Narges; Barghian, Majid

    2014-01-01

    Integral abutment bridges (IABs) have many advantages over conventional bridges in terms of strength and maintenance cost. Due to the integrity of these structures uniform thermal and seismic loads are known important ones on the structure performance. Although all bridge design codes consider temperature and earthquake loads separately in their load combinations for conventional bridges, the thermal load is an “always on” load and, during the occurrence of an earthquake, these two important loads act on bridge simultaneously. Evaluating the safety level of IABs under combination of these loads becomes important. In this paper, the safety of IABs—designed by AASHTO LRFD bridge design code—under combination of thermal and seismic loads is studied. To fulfill this aim, first the target reliability indexes under seismic load have been calculated. Then, these analyses for the same bridge under combination of thermal and seismic loads have been repeated and the obtained reliability indexes are compared with target indexes. It is shown that, for an IAB designed by AASHTO LRFD, the indexes have been reduced under combined effects. So, the target level of safety during its design life is not provided and the code's load combination should be changed. PMID:25405232

  1. Bridging UX and web development better results through team integration

    CERN Document Server

    Moffett, Jack

    2014-01-01

    The divide between UX and Web development can be stifling. Bridging UX and Web Development prepares you to break down those walls by teaching you how to integrate with your team's developers. You examine the process from their perspective, discovering tools and coding principles that will help you bridge the gap between design and implementation. With these tried and true approaches, you'll be able to capitalize on a more productive work environment. Whether you're a novice UX professional finding your place in the software industry and looking to nail down your technical skills, or a seasone

  2. LATERAL CAPACITY OF AL NAJIBIYA BRIDGE PIER FOUNDATION

    OpenAIRE

    Samir Abdul Baki Jabbar Al-Jassim*, Rafi Mohammed Qasim

    2017-01-01

    Al-Najibiya Bridge was designed to be constructed on Shat Al Arab River in Basra district, Iraq. The bridge consists of five spans 33m length each with four intermediate piers. Each pier is supported on pile cap of 9m width, 17m length and 2m depth. The pile cap is stand over six cast in drilled hole piles of 1.8m diameter arranged at five meter center to center in both directions. The piles are stand 10 to 12m above river bed and embedded 30m in an over consolidated clayey soil with stiffnes...

  3. Simplified air bridge technique using photoresist UV stabilization process

    Science.gov (United States)

    Tajadod, James; Insalaco, Linda J.

    1993-09-01

    Due to their favorable structural and electrical properties, air bridges are used extensively by silicon and GaAs monolithic microwave integrated circuit (MMIC) designers. Fabrication of such structures using the conventional techniques is complex. In this paper novel construction of air bridge structures of up to 7.5 micrometers high using an ultra violet (UV) stabilized bi-layer photoresist process, evaporated metal scheme, and lift-off patterning procedure, is realized. Deep UV stabilization of positive photo resist is discussed. Removal of the hardened resist via organic photo resist stripper is addressed.

  4. Very High Frequency Half Bridge DC/DC Converter

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    This paper presents the first, off chip, class DE (resonant half bridge) converter working in the Very High Frequency (VHF) range. The benefits of using half bridge circuits both in the inverter and rectifier part of a VHF resonant dc/dc converter are analyzed and design equations for all...... components in the power stage are given. The circuit has been simulated to verify the accuracy of the presented equations and an efficiency of 89% has been shown. A prototype has been implemented with self-oscillating resonant gate drives driving the switches. The prototype has been used to drive an LED...

  5. Implant-supported full-mouth reconstruction Malo Implant Bridge.

    Science.gov (United States)

    Kodama, Taishi

    2012-06-01

    This article describes the clinical techniques and laboratory procedures for fabricating a predictable Malo Implant Bridge involving application of an occlusal screw-retained implant superstructure on the basis of the All-on-4 concept. The Malo Implant Bridge features a removable occlusal screw-retained superstructure; fabrication of the framework with a computer-aided design/computer-aided manufacturing system allowing accurate adaptation; and use of the final tooth position model with guide temporary crowns allowing easy porcelain build-up and satisfying the patient's esthetic concerns.

  6. Control of liquid bridging induced stiction of micromechanical structures

    Science.gov (United States)

    Abe, Takeshi; Reed, Michael L.

    1996-06-01

    Stiction, the unwanted adhesion of micromachined components to the underlying substrate, is a vexing problem encountered during the fabrication of microelectromechanical systems. Liquid bridging of rinse liquids after release etch processing introduces significant surface tension forces which can initiate stiction. We show that liquid bridging can be substantially eliminated by appropriate design of the microstructure periphery. Antistiction tabs located at the center of doubly clamped beams, or at the ends of cantilevered beams, are shown to improve release yield significantly in both surface and bulk micromachining processes.

  7. Ohio River Bridges: Partial Cane Run Watershed Relocation Case Study

    OpenAIRE

    Gavelek, Matt

    2014-01-01

    The Ohio River Bridges design-build project, at just under $2 billion, is one the nation’s largest transportation projects. The project consists of six sections. Section 3, the Indiana approach to the downtown crossing, consists of 21 bridges, 25 ramps, 1.3 miles of I-65 widening, & US-31 reconfiguration in a dense, urban setting. Section 3 is located in a complicated hydraulic scenario involving a flood wall and an urban stream, Cane Run, with a history of flooding problems. It became eviden...

  8. Study of displacements of a bridge abutment using FEM

    Directory of Open Access Journals (Sweden)

    Wymysłowski Michał

    2016-06-01

    Full Text Available Steel sheet piles are often used to support excavations for bridge foundations. When they are left in place in the permanent works, they have the potential to increase foundation bearing capacity and reduce displacements; but their presence is not usually taken into account in foundation design. In this article, the results of finite element analysis of a typical abutment foundation, with and without cover of sheet piles, are presented to demonstrate these effects. The structure described is located over the Więceminka river in the town of Kołobrzeg, Poland. It is a single-span road bridge with reinforced concrete slab.

  9. 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.

  10. 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.

  11. 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

  12. A Literature review of life cycle assessment for bridge infrastructure

    DEFF Research Database (Denmark)

    Du, Guangli

    2010-01-01

    Currently, the whole world is confronted with great challenges related to environmental issues. As a fundamentalinfrastructure in transport networks, railway bridges are responsible for numerous material and energy consumption throughtheir life cycle, which in turn leads to significant...... environmental burdens. However, present management of railway bridgeinfrastructures is mainly focused on the technical and financial aspects, whereas the environmental assessment is rarely integrated. Life cycle assessment (LCA) is deemed as a systematic method for also assessing the environmental impact...... of products and systems, but its application in railway bridge infrastructures is rare. Very limited literature and research studies are available in this area. In order to incorporate the implementation of LCA into railway bridges and set new design criteria, this article performs an elaborate literature...

  13. Construction of the Chamagawa bridge; Chamagawabashi no seko

    Energy Technology Data Exchange (ETDEWEB)

    Kawado, A.; Okawa, M. [Honshu-Shikoku Bridge Authority, Tokyo (Japan); Yoshii, M.; Oda, I.

    1997-09-30

    The Chamagawa Bridge is a reinforced concrete fixed-arch bridge which is located at the northern end of Awaji Island, 1.5 km away from the Honshu-Shikoku linking large-scale Akashi Strait Bridge. This paper describes the design and construction of the bridge. Overhang construction method using cable stayed members was adopted. Against the tensile stress generated in the arch-ring under construction, reaction force was burdened with cable stayed columns, anchor blocks and ground anchors by regulating stress using cable stayed members and by resisting using PC steel rods arranging in the arch-ring. For the construction of arch-ring, a space was made for fabricating a specific large-scale movable working vehicle by the grounding support. Then, overhang construction was started. For the construction of overhang, construction of cable stayed members, regulation of stress, and tension of ground anchors were conducted with the construction of each block. The construction of linking block in the center was conducted by hanging support method after the specific large-scale movable working vehicle was taken to pieces. After the connection of arch-ring, tensile forces of cable stayed members and ground anchors were released. The bridge was completed in the down road in 1997. 1 ref., 21 figs., 6 tabs.

  14. Bridge structure PZT thin film microtransducer with mass loading

    Science.gov (United States)

    Zang, Ming; Zurn, Shayne M.; Robbins, William P.; Polla, Dennis L.; Markus, David T.

    2001-12-01

    We report on a bridge structure PZT [Pb(ZrxTi1- x)O3] thin film microtransducer with proof mass that has been fabricated successfully at the Microtechnology Laboratory (MTL) of the University of Minnesota. The bridge microtransducer is made on silicon wafer using bulk micromachining of microelectromechanical systems (MEMS) and special techniques for deposition of a PZT thin film. The bridge is 300 micrometers wide, 1000 micrometers long, and a few micrometers thick. A proof mass made from the silicon wafer is loaded under the bridge at the central region, its area is 300 X 300 square micrometers and its thickness is 475 micrometers (same as the wafer). Used as an accelerometer, the microtransducer is calibrated using a Vibration Test Systems (VTS), which is a commercial accelerometer calibration instrument. The sensitivity of the microtransducer is constant over the range of frequencies from zero to 10 kHz, 240(mu) V/g at 0.5g with a dc bias voltage of 0.2 volts and a deviation of 5%. The Brownian thermal noise equivalent acceleration is 9.072(mu) g/(root)Hz. Design of a bridge structure with mass loading is modeled using ANSYS. Simulation analysis shows that the fundamental natural frequency of the microtransducer is 11.352 kHz, which is close to the measured resonant frequency of 12.28 kHz.

  15. Seismic Response Analysis of Continuous Multispan Bridges with Partial Isolation

    Directory of Open Access Journals (Sweden)

    E. Tubaldi

    2015-01-01

    Full Text Available Partially isolated bridges are a particular class of bridges in which isolation bearings are placed only between the piers top and the deck whereas seismic stoppers restrain the transverse motion of the deck at the abutments. This paper proposes an analytical formulation for the seismic analysis of these bridges, modelled as beams with intermediate viscoelastic restraints whose properties describe the pier-isolator behaviour. Different techniques are developed for solving the seismic problem. The first technique employs the complex mode superposition method and provides an exact benchmark solution to the problem at hand. The two other simplified techniques are based on an approximation of the displacement field and are useful for preliminary assessment and design purposes. A realistic bridge is considered as case study and its seismic response under a set of ground motion records is analyzed. First, the complex mode superposition method is applied to study the characteristic features of the dynamic and seismic response of the system. A parametric analysis is carried out to evaluate the influence of support stiffness and damping on the seismic performance. Then, a comparison is made between the exact solution and the approximate solutions in order to evaluate the accuracy and suitability of the simplified analysis techniques for evaluating the seismic response of partially isolated bridges.

  16. 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, ...

  17. 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 ...

  18. Development Length for Headed Bars in Slab-Column Joints of RC Slab Bridges

    Science.gov (United States)

    2015-12-04

    In accordance with the Caltrans Seismic Design Criteria, the superstructure in a slab bridge should remain essentially elastic and only the pile extensions/columns are permitted to develop inelastic deformations during a seismic event. Hence, the lon...

  19. Forensic investigation of two voided slab bridges in the Virginia Department of Transportation's Richmond District.

    Science.gov (United States)

    2017-06-01

    The precast prestressed concrete voided slab structure is a popular bridge design because of its rapid construction and cost : savings in terms of eliminating formwork at the jobsite. However, the longitudinal shear transfer mechanism often fails, le...

  20. The development of crashworthy rails for fiber reinforced polymer honeycomb bridge deck system.

    Science.gov (United States)

    2015-07-01

    Fiber reinforced polymer (FRP) honeycomb panels offer an efficient and rapid replacement to : concrete decks. The system consists of FRP honeycomb sandwich panels with adequate guardrails. Although : FRP bridge deck panels have already been designed ...