WorldWideScience

Sample records for bridge engineering

  1. Architectural engineering of FRP bridges

    OpenAIRE

    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 architectural application of FRP's derived from the authors architectural practice.

  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 archit

  3. 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

  4. Translating Climate Projections for Bridge Engineering

    Science.gov (United States)

    Anderson, C.; Takle, E. S.; Krajewski, W.; Mantilla, R.; Quintero, F.

    2015-12-01

    A bridge vulnerability pilot study was conducted by Iowa Department of Transportation (IADOT) as one of nineteen pilots supported by the Federal Highway Administration Climate Change Resilience Pilots. Our pilot study team consisted of the IADOT senior bridge engineer who is the preliminary design section leader as well as climate and hydrological scientists. The pilot project culminated in a visual graphic designed by the bridge engineer (Figure 1), and an evaluation framework for bridge engineering design. The framework has four stages. The first two stages evaluate the spatial and temporal resolution needed in climate projection data in order to be suitable for input to a hydrology model. The framework separates streamflow simulation error into errors from the streamflow model and from the coarseness of input weather data series. In the final two stages, the framework evaluates credibility of climate projection streamflow simulations. Using an empirically downscaled data set, projection streamflow is generated. Error is computed in two time frames: the training period of the empirical downscaling methodology, and an out-of-sample period. If large errors in projection streamflow were observed during the training period, it would indicate low accuracy and, therefore, low credibility. If large errors in streamflow were observed during the out-of-sample period, it would mean the approach may not include some causes of change and, therefore, the climate projections would have limited credibility for setting expectations for changes. We address uncertainty with confidence intervals on quantiles of streamflow discharge. The results show the 95% confidence intervals have significant overlap. Nevertheless, the use of confidence intervals enabled engineering judgement. In our discussions, we noted the consistency in direction of change across basins, though the flood mechanism was different across basins, and the high bound of bridge lifetime period quantiles exceeded

  5. Helping System Engineers Bridge the Peaks

    Science.gov (United States)

    Rungta, Neha; Tkachuk, Oksana; Person, Suzette; Biatek, Jason; Whalen, Michael W.; Castle, Joseph; Castle, JosephGundy-Burlet, Karen

    2014-01-01

    In our experience at NASA, system engineers generally follow the Twin Peaks approach when developing safety-critical systems. However, iterations between the peaks require considerable manual, and in some cases duplicate, effort. A significant part of the manual effort stems from the fact that requirements are written in English natural language rather than a formal notation. In this work, we propose an approach that enables system engineers to leverage formal requirements and automated test generation to streamline iterations, effectively "bridging the peaks". The key to the approach is a formal language notation that a) system engineers are comfortable with, b) is supported by a family of automated V&V tools, and c) is semantically rich enough to describe the requirements of interest. We believe the combination of formalizing requirements and providing tool support to automate the iterations will lead to a more efficient Twin Peaks implementation at NASA.

  6. Review on antibacterial characteristics of bridge engineering biomaterials.

    Science.gov (United States)

    Zhao, Qing-Qing; Chen, Meng-Yao; He, Rui-Lin; Zhang, Zhong-Feng; Ashraf, Muhammad Aqeel

    2016-01-01

    This review summarizes the research on timber construction materials used in bridge construction. It focuses on the application of antiseptic treatments and the use of timber engineering materials in decks and bridges. This review also provides an overview on the future research and prospects of engineered timber materials. PMID:26858558

  7. Bridge Engineering-Oriented Parametric Model

    Institute of Scientific and Technical Information of China (English)

    周凌远; 李乔

    2004-01-01

    A new model is proposed to improve the efficiency of structural modeling. In this model, the bridge structural components are expressed with component description, parametric description and geometric description in a software system. This model provides both convenience and flexibility for users in structural modeling process. The object-oriented method is applied in the model implementation. A bridge analysis preprocessor is developed on the basis of this model. It provides an effective way for bridge modeling.

  8. Information Geography: A Bridge between Engineering and the Social Sciences

    Science.gov (United States)

    Paradiso, Maria

    2006-01-01

    This paper presents the metaphor of engineering and the social sciences located on either side of a chasm and connected by the bridge of information geography. Information geography is not an integral part of engineering and is a new field within geography, a social science discipline. The specialty of information geography is one of the newest in…

  9. Bridging Resilience Engineering and Human Reliability Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ronald L. Boring

    2010-06-01

    There has been strong interest in the new and emerging field called resilience engineering. This field has been quick to align itself with many existing safety disciplines, but it has also distanced itself from the field of human reliability analysis. To date, the discussion has been somewhat one-sided, with much discussion about the new insights afforded by resilience engineering. This paper presents an attempt to address resilience engineering from the perspective of human reliability analysis (HRA). It is argued that HRA shares much in common with resilience engineering and that, in fact, it can help strengthen nascent ideas in resilience engineering. This paper seeks to clarify and ultimately refute the arguments that have served to divide HRA and resilience engineering.

  10. Bridging the Gap Between Engineering Workforce Needs and Student Engagement

    OpenAIRE

    Goold, Eileen

    2015-01-01

    This paper is inspired by the development of the proposed new technological university in Dublin; TU4Dublin is to become “Dublin’s Globally Engaged University” and is to be located at the nexus between learning and engagement (TU4Dublin, 2015). This study investigates engineering education in the context of career focused education. The main objective of this study is to investigate whether engineering students’ cognitive engagement benefits from bridging the gap between technical issues and ...

  11. State-of-the-art of long-span bridge engineering in China

    Institute of Scientific and Technical Information of China (English)

    XIANG Haifan; GE Yaojun

    2007-01-01

    This paper introduces the state-of-the-art of long-span bridge engineering in China with emphases on recent long-span bridge projects,bridge deck configuration and material,design codes of long-span bridges and improvement of aerodynamic performance.The recent long-span bridge projects include thirty-eight completed suspension bridges,cable-stayed and arch bridges with a main span over 400 m,and eighteen major bridges are under construction.The bridge deck configuration and material,with prestressed concrete decks,steel-concrete composite decks and steel box decks together with several popular cross-sections,are presented.The third part briefly outlines four design codes,including static and dynamic design for highway long-span bridges,and the recent engineering experiences gained from several aerodynamic vibration control projects of long-span bridges are shared in the last part.

  12. Exploring Bridge-Engine Control Room Collaborative Team Communication

    Directory of Open Access Journals (Sweden)

    Aditi Kataria

    2015-06-01

    Full Text Available The EC funded CyClaDes research project is designed to promote the increased impact of the human element in shipping across the design and operational lifecycle. It addresses the design and operation of ships and ship systems. One of the CyClaDes’ tasks is to create a crew-centered design case-study examination of the information that is shared between the Bridge and Engine Control Room that helps the crew co-ordinate to ensure understanding and complete interconnected tasks. This information can be provided in various ways, including communication devices or obtained from a common database, display, or even the ship environment (e.g., the roll of the ship. A series of semi-structured interviews were conducted with seafarers of diverse ranks to get a better idea of what communication does, or should, take place and any problems or challenges existing in current operations, as seen from both the bridge and ECR operators’ perspectives. Included in the interview were both the standard communications and information shared during planning and executing a voyage, as well as special situations such as safety/casualty tasks or heavy weather. The results were analyzed in terms of the goals of the communication, the primary situations of interest for communication and collaboration, the communication media used, the information that is shared, and the problems experienced. The results of seafarer interviews are presented in the paper to explore on-board inter-departmental communication.

  13. Application of Composite Structures in Bridge Engineering. Problems of Construction Process and Strength Analysis

    Directory of Open Access Journals (Sweden)

    Flaga Kazimierz

    2015-03-01

    Full Text Available Steel-concrete composite structures have been used in bridge engineering from decades. This is due to rational utilisation of the strength properties of the two materials. At the same time, the reinforced concrete (or prestressed deck slab is more favourable than the orthotropic steel plate used in steel bridges (higher mass, better vibration damping, longer life.

  14. Bridging the Gap between Design and Engineering in Packaging Development

    OpenAIRE

    Ten Klooster, R.; Lutters, D.

    2009-01-01

    Packaging designers often come up with splendid design proposals, without being aware of technical, marketing or economical restrictions. This leads to infeasible proposals, so many packaging design projects fail. To bridge the gap between design and marketing, a tool has been developed that shows several designs to an extensive community. Designers now have the possibility to get feedback of the target market on the design proposals. In a case study (redesigning a packaging), the...

  15. Bridging the Divide between Neuroprosthetic Design, Tissue Engineering and Neurobiology

    OpenAIRE

    Jennie Leach; Achyuta, Anil Kumar H.; Murthy, Shashi K

    2010-01-01

    Neuroprosthetic devices have made a major impact in the treatment of a variety of disorders such as paralysis and stroke. However, a major impediment in the advancement of this technology is the challenge of maintaining device performance during chronic implantation (months to years) due to complex intrinsic host responses such as gliosis or glial scarring. The objective of this review is to bring together research communities in neurobiology, tissue engineering, and neuroprosthetics to addre...

  16. Bridging the divide between neuroprosthetic design, tissue engineering and neurobiology

    Directory of Open Access Journals (Sweden)

    Jennie Leach

    2010-02-01

    Full Text Available Neuroprosthetic devices have made a major impact in the treatment of a variety of disorders such as paralysis and stroke. However, a major impediment in the advancement of this technology is the challenge of maintaining device performance during chronic implantation (months to years due to complex intrinsic host responses such as gliosis or glial scarring. The objective of this review is to bring together research communities in neurobiology, tissue engineering, and neuroprosthetics to address the major obstacles encountered in the translation of neuroprosthetics technology into long-term clinical use. This article draws connections between specific challenges faced by current neuroprosthetics technology and recent advances in the areas of nerve tissue engineering and neurobiology. Within the context of the device-nervous system interface and central nervous system (CNS implants, areas of synergistic opportunity are discussed, including platforms to present cells with multiple cues, controlled delivery of bioactive factors, three-dimensional constructs and in vitro models of gliosis and brain injury, nerve regeneration strategies, and neural stem/progenitor cell (NPC biology. Finally, recent insights gained from the fields of developmental neurobiology and cancer biology are discussed as examples of exciting new biological knowledge that may provide fresh inspiration towards novel technologies to address the complexities associated with long-term neuroprosthetic device performance.

  17. Mathematics Education for Engineering Technology Students – A Bridge Too Far?

    Directory of Open Access Journals (Sweden)

    Noraishiyah Abdullah

    2013-03-01

    Full Text Available Trying to decide what is best suited for someone or something is an ever enduring task let alone trying to prepare students with the right engineering mind. So ‘how do you build an engineer?’ if that is the right word. What is the right ingredient? Mathematics has been said as the most important foundation in engineers’ life. Curriculum has been developed and reviewed over the years to meet this target. This work explores how much or lack of it has the curriculum prepares the future technologist to face the world of engineering technology as far as mathematics is concerned. Analysis of mathematics lectures, interviews of engineering technologist students and engineering technology subject lecturer is undertaken. Understand what each contributes help in understanding the picture that the current education is painting. Based on the theory of learning, APOS theory helps in explaining how students bridge their knowledge of mathematics when it comes to solving engineering technology problems. The question is, is it a bridge too far? 

  18. Practice and experience of engineering culture development in the Sutong Bridge project

    Institute of Scientific and Technical Information of China (English)

    Yu Chunsheng; Yao Bei; Wang Qian

    2009-01-01

    To keep up with the time, culture is integrated to large-scale construction project management in China, which will absolutely add more vitality into construction project management in our country. Engineering culture is an integration of project construction and engineering culture. However, engineering culture development enjoys its own particularity as a project is constructed once only within a limited period of time. This paper gives affirmative opinion that engineering culture development in large-scale projects backs project management on the basis of thorough investigation of engineering culture development in Sutong Bridge Project and after deepened analysis, proposes new thinking pattern of engineering culture development in large-scale projects in a systematic manner, including thorough understanding of the essence of engineering culture, principle and contents of engineering culture development as well as efficient method in respect of establishment and implementation of engineering culture, and therefore provides a standard reference and systematic thinking pattern for engineering culture development in future large-scale projects.

  19. Agile Market Engineering: Bridging the gap between business concepts and running markets

    OpenAIRE

    Block, Carsten Alexander

    2010-01-01

    The agile market engineering process model (AMEP) is built on the insight, that market design and development is a wicked problem. Electronic markets are too complex to be completely designed upfront. Instead, AMEP tries to bridge the gap between theoretic market design and practical electronic market platform development using an agile, iterative approach that relies on early customer feedback and continuous improvement. The AMEP model is complemented by several supporting software artifacts.

  20. An Automatic Method for Geometric Segmentation of Masonry Arch Bridges for Structural Engineering Purposes

    Science.gov (United States)

    Riveiro, B.; DeJong, M.; Conde, B.

    2016-06-01

    Despite the tremendous advantages of the laser scanning technology for the geometric characterization of built constructions, there are important limitations preventing more widespread implementation in the structural engineering domain. Even though the technology provides extensive and accurate information to perform structural assessment and health monitoring, many people are resistant to the technology due to the processing times involved. Thus, new methods that can automatically process LiDAR data and subsequently provide an automatic and organized interpretation are required. This paper presents a new method for fully automated point cloud segmentation of masonry arch bridges. The method efficiently creates segmented, spatially related and organized point clouds, which each contain the relevant geometric data for a particular component (pier, arch, spandrel wall, etc.) of the structure. The segmentation procedure comprises a heuristic approach for the separation of different vertical walls, and later image processing tools adapted to voxel structures allows the efficient segmentation of the main structural elements of the bridge. The proposed methodology provides the essential processed data required for structural assessment of masonry arch bridges based on geometric anomalies. The method is validated using a representative sample of masonry arch bridges in Spain.

  1. HVAC in sustainable office buildings a bridge between owners and engineers

    CERN Document Server

    Hovorka, Frank; Kurnitski, Jarek; Litiu, Andrei

    2012-01-01

    This guidebook aims to build a bridge between the real estate community and the engineering community. It explains the challenges of property valuation based on real data and how the sustainability and HVAC-technology can have an impact on value. It also gathers the latest HVAC- and other technologies used in sustainable buildings and gives some real case study examples. But maybe the most important part in terms of improved communication between the owners and engineers is the list of questions to be asked during the life time of a building. It is impossible to give all the right answers in this guidebook, but we will raise some pertinent questions. As climates and cultures are different, as well as existing building types and energy production, the same solutions do not solve problems universally. This guidebook is aimed for the owners and architects as well as engineers. It doesn’t require deep technical knowhow of HVAC-systems or real estate valuation.

  2. Construction engineering of steel tub-girder bridge systems for skew effects

    Science.gov (United States)

    Jimenez Chong, Juan Manuel

    understanding of the level of sophistication of analysis models required to properly predict forces and deformations of curved and/or skewed bridges during construction is limited. The development of guidelines regarding the sufficiency of simplified methods of structural analysis is the overall motivation and objective of this dissertation. This research addresses the construction load effects due to skew and due to combined skew and curvature and develops design recommendations and analytical tools for the construction engineering of tub-girder bridges. The effects of skew and curvature are studied by examining the results for different levels of analysis for 18 representative bridges. These bridges reflect the range of bridge curvature and skew used in current practice. By comparing the output from simplified analysis methods to validated refined 3D FEA solutions, general conclusions are developed as to when the simplified methods provide sufficient results. An important original contribution of this research is that the data generated constitutes the first systematic study on a large set of curved and skewed tub-girder bridges using consistent refined 3D FEA models to model construction forces and deformations. As such, the results of this research can serve as a benchmark for current and future improvements in methods of analysis and design for the construction engineering of curved and skewed tub-girder bridges. In the current research, this data has been used in both straight and curved tub-girder bridges to: • Develop a simplified 1D analysis method to account for the effect of skew on girder twist rotations and internal torques, • Evaluate the effect of skew on component forces, and propose improved simplified procedures to capture these effects, • Identify interactions between components and develop improved simplified analysis methods to account for these effects, • Establish limits for when the improved 1D and 2D simplified methods of analysis are sufficient

  3. Assessment of factors impacting success for incoming college engineering students in a summer bridge program

    Science.gov (United States)

    Reisel, John R.; Jablonski, Marissa; Hosseini, Hossein; Munson, Ethan

    2012-06-01

    A summer bridge program for incoming engineering and computer science freshmen has been used at the University of Wisconsin-Milwaukee from 2007 to 2010. The primary purpose of this program has been to improve the mathematics course placement for incoming students who initially place into a course below Calculus I on the math placement examination. The students retake the university's math placement examination after completing the bridge program to determine if they then place into a higher-level mathematics course. If the students improve their math placement, the program is considered successful for that student. The math portion of the bridge program is designed around using the ALEKS software package for targeted, self-guided learning. In the 2007 and 2008 versions of the program, both an on-line version and an on-campus version with additional instruction were offered. In 2009 and 2010, the program was exclusively in an on-campus format, and also featured a required residential component and additional engineering activities for the students. From the results of these four programs, we are able to evaluate the success of the program in its different formats. In addition, data has been collected and analysed regarding the impact of other factors on the program's success. The factors include student preparation before the beginning of the program (as measured by math ACT scores) and the amount of time the student spent working on the material during the program. Better math preparation and the amount of time spent on the program were found to be good indicators of success. Furthermore, the on-campus version of the program is more effective than the on-line version.

  4. Engineering approach to in-situ bridge health monitoring with fiber bragg gratings

    Institute of Scientific and Technical Information of China (English)

    WU Zhan-jun; ZHANG Bo-ming; WAN Li-bing; ZHOU Zhi; OU Jin-ping

    2006-01-01

    In this presentation the feasibility and capability of fiber Bragg gratings (FBG) employed in bridge health monitoring are demonstrated on a real bridge. FBG's wavelength shift depending on strain variance has been tested. The technique of FBG installation on bridges has been developed. 12 FBG strain sensors and 3temperature sensors have been successfully embedded in the prestressed concrete box girder during the construction of Heilongjiang Hulan River Bridge. The prestressing tension process and quasi-static loading process of the girder were monitored with those sensors before it was installed onto the bridge. After the bridge was completed,the FBG sensors embedded have been utilized to monitor the strain shift of the beam under quasi-static load,traffic load and temperature. The results show that the traffic fluxes, possible fatigue damage and deflection of the bridge can be revealed conveniently through strain measurements with these FBG sensors, which provide key information for structural health diagnosis. The fact that the FBG strain sensors have withstood the ordeal of harsh construction process and lasted for more than one year proves that their durability and stability can satisfy the requirements for bridge health monitoring. It is also shown that the FBG strain sensor is more adaptive to long-term structural health monitoring than the electric resistance strain gauge.

  5. DETERMINATION OF ENGINEERING CRITERIA OF DELICE (ANKARA BRIDGE BY CPM METHOD

    Directory of Open Access Journals (Sweden)

    M. Haluk ÇELİK

    1995-02-01

    Full Text Available In this study, CPM-PERT method is used to find out the minimum time and cost of the bridge constructed in Delice (Ankara on the Koru river. The reinforced concrete bridge has a 13.70 m support distance and an 8 m platform witdh. In the method; planning, management and cost prices in Early Finish and Late Finish times were taken into account.

  6. Iron, Engineering and Architectural History in Crisis: Following the Case of the River Dee Bridge Disaster, 1847

    Directory of Open Access Journals (Sweden)

    William Max Taylor

    2013-10-01

    Full Text Available This paper establishes relations—historical, material and evidential connections—between two responses to a ‘crisis’. The first features in the history of industrialised iron construction, specifically period reporting on the spectacular collapse of the River Dee bridge in Cheshire, England, in 1847. The second response highlights a blind spot in the historiography of modern architecture. Robert Stephenson became suspect when his cast- and wrought-iron railway bridge across the River Dee failed, resulting in death and injury and continuing uncertainty as to its cause. At the time the incident sparked national furore, setting off a coroner’s inquest followed by a Royal Commission into the perilous state of Britain’s bridges. The inquest jury concluded no one was to blame; rather, it was an accident brought about by use of iron, an uncertain and “treacherous” metal. This explanation has failed to satisfy contemporary materials specialists who have reopened the case, albeit under different terms of reference.      The paper examines the initial verdict, firstly, in view of aspects of the social context of evidence and proof prevailing at the inquest and, secondly, given historical writing on iron construction whereby the inquest’s seemingly imprecise and arbitrary judgment is taken as sign of the subsequent progress of engineering as a practical and moral science. This paper adopts the leitmotif of ‘crisis’ to highlight a parallel history that challenges progressivist narratives of industrialised iron construction and modernist architecture. It invites reflection on the provenance and unstable forms of agency associated with engineering as a propositional and socially contingent enterprise.

  7. CIM's bridge from CADD to CAM: Data management requirements for manufacturing engineering

    Science.gov (United States)

    Ford, S. J.

    1984-01-01

    Manufacturing engineering represents the crossroads of technical data management in a Computer Integrated Manufacturing (CIM) environment. Process planning, numerical control programming and tool design are the key functions which translate information from as engineered to as assembled. In order to transition data from engineering to manufacturing, it is necessary to introduce a series of product interpretations which contain an interim introduction of technical parameters. The current automation of the product definition and the production process places manufacturing engineering in the center of CAD/CAM with the responsibility of communicating design data to the factory floor via a manufacturing model of the data. A close look at data management requirements for manufacturing engineering is necessary in order to establish the overall specifications for CADD output, CAM input, and CIM integration. The functions and issues associated with the orderly evolution of computer aided engineering and manufacturing are examined.

  8. Educating Maritime Engineers for a Globalised Industry - Bridging the Gap Between Industry and Universities

    DEFF Research Database (Denmark)

    Andersen, Ingrid Marie Vincent; Nielsen, Ulrik Dam

    2012-01-01

    for maritime engineers in the industry is considerably larger than the output from the technical universities. Moreover, it sets forth a series of recommendations to the industry as well as to the universities to facilitate meeting the demand for maritime engineers in Denmark in the future. The recommendations......In Denmark, the maritime engineering competences requested by the industry have changed in the past one to two decades. The typical naval architects do no longer find themselves working in the ship-building industry but rather in the industry of ship operators, consultancies, class societies, etc....... This means that universities educating maritime engineers need to reflect the changes in the curricula for their maritime engineering students. Topics and issues regarding this matter have recently been addressed in a survey made in the Danish maritime industry. The survey concludes that the demand...

  9. Reverse engineering of mandible and prosthetic framework: Effect of titanium implants in conjunction with titanium milled full arch bridge prostheses on the biomechanics of the mandible.

    Science.gov (United States)

    De Santis, Roberto; Gloria, Antonio; Russo, Teresa; D'Amora, Ugo; Varriale, Angelo; Veltri, Mario; Balleri, Piero; Mollica, Francesco; Riccitiello, Francesco; Ambrosio, Luigi

    2014-12-18

    This study aimed at investigating the effects of titanium implants and different configurations of full-arch prostheses on the biomechanics of edentulous mandibles. Reverse engineered, composite, anisotropic, edentulous mandibles made of a poly(methylmethacrylate) core and a glass fibre reinforced outer shell were rapid prototyped and instrumented with strain gauges. Brånemark implants RP platforms in conjunction with titanium Procera one-piece or two-piece bridges were used to simulate oral rehabilitations. A lateral load through the gonion regions was used to test the biomechanical effects of the rehabilitations. In addition, strains due to misfit of the one-piece titanium bridge were compared to those produced by one-piece cast gold bridges. Milled titanium bridges had a better fit than cast gold bridges. The stress distribution in mandibular bone rehabilitated with a one-piece bridge was more perturbed than that observed with a two-piece bridge. In particular the former induced a stress concentration and stress shielding in the molar and symphysis regions, while for the latter design these stresses were strongly reduced. In conclusion, prosthetic frameworks changed the biomechanics of the mandible as a result of both their design and manufacturing technology.

  10. Discuss How to Strengthen the Quality Management of Bridge Engineering%探讨如何加强桥梁工程质量管理

    Institute of Scientific and Technical Information of China (English)

    张应赞

    2014-01-01

    At present, the bridge project is stil a very serious problem. At the same time, the quality system of bridge, the control and management of supervision department, the know-ledge popularization of bridge experts and patent protection are facing unprecedented chalenges. Therefore, this article carries on the discussion of how to strengthen the quality man-agement of bridge engineering.%目前,我国桥梁工程仍旧存在十分严峻的问题。同时,桥梁的质量体系、监理部门的职能控管、桥梁专家的知识普及和专利保护都面临绝无仅有的挑战。因此,本文对如何加强桥梁工程质量管理进行了探讨。

  11. 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.

  12. Hybrid coordination-network-engineering for bridging cascaded channels to activate long persistent phosphorescence in the second biological window

    Science.gov (United States)

    Qin, Xixi; Li, Yang; Zhang, Ruili; Ren, Jinjun; Gecevicius, Mindaugas; Wu, Yiling; Sharafudeen, Kaniyarakkal; Dong, Guoping; Zhou, Shifeng; Ma, Zhijun; Qiu, Jianrong

    2016-02-01

    We present a novel “Top-down” strategy to design the long phosphorescent phosphors in the second biological transparency window via energy transfer. Inherence in this approach to material design involves an ingenious engineering for hybridizing the coordination networks of hosts, tailoring the topochemical configuration of dopants, and bridging a cascaded tunnel for transferring the persistent energy from traps, to sensitizers and then to acceptors. Another significance of this endeavour is to highlight a rational scheme for functionally important hosts and dopants, Cr/Nd co-doped Zn1-xCaxGa2O4 solid solutions. Such solid-solution is employed as an optimized host to take advantage of its characteristic trap site level to establish an electron reservoir and network parameters for the precipitation of activators Nd3+ and Cr3+. The results reveal that the strategy employed here has the great potential, as well as opens new opportunities for future new-wavelength, NIR phosphorescent phosphors fabrication with many potential multifunctional bio-imaging applications.

  13. Integrating Solar Power onto the Electric Grid - Bridging the Gap between Atmospheric Science, Engineering and Economics

    Science.gov (United States)

    Ghonima, M. S.; Yang, H.; Zhong, X.; Ozge, B.; Sahu, D. K.; Kim, C. K.; Babacan, O.; Hanna, R.; Kurtz, B.; Mejia, F. A.; Nguyen, A.; Urquhart, B.; Chow, C. W.; Mathiesen, P.; Bosch, J.; Wang, G.

    2015-12-01

    One of the main obstacles to high penetrations of solar power is the variable nature of solar power generation. To mitigate variability, grid operators have to schedule additional reliability resources, at considerable expense, to ensure that load requirements are met by generation. Thus despite the cost of solar PV decreasing, the cost of integrating solar power will increase as penetration of solar resources onto the electric grid increases. There are three principal tools currently available to mitigate variability impacts: (i) flexible generation, (ii) storage, either virtual (demand response) or physical devices and (iii) solar forecasting. Storage devices are a powerful tool capable of ensuring smooth power output from renewable resources. However, the high cost of storage is prohibitive and markets are still being designed to leverage their full potential and mitigate their limitation (e.g. empty storage). Solar forecasting provides valuable information on the daily net load profile and upcoming ramps (increasing or decreasing solar power output) thereby providing the grid advance warning to schedule ancillary generation more accurately, or curtail solar power output. In order to develop solar forecasting as a tool that can be utilized by the grid operators we identified two focus areas: (i) develop solar forecast technology and improve solar forecast accuracy and (ii) develop forecasts that can be incorporated within existing grid planning and operation infrastructure. The first issue required atmospheric science and engineering research, while the second required detailed knowledge of energy markets, and power engineering. Motivated by this background we will emphasize area (i) in this talk and provide an overview of recent advancements in solar forecasting especially in two areas: (a) Numerical modeling tools for coastal stratocumulus to improve scheduling in the day-ahead California energy market. (b) Development of a sky imager to provide short term

  14. Bridging sciatic nerve gap using tissue-engineered nerves constructed with neural tissue-committed stem cells derived from bone marrow

    Institute of Scientific and Technical Information of China (English)

    Zhiying Zhang; Congli Ren; Chuansen Zhang; Fang Liu; Liang Li

    2009-01-01

    BACKGROUND: Schwann cells are the most commonly used cells for tissue-engineered nerves. However, autologous Schwann cells are of limited use in a clinical context, and allogeneic Schwann cells induce immunological rejections. Cells that do not induce immunological rejections and that are relatively easy to acquire are urgently needed for transplantation.OBJECTIVE: To bridge sciatic nerve defects using tissue engineered nerves constructed with neural tissue-committed stem cells (NTCSCs) derived from bone marrow; to observe morphology and function of rat nerves following bridging; to determine the effect of autologous nerve transplantation, which serves as the gold standard for evaluating efficacy of tissue-engineered nerves.DESIGN, TIME AND SETTING: This randomized, controlled, animal experiment was performed in the Anatomical laboratory and Biomedical Institute of the Second Military Medical University of Chinese PLA between September 2004 and April 2006.MATERIALS: Five Sprague Dawley rats, aged 1 month and weighing 100-150 g, were used for cell culture. Sixty Sprague Dawiey rats aged 3 months and weighing 220-250 g, were used to establish neurological defect models. Nestin, neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP), and S-100 antibodies were provided by Santa Cruz Biotechnology, Inc., USA. Acellular nerve grafts were derived from dogs.METHODS: All rats, each with 1-cm gap created in the right sciatic nerve, were randomly assigned to three groups. Each group comprised 20 rats. Autograft nerve transplantation group: the severed 1-cm length nerve segment was reverted, but with the two ends exchanged; the proximal segment was sutured to the distal sciatic nerve stump and the distal segment to the proximal stump. Blank nerve scaffold transplantation group: a 1-cm length acellular nerve graft was used to bridge the sciatic nerve gap. NTCSC engineered nerve transplantation group: a 1-cm length acellular nerve graft, in which NTCSCs were

  15. 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...

  16. 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...

  17. 桥梁工程科技信息检索技术及动态%Technique and Development of Bridge Engineering Information Retrieval System

    Institute of Scientific and Technical Information of China (English)

    魏利明

    1999-01-01

    在介绍桥梁工程科技文献检索系统(BIRS-Bridge Engineering Information Retrieval System)的基础上,对涉及桥梁工程科技文献的信息检索技术进行概述,并列举了几个桥梁工作者理应了解且日臻完善的数据库,旨在为桥梁工程技术人员进行信息检索时提供借鉴.

  18. The brief talk of X128 shui -da line yuliang bridge strengthening engineering construction management%浅谈 X128水大线渔梁桥加固工程建设管理

    Institute of Scientific and Technical Information of China (English)

    瓦庆标

    2016-01-01

    随对我局管养的 X128水大线渔梁桥加固工程建设管理进行简单的阐述。%With the rapid development of Chinese social economy,the development of?highway transportation is also ad-vanced rapidly,and the bridge number is also increased.A large number of highway bridges?were founded in 60,70s in our province,under the function of increasing vehicle load,the technical state rapid decreased,soon the level of bridge de-veloped from class one or two to the three or four or even five,which was a threat to people's lives and property safety,and the bridge collapse accident sometimes happened.The paper mainly conduct a Simple exposition on the X128 Shui -Da line Yuliang Bridge strengthening engineering construction management.

  19. 桥梁工程鉴识专家系统设计开发%Developing a Bridge Engineering Forensic Expert System

    Institute of Scientific and Technical Information of China (English)

    林立

    2012-01-01

    考虑桥梁工程鉴识过程中影响要素的复杂性,将其视为灰系统反问题,应用神经网络方法避免解的不适定问题带来的求解困难.采用VFP和MATLAB语言分别构建了"桥梁工程鉴识专家系统"的知识数据模块和神经网络仿真模块,并通过两大核心模块与其他辅助模块的良性互动,实现了该系统的信息收集、系统仿真及鉴识分析等各项功能.为进一步的信息完善和网络训练提供开放、友好、安全的平台,以实现鉴识专家系统的准确性和稳定性.%This paper discussed complexity factors influencing bridge engineering forensic.Forensic process was considered as a grey system inverse problem and solved by neural network method in order to avoid difficulty from ill-posed problems.VFP and MATLAB language were used to design knowledge data module and neural network simulation module of Bridge Engineering Forensics Expert System.This two core modules and the others auxiliary module worked together well to achieve information collection,system simulation,and forensic analysis,which helps to provide open,friendly and secure plat-form for further data collection and network training towards accuracy and stability of the forensic expert systems.

  20. Engineering characteristics of near-fault vertical ground motions and their effect on the seismic response of bridges

    Institute of Scientific and Technical Information of China (English)

    Li Xinle; Dou Huijuan; Zhu Xi

    2007-01-01

    A wide variety of near-fault strong ground motion records were collected from various tectonic environments worldwide and were used to study the peak value ratio and response spectrum ratio of the vertical to horizontal component of ground motion,focusing on the effect of earthquake magnitude,site conditions,pulse duration,and statistical component.The results show that both the peak value ratio and response spectrum ratio are larger than the 2/3 value prescribed in existing seismic codes,and the relationship between the vertical and horizontal ground motions is comparatively intricate.In addition,the effect of the near-fault ground motions on bridge performance is analyzed,considering both the material nonlinear characteristics and the P~△ effect.

  1. Knowledge engineering for health: A new discipline required to bridge the “ICT gap” between research and healthcare

    DEFF Research Database (Denmark)

    Beck, Tim; Gollapudi, Sirisha; Brunak, Søren;

    2012-01-01

    on “knowledge engineering for health” is needed to facilitate knowledge transmission across the research–healthcare gap. This discipline is required to engineer the bidirectional flow of data: processing research data and knowledge to identify clinically relevant advances and delivering these into healthcare......Despite vast amount of money and research being channeled toward biomedical research, relatively little impact has been made on routine clinical practice. At the heart of this failure is the information and communication technology “chasm” that exists between research and healthcare. A new focus...... the key aims and objectives, namely “integrating and interpreting information for individualized healthcare,” by developing the “knowledge engineering for health” domain. Hum Mutat 33:797–802, 2012. © 2012 Wiley Periodicals, Inc....

  2. 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.

  3. Research and Researchers in the Field of Works of Art and Historical Monuments. The School of Bridges and Roads in France -- the first school of engineers in this field in the world

    Directory of Open Access Journals (Sweden)

    Ana-Raluca Chiriac

    2006-01-01

    Full Text Available Romanian higher education began a long time ago, having its own national specificity but being also influenced by the education from other developed countries. Between 1813 -- 1840 Gh. Asachi created the School of Terminal Engineering, establi-shing the foundations of the Technical Engineering University. In Moldavia, higher education in engineering, in the field of roads and bridges, coincides with the official opening of the Faculty of Construction of Jassy, in 1941, as part of the Polytechnic Institute, today the „Gheorghe Asachi” Technical University. Over the years, this type of education has evolved and developed, under the influence of schools of engineering such as The School of Bridges and Roads in France. The French School of Bridges and Roads was created by a decree of the king, on the 14th of February 1747. In two and a half centuries, it has trained about 15,000 engineers, who accomplished great works both in their native country and abroad. The reputation of this school is based especially on the discoveries, the accomplishments and the activity of these engineers, who have a great impact on the development of this institution. Most of these engineers did not go down in history (we seldom know the name of the person who built a bridge or a road. We remember some of them by a formula, a machine, a plate on a road, without actually knowing who is the person behind the name. Shaping their portraits, we could bring them back to the memory of the public, emphasizing the common aspects of their professional training at the School of Bridges and Roads. A free professional background, of a high scientific level, comprising a lot of practical issues, based on public transport in the beginning, where reflection and action play an important part. Except a lot of great scientists (among them, a Nobel prize laureate, inventors, entrepreneurs, engineers with prestigious accomplishments, there are also politicians (even a president, writers

  4. Examples of Solutions for Steel-Concrete Composite Structures in Bridge Engineering / Przykłady Konstrukcji Zespolonych W Budownictwie Mostowym

    Science.gov (United States)

    Flaga, Kazimierz; Furtak, Kazimierz

    2015-03-01

    The aim of the article [1] was to discuss the application of steel-concrete composite structures in bridge engineering in the aspect of structural design, analysis and execution. It was pointed out that the concept of steel-concrete structural composition is far from exhausted and new solutions interesting from the engineering, scientific and aesthetic points of view of are constantly emerging. These latest trends are presented against the background of the solutions executed in Poland and abroad. Particular attention is focused on structures of double composition and steel-concrete structures. Concrete filled steel tubular (CFST) structures are highlighted. W artykule [1] omówiono problemy konstrukcyjne, obliczeniowe i realizacyjne, związane z zastosowaniem konstrukcji zespolonych stal-beton w mostownictwie. Wskazano tam, że idea konstrukcyjnego zespolenia stali z betonem jest jeszcze daleka do wyczerpania i że wciąż pojawiają się nowe rozwiązania interesujące z inżynierskiego, naukowego i estetycznego punktu widzenia. W artykule niniejszym pokazano te nowoczesne trendy na tle rozwiązań zrealizowanych w Polsce i na świecie. Szczególną uwagę poświęcono konstrukcjom podwójnie zespolonym oraz konstrukcjom stalowobetonowym. Wyeksponowano tu szczególnie konstrukcje z rur stalowych wypełnionych betonem, typu CFST. Dają one nadzieję na ich szersze zastosowanie w warunkach polskich.

  5. Bridging the Gap between Engineering Design and PK-12 Curriculum Development through the Use of the STEM Education Quality Framework

    Science.gov (United States)

    Pinnell, Margaret; Rowly, James; Preiss, Sandi; Franco, Suzanne; Blust, Rebecca; Beach, Renee

    2013-01-01

    This paper will describe a unique partnership among the Department of Teacher Education and School of Engineering at the University of Dayton (UD) and the Dayton Regional STEM Center (DRSC). This partnership resulted in the development of the STEM Education Quality Framework (SQF), a tool to guide educators in teaching, learning and refining STEM…

  6. 工程量清单计价模式在路桥工程造价管理中的应用%Application of the Engineering Quantity List Valuation Mode in the Cost Management of Road and Bridge Project

    Institute of Scientific and Technical Information of China (English)

    彭于东

    2013-01-01

    路桥工程工期较长,传统的定额计价模式在路桥工程整个周期中不能体现市场因素的浮动性,而工程量清单计价模式克服了这种缺点,在路桥造价管理中得到广泛应用,下面重点介绍工程量清单计价的特点和在路桥工程造价管理中的应用。%The duration of road and bridge project is longer, floating traditional quota valuation mode does not reflect the market factors in the cycle of road and bridge project, but the engineering quantity list valuation model overcame this shortc-oming, obtained the widespread application in the cost manag-ement of road and bridge project, the fol owing introduces cha-racteristics of engineering quantity list valuation and the appli-cation in the engineering cost management of road and bridge project.

  7. 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.

  8. 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

  9. 桥梁工程石质边坡施工方法探讨%Rocky Slope Construction Method in Bridge Engineering

    Institute of Scientific and Technical Information of China (English)

    涂涛

    2012-01-01

      随着高速公路的发展,山区高速公路的修建越来越多,怎么样更好的实现桥梁边坡工程在复杂地质条件下的施工,是值得每一名道路人值得探讨的问题。本文主要以实际工程为案例,对桥梁石质边坡的爆破、防护及其他相关施工方法进行了阐述。%  With the development of the highway, the const-ruction of mountain highway are more andmore. How to bet er achieve the construction of the bridge slope engineering in complex geological conditions. It is a problem worth explor-ing.Taking the actual project as a case, this paper introduces the blasting of the rocky slope and its protection and some other construction methods

  10. 小直径沉管灌注桩在桥梁工程中的应用%Application of Small Diameter Sinking Pipe of Filling Pile in Bridge Engineering

    Institute of Scientific and Technical Information of China (English)

    陶斌铮; 廖鸿华

    2013-01-01

    Small diameter tube-sinking filling pile is widely used in the urban housing construction projects; however, it is less used in bridge engineering. However, due to the relatively low cost of sinking -pipe bored pile with small diameter, its application in bridge engineering is significant.%  小直径沉管灌注在市政房屋建筑工程建设经常采用,在桥梁工程中较少采用。但是由小直径沉管灌注桩造价相对较低,在一些特定条件下,将小直径沉管灌注桩应用桥梁工程中是有现实意义。

  11. 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.......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....

  12. Programmevaluierung Bridge

    OpenAIRE

    Warta, Katharina; Good, Barbara; Geyer, Anton

    2009-01-01

    BRIDGE is an initiative funded by the Ministry for Transport, Innovation and Technology (BMVIT) that aims to close the “funding gap” between basic and applied research in stand-alone projects with the primary objective of jointly developing the potential of basic and applied research. BRIDGE acts as an  umbrella structure under which the Austrian Science Fund (FWF) and the  Austrian Research Promotion Agency (FFG) coordinate two thematically open funding programmes: The ...

  13. Development of cooperative system bridges

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhe; WAN Qi-bai; SHI Lei

    2008-01-01

    Cooperative system bridges comprise several basic structures that act jointly to improve structural characteristics. We delved into the historical development of cooperative system bridges. Cooperative systems are classified as different-load cooperative systems and same-load cooperative systems by distinguishing the modes of load distribution. For different-load cooperation, individual basic structures are at different positions in the direction along bridge axis and carry the loads separately. While for same-load cooperation, all basic structures overlap in geometrical locations and support the entire loads conjointly. The choosing of span ratios between basic structures, the design of connections of different-load cooperative systems were discussed as well as optimizations of relative rigidity for same-load cooperative systems which greatly influence structural characteristics. The general situation and several structural measurements of several cooperative bridges were demonstrated. This information can assist engineers in developing their concepts in cooperative systems and can lead to more efficient and economical cooperative bridges.

  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. Theory of bridge aerodynamics

    CERN Document Server

    Strømmen, Einar

    2006-01-01

    This text book is intended for studies in wind engineering, with focus on the stochastic theory of wind induced dynamic response calculations for slender bridges or other line ?like civil engineering type of structures. It contains the background assumptions and hypothesis as well as the development of the computational theory that is necessary for the prediction of wind induced fluctuating displacements and cross sectional forces. The simple cases of static and quasi-static structural response calculations are for the sake of completeness also included. The text is at an advanced level in the

  16. 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...

  17. The construction quality control on mass concrete of bridge engineering pile cap%桥梁工程承台大体积混凝土施工质量控制

    Institute of Scientific and Technical Information of China (English)

    赵喜红

    2012-01-01

    Taking Sichuan river super-big bridge project of Shanxi Huo-Yong highway western part as an example, this paper introduced in detail the construction quality control measures on mass concrete of bridge engineering pile cap from construction preparation, construction organization, construction method and other aspects, had guiding significance for future similar projects.%以山西省霍永高速公路西段城川河特大桥工程为例,从施工准备,前期工程施工组织,施工方法等方面入手,详细介绍了桥梁工程承台大体积混凝土施工质量控制措施,对今后同类工程具有参考意义。

  18. 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...

  19. 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.

  20. 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 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...... the results obtained using the numerical models given in details in "Heavy Vehicles on Minor Highway Bridges : dynamic modelling of vehicles and bridges". The models are established using a ordinary vehicle which consists of a 48 t Scania with a 3 axle tractor and a 3 axle trailer, joined in a flexible hinge...

  1. 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 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...... 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....

  2. 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...

  3. Engineering Mathematics Teaching Reform of Vocational Road and Bridge Professional Based on Working Process%基于工作过程的高职路桥专业工程数学教学改革初探

    Institute of Scientific and Technical Information of China (English)

    曹晓平

    2011-01-01

    文章以路桥专业的工程数学改革为例,就工作过程的工程数学改革指导思想、改革教学内容体系、培养学生数学能力、创新方法与手段进行了探讨,实践并取得了一定的成效。%This paper takes road and bridge professional engineering mathematics reform for example, the work process engineering mathematics guiding the reform, the reform of educational content, mathematical ability of students, innovative approaches and means were discussed, practice and have achieved some results.

  4. A strange bridge by Leonardo

    CERN Document Server

    Huylebrouck, Dirk

    2013-01-01

    On folio 855 recto of the Codex Atlanticus, Leonardo da Vinci drew three 'easily movable' bridges, but one of them is enigmatic: all 'replicas' in Leonardo museums and exhibitions come as a surprise, to say the least, to any engineer or architect whose attention is drawn to it. This is the case for models in Amboise (France), Chicago and Portland (USA), Florence (Italy) and for the one of the traveling exhibition by the Australian company 'Grande Exhibitions' that already visited 40 major cities in the world. All 'replicas' of the bridge model attributed to Leonardo have pillars standing on the deck of the bridge, while the deck is suspended by cables attached on these pillars. At first sight this problem does not catch the attention of the observer, as the bridge seems to be a mixed form of a beam and a suspension bridge, but it was not overlooked by my colleague architect-engineer Dr. Laurens Luyten (Gent, Belgium). Yet, after a TV-interview in Brussels so much pressure was exerted by some of the museum col...

  5. Study on structural system of Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

    Zhang Xigang; Pei Minshan; Yuan Hong; Xu Liping; Zhu Bin

    2009-01-01

    Sutong Bridge, whose layout is [ (100 + 100 + 300) + 1 088 + ( 300 + 100 + 100) ] m, marks the largest span of cable-stayed bridges in the world. The complex natural condition at the bridge site and the strict requirements for resistance of wind and seismic action make it crucial to choose a favorable structural system to assure the function and safety of the bridge. The comparison among several optional structural systems for Sutong Bridge is illustrated. After detailed analysis is carried out for viscous damper and hydraulic buffer, super liquid viscous damper with additional displacement limitation is designed for the first application in bridge engineering. The parameters for the damper is analyzed and studied and the dampers are installed suecessfuUy after quality tests.

  6. 轻质粒料混凝土在预力桥梁工程应用%The Application of Lightweight Aggregate Concrete in the Prestress Bridge Engineering

    Institute of Scientific and Technical Information of China (English)

    王侃

    2014-01-01

    随著科学技术的发展,桥梁逐渐朝向大跨距、减轻自重、轻质、耐久方向发展的今天,应用轻质粒料混凝土不但可减少构材断面、增大结构跨度、提高空间使用效率,对桥梁设计及施工竞争力也会有所提升。%With the development of science and technology, bridges gradual y toward the direction of large span, reduce weight, lightweight, and durable to develop today and the ap-plication of lightweight aggregate concrete not only can reduce the structural material section, increase the span structure and improve the efficiency of space service, but also improve the bridge design and construction competitiveness.

  7. Performance of damage detection methods in bridges through vibration monitoring

    OpenAIRE

    Cruz, Paulo J. S.; Salgado, R.

    2009-01-01

    The important advances achieved in the modal identification, sensors and structural monitoring of bridges have motivated the bridge engineering community to develop damage detection methods based on vibration monitoring. Some of these methods have already been demonstrated under certain conditions in bridges with deliberate damage (Farrar et al., 1998). However, the performance of these methods for damage detection in bridges has not been fully proven so far and more research n...

  8. 桥梁工程速凝膏浆帷幕注浆的应用%Application of Quick Setting Slurry Curtain Grouting in Bridge Engineering

    Institute of Scientific and Technical Information of China (English)

    裴野

    2014-01-01

    The eastern main tower abutment of Egongyan tra- ck bridge of Chongqing rail link is located in the Yangtze River. The Yangtze River has great peak height is in low water period and high water period, and the distance between main tower caps and old Egongyan highway bridge pile cap is only 16.1m, so it cannot use blasting. In order to solve this problem, this paper established the construction scheme. The results showed the effect is good.%重庆市轨道环线鹅公岩轨道专用桥东岸主塔承台顶面常年位于长江江面以下,且长江枯水期和丰水期洪峰高差极大,主塔承台与老鹅公岩公路桥承台间距才16.1 m,不能使用爆破。为解决此问题,本文制定了施工方案。结果显示,实施效果良好。

  9. 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...

  10. The frequency-dependent elements in the code SASSI: A bridge between civil engineers and the soil-structure interaction specialists

    Energy Technology Data Exchange (ETDEWEB)

    Tyapin, Alexander [Atomenergoproject, 7/1 Bakuninskaya Str., Moscow 105005 (Russian Federation)]. E-mail: Atyapin@bvcp.ru

    2007-07-15

    After four decades of the intensive studies of the soil-structure interaction (SSI) effects in the field of the NPP seismic analysis there is a certain gap between the SSI specialists and civil engineers. The results obtained using the advanced SSI codes like SASSI are often rather far from the results obtained using general codes (though match the experimental and field data). The reasons for the discrepancies are not clear because none of the parties can recall the results of the 'other party' and investigate the influence of various factors causing the difference step by step. As a result, civil engineers neither feel the SSI effects, nor control them. The author believes that the SSI specialists should do the first step forward (a) recalling 'viscous' damping in the structures versus the 'material' one and (b) convoluting all the SSI wave effects into the format of 'soil springs and dashpots', more or less clear for civil engineers. The tool for both tasks could be a special finite element with frequency-dependent stiffness developed by the author for the code SASSI. This element can represent both soil and structure in the SSI model and help to split various factors influencing seismic response. In the paper the theory and some practical issues concerning the new element are presented.

  11. 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....

  12. SMART BRIDGE: A tool for estimating the military load classification of bridges using varying levels of information

    Energy Technology Data Exchange (ETDEWEB)

    Van Groningen, C.N.; Paddock, R.A.

    1997-03-01

    A major consideration in planning and executing military deployments is determining the routes available for moving troops and equipment. Part of this planning ensures that all of the bridges along the routes can support the specialized equipment needed. Because few trained and experienced bridge analysts are available, and automated tool is required to help military engineers and planners quickly and accurately determine the capacity, or the military load classification, of bridges. However, because detailed information about each bridge may not always be available, the tool also needs to include alternative methods for estimating bridge capacities. SMART BRIDGE, developed by Argonne National Laboratory, provides this capacity. The tool consists of a collection of modules that interact with each other to accommodate various bridge types, analytical techniques, and database functions. 5 refs., 6 figs., 2 tabs.

  13. Influence of Icing on Bridge Cable Aerodynamics

    DEFF Research Database (Denmark)

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

    2013-01-01

    In recent years the relevance of ice accretion for wind-induced vibration of structural bridge cables has been recognised and became a subject of research in bridge engineering. Full-scale monitoring and observation indicate that light precipitation at moderate low temperatures between zero and -5......°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...... forces of different bridge cables types. The experiments were conducted in a wind tunnel facility capable amongst others to simulate incloud icing conditions....

  14. Taizhou Yangtze River Bridge

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Taizhou Bridge lies between Taizhou, Zhenjiang and Changzhou City in Jiangsu Province. The total length of Taizhou Bridge is 62.088 kin. The whole line is designed by freeway codes with six lanes in two directions. The wholeinvestment is 9.37 billion RMB and the planned construction duration is 5.5 years. The main bridge crossing the Yangtze River is a continuous three-pylon two-span suspension bridge with the main span of 1 080 m. The bridge system is realized for the first time and ranks first in the world until now.

  15. Programmed Nanomaterial Assemblies in Large Scales: Applications of Synthetic and Genetically- Engineered Peptides to Bridge Nano-Assemblies and Macro-Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, Hiroshi

    2014-09-09

    Work is reported in these areas: Large-scale & reconfigurable 3D structures of precise nanoparticle assemblies in self-assembled collagen peptide grids; Binary QD-Au NP 3D superlattices assembled with collagen-like peptides and energy transfer between QD and Au NP in 3D peptide frameworks; Catalytic peptides discovered by new hydrogel-based combinatorial phage display approach and their enzyme-mimicking 2D assembly; New autonomous motors of metal-organic frameworks (MOFs) powered by reorganization of self-assembled peptides at interfaces; Biomimetic assembly of proteins into microcapsules on oil-in-water droplets with structural reinforcement via biomolecular recognition-based cross-linking of surface peptides; and Biomimetic fabrication of strong freestanding genetically-engineered collagen peptide films reinforced by quantum dot joints. We gained the broad knowledge about biomimetic material assembly from nanoscale to microscale ranges by coassembling peptides and NPs via biomolecular recognition. We discovered: Genetically-engineered collagen-like peptides can be self-assembled with Au NPs to generate 3D superlattices in large volumes (> μm{sup 3}); The assembly of the 3D peptide-Au NP superstructures is dynamic and the interparticle distance changes with assembly time as the reconfiguration of structure is triggered by pH change; QDs/NPs can be assembled with the peptide frameworks to generate 3D superlattices and these QDs/NPs can be electronically coupled for the efficient energy transfer; The controlled assembly of catalytic peptides mimicking the catalytic pocket of enzymes can catalyze chemical reactions with high selectivity; and, For the bacteria-mimicking swimmer fabrication, peptide-MOF superlattices can power translational and propellant motions by the reconfiguration of peptide assembly at the MOF-liquid interface.

  16. 公路桥梁工程施工安全重大风险源的评估与控制%The Evaluation and Control of Major Hazard of Road and Bridge's Engineering Construction Safety

    Institute of Scientific and Technical Information of China (English)

    余雪娟

    2014-01-01

    以灌河大桥施工为例,从风险安全控制出发,通过定性定量分析,确定了公路桥梁施工重大风险源的风险等级,在风险预测和相应的监测手段的基础上,提出相应的风险控制措施,使公路桥梁施工中的风险得到有效的控制,保证了公路桥梁施工的安全和工程质量。%This paper confirms the risk level of major hazard in road and bridge‘s construction through qualitative and quantitative analysis for the safety control based on the example of Guanhe Bridge Construc-tion. The paper comes up with respective measures for risk control based on the risk prediction and monitor-ing methods and makes the effectively control of the risk in the road and bridge’ s construction to ensure the safety and engineering quality of road and bridge‘s construction.

  17. Engineering mechanics

    CERN Document Server

    Gross, Dietmar; Schröder, Jörg; Wall, Wolfgang A; Rajapakse, Nimal

    Statics is the first volume of a three-volume textbook on Engineering Mechanics. The authors, using a time-honoured straightforward and flexible approach, present the basic concepts and principles of mechanics in the clearest and simplest form possible to advanced undergraduate engineering students of various disciplines and different educational backgrounds. An important objective of this book is to develop problem solving skills in a systematic manner. Another aim of this volume is to provide engineering students as well as practising engineers with a solid foundation to help them bridge the gap between undergraduate studies on the one hand and advanced courses on mechanics and/or practical engineering problems on the other. The book contains numerous examples, along with their complete solutions. Emphasis is placed upon student participation in problem solving. The contents of the book correspond to the topics normally covered in courses on basic engineering mechanics at universities and colleges. Now in i...

  18. Ergonomic aspects of automation in navigation bridges

    NARCIS (Netherlands)

    Lazet, A.; Walraven, P.L.

    1971-01-01

    New ergonomic questions arise from the tendency toward increasing automation in maritime operations. Direct control of engines and rudder from the bridge promises improved ship control, provided that the operator can really exploit the technical improvements. To make such direct control most efficie

  19. Application of Safety Risk Evaluation in Railway and Bridge Engineering%安全风险评价在铁路桥梁工程中的应用

    Institute of Scientific and Technical Information of China (English)

    王晓

    2014-01-01

    文章以京沪高铁项目施工安全风险管理为例,展开了在项目管理过程中如何进行风险管理,在风险管理的过程中如何识别风险、分析风险、控制风险和应对风险,重点介绍了铁路工程项目风险管理中安全风险评价的应用。%The paper taking the management of construction safety risk of the high-speed road between Beijing and Shang-hai as an example, launched to make risk management in the project management process and put forward measures on how to identify risk, to analyze risk, to control risk and to deal with the risk in the process of risk management. The paper focused on the application of safety risk evaluation of risk management in railway engineering project.

  20. Professional Formation of Engineers: Enhancing the First Year Student Experience

    OpenAIRE

    Goold, Eileen

    2015-01-01

    This paper reports on a study investigating engineering students’ perceptions of engineering practice and whether engineering students’ cognitive engagement benefits from bridging the gap between the technical issues in their education and the practical realities of modern engineering practice.

  1. Theoretical mechanics: Crowd synchrony on the Millennium Bridge

    Science.gov (United States)

    Strogatz, Steven H.; Abrams, Daniel M.; McRobie, Allan; Eckhardt, Bruno; Ott, Edward

    2005-11-01

    Soon after the crowd streamed on to London's Millennium Bridge on the day it opened, the bridge started to sway from side to side: many pedestrians fell spontaneously into step with the bridge's vibrations, inadvertently amplifying them. Here we model this unexpected and now notorious phenomenon - which was not due to the bridge's innovative design as was first thought - by adapting ideas originally developed to describe the collective synchronization of biological oscillators such as neurons and fireflies. Our approach should help engineers to estimate the damping needed to stabilize other exceptionally crowded footbridges against synchronous lateral excitation by pedestrians.

  2. Concrete bridge prioritization system

    OpenAIRE

    Kesselring, Debbie Anne

    1995-01-01

    An alternative method of prioritization for concrete bridge maintenance, repair, and rehabilitation activities is required due to the inability of the current system to manage the increasing nmnber of aging concrete bridges. The Concrete Bridge Prioritization System was proposed because of its ability to address the critical technical parameters of safety and cost benefit in prioritization of funding and work allocation. The analysis includes four parts, service life assessment, s...

  3. 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....

  4. Bridging the Gap

    OpenAIRE

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska; Murdock, Karen; Schmidt, Iben Julie

    2015-01-01

    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 ve...

  5. Semiconductor bridge (SCB) detonator

    Science.gov (United States)

    Bickes, Jr., Robert W.; Grubelich, Mark C.

    1999-01-01

    The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length.

  6. Disulfide Bridges: Bringing Together Frustrated Structure in a Bioactive Peptide.

    Science.gov (United States)

    Zhang, Yi; Schulten, Klaus; Gruebele, Martin; Bansal, Paramjit S; Wilson, David; Daly, Norelle L

    2016-04-26

    Disulfide bridges are commonly found covalent bonds that are usually believed to maintain structural stability of proteins. Here, we investigate the influence of disulfide bridges on protein dynamics through molecular dynamics simulations on the cysteine-rich trypsin inhibitor MCoTI-II with three disulfide bridges. Correlation analysis of the reduced cyclic peptide shows that two of the three disulfide distances (Cys(11)-Cys(23) and Cys(17)-Cys(29)) are anticorrelated within ∼1 μs of bridge formation or dissolution: when the peptide is in nativelike structures and one of the distances shortens to allow bond formation, the other tends to lengthen. Simulations over longer timescales, when the denatured state is less structured, do not show the anticorrelation. We propose that the native state contains structural elements that frustrate one another's folding, and that the two bridges are critical for snapping the frustrated native structure into place. In contrast, the Cys(4)-Cys(21) bridge is predicted to form together with either of the other two bridges. Indeed, experimental chromatography and nuclear magnetic resonance data show that an engineered peptide with the Cys(4)-Cys(21) bridge deleted can still fold into its near-native structure even in its noncyclic form, confirming the lesser role of the Cys(4)-Cys(21) bridge. The results highlight the importance of disulfide bridges in a small bioactive peptide to bring together frustrated structure in addition to maintaining protein structural stability. PMID:27119635

  7. The floating water bridge

    International Nuclear Information System (INIS)

    When high voltage is applied to distilled water filled in two glass beakers which are in contact, a stable water connection forms spontaneously, giving the impression of a floating water bridge. A detailed experimental analysis reveals static and dynamic structures as well as heat and mass transfer through this bridge

  8. ENGINEERING GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20110579 Cao Shenghua(Construction Headquarters of Sutong Yangtze River Bridge,Nanjing 210001,China)A Preliminary Study on Engineering Characters of Interbedded Soils in Littoral and River Facies(Journal of Geology,ISSN1674-3636,CN32-1796/P,34(1),2010,p.61-66,4 illus.,3 tables,5 refs.,with English abstract)Key words:cohesive soil,soil mechanics 20110580 Chen Shangrong(Shanghai Geological

  9. 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

  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. Long Span Bridges in Scandinavia

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1998-01-01

    The first Scandinavian bridge with a span of more than 500 m was the Lillebælt Suspension Bridge opened to traffic in 1970.Art the end of the 20th century the longest span of any European bridge is found in the Storebælt East Bridge with a main span of 1624 m. Also the third longest span in Europ...

  12. 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.

  13. Integral Abutment and Jointless Bridges

    OpenAIRE

    Cristian-Claudiu Comisu

    2005-01-01

    Integral bridges, or integral abutment and jointless bridges, as they are more commonly known in the USA, are constructed without any movement joints between spans or between spans and abutments. Typically these bridges have stub-type abutments supported on piles and continuous bridge deck from one embankment to the other. Foundations are usually designed to be small and flexible to facilitate horizontal movement or rocking of the support. Integrally bridges are simple or multiple span ones t...

  14. Assessment of Infrared Thermography for NDE of FRP Bridge Decks

    OpenAIRE

    Miceli, Marybeth

    2000-01-01

    Statistics released in the fall 1989 showed that 238,357 (41%) of the nation's 577,710 bridges are either structurally deficient or functionally obsolete. New materials, such as fiber reinforced polymeric composites (FRP), are being suggested for use in bridge systems to solve some of the current problems. These materials are thought to be less affected by corrosive environmental conditions than conventional civil engineering materials. Therefore they may require less maintenance and provi...

  15. The calculation of noise from railway bridges and viaducts

    OpenAIRE

    Bewes, Oliver Guy

    2005-01-01

    Pandrol Rail Fastenings Limited are a designer and manufacturer of railway rail-fastening systems. As an organisation they have the capability to reduce the noise impact of bridges using resilient track components. They also have a commercial interest in providing such technology. Knowledge of the processes behind bridge noise is important to Pandrol in two ways; to aid the engineers within the organisation in the design of fastening systems and to demonstrate a state-of-the-ar...

  16. Surface salt bridges stabilize the GCN4 leucine zipper.

    OpenAIRE

    Spek, E. J.; Bui, A. H.; Lu, M.; Kallenbach, N R

    1998-01-01

    We present a study of the role of salt bridges in stabilizing a simplified tertiary structural motif, the coiled-coil. Changes in GCN4 sequence have been engineered that introduce trial patterns of single and multiple salt bridges at solvent exposed sites. At the same sites, a set of alanine mutants was generated to provide a reference for thermodynamic analysis of the salt bridges. Introduction of three alanines stabilizes the dimer by 1.1 kcal/mol relative to the wild-type. An arrangement c...

  17. Critical traffic loading for the design of prestressed concrete bridge

    International Nuclear Information System (INIS)

    A study has been carried out to determine critical traffic loadings for the design of bridge superstructures. The prestressed concrete girder bridge already constructed in Lahore is selected for the analysis as an example. Standard traffic loadings according to AASHTO (American Association of State Highway and Transportation Officials) and Pakistan Highway Standards are used for this purpose. These include (1) HL-93 Truck, (2) Lane and (3) Tandem Loadings in addition to (4) Military tank loading, (5) Class-A, (6) Class-B and (7) Class-AA loading, (8) NLC (National Logistic Cell) and (9) Volvo truck loadings. Bridge superstructure including transom beam is analyzed Using ASD and LRFD (Load and Resistance Factor Design) provisions of AASHTO specifications. For the analysis, two longer and shorter spans are selected. This includes the analysis of bridge deck; interior and exterior girder; a typical transom beam and a pier. Dead and live loading determination is carried out using both computer aided and manual calculations. Evaluation of traffic loadings is done for all the bridge components to find out the critical loading. HL-93 loading comes out to be the most critical loading and where this loading is not critical in case of bridge decks; a factor of 1.15 is introduced to make it equivalent with HL-93 -Ioading. SAP-2000 (Structural Engineering Services of Pakistan) and MS-Excel is employed for analysis of bridge superstructure subjected to this loading. Internal forces are obtained for the structural elements of the bridge for all traffic loadings mentioned. It is concluded that HL-93 loading can be used for the design of prestressed concrete girder bridge. Bridge design authorities like NHA (National Highway Authority) and different cities development authorities are using different standard traffic loadings. A number of suggestions are made from the results of the research work related to traffic loadings and method of design. These recommendations may be

  18. 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...

  19. 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.

  20. The Ultrasonic Testing of the Yangtze River Terraces Bridge Foundation Engineering Analysis of Packet of Sand Case in Acoustic Pipe%长江阶地桥梁桩基工程超声波检测声测管包沙案例分析

    Institute of Scientific and Technical Information of China (English)

    王俊丽; 徐军

    2012-01-01

      Yangtze River Bridge construction is often located in the Yangtze River terraces, and the Yangtze River terraces with the characteristics of thick sand.Wuhan Yangtze River Bridge Pile Foundation Engineering uses ultrasonic nondes-tructive testing technology to detect al pile foundation, and as wel as uses ultrasonic testing, coring and borehole excavation in a comprehensive way, and then makes detailed identification of individual pile foundation shal ow acoustic tube wrapped Sand Mission , clod phenomenon, to ensure the quality of the pile foundation engineering,which has a good reference for similar projects.%  长江大桥的施工往往位于长江阶地,长江阶地具有砂层厚的特点。武汉某长江大桥桥梁桩基工程采用超声波无损检测技术,对所有桩基进行检测,并采用超声波检测、钻芯和凿洞开挖等综合手段,详细查明个别桩基浅部声测管包裹沙团、泥块的现象,保证了桩基工程质量,对类似工程具有很好的借鉴性。

  1. Fiber reinforced polymer composites for bridge structures

    Directory of Open Access Journals (Sweden)

    Alexandra CANTORIU

    2013-12-01

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

  2. Engineering Geological Investigation and Monitor of Jinglan Bridge Reconstruction in LiuZhou%柳州市静兰大桥改建工程地质勘察及监测

    Institute of Scientific and Technical Information of China (English)

    关键超; 韦少典

    2012-01-01

    柳州市静兰大桥改建工程是将一座1992年8月建成通车、总长550m、主桥为5孔90rn跨的钢筋混凝土箱肋拱桥拆除原地重建,使桥面宽度由原来的16.5m扩至31m,桥面标高由原来的97m升高至98.6m。原桥位于河水中的四个桥墩乃利用石灰岩作浅基础形式,潜水录像显示墩基结构基本完好,但原灌浆固结处理溶蚀沟槽里的砾卵石层已不同程度地被淘蚀。通过勘察工作分析,认为经过基底补强处理后,利用旧桥墩建新桥的方案是可行的。%LiuZhou Jinglan Bridge is a Reinforced concrete box arch bridge, the overall length 550m, The main bridge for 5 holes 90m cross and built in August 1992. The project of the bridge reconstruction is to dismantle and rebuild it in the same place and to broaden the width of the bridge from 16.5 to 31 m, heighten the demarcate height from 97m to 98.6m. The shallow basement modalities of the former four piers lying in the river is limestone, as the diving video shows, the framework of the pier foundation is in good condition. But the former gravel pebble stratum in the corrode groove which treated by grouting concretion has been scouring; Through reconnaissance and job analysis, I think it's feasible that build the new bridge which base on the former piers after reinforcing the fundus.

  3. Quantum Bidding in Bridge

    Science.gov (United States)

    Muhammad, Sadiq; Tavakoli, Armin; Kurant, Maciej; Pawłowski, Marcin; Żukowski, Marek; Bourennane, Mohamed

    2014-04-01

    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.

  4. Bridge of Light

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Lying gleaming white under a brooding sky,the Lhasa River Railway Bridge forms a gate to Lhasa City.Built as a part of Qinghai-Tibet Railway,on July 1,2011, the highest altitude railway in the world has been in service for five years. Lhasa,Tibet

  5. 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...

  6. Building Bridges to China.

    Science.gov (United States)

    Wasta, Stephanie; Scott, Margaret

    1998-01-01

    Describes a theme cycle called "Building Bridges to China" developed for third grade students that focuses on the similarities between the lives of children and families in China and the United States. Explains that the theme cycle addresses the National Geography Standards and three of the National Council for the Social Studies standards. (CMK)

  7. On the Performance of Super-Long Integral Abutment Bridges: Parametric Analyses and Design Optimization

    OpenAIRE

    Lan, Cheng

    2012-01-01

    The concept of "integral abutment bridge" has recently become a topic of remarka-ble interest among bridge engineers, not only for newly built bridges but also during refurbishment processes. The system constituted by the substructure and the superstructure can achieve a composite action responding as a single structural unit; the elimination of expansion joint and bearings on the abutments, greatly reduce the construction and maintenance costs. To maximize the benefits from integral abutment...

  8. 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....

  9. Development Analysis of Soft Soil Foundation Treatment Technology in Road and Bridge Engineering Construction%路桥工程施工中软土地基处理技术发展探析

    Institute of Scientific and Technical Information of China (English)

    王丹忠

    2013-01-01

    This paper analyzes the necessity of the soft foun-dation treatment in road and bridge construction, and discusses its technology development, hopes to improve the quality of t-he construction.%本文分析了路桥工程施工中处理软土地基的必要性,并就其技术发展进行了探讨,希望对提高施工质量有所助益。

  10. Deformation Monitoring and Analysis for Reinforcement Engineering of Jialing River Bridge in Kang-ba Highway%唐巴公路嘉陵江大桥加固工程变形监测分析

    Institute of Scientific and Technical Information of China (English)

    李章树

    2013-01-01

      结合嘉陵江大桥加固工程的建设实际,在旧桥不减载的情况下,采用全站仪对大桥拱轴线进行监测。采用三角高程测量法计算观测点的高程坐标;再根据各观测点的高程值计算各点的挠度,比较挠度的实际迭加值和设计的理论迭加值,二者的差异在许可范围内,从而确认该方法切实可行。该监测分析方法可为同类工程提供参考。%Combined with the actual works of reinforcement for Jialing River Bridge with full cargo for old bridge ,total station moni-toring was conducted for the arch axis of this large bridge .Trigonometric Leveling Method was used to calculate the coordinates of the observation point elevation;according to the observation point elevation values calculated for each point of deflection was calculated , the actual Diego bonus and the design theory Diego added value were compared .The difference was in permission range , which con-firmed that the method was feasible.The monitoring and analysis methods can provide reference for similar projects .

  11. Dynamic Bridge Response for a Bridge-friendly Truck

    Directory of Open Access Journals (Sweden)

    V. Šmilauer

    2004-01-01

    Full Text Available A truck with controlled semi-active suspensions traversing a bridge is examined for benefits to the bridge structure. The original concept of a road-friendly truck was extended to a bridge-friendly vehicle, using the same optimization tools. A half-car model with two independently driven axles is coupled with simply supported bridges (beam, slab model with the span range from 5 m to 50 m. Surface profile of the bridge deck is either stochastic or in the shape of a bump or a pot in the mid-span. Numerical integration in the MATLAB/SIMULINK environment solves coupled dynamic equations of motion with optimized truck suspensions. The rear axle generates the prevailing load and to a great extent determines the bridge response. A significant decrease in contact road-tire forces is observed and the mid-span bridge deflections are on average smaller, when compared to commercial passive suspensions. 

  12. Accelerated aging of polymer composite bridge materials

    Science.gov (United States)

    Carlson, Nancy M.; Blackwood, Larry G.; Torres, Lucinda L.; Rodriguez, Julio G.; Yoder, Timothy S.

    1999-05-01

    Accelerated aging research on samples of composite materials and candidate UV protective coatings is determining the effects of six environmental factors on material durability. Candidate fastener materials are being evaluated to determine corrosion rates and crevice corrosion effects at load-bearing joints. This work supports field testing of a 30-ft long, 18-ft wide polymer matrix composite (PMC) bridge at the Idaho National Engineering and Environmental Laboratory. Durability results and sensor data form test with live loads provide information required for determining the cost/benefit measures to use in life-cycle planning, determining a maintenance strategy, establishing applicable inspection techniques, and establishing guidelines, standards and acceptance criteria for PMC bridges for use in the transportation infrastructure.

  13. [Retention of adhesive bridges].

    Science.gov (United States)

    Raes, F; De Boever, J

    1994-04-01

    Since the development of adhesive bridges in the early seventies, the retention and therefore the durability of these bridges has been tremendously improved. Conditioning of the non-precious metal by silanisation, careful acid etching of the enamel and the use of the appropriate composite resin are of prime importance. Furthermore, the meticulous preparation with enough interproximal embrace, occlusal rests, interocclusal clearance and cingulum stops is equally important. Including more teeth in the design does not necessarily lead to an improved retention. Besides the material and technical aspects, the whole clinical procedure needs much attention. The retention does not depend on one single factor, but on the precision of all the necessary clinical steps and on a well-defined selection of the material. In this way a five-year survival rate of close to 80% can be obtained. PMID:11830965

  14. 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...

  15. BRIDGING SERVICE QUALITY GAPS

    OpenAIRE

    BARKATH UNISSA

    2012-01-01

    Bridging the Service quality gaps is one of the foremost areas of concern for amarketer. Service marketing is inherently different from product or goods marketing.Services are distinctively characterized by their intangible, heterogeneous, inseparableand perishable nature. The importance of the service sector in today's world is a verywidely accepted and renowned idea. “We are already experiencing a service society“services do have some basic characteristics which make them fundamentally diff...

  16. Bridging as Coercive Accommodation

    CERN Document Server

    Bos, J W; Mineur, A M; Bos, Johan; Buitelaar, Paul; Mineur, Anne-Marie

    1995-01-01

    In this paper we discuss the notion of "bridging" in Discourse Representation Theory as a tool to account for discourse referents that have only been established implicitly, through the lexical semantics of other referents. In doing so, we use ideas from Generative Lexicon theory, to introduce antecedents for anaphoric expressions that cannot be "linked" to a proper antecedent, but that do not need to be "accommodated" because they have some connection to the network of discourse referents that is already established.

  17. Nematic liquid crystal bridges

    Science.gov (United States)

    Doss, Susannah; Ellis, Perry; Vallamkondu, Jayalakshmi; Danemiller, Edward; Vernon, Mark; Fernandez-Nieves, Alberto

    We study the effects of confining a nematic liquid crystal between two parallel glass plates with homeotropic boundary conditions for the director at all bounding surfaces. We find that the free surface of the nematic bridge is a surface of constant mean curvature. In addition, by changing the distance between the plates and the contact angle with the glass plates, we transition between loops and hedgehogs that can be either radial or hyperbolic.

  18. 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

    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......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...

  19. 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...... endangered people safety in few cases. Purpose of this paper is making a focus on the state of the art of the research and current regulations concerning the response of bridges to fire. Several cases of bridge fires are reported and a focus is made on the occurrence and consequence of bridge fires......, considering both the costs deriving by structural damages and by limited serviceability and other indirect societal aspects. Few cases of recent bridge fire are reviewed in detail and structural consequences are highlighted, distinguishing between damages directly induced by fire and damages induced by local...

  20. Aesthetic design of bridges; Kyoryo ni okeru keikan sekkei no rekishi

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, H. [Kyushu Institute of Technology, Kitakyushu (Japan)

    1995-01-01

    The present paper outlines the bridge design in harmony with both ambient and natural environments. The condition which the bridge must clear has its two phases, i.e., `rational phase` focused on the practical utility to be managed by the engineering and `sensible phase` for the aesthetic achievement. The profile and scenery of bridge are based on the perfect teleology to engineer and process them by taking the influence into consideration on the mental phase. The beauty of bridge belongs to a category of technical beauty converting the technical product into an aesthetic object. The technical beauty is composed of `formal beauty` (The composition of all different members forms the beauty of harmony.), `functional beauty` (All different members under tension generate the dynamic beauty.) and `harmony with the environment`. For the harmony with the environment, what is taken into consideration is the steel, concrete and other material feeling, type of bridge adaptable to the environment, and color good for the environment. The following three methods are applied to the combination of bridge and environment: elimination method to vaguely immerse the bridge in the environment. Accentuation method to select the bridge as a main element of scenery. Harmonization method to harmonize the bridge with the environment. 21 refs., 14 figs.

  1. Modelling railway bridge asset management

    OpenAIRE

    Le, Bryant Linh Hai

    2014-01-01

    The UK has a long history in the railway industry with a large number of railway assets. Railway bridges form one of the major asset groups with more than 35,000 bridges. The majority of the bridge population are old being constructed over 100 years ago. Many of the bridges were not designed to meet the current network demand. With an expected increasing rate of deterioration due to the increasing traffic loads and intensities, the management authorities are faced with the difficult task of k...

  2. Study on longitudinal wind load calculation method of cables for cable-stayed bridge

    Institute of Scientific and Technical Information of China (English)

    Pei Minshan; Zhang Xigang; Zhu Bin; Hou Bin; Liu Changpeng

    2009-01-01

    Along with the expanding of span of cable-stayed bridge, wind load becomes a more and more important controlling factor for bridge the design. A very large proportion of the wind load acting on cables has exceeded that acting on deck. There was not any detailed prescript in Chinese code for calculation of longitudinal wind load on cables due to lack of theoretical research and experiment, and conservative simplified calculation was adopted during design, which leads to conservative and uneconomical design of structures. To resolve this problem, cable force experiment was carried out during the design of Sutong Bridge. By comparing with international research results, the calculation formula of longitudinal wind drag coefficient for cables was advanced to fill the blank of bridge wind resistant code of China, and has already been adopted in the Highway Bridge Wind Resistant Design Code (JTG/T D60-01-2004) with great significance for bridge engineering.

  3. Design of bridges against large tectonic deformation

    Institute of Scientific and Technical Information of China (English)

    I.Anastasopoulost; G.Gazetas; V.Drosos; T.Georgarakos; R.Kourkoulis

    2008-01-01

    The engineering community has devoted much effort to understanding the response of soil-structure systems to seismic ground motions,but little attention to the effects of an outcropping fault offset.The 1999 earthquakes of Turkey and Taiwan,offering a variety of case histories of structural damage due to faulting,have (re)fueled the interest on the subject.This paper presents a methodology for design of bridges against tectonic deformation.The problem is decoupled in two analysis steps:the first (at the local level) deals with the response of a single pier and its foundation to fault rupture propagating through the soil,and the superstructure is modeled in a simplified manner;and the second (at the global level)investigates detailed models of the superstructure subjected to the support (differential) displacements of Step 1.A parametric study investigates typical models of viaduct and overpass bridges,founded on piles or caissons.Fixed-head piled foundations are shown to be rather vulnerable to faulting-induced deformation.End-bearing piles in particular are unable to survive bedrock offsets exceeding 10 cm.Floating piles perform better,and if combined with hinged pile-to-cap connections,they could survive much larger offsets.Soil resilience is beneficial in reducing pile distress.Caisson foundations are almost invariably successful.Statically-indeterminate superstructures are quite vulnerable,while statically-determinate are insensitive (allowing differential displacements and rotations without suffering any distress).For large-span cantilever construction bridges,where a statically determinate system is hardly an option,inserting resilient seismic isolation bearings is advantageous as long as ample seating can prevent the deck from falling off the supports.An actual application of the developed method is presented for a major bridge,demonstrating the feasibility of design against tectonic deformation.

  4. 南澳大桥工程技术代管组织管理模式应用研究%Application research of organization management mode of Nan’ao bridge engineering technology escrow

    Institute of Scientific and Technical Information of China (English)

    傅光奇; 蔡奕生; 袁永平; 陈俊生; 田又强

    2015-01-01

    Taking Nan’ao bridge project in Guangdong province as an example,on the basis of describing technology escrow connotation and characteristics,the paper analyzes its organization mode,discusses characteristics of technology escrow mode,which has provided some basis for organization management of other governmental-invested facility project in other fields.%以广东省南澳大桥项目为例,在深入阐述技术代管的内涵和特点的基础上,分析了其组织模式,并据此提炼了技术代管模式的特点,为日后海上超长桥梁工程,甚至其他领域政府投资基础设施项目的组织管理提供了实例性依据。

  5. Curriculum reform and practice on"Construction technique of bridge engineering"in higher vocational education%高职桥梁工程施工技术课程改革与实践

    Institute of Scientific and Technical Information of China (English)

    王瑞雪; 张威琪; 吴丽萍

    2014-01-01

    In order to achieve the goal of training high-qualified and skilled talents and lay a strong foundation for the graduates who will work on bridge construction, through investigating and surveying into the road and bridge construction enterprises we ifnd out the problems in the existing curriculum content and propose the curriculum reform objectives, concepts and train of thoughts, then we formulate the course standard to meet the needs of personnel training, construct targeted course content, compile practicability teaching materials and implement action-oriented teaching to mobilize students’ learning initiative, enhance their teamwork spirit for the purpose of serving the goal of training professional talents.%为了实现高素质技能型专门人才的培养目标,为学生毕业后从事桥梁施工工作打下坚实的基础,我们通过深入路桥施工企业进行调研,找出现有课程内容存在的问题,提出了课程改革的目标、理念和思路。制定适应人才培养需要的课程标准,构建有针对性的课程内容,编写实用性教材和实施行动导向教学,调动学生学习积极性,增强团队协作,为专业人才培养目标服务。

  6. 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.

  7. Fuzzy Based Decision Support System for Condition Assessment and Rating of Bridges

    Science.gov (United States)

    Srinivas, Voggu; Sasmal, Saptarshi; Karusala, Ramanjaneyulu

    2016-06-01

    In this work, a knowledge based decision support system has been developed to efficiently handle the issues such as distress diagnosis, assessment of damages and condition rating of existing bridges towards developing an exclusive and robust Bridge Management System (BMS) for sustainable bridges. The Knowledge Based Expert System (KBES) diagnoses the distresses and finds the cause of distress in the bridge by processing the data which are heuristic and combined with site inspection results, laboratory test results etc. The coupling of symbolic and numeric type of data has been successfully implemented in the expert system to strengthen its decision making process. Finally, the condition rating of the bridge is carried out using the assessment results obtained from the KBES and the information received from the bridge inspector. A systematic procedure has been developed using fuzzy mathematics for condition rating of bridges by combining the fuzzy weighted average and resolution identity technique. The proposed methodologies and the decision support system will facilitate in developing a robust and exclusive BMS for a network of bridges across the country and allow the bridge engineers and decision makers to carry out maintenance of bridges in a rational and systematic way.

  8. Fuzzy Based Decision Support System for Condition Assessment and Rating of Bridges

    Science.gov (United States)

    Srinivas, Voggu; Sasmal, Saptarshi; Karusala, Ramanjaneyulu

    2016-09-01

    In this work, a knowledge based decision support system has been developed to efficiently handle the issues such as distress diagnosis, assessment of damages and condition rating of existing bridges towards developing an exclusive and robust Bridge Management System (BMS) for sustainable bridges. The Knowledge Based Expert System (KBES) diagnoses the distresses and finds the cause of distress in the bridge by processing the data which are heuristic and combined with site inspection results, laboratory test results etc. The coupling of symbolic and numeric type of data has been successfully implemented in the expert system to strengthen its decision making process. Finally, the condition rating of the bridge is carried out using the assessment results obtained from the KBES and the information received from the bridge inspector. A systematic procedure has been developed using fuzzy mathematics for condition rating of bridges by combining the fuzzy weighted average and resolution identity technique. The proposed methodologies and the decision support system will facilitate in developing a robust and exclusive BMS for a network of bridges across the country and allow the bridge engineers and decision makers to carry out maintenance of bridges in a rational and systematic way.

  9. Studies on Technical Development of Railway Steel-Concrete Composite Cirider Bridges in China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Steel-concrete composite girder bridge boasts the advantages of strong rigidity,low noise and low construction height.Along with the large-scale construction of passengerdedicated lines (PDL) and high-speed lines (HSL),tests and researches on steel-concrete composite girder bridges have been conducted with the main types of which including steel plate girder-concrete composite girder bridge,deck steel truss girder-concrete composite girder bridge,through steel truss girder-concrete composite girder bridge and through type tied arch composite girder bridge.Based on the application and researches on steel-concrete composite technology and in combination with the engineering construction of railway bridges,the construction of HSL and PDL and upgrading of existing lines for speed-up in China,this paper analyzes the main structural forms of through steel truss girder-concrete composite girder bridges with different spans and structure systems,carries out studies on the force acted upon these bridges and the related theory and methods for design and computation,and puts forward the solutions required in relation to the key technologies for further development of railway steel-concrete composite girder bridges.

  10. Fatigue tests on aluminium bridges

    NARCIS (Netherlands)

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

    2005-01-01

    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 load

  11. 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 load

  12. 9th Structural Engineering Convention 2014

    CERN Document Server

    2015-01-01

    The book presents research papers presented by academicians, researchers, and practicing structural engineers from India and abroad in the recently held Structural Engineering Convention (SEC) 2014 at Indian Institute of Technology Delhi during 22 – 24 December 2014. The book is divided into three volumes and encompasses multidisciplinary areas within structural engineering, such as earthquake engineering and structural dynamics, structural mechanics, finite element methods, structural vibration control, advanced cementitious and composite materials, bridge engineering, and soil-structure interaction. Advances in Structural Engineering is a useful reference material for structural engineering fraternity including undergraduate and postgraduate students, academicians, researchers and practicing engineers.

  13. Cascaded resonant bridge converters

    Science.gov (United States)

    Stuart, Thomas A. (Inventor)

    1989-01-01

    A converter for converting a low voltage direct current power source to a higher voltage, high frequency alternating current output for use in an electrical system where it is desired to use low weight cables and other circuit elements. The converter has a first stage series resonant (Schwarz) converter which converts the direct current power source to an alternating current by means of switching elements that are operated by a variable frequency voltage regulator, a transformer to step up the voltage of the alternating current, and a rectifier bridge to convert the alternating current to a direct current first stage output. The converter further has a second stage series resonant (Schwarz) converter which is connected in series to the first stage converter to receive its direct current output and convert it to a second stage high frequency alternating current output by means of switching elements that are operated by a fixed frequency oscillator. The voltage of the second stage output is controlled at a relatively constant value by controlling the first stage output voltage, which is accomplished by controlling the frequency of the first stage variable frequency voltage controller in response to second stage voltage. Fault tolerance in the event of a load short circuit is provided by making the operation of the first stage variable frequency voltage controller responsive to first and second stage current limiting devices. The second stage output is connected to a rectifier bridge whose output is connected to the input of the second stage to provide good regulation of output voltage wave form at low system loads.

  14. Liquid-Bridge Breaking Limits

    Science.gov (United States)

    Macner, Ashley; Steen, Paul

    2011-11-01

    Wet adhesion by liquid bridges in large arrays shows promise for use in lightweight, controllable on-demand devices. Applications include grab/release of wafer substrates, transport of micron-sized tiles for use in 3D printing and micro-dosing of personalized pharmaceutical drugs. By wetting and spreading, a drop can form a bridge and thereby ``grab'' a nearby solid substrate. By volume decrease or extension, the bridge can break. The breaking limit corresponds to bridge instability which can be predicted, knowing the static mechanical response of the bridge. Mechanical behaviors include force-volume (FV), pressure-volume (pV) and force-length (FL) responses. Instability crucially depends on the mode of failure - failure under constant-force or constant length are typical cases. We study single bridge equilibria for their breaking limits. FV diagrams for the pin-pin equal and pin-pin unequal radii boundary conditions for different bridge heights are measured in the laboratory. The FL response in the case of pin-pin equal radii is also measured. Results are compared to predictions of static theory. Static results are then used to compare to dynamical sequences where volume is driven quasistatically by syringe or an electro-osmotic pump. As the breaking limit is approached, the shape deformation accelerates leading to non-equilibrium shapes not captured by the static analysis.

  15. 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...

  16. National Bridge Inventory - National Geospatial Data Asset (NGDA) Bridges

    Data.gov (United States)

    Department of Transportation — The NBI (NTAD 2015) is a collection of information (database) describing the more than 610,000 of the Nation's bridges located on public roads, including Interstate...

  17. 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.

  18. General design of Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

    Zhang Xigang; Yuan Hong; Pei Minshan; Dai Jie; Xu Lin

    2009-01-01

    The main span of Sutong Bridge is a double-pylon, double-plane cable-stayed bridge with steel box girder, which has the world's longest central span of 1 088 m within cable-stayed bridges. To overcome problems caused by severe meteorological conditions, perplexing hydrological conditions, deep buried bedrock and higher navigation level, many new technics and methods were created. Keys including structural system, steel box girder, stayed cable, tower, pier, tower foundation, collision avoidance system, wind-resistance, seismic-resistance, structural nonlinear response and structural static stability were presented individually in this paper.

  19. 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...

  20. 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]....

  1. Synthesis of 2',4'-propylene-bridged (carba-ENA) thymidine and its analogues: the engineering of electrostatic and steric effects at the bottom of the minor groove for nuclease and thermodynamic stabilities and elicitation of RNase H.

    Science.gov (United States)

    Liu, Yi; Xu, Jianfeng; Karimiahmadabadi, Mansoureh; Zhou, Chuanzheng; Chattopadhyaya, Jyoti

    2010-11-01

    2',4'-Propylene-bridged thymidine (carba-ENA-T) and five 8'-Me/NH(2)/OH modified carba-ENA-T analogues have been prepared through intramolecular radical addition to C═N of the tethered oxime-ether. These carba-ENA nucleosides have been subsequently incorporated into 15mer oligodeoxynucleotides (AON), and their affinity toward cDNA and RNA, nuclease resistance, and RNase H recruitment capability have been investigated in comparison with those of the native and ENA counterparts. These carba-ENAs modified AONs are highly RNA-selective since all of them led to slight thermal stabilization effect for the AON:RNA duplex, but quite large destabilization effect for the AON:DNA duplex. It was found that different C8' substituents (at the bottom of the minor groove) on carba-ENA-T only led to rather small variation of thermal stability of the AON:RNA duplexes. We, however, observed that the parent carba-ENA-T modified AONs exhibited higher nucleolytic stability than those of the ENA-T modified counterparts. The nucleolytic stability of carba-ENA-T modified AONs can be further modulated by C8' substituent to variable extents depending on not only the chemical nature but also the stereochemical orientation of the C8' substituents: Thus, (1) 8'S-Me on carba-ENA increases the nucleolytic stability but 8'R-Me leads to a decreased effect; (2) 8'R-OH on carba-ENA had little, if any, effect on nuclease resistance but 8'S-OH resulted in significantly decreased nucleolytic stability; and (3) 8'-NH(2) substituted carba-ENA leads to obvious loss in the nuclease resistance. The RNA strand in all of the carba-ENA derivatives modified AON:RNA hybrid duplexes can be digested by RNase H1 with high efficiency, even at twice the rate of those of the native and ENA modified counterpart.

  2. Encyclopedia of earthquake engineering

    CERN Document Server

    Kougioumtzoglou, Ioannis; Patelli, Edoardo; Au, Siu-Kui

    2015-01-01

    The Encyclopedia of Earthquake Engineering is designed to be the authoritative and comprehensive reference covering all major aspects of the science of earthquake engineering, specifically focusing on the interaction between earthquakes and infrastructure. The encyclopedia comprises approximately 265 contributions. Since earthquake engineering deals with the interaction between earthquake disturbances and the built infrastructure, the emphasis is on basic design processes important to both non-specialists and engineers so that readers become suitably well-informed without needing to deal with the details of specialist understanding. The content of this encyclopedia provides technically inclined and informed readers about the ways in which earthquakes can affect our infrastructure and how engineers would go about designing against, mitigating and remediating these effects. The coverage ranges from buildings, foundations, underground construction, lifelines and bridges, roads, embankments and slopes. The encycl...

  3. 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.

  4. Performance-based concept on seismic evaluation of existing bridges

    Institute of Scientific and Technical Information of China (English)

    Yu-Chi Sung; Wen-I Liao; W.Phillip Yen

    2009-01-01

    Conventional seismic evaluation of existing bridges explores the ability of a bridge to survive under significant earthquake excitations. This approach has several major drawbacks, such as only a single structural performance of near collapse is considered, and the simplified approach of adopting strength-based concept to indirectly estimate the nonlinear behavior of a structure lacks accuracy. As a result, performance-based concepts that include a wider variety of structural performance states of a given bridge excited by different levels of earthquake intensity is needed by the engineering community. This paper introduces an improved process for the seismic evaluation of existing bridges. The relationship between the overall structural performance and earthquakes with varying levels of peak ground acceleration (PGA) can successfully be linked. A universal perspective on the seismic evaluation of bridges over their entire life-cycle can be easily obtained to investigate multiple performance objectives. The accuracy of the proposed method, based on pushover analysis, is proven in a case study that compares the results from the proposed procedure with additional nonlinear time history analyses.

  5. Development of a numerical model for vehicle-bridge interaction analysis of railway bridges

    Science.gov (United States)

    Kim, Hee Ju; Cho, Eun Sang; Ham, Jun Su; Park, Ki Tae; Kim, Tae Heon

    2016-04-01

    In the field of civil engineering, analyzing dynamic response was main concern for a long time. These analysis methods can be divided into moving load analysis method and moving mass analysis method, and formulating each an equation of motion has recently been studied after dividing vehicles and bridges. In this study, the numerical method is presented, which can consider the various train types and can solve the equations of motion for a vehicle-bridge interaction analysis by non-iteration procedure through formulating the coupled equations for motion. Also, 3 dimensional accurate numerical models was developed by KTX-vehicle in order to analyze dynamic response characteristics. The equations of motion for the conventional trains are derived, and the numerical models of the conventional trains are idealized by a set of linear springs and dashpots with 18 degrees of freedom. The bridge models are simplified by the 3 dimensional space frame element which is based on the Euler-Bernoulli theory. The rail irregularities of vertical and lateral directions are generated by PSD functions of the Federal Railroad Administration (FRA).

  6. The Higgs Bridge

    CERN Document Server

    Allen, Roland E

    2013-01-01

    The particle recently discovered at the Large Hadron Collider near Geneva is almost certainly a Higgs boson, the long-sought completion of the Standard Model of particle physics. But this discovery, an achievement by more than six thousand scientists (including students), is actually much more than a mere capstone of the Standard Model. It instead represents a bridge from the Standard Model to exciting discoveries of the future, at higher energies or in other experiments, and to the properties of matter at very low temperatures. The mere existence of a particle with zero spin implies a need for new physics, with the most likely candidate being supersymmetry, which requires that every known particle has a superpartner yet to be discovered. And phenomena similar to the Higgs are seen in superconducting metals and superfluid gases at low temperatures, which extend down to a millionth or even a billionth of a degree Kelvin. So the discovery of a Higgs boson has a central place in our attempts both to achieve a tr...

  7. Mineral bridges in nacre revisited

    CERN Document Server

    Checa, Antonio G; Willinger, Marc-Georg

    2012-01-01

    We confirm with high-resolution techniques the existence of mineral bridges between superposed nacre tablets. In the towered nacre of both gastropods and the cephalopod Nautilus there are large bridges aligned along the tower axes, corresponding to gaps (150-200 nm) in the interlamellar membranes. Gaps are produced by the interaction of the nascent tablets with a surface membrane that covers the nacre compartment. In the terraced nacre of bivalves bridges associated with elongated gaps in the interlamellar membrane (> 100 nm) have mainly been found at or close to the edges of superposed parental tablets. To explain this placement, we hypothesize that the interlamellar membrane breaks due to differences in osmotic pressure across it when the interlamellar space below becomes reduced at an advanced stage of calcification. In no cases are the minor connections between superimposed tablets (< 60 nm), earlier reported to be mineral bridges, found to be such.

  8. 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...

  9. Applications of overburden conveyor bridges

    Energy Technology Data Exchange (ETDEWEB)

    Schachtschneider, H.

    1987-06-01

    In large scale surface mines of the capacities required today, a cross-pit operation with overburden conveyor bridges is the most economical method of overburden removal and disposal. In order to provide the production capacity required in surface mining equipment by the GDR brown coal industry, VEB Schwermaschinenbau Lauchhammerwerk undertook the design and manufacture of standard overburden conveyor bridges for cut heights of 34 m, 45 m and 60 m. All three base types may be equipped to match the site specific geological and geotechnical conditions, and to meet customer's demands. Specifications of the bridges are given as well as details of conveyor belt speeds, modifications to the standards, and number manufactured. Design problems faced with the 60 m bridge are discussed, together with details of the superstructure, method of operation, transportation rates, structural steel used, assembly and power supply. 5 refs.

  10. Bridge Culture of Langde Village

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Langde, a village in Leishan County ofsouthwestern Guizhou province, is known for itslarge number of unique bridges bearing the distinctdesign style of the Miao ethnic group. Animpressive variety of well-preserved ancient

  11. ANGIOGRAPHIC ASPECTS OF MYOCARDIAL BRIDGES

    Directory of Open Access Journals (Sweden)

    Sujatha. M

    2015-12-01

    Full Text Available Introduction: The segment of epicardial coronary artery that traverses intramurally through the myocardium and bridged by a bunch of cardiac muscle fibers is called tunneled artery or intramural artery. The band of cardiac muscle fibers passing over the tunneled artery segment is named as myocardial bridge. During angiography milking effect is observed during systole due to the external pressure of muscle fibers on the tunneled artery that leads to narrowing of vessel lumen and further ischemia. Materials & Methods: It is a prospective study performed from 2012- 2015 in cardiac centers available around Tirupati, Andhra Pradesh, South India. A total number of 2015 adult patients who underwent diagnostic coronary angiography were evaluated to detect myocardial bridges. With the informed consent the relevant data was collected from the patients and analyzed. Results: The prevalence of myocardial bridges was 3.17%. Among the 2015 patients 70.7% are males and 29.2% are females. Among 64 myocardial bridge positive cases 62.5% were male and 37.5% were female patients. Regarding coronary dominance 84% were right dominant and 14.4% were left dominant and 1.6% are balanced. The percentage incidence of myocardial bridging according to dominance was 3.01% for right dominant patients, 4.12% for left dominant patients and 3.1% for balanced dominant patients. In all the myocardial bridge positive cases they were located on the left anterior descending artery (LAD. According to diagnosis the patients with normal coronaries were 22.6%, patients with MILD CAD were 17.9%, patients with single vessel disease were 23.4%, patients with two vessel disease were 14.7% and the patients with triple vessel disease were 21.3%. The 64 myocardial bridging cases were grouped in to three groups according to their age. Incidence of double bridges was observed in 3 cases of which 66.7% males & 33.3% in females. Conclusion: These results show that Andhra Pradesh population are

  12. 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....

  13. An Expert System for Concrete Bridge Management

    DEFF Research Database (Denmark)

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

    1997-01-01

    The importance of bridge repair versus new bridge construction has risen in recent decades due to high deterioration rates that have been observed in these structures. Budgets both for building new bridges and keeping the existing ones are always limited. To help rational decision-making, bridge...

  14. Risk assessment study on bridge foundation in deep overlying stratum

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiangqun; Wang Jingguo; Liu Manhong

    2012-01-01

    Based on the analysis about the hydrogeological conditions and engineering geological conditions, this paper makes analysis on the possible risks of the deep overlying stratum foundation and establishes the risk evaluation index system during the foundation operating period. Such methods as analytic hierarchy process (AHP) , Delphi method and fuzzy comprehensive evaluation method are adopted to make the quantitative analysis on the risk factors and establish the risk judgment model. According to the actual engineering of Taizhou Bridge, the paper evaluates the risk of the foundation during the operating period at the condition of deep overlying stratum. The evaluation results can provide the reference for the risk management of the bridge foundation durin~ the ooerating period.

  15. Stability of liquid crystalline bridges

    Science.gov (United States)

    Mahajan, Milind P.; Tsige, Mesfin; Taylor, P. L.; Rosenblatt, Charles

    1999-02-01

    The stability of cylindrical bridges of the liquid crystal octylcyanobiphenyl in an immiscible liquid bath was investigated in the nematic and smectic A phases. In the nematic phase the bridge was found to destabilize at a length-to-diameter (slenderness) ratio R similar to that of ordinary Newtonian fluids. On the other hand, the Bingham behavior of the smectic A phase, i.e., an apparent yield stress, enabled the formation of stable columns with R well in excess of π.

  16. Microscale technologies for cell engineering

    CERN Document Server

    Gaharwar, Akhilesh

    2016-01-01

    This book offers readers cutting-edge research at the interface of polymer science and engineering, biomedical engineering, materials science, and biology. State-of-the-art developments in microscale technologies for cell engineering applications are covered, including technologies relevant to both pluripotent and adult stem cells, the immune system, and somatic cells of the animal and human origin. This book bridges the gap in the understanding of engineering biology at multiple length scale, including microenvironmental control, bioprocessing, and tissue engineering in the areas of cardiac, cartilage, skeletal, and vascular tissues, among others. This book also discusses unique, emerging areas of micropatterning and three-dimensional printing models of cellular engineering, and contributes to the better understanding of the role of biophysical factors in determining the cell fate. Microscale Technologies for Cell Engineering is valuable for bioengineers, biomaterial scientists, tissue engineers, clinicians,...

  17. Recent research and applications of numerical simulation for dynamic response of long-span bridges subjected to multiple loads.

    Science.gov (United States)

    Chen, Zhiwei; Chen, Bo

    2014-01-01

    Many long-span bridges have been built throughout the world in recent years but they are often subject to multiple types of dynamic loads, especially those located in wind-prone regions and carrying both trains and road vehicles. To ensure the safety and functionality of these bridges, dynamic responses of long-span bridges are often required for bridge assessment. Given that there are several limitations for the assessment based on field measurement of dynamic responses, a promising approach is based on numerical simulation technologies. This paper provides a detailed review of key issues involved in dynamic response analysis of long-span multiload bridges based on numerical simulation technologies, including dynamic interactions between running trains and bridge, between running road vehicles and bridge, and between wind and bridge, and in the wind-vehicle-bridge coupled system. Then a comprehensive review is conducted for engineering applications of newly developed numerical simulation technologies to safety assessment of long-span bridges, such as assessment of fatigue damage and assessment under extreme events. Finally, the existing problems and promising research efforts for the numerical simulation technologies and their applications to assessment of long-span multiload bridges are explored.

  18. Designing of support zones of concrete bridges to withstand action of static and dynamic load

    Directory of Open Access Journals (Sweden)

    Gligorijević Milan

    2010-01-01

    Full Text Available In the paper are presented some of the acquired experiences in designing and construction of bridge structures in several countries, with a special attention to the analysis of support zones and expansion joints behavior of a number of road bridges. During destruction or damage of bridges, there is a small probability, but still there, that the human lives might be endangered (Kobe, Japan 17th January 1995; what is likely, however, is that it will be very difficult to help the injured in the region. Considering that the characteristics of removal of supports has a great influence on the behavior of the entire bridge structure, the design of support joints and connections must be paid due attention. In the recent decades, efforts are made to enhance research of all engineering structure, and thus the bridge structures and their weak points.

  19. Catastrophic model for stability analysis of high pile-column bridge pier

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    According to the engineering features of higher pile-column bridge pier in mountainous area, a clamped beam mechanical model was set up by synthetically analyzing the higher pile-column bridge pier buckling mechanism. Based on the catastrophe theory, the cusp catastrophe model of higher pile-column bridge pier was established by the determination of its potential function and bifurcation set equation, the necessary instability conditions of high pile-column bridge pier were deduced, and the determination method for column-buckling and lateral displacement of high pile-column bridge pier was derived. The comparison between the experimental and calculated results show that the calculated curves agree with testing curves and the method is reasonable and effective.

  20. Deployment aspects of a tensegrity-ring pedestrian bridge

    OpenAIRE

    Rhode-Barbarigos, Landolf; Bel Hadj Ali, Nizar; Motro, René; Smith, Ian F.C.

    2011-01-01

    International audience Tensegrity structures are spatial systems that are composed of tension and compression components in a self-equilibrated prestress stable state. Although tensegrity systems were first introduced in 1950s, few examples have been used for civil engineering purposes. In this paper, tensegrity-ring modules are used for a deployable pedestrian bridge. Ring modules belong to a special family of tensegrity systems composed of a single strut circuit. Assembled in a "hollow-r...

  1. Dynamic characterization and damage detection in the I-40 bridge over the Rio Grande

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, C.R.; Baker, W.E.; Bell, T.M.; Cone, K.M.; Darling, T.W.; Duffey, T.A.; Eklund, A.; Migliori, A.

    1994-06-01

    In the 1960`s and 1970`s over 2500 bridges were built in the U.S. with a design similar to those on Interstate 40 over the Rio Grande in Albuquerque, New Mexico. These bridges were built without structural redundancy and typically have only two plate girders carrying the entire dead and live loads. Failure of either girder is assumed to produce catastrophic failure of the bridge, hence these bridges are referred to as fracture-critical bridges. The Federal Highway Administration (FHWA) and the National Science Foundation (NSF) have provided funds to New Mexico State University (NMSU) through the New Mexico State Highway and Transportation Department (NMSH&TD) and The Alliance For Transportation Research (ATR) for evaluation and testing of the existing fracture critical bridges over the Rio Grande. Because the 1-40 bridges over the Rio Grande were to be razed during the summer of 1993, the investigators were able to introduce simulated fatigue cracks, similar to those observed in the field, into the structure in order to test various damage identification methods and to observe the changes in load paths through the structure caused by the cracking. To support this research effort, NMSU contracted Los Alamos National Laboratory (LANL) to perform experimental modal analyses, and to develop experimentally verified numerical models of the bridge. Scientists from the LANL`s Condensed Matter and Thermal Physics Group (P-10) applied state-of-the-art sensors and data acquisition software to the modal tests. Engineers from the LANL`s Advanced Engineering Technology Group (MEE-13) conducted ambient and forced vibration tests to verify detailed and simplified finite element models of the bridge. Forced vibration testing was done in conjunction with engineers from Sandia National Laboratory (SNL) who provided and operated a hydraulic shaker.

  2. Modal Identification and Damage Detection on a Concrete Highway Bridge by Frequency Domain Decomposition

    DEFF Research Database (Denmark)

    Brincker, Rune; Andersen, Palle; Zhang, Lingmi

    2007-01-01

    As a part of a research project co-founded by the European Community, a series of 15 damage tests were performed on a prestressed concrete highway bridge in Switzerland. The ambient response of the bridge was recorded for each damage case. A dense array of instruments allowed the identification...... is to show the application of the FDD method as an efficient way to perform health monitoring of civil engineering structures. The modal properties, frequencies, damping ratios and mode shapes for the different damage cases were compared with those for the undamaged bridge....

  3. Bridging nations through muons

    CERN Multimedia

    2006-01-01

    From America to Israel and Japan, a team of international technicians and scientists are working together to build the ATLAS endcap muon chambers. The Israeli and Pakistani teams stand in front of part of the ATLAS endcap muon spectrometer. They are working on the project along with...... a team from American universities and research institutions. It's a small world; at least you might think so after a visit to Building 180. Inside, about 30 engineers and physicists weld, measure and hammer away, many of whom are miles from their homes and families. They hail from Pakistan, Israel, Japan, China, Russia and the United States. Coordinated by a group of CERN engineers, the team represents an international collaboration in every sense. Whether they've been here for years or months, CERN is their temporary home as they work toward one common goal: the completion of the ATLAS muon chamber endcaps. When finished, the ATLAS muon spectrometer will include four moving 'big wheel'structures on each end of the detecto...

  4. Thermodynamics an engineering approach

    CERN Document Server

    Cengel, Yunus A

    2014-01-01

    Thermodynamics, An Engineering Approach, eighth edition, covers the basic principles of thermodynamics while presenting a wealth of real-world engineering examples so students get a feel for how thermodynamics is applied in engineering practice. This text helps students develop an intuitive understanding by emphasizing the physics and physical arguments. Cengel and Boles explore the various facets of thermodynamics through careful explanations of concepts and use of numerous practical examples and figures, having students develop necessary skills to bridge the gap between knowledge and the confidence to properly apply their knowledge. McGraw-Hill is proud to offer Connect with the eighth edition of Cengel/Boles, Thermodynamics, An Engineering Approach. This innovative and powerful new system helps your students learn more efficiently and gives you the ability to assign homework problems simply and easily. Problems are graded automatically, and the results are recorded immediately. Track individual stude...

  5. Floating liquid bridge charge dynamics

    Science.gov (United States)

    Teschke, Omar; Soares, David Mendez; Gomes, Whyllerson Evaristo; Valente Filho, Juracyr Ferraz

    2016-01-01

    The interaction of liquid with electric fields is investigated in a configuration where up to 13 kV are applied between electrodes resulting in a 106 V/m electric field in the capillaries and where there is the formation of a free-standing fluid bridge in the interelectrode gap. The Mott-Gurney equation was fitted to the measured ionization current vs applied voltage curve which indicates that the ionization rate at the high-voltage anode electrode dimethylsulfoxide (DMSO) interface and space charging in the interelectrode gap determine the floating liquid bridge current for a given cathode-to-anode voltage. Space charge effects were measured in the cathode becker and also at the liquid bridge since the ionized charges at the anode migrate to the bridge outer surface and decrease the interfacial tension from 43 mJ/m2 to 29 mJ/m2. Two distinct structural regions then form the bridge, a charged plastic (bulk modulus ˜100 MPa) conducting outer layer with a surface conductivity of ˜10-9 Ω-1, which shapes and supports the floating fluid structure, and an inner liquid cylinder, where DMSO molecules flow.

  6. Evaluation of Dynamic Load Factors for a High-Speed Railway Truss Arch Bridge

    Directory of Open Access Journals (Sweden)

    Ding Youliang

    2016-01-01

    Full Text Available Studies on dynamic impact of high-speed trains on long-span bridges are important for the design and evaluation of high-speed railway bridges. The use of the dynamic load factor (DLF to account for the impact effect has been widely accepted in bridge engineering. Although the field monitoring studies are the most dependable way to study the actual DLF of the bridge, according to previous studies there are few field monitoring data on high-speed railway truss arch bridges. This paper presents an evaluation of DLF based on field monitoring and finite element simulation of Nanjing DaShengGuan Bridge, which is a high-speed railway truss arch bridge with the longest span throughout the world. The DLFs in different members of steel truss arch are measured using monitoring data and simulated using finite element model, respectively. The effects of lane position, number of train carriages, and speed of trains on DLF are further investigated. By using the accumulative probability function of the Generalized Extreme Value Distribution, the probability distribution model of DLF is proposed, based on which the standard value of DLF within 50-year return period is evaluated and compared with different bridge design codes.

  7. Seismic Analysis for Rigid-Framed Prestressed Reinforced Concrete Bridge in Tianjin Light Railway

    Institute of Scientific and Technical Information of China (English)

    丁阳; 李楠; 李忠献

    2004-01-01

    The seismic analysis of a rigid-framed prestressed concrete bridge in Tianjin Light Railway is performed. A 3-D dynamic finite element model of the bridge is established considering the weakening effect caused by the soft soil foundation. After the dynamic characteristics are calculated in terms of natural frequencies and modes, the seismic analysis is carried out using the modal response spectrum method and the time-history method, respectively. Based on the calculated results, the reasonable design values are finally suggested as the basis of the seismic design of the bridge, and meanwhile the problems encountered were also analyzed. Finally, some conclusions are drawn as: 1) Despite the superiority of rigid-framed prestressed concrete bridge, the upper and lower ends of the piers of the bridge are proved to be the crucial parts of the bridge, which are easily destroyed under designed earthquake excitations and should be carefully analyzed and designed; 2) The soft soil foundation can possibly result in rather weakening of the lateral rigidity of the rigid-framed bridge, and should be paid considerable attention; 3) The modal response spectrum method, combined with time-history method, is suggested for the seismic analysis in engineering design of the rigid-framed prestressed concrete bridge.

  8. Bridging history and social psychology

    DEFF Research Database (Denmark)

    Glaveanu, Vlad Petre; Yamamoto, Koji

    2012-01-01

    This special issue aims to bridge history and social psychology by bringing together historians and social psychologists in an exercise of reading and learning from each other’s work. This interdisciplinary exercise is not only timely but of great importance for both disciplines. Social...... hand historians can enhance their analysis of historical sources by drawing upon the conceptual tools developed in social psychology. They can “test” these tools and contribute to their validation and enrichment from completely different perspectives. Most important, as contributions to this special......-traditionalized societies—a distinction that lies at the heart of many social psychology accounts of the world we live in. The present editorial will introduce and consider this act of bridging history and social psychology by focusing on three main questions: What is the bridge made of? How can the two disciplines...

  9. 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.

  10. Bridge Number and Conway Products

    OpenAIRE

    Blair, Ryan C.

    2007-01-01

    Schubert proved that, given a composite link $K$ with summands $K_{1}$ and $K_{2}$, the bridge number of $K$ satisfies the following equation: $$\\beta(K)=\\beta(K_{1})+\\beta(K_{2})-1.$$ In ``Conway Produts and Links with Multiple Bridge Surfaces", Scharlemann and Tomova proved that, given links $K_{1}$ and $K_{2}$, there is a Conway product $K_{1}\\times_{c}K_{2}$ such that $$\\beta(K_{1}\\times_{c} K_{2}) \\leq \\beta(K_{1}) + \\beta(K_{2}) - 1$$ In this paper, we define the generalized Conway prod...

  11. Optimum selection on bridge erection with floating crane in East China Sea Bridge and Hangzhou Bay Bridge

    Institute of Scientific and Technical Information of China (English)

    Shunquan Qin; Pu Zhou; Youheng Hua

    2004-01-01

    @@ Introduction With the rapid development of China′s economy, many bridges will be built over the Chinese coastal waters of Pacific Ocean. Among them, construction of East China Sea Bridge has been commenced in June 2001, and will be completed at the end of 2005, Hangzhou Bay Bridge was also started to construct in June 2003(Fig. 1). These two ultralong bridges are designed as twin expressway bridges standing side by side each carries a 3-lane one-way carriageway. The total width is 31.5m and 33.0m respectively. East China Sea Bridge starts from Nanhui District, Shanghai and extends to the Yangshan Deep Water Port Area, which is located at one of the Qiqu Islands. The total length of the bridge is about 31.0 km, in which 25 km are on the sea, and 22 km is in the unnavigable region. Hangzhou Bay Bridge across the mouth of Qiantang River.

  12. Is myocardial bridging a bridge connecting to cardiovascular events?

    Institute of Scientific and Technical Information of China (English)

    LI Jian-jun

    2010-01-01

    @@ Coronary arteries and their major branches usually course on the surface of the heart in the subepicardial tissue. However, a muscle hber overlying the intramyocardial segment of an epicardial coronary artery was defined as myocardial bridging (MB), and subsequently the artery coursing within the myocardium is called a tunneled artery.

  13. Engineering Encounters: Engineering Adaptations

    Science.gov (United States)

    Gatling, Anne; Vaughn, Meredith Houle

    2015-01-01

    Engineering is not a subject that has historically been taught in elementary schools, but with the emphasis on engineering in the "Next Generation Science Standards," curricula are being developed to explicitly teach engineering content and design. However, many of the scientific investigations already conducted with students have…

  14. Instability of the capillary bridge

    Science.gov (United States)

    Pare, Gounseti; Hoepffner, Jerome

    2014-11-01

    Capillary adhesion is a physical mechanism that maintains two bodies in contact by capillarity through a liquid ligament. The capillary bridge is an idealization of this capillary adhesion. In this study we first focus on the classical case of the stability of the capillary bridge. Secondly we study a slightly more complex configuration, imagining a flow in the capillary bridge as in the case of the dynamics of the neck of a liquid ligament, in its withdrawal under the effect of capillarity. Inspired by the experiments on soap films of Plateau, the configuration analyzed consists of an initially axisymmetric, mass of fluid held by surface tension forces between two parallel, coaxial, solid pipes of the same diameter. The results presented are obtained by numerical simulations using the free software, Gerris Flow Solver. We first focus on the capillary Venturi. In the static configuration the stability diagram of the capillary bridge obtained is in perfect agreement with the results of Lev A. Slobozhanin. In the dynamic case we develop a matlab code based on the one dimensional equations of Eggers and Dupont. The comparison of the bifurcation diagram obtained and the numerical simulations shows a good agreement.

  15. 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...

  16. Intercellular bridges in vertebrate gastrulation.

    Directory of Open Access Journals (Sweden)

    Luca Caneparo

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

  17. Dynamic identification of paradela historic railway bridge

    OpenAIRE

    Ramos, Luís F.; Valente, Isabel; Guimarães, Paulo; Vazquez, Kevin; Lourenço, Paulo B.

    2013-01-01

    Paradela Bridge is a metallic bridge located along the bank of the Tua River in northern Portugal. While the bridge is not currently in service, its structure is representative of many metallic truss structures built across the country between the 19th and the 20th century. The construction of the Paradela Bridge was completed in 1886 and served for about 120 years connecting northern Portugal. Tua Line belongs to the Douro area that UNESCO recently declared as world heritage. This work acqui...

  18. Transition Slabs of Integral Abutment Bridges

    OpenAIRE

    Dreier, Damien; Muttoni, Aurelio; BURDET, Olivier

    2011-01-01

    Over the past decades, an increasing number of bridges with integral abutment have been built in Switzerland. This type of bridge offers various advantages over standard bridges with abutments, equipped with expansion joints and bearings that require regular inspection and maintenance. One main concern of integral abutment bridges is related to the soil-structure interaction, in particular between the transition slab and the embankment. To avoid any expansion joints, transition slabs are dire...

  19. Path transformations of first passage bridges

    OpenAIRE

    Bertoin, Jean

    2003-01-01

    We define the first passage bridge from 0 to $\\lambda$ as the Brownian motion on the time interval $[0,1]$ conditioned to first hit $\\lambda$ at time 1. We show that this process may be related to the Brownian bridge, the Bessel bridge or the Brownian excursion via some path transformations, the main one being an extension of Vervaat's transformation. We also propose an extension of these results to certain bridges with cyclically exchangeable increments.

  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... position). I plan to (give proposed course of action). Over. (3) (Coast station), this is (vessel's...

  1. 广乐高速公路马渡互通桥工程8m以上大溶洞施工技术%Over eight meters large karst cave construction technology of GuangLe highway exchange bridge engineering

    Institute of Scientific and Technical Information of China (English)

    李福恩; 牛紫龙

    2011-01-01

    马渡枢纽互通桥工程8 m以上大型溶洞共有23个,其中有全填充13个、半充填7个和无充填3个.勘察揭露充填物质多为黏性土、砂、灰岩碎块及卵石土.岩溶发育情况显示岩溶顶板厚度小、洞体高度大,且充填不好,在受到外力作用情况下,可造成顶板塌落、地面发生塌陷,对于结构稳定性和桩基施工影响较大.施工中,全填充溶洞采取注浆加固处理;半填充溶洞采取先注浆加固,后对未填充部分灌注低标号细石混凝土处理;未填充溶洞全部灌注低标号细石混凝土处理,取得了良好的效果.%Madu communication bridge engineering has twenty three karst cave over eight meters, including the filling 13,half filled seven and no filling 3. Investigation revealed filling material is clayey soil,sand and gravel soils and limestone pieces. Karst development situation of karst thickness, that dongti height, and filling in the external force, by circumstance, can cause the roof collapsing,collapsing,for structural stability and pile foundation construction. Construction of the karst grouting reinforcement to fill;half filled cave after grouting strengthening, take part in not filled perfusion label fine stone concrete processing;no filling cave perfusion label fine stone concrete processing. Achieved good effect.

  2. Removal of failed crown and bridge.

    Science.gov (United States)

    Sharma, Ashu; Rahul, G R; Poduval, Soorya T; Shetty, Karunakar

    2012-07-01

    Crown and bridge have life span of many years but they fail for a number of reasons. Over the years, many devices have been designed to remove crowns and bridges from abutment teeth. While the removal of temporary crowns and bridges is usually very straightforward, the removal of a definitive cast crown with unknown cement is more challenging. Removal is often by destructive means. There are a number of circumstances, however, in which conservative disassembly would aid the practitioner in completing restorative/endodontic procedures. There are different mechanisms available to remove a failed crown or bridge. But there is no information published about the classification of available systems for crown and bridge removal. So it is logical to classify these systems into different groups which can help a clinician in choosing a particular type of system depending upon the clinical situation. The aim of this article is to provide a classification for various crown and bridge removal systems; describe how a number of systems work; and when and why they might be used. A PubMed search of English literature was conducted up to January 2010 using the terms: Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure. Additionally, the bibliographies of 3 previous reviews, their cross references as well as articles published in various journals like International Endodontic Journal, Journal of Endodontics and were manually searched. Key words:Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure. PMID:24558549

  3. Remediation: Higher Education's Bridge to Nowhere

    Science.gov (United States)

    Complete College America, 2012

    2012-01-01

    The intentions were noble. It was hoped that remediation programs would be an academic bridge from poor high school preparation to college readiness. Sadly, remediation has become instead higher education's "Bridge to Nowhere." This broken remedial bridge is travelled by some 1.7 million beginning students each year, most of whom will…

  4. Coordination and communication inside game engine

    OpenAIRE

    Kukkamaa, T. (Tuomas)

    2015-01-01

    This study examines the communication and coordination among different parts of game engine. As games contain multiple co-operating processes, each of which handles a small part of whole game experience, game engines must handle the management of co-operation efficiently. The issue is that while the competitive and demanding game industry has hastened the development of game engines, the academic research has been lagging behind. This study aims to bridge the gap between industrial know-h...

  5. Comparison between Modern Violin Bridge and Baroque Violin Bridge by Photoelastic Observation and Frequency Analysis

    Science.gov (United States)

    Matsutani, Akihiro

    2004-05-01

    A comparison between the modern bridge and the baroque bridge of the violin by photoelastic observation was carried out. The relationship between the stress part and the hole is symmetric in the modern and baroque bridges. The measured spectral envelopes of baroque bridges are similar to those of modern bridges in D- or G-strings, and have peaks at a frequency higher than those of modern bridges in E-string. The visualization method as used in this study may provide hints for the design of violin bridges.

  6. Intelligent control for braking-induced longitudinal vibration responses of floating-type railway bridges

    International Nuclear Information System (INIS)

    This paper presents an intelligent control method and its engineering application in the control of braking-induced longitudinal vibration of floating-type railway bridges. Equations of motion for the controlled floating-type railway bridges have been established based on the analysis of the longitudinal vibration responses of floating-type railway bridges to train braking and axle-loads of moving trains. For engineering applications of the developed theory, a full-scale 500 kN smart magnetorheologic (MR) damper has been designed, fabricated and used to carry out experiments on the intelligent control of braking-induced longitudinal vibration. The procedure for using the developed intelligent method in conjunction with the full-scale 500 kN MR dampers has been proposed and used to control the longitudinal vibration responses of the deck of floating-type railway bridges induced by train braking and axle-loads of moving trains. This procedure has been applied to the longitudinal vibration control of the Tian Xingzhou highway and railway cable-stayed bridge over the Yangtze River in China. The simulated results have shown that the intelligent control system using the smart MR dampers can effectively control the longitudinal response of the floating-type railway bridge under excitations of braking and axle-loads of moving trains

  7. Analysis of local influences in structural details of the bridges

    Directory of Open Access Journals (Sweden)

    Adam RUDZIK

    2015-03-01

    Full Text Available The article analyses the problems of local influences in structural details of bridges as the critical locations, whose damages or excessive force may directly affect the safety of users. These analyses are shown on selected examples. Presented is the example of local changes in the forms of proper vibrations in the node of the truss bridge that can be used in expert issues concerning the causes of damages. The second example are the changes in stresses in the stay cable anchorage element including the nonlinear material models. Models of this type can be successfully used by engineers as they allow for analysis of selected structural details without the need for detailed mapping of the entire structure, but only a selected section.

  8. Comprehensive Real-Time Bridge Health Monitoring System of Tongtai Bridge

    OpenAIRE

    Lei Su-su; Gao Yong-tao; Pan Dan-guang

    2015-01-01

    Tongtai Bridge is the world’s largest suspension curve-girder-skew-arch bridge, which is located in Zhangjiakou, China. The understanding of mechanics characteristics is limited to such complex bridges, so it is necessary to establish reliable health monitoring system to investigate the static and dynamic responses and monitor the safety of the bridge. A comprehensive real-time bridge health monitoring system is establish, which includes four aspects: sensor system, data acquisition and trans...

  9. Structural health monitoring of long-span suspension bridges using wavelet packet analysis

    Institute of Scientific and Technical Information of China (English)

    Ding Youliang; Li Aiqun

    2007-01-01

    During the service life of civil engineering structures such as long-span bridges, local damage at key positions may continually accumulate, and may finally result in their sudden failure. One core issue of global vibration-based health monitoring methods is to seek some damage indices that are sensitive to structural damage. This paper proposes an online structural health monitoring method for long-span suspension bridges using wavelet packet transform (WPT). The WPTbased method is based on the energy variations of structural ambient vibration responses decomposed using wavelet packet analysis. The main feature of this method is that the proposed wavelet packet energy spectrum (WPES) has the ability to detect structural damage from ambient vibration tests of a long-span suspension bridge. As an example application, the WPES-based health monitoring system is used on the Runyang Suspension Bridge under daily environmental conditions. The analysis reveals that changes in environmental temperature have a long-term influence on the WPES, while the effect of traffic loadings on the measured WPES of the bridge presents instantaneous changes because of the nonstationary properties of the loadings. The condition indication indices VD reflect the influences of environmental temperature on the dynamic properties of the Runyang Suspension Bridge. The field tests demonstrate that the proposed WPES-based condition indication index VD is a good candidate index for health monitoring of long-span suspension bridges under ambient excitations.

  10. Field Application of Automated Power Arc Spraying System on Steel Bridge Deck

    Institute of Scientific and Technical Information of China (English)

    YI Chun-long; SUO Shuang-fu; SUN Zhi; PANG Xu-nan

    2004-01-01

    The effective corrosion protection coating and high productive coating equipment for steel bridge deck has been a challenge for bridge engineers for many years. An automated power arc spraying system was first designed and field applied to coating the deck of Wuhan Junshan Yangtze River Bridge in high efficiency. This steel bridge is a continuous orthotropic deck box girder cable-stayed bridge with 962 m in length and 38.8 m in width, whose width is the No. 1 in China. The whole orthotropic deck with over 35,000 m2surface area was arc-sprayed a protective coating of zinc on site, followed by a sealant and SMA paving material. The side face and bottom of box girders were arc-sprayed with aluminum in factory.Field application indicated that the newly designed automated power arc spraying system with fan nozzle and separate primary & secondary atomizing air had some advantages over the conventional arc spraying system, such as automated operation,big arc spray current, high spraying rate, big breadth of each coat, even and small atomized particles, high density and low porosity of sprayed coating, and high adhesive strength to the substrate.Working procedure of surface preparation and automated arc spraying on bridge deck were introduced, and the quality of sprayed coating is controlled strictly. Field tests proved that the application of this automated power arc spraying system is successful and suitable for coating the steel bridge deck.

  11. Investigations concerning seismic response control of self-anchored suspension bridge with MR dampers

    Institute of Scientific and Technical Information of China (English)

    Menggang YANG; Zhengqing CHEN; Jianhua HU

    2008-01-01

    To mitigate the seismic response of selfanchored suspension bridges, equations of motion governing the coupled system of bridge- magneto-rheological (MR) dampers subject to seismic excitation are formulated by employing the phenomenological model of MR dampers. A corresponding computer program is developed and employed for studying the seismic response control of a self-anchored suspension bridge with a main span of 350 m. The effect of variable current and number of dampers on seismic response control is investigated. The numerical results indicate the longitudinal displacement of the tower top and bridge girder decrease with the increase in input current and number of MR dampers attached longitudinally at the tower-girder connections, and the internal forces of the tower are effectively attenuated as well. It appears that small electronic current (0.5 A in this study) may sufficiently attenuate the seismic responses for practical engineering applications.

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

    DEFF Research Database (Denmark)

    Koss, Holger

    2014-01-01

    In recent years the relevance of ice accretion for wind-induced vibration of structural bridge cables has been recognised and became a subject of research in bridge engineering. Full-scale monitoring and observation indicate that light precipitation at moderate low temperatures between zero and -5......°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...

  13. New Concept for Durable Concrete Bridges

    OpenAIRE

    Damek, Marek

    2015-01-01

    This master’s thesis covers the design of a post-tensioned concrete bridge in Trondheim municipality in Norway, in collaboration with Statens vegvesen (SVV). The concept of the bridge is inspired by Egg-Graben-Brücke in Austria, which was designed and built without steel reinforcement in the bridge deck. The idea is to eliminate steel reinforcement which can corrode in the bridge deck. The total length of the bridge is 73 meters and it is divided into 3 spans. The crosssection ...

  14. Development of the applicability of simplified Henry's method for skewed multicell box-girder bridges under traffic loading conditions

    Institute of Scientific and Technical Information of China (English)

    Iman MOHSENI; A.R.Khalim RASHID

    2012-01-01

    Concrete precast multicell box-girder (MCB) bridges combine aesthetics with torsional stiffness perfectly.Previous analytical studies indicate that currently available specifications are unable to consider the effect of the twisting moment (torsional moment) on bridge actions.In straight bridges the effect of torsion is negligible and the transverse reinforced design is governed by other requirements.However,in the case of skewed bridges the effect of the twisting moment should be considered.Therefore,an in-depth study was performed on 90 concrete MCB bridges with skew angles ranging from 0° to 60°.For each girder the bridge actions were determined under the American Association of State Highway and Transportation Officials (AASHTO) live load conditions.The analytical results show that torsional stiffness and live load positions greatly affected the bridges' responses.In addition,based on a statistical analysis of the obtained results,several skew correction factors are proposed to improve the precision of the simplified Henry's method,which is widely used by bridge engineers to predict bridge actions.The relationship between the bending moment and secondary moments was also investigated and it was concluded that all secondary actions increase with an increase in skewness.

  15. Full-bridge capacitive extensometer

    Science.gov (United States)

    Peters, Randall D.

    1993-08-01

    Capacitive transducers have proven to be very effective sensors of small displacements, because of inherent stability and noninvasive high resolution. The most versatile ones have been those of a differential type, in which two elements are altered in opposite directions in response to change of the system parameter being monitored. Oftentimes, this differential pair has been incorporated into a bridge circuit, which is a useful means for employing synchronous detection to improve signal to noise ratios. Unlike previous differential capacitive dilatometers which used only two active capacitors, the present sensor is a full-bridge type, which is well suited to measuring low-level thermal expansions. This analog sensor is capable of 0.1 μm resolution anywhere within a range of several centimeters, with a linearity of 0.1%. Its user friendly output can be put on a strip chart recorder or directed to a computer for sophisticated data analysis.

  16. Noise Considerations in Resistance Bridges

    DEFF Research Database (Denmark)

    Diamond, Joseph M.

    1963-01-01

    thermometry, where the noise in the unknown resistor will predominate strongly. An impedance step-up device (transformer or tuned circuit) is valuable in raising the bridge signal and noise level above the noise of the first amplifier tube. However, as the step-up ratio is increased, two counterfactors appear......, namely, noise in the loss resistance of the step-up device, and grid current noise. There is therefore an optimum step-up ratio, which has been found. The step-up device is permitted to have a different temperature from the unknown and standard resistors, to evaluate the advantage of cooling it....... With certain assumptions about the noise and grid current of the first tube it is found that the equivalent temperature of a unity ratio (Mueller) bridge used for liquid helium measurements may be 400°K....

  17. Stability of Axisymmetric Liquid Bridges

    CERN Document Server

    Rubinstein, Boris

    2016-01-01

    We study stability of axisymmetric liquid bridges between two axisymmetric solid bodies in the absence of gravity under arbitrary asymmetric perturbations which are expanded into a set of angular Fourier modes. We determine the stability region boundary for every angular mode in case of both fixed and free contact lines. Application of this approach allows us to demonstrate existence of stable convex nodoid menisci between two spheres.

  18. 2015 Bridge Inspection ERC Training

    OpenAIRE

    Dougherty, Merril

    2015-01-01

    This presentation will discuss recent changes to the County Bridge Inspection Program from the perspective of both the FHWA and INDOT. We will also discuss the responsibilities of the local public agency’s (LPA’s) employee in responsible charge (ERC) with respect to managing this program. As this course is a yearly requirement, all county ERCs are encouraged to attend. Pre-registering is strongly encouraged by e-mailing your contact information to .

  19. The Bridge Program - Participant Perspectives

    OpenAIRE

    Rönnqvist, Riitta; Hakonen, Anu; Vartiainen, Matti

    2015-01-01

    The Nokia Bridge Program was established in summer 2011 in order to "make the best of the restructuring: create meaningful opportunities for individuals and local economies impacted by workforce reductions" and to "assist individuals in re-employment". This document reports whether and how the program helped individuals avoid the known negative effects of job loss and find meaningful re-employment. The document also reports how affected employees formed perceptions about Nokia´s fairness and ...

  20. 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....

  1. Parabolic metamaterials and Dirac bridges

    Science.gov (United States)

    Colquitt, D. J.; Movchan, N. V.; Movchan, A. B.

    2016-10-01

    A new class of multi-scale structures, referred to as `parabolic metamaterials' is introduced and studied in this paper. For an elastic two-dimensional triangular lattice, we identify dynamic regimes, which corresponds to so-called `Dirac Bridges' on the dispersion surfaces. Such regimes lead to a highly localised and focussed unidirectional beam when the lattice is excited. We also show that the flexural rigidities of elastic ligaments are essential in establishing the `parabolic metamaterial' regimes.

  2. Severe ASR damaged concrete bridges

    DEFF Research Database (Denmark)

    Antonio Barbosa, Ricardo; Gustenhoff Hansen, Søren

    2015-01-01

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

  3. Evaluation of streambed scour at bridges over tidal waterways in Alaska

    Science.gov (United States)

    Conaway, Jeffrey S.; Schauer, Paul V.

    2012-01-01

    Engineering Center’s River Analysis System model, and scour depths were calculated using methods recommended by the Federal Highway Administration. Computed contraction-scour depths were greater than 2.0 feet at five bridges and computed pier-scour depths were 4.0 feet or greater at 15 bridges. The potential for streambed scour by both coastal and riverine processes at the bridges considered in this study were evaluated, ranked, and summed to determine a cumulative risk factor for each bridge. Possible factors that could mitigate the scour risks were investigated at 22 bridges that had high individual or cumulative rankings. Mitigating factors such as piers founded in bedrock, deep pier foundations relative to scour depths, and lack of observed scour during field measurements were documented for 13 sites, but additional study and monitoring is needed to better quantify the streambed scour potential for nine sites. Three bridges prone to being affected by storm surges will require more data collection and possibly complex hydrodynamic modeling to accurately quantify the streambed scour potential. Continuous monitoring of water-surface and streambed elevation at one or more piers is needed for two bridges to better understand the tidal and riverine influences on streambed scour.

  4. Halliburton Composite Bridge Plug Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Starbuck, J.M.; Luttrell, C.R.; Aramayo, G.

    2005-01-15

    The overall objectives of this CRADA were to assist Halliburton in analyzing a composite bridge plug and to determine why their original design was failing in the field. In Phase 1, finite element analyses were done on the original composite slip design and several alternative designs. The composite slip was the component in the bridge plug that was failing. The finite element code ABAQUS was used for these calculations and I-DEAS was used as the pre- and post-processor in the analyses. Several different designs and materials were analyzed and recommendations were made towards improving the design. In Phase 2, the objective was to develop finite element models that would accurately represent the deformations in the entire all-composite 4-1/2' diameter bridge plug assembly. The finite element code LS-DYNA was used and the results from this effort were intended to expand Halliburton's composite design and analysis capabilities with regard to developing future composite components for downhole tools. In addition to the finite element modeling, this effort involved the utilization of micromechanics to determine the necessary composite material properties that were needed as input for finite element codes.

  5. Welding engineering manual for constructing engineers. Pt. 2

    International Nuclear Information System (INIS)

    The manual is a real treasure trove of knowledge and experience for the statics expert, the constructing engineer, and the welding engineer, who have to do with design and dimensioning of welding engineering work for steel structures, bridges, boilers, vessels, and pipes. Many practical examples are given together with numerous data that provide helpful information for the task of technical and economic design and dimensioning. Determination of efficient and appropriate cross-sectional dimensions and materials is the main goal of the manual. Structural steel engineering and installations subject to monitoring and inspection such as boilers, pipings, pressure vessels, and nuclear installations are the subject fields dealt with in separate chapters. The dimensioning rules presented are based on the regulations and technical codes valid in the GDR and the FRG. The catalogue of technical rules of the FRG concerning structural steel engineering and installations as above are given in supplementary chapters. (orig./HP)

  6. Study on the Safety of the Rock Mass in the Tongling Bank of Taipinghu Bridge

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The Taipinghu Bridge is an important engineering construction, and the safety of rock mass of its foundation is very crucial. This article adopts FLAC 3D to analysis the geologic model. The simulating process shows that no mater the excavating process or the loading process the rock mass are safe. The modeling and analyzing process can be used for reference.

  7. Knowledge-Based Systems for the Assessment and Management of Bridge Structures

    DEFF Research Database (Denmark)

    Miyamoto, A.; Thoft-Christensen, Palle; Yan, B.

    2004-01-01

    . The aim of this paper is to summarize the finding of up-to-date research articles concerning the application of knowledge-based systems to assessment and management of structures and to illustrate the potential of such systems in the structural engineering. Two modern bridge management systems (BMS...

  8. Research and Teaching: Association of Summer Bridge Program Outcomes with STEM Retention of Targeted Demographic Groups

    Science.gov (United States)

    Tomasko, David L.; Ridgway, Judith S.; Waller, Rocquel J.; Olesik, Susan V.

    2016-01-01

    Retention of students to science, technology, engineering, and mathematics (STEM) major has been studied for four cohorts participating in a summer bridge program supported by the National Science Foundation. Students participated in a 6-week program prior to their first term of enrollment at a research-intensive land grant university. Comparisons…

  9. Nondestructive evaluation techniques for enhanced bridge inspection

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, G.; Benson, S.; Durbin, P.; Del Grande, N.; Haskins, J.; Brown, A.; Schneberk, D.

    1993-10-01

    Nondestructive evaluation of bridges is a critical aspect in the US aging infrastructure problem. For example in California there are 26,000 bridges, 3000 are made of steel, and of the steel bridges, 1000 are fracture critical. California Department of Transportation (Caltrans), Federal Highway Administration, and Lawrence Livermore National Laboratory (LLNL) are collaborating to develop and field NDE techniques to improve bridge inspections. We have demonstrated our NDE technologies on several bridge inspection applications. An early collaboration was to ultrasonically evaluate the steel pins in the E-9 pier on the San Francisco Bay Bridge. Following the Loma-Prieta earthquake in 1989 and the road way collapse at the E-9 pier, a complete nondestructive evaluation was conducted by Caltrans inspectors and several ultrasonic indications were noted. LLNL worked with Caltrans to help identify the source of these reflections. Another project was to digitally enhance high energy radiographs of bridge components such as cable end caps. We demonstrated our ability to improve the detection of corrosion and fiber breakage inside the end cap. An extension of this technology is limited view computer tomography (CT). We implemented our limited view CT software and produced cross-sectional views of bridge cables from digitized radiographic films. Most recently, we are developing dual band infrared imaging techniques to assess bridge decks for delaminations. We have demonstrated the potential of our NDE technology for enhancing the inspection of the country`s aging bridges.

  10. On the Maintenance and Management of Highway Bridge%公路桥梁养护管理问题探析

    Institute of Scientific and Technical Information of China (English)

    王兴刚

    2015-01-01

    This paper expounds the important significance of road and bridge maintenance management, and analyzes the bridge maintenance problems in bridge engineering construction, and puts forward the measures to improve the maintenance of road and bridge.%文章阐述了道路桥梁养护管理的重要意义,并探析了在桥梁工程建设中面临的桥梁养护问题,提出提高道路桥梁养护的应对措施。

  11. Study on the Safety of the Foundation Rock Masses in the Tangkou Bank of the Taipinghu Bridge

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The Taipinghu Bridge is an important project, and the safety of rock masses of its foundation is very crucial. This article analyzes the potential causes of the deformation of the rock masses of the bridge foundation, and uses the Fast Lagrangian Analysis of Continua to analyze the geologic model. The simulating process shows that no mater in the excavating process or in the loading process the rock masses are suit for the engineering. The modeling and analyzing process can be used for reference.

  12. The Behaviour of the Embedded Rail in Interaction with Bridges

    Science.gov (United States)

    Ryjáček, P.; Howlader, Md M.; Vokáč, M.

    2015-11-01

    Since the introduction of the direct fastening system, Embedded Rail System (ERS) is probably one of the most spectacular and innovative developments in railway engineering. The development has become more rapid, especially in the last decade due to competitive advantages in comparison toother systems with respect to higher speed, cost effectiveness, environmental-material sustainability and others. But still there is a lack of specific interaction model, especially when it comes to bridges equipped with ERS system. Previous studies on ERS by Estzer Ludvigh2 found out some important coefficients (vertical and longitudinal bedding coefficient) and compared the longitudinal resistance of ERS with flexible fastening systems. Other studies on ERS do not specifically deal with the evaluation of longitudinal resistance of such a system. With a view to establish the typical behaviour pattern of ERS, this paper is dedicated to find out the interaction of a specific Embedded Rail System with bridges. A small scale test was conducted on a sample of ERS in the laboratory under different combinations of vertical and longitudinal track loads and subsequently a Finite Element Model (FEM) was developed to simulate the test. The paper presents the FEA result validation with test results, the interaction pattern, longitudinal resistance of ERS track for both loaded and unloaded conditions, design load distribution for such systems and some specific influences of ERS on simply supported bridge systems.

  13. Evaluation method research on prestressed concrete bridges

    Institute of Scientific and Technical Information of China (English)

    HUANG Qiao; LIN Yang-zi; REN Yuan

    2008-01-01

    Considering the construction features of prestressed concrete bridge, the comprehensive evaluation method about the bridge damage conditions are studied. Particular attentions are paid on establishing a multi-level evaluation model for damaged prestressed concrete bridge, and the evaluation indices of the model as well as the rating standards are defined in the model. A normal relative function about the evaluation indices of each element is developed to calculate the relative degree, and for each element which is no sub-level elements. When evaluating the elements in sub-item level or index level of the model, the weights of elements that are pertained to one element are adopted, taking account of their deterioration degree. At the same time, the dam-age conditions of bridge are characterized by relative degree, element evaluation scale and structural technology mark of bridge ,so it agrees with Code for Maintenance of Highway Bridges and Culvers.

  14. Seismic Evaluation of Highway Bridges - Phase 1

    OpenAIRE

    Ramirez, J.A.; Pan, Austin D.; Mwakasisi, Frank Thompson

    1996-01-01

    The primary objective of the study was to establish the guidelines for screening, assessing, and ranking Indiana bridges for seismic upgrade. The outcome of the study is a complete strategy for the detailed structural assessment of Indiana highway bridges subjected to seismic forces. The structural evaluation is conducted using a nonlinear time-history analysis of the bridge for simulated or actual records. The specific soil conditions at the site are accounted in terms of the ground motio...

  15. REPORT: BioMedBridges standards workshop

    OpenAIRE

    Conte, Nathalie; Hancocks, Tom; Suhr, Stephanie

    2014-01-01

    This workshop, co-organized by BioMedBridges WP3 and 12, was held on 24-25 June and hosted by BioMedBridges partners at VUMC in Amsterdam. Attendees included BioMedBridges personnel, members from the ESFRI BMS research infrastructures and invited external experts from existing standards organisations. The following aspects of data standardisation were explored: Defining entity identifiers and identifiers best practice Development of a Meta models and Mappings Registry for bio...

  16. Analysis of liquid bridge between spherical particles

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A pair of central moving spherical particles connected by a pendular liquid bridge with interstitial Newtonian fluid is often encountered in pariculate coalescence process. In this paper, by assuming perfect-wet condition, the effects of liquid volume and separation distance on static liquid bridge are analyzed, and the relation between rupture energy and liquid bridge volume is also studied. These points would be of significance in industrial processes related to adhesive particles.

  17. Markovian Bridges: Weak continuity and pathwise constructions

    OpenAIRE

    Chaumont, Loïc; Uribe Bravo, Gerónimo

    2009-01-01

    A Markovian bridge is a probability measure taken from a disintegration of the law of an initial part of the path of a Markov process given its terminal value. As such, Markovian bridges admit a natural parameterization in terms of the state space of the process. In the context of Feller processes with continuous transition densities, we construct by weak convergence considerations the only versions of Markovian bridges which are weakly continuous with respect to their parameter. We use this ...

  18. Life Cycle Assessment of a Norwegian Bridge

    OpenAIRE

    Dequidt, Thomas Charles Edouard

    2012-01-01

    Life cycle assessment (LCA) methodology aims at evaluating the environmental impacts of a product or system from a holistic approach. In this methodology, all life cycle phases of the product are identified and assessed, from the raw material acquisition to the end-of-life phase. This master thesis is dealing with the LCA of a Norwegian bridge. First, a literature review is realized by going through 14 bridge LCA references. Then, a detailed description of bridge LCA methodology ...

  19. Dynamics and Statics of Nonaxisymmetric Liquid Bridges

    Science.gov (United States)

    Alexander, J. Iwan D.; Resnick, Andrew H.; Slobozhanin, L. A.

    1996-01-01

    Theoretical and experimental investigation of the stability of nonaxisymmetric and nonaxisymmetric bridges contained between equal and unequal radii disks as a function of Bond and Weber number with emphasis on the transition from unstable axisymmetric to stable nonaxisymmetric shapes, are conducted. Numerical analysis of the stability of nonaxisymmetric bridges between unequal disks for various orientations of the gravity vector is performed. Experimental and theoretical investigation of large (nonaxisymmetric) oscillations and breaking of liquid bridges are also conducted.

  20. Maximal liquid bridges between horizontal cylinders

    OpenAIRE

    Cooray, Himantha; Huppert, Herbert E.; Neufeld, Jerome A

    2016-01-01

    We investigate two-dimensional liquid bridges trapped between pairs of identical horizontal cylinders. The cylinders support forces due to surface tension and hydrostatic pressure which balance the weight of the liquid. The shape of the liquid bridge is determined by analytically solving the nonlinear Laplace-Young equation. Parameters that maximize the trapping capacity (defined as the cross-sectional area of the liquid bridge) are then determined. The results show that these parameters can ...

  1. Axisymmetric long liquid bridges stability and resonances

    OpenAIRE

    Meseguer Ruiz, José; Sanz Andres, Angel Pedro; Perales Perales, José Manuel

    1990-01-01

    In this paper mathematical expressions for minimum-volume stability limits and resonance frequencies of axisymmetric long liquid bridges are presented. These expressions are valid for a wide range of liquid bridge configurations, accounting for ef-fects like unequal disks and axial microgravity in the case of minimum-volume stability limits,and unequal disks, axial microgravity,non-zero viscosity and liquid bridge volume different from the cylindrical one in the case of resonance frequenc...

  2. Crystal growth under bridge foundation

    OpenAIRE

    Ramon Tarragona, Anna; Alonso Pérez de Agreda, Eduardo

    2012-01-01

    W(H)YDOC PhD Prize 2012, durant el 4th International Workshop of Young Doctors in Geomechanics W(H)YDOC 2012. A high-speed railway viaduct experienced a sustained heave at high rates after its construction. The pillars of the bridge are founded on an Eocene hard anhydritic-gypsiferous claystone by means of massive foundations. Field investigations identified an active layer below the piles’ tips where expansions occur as a result of gypsum crystal growth in discontinuities from supersatura...

  3. Nanoclusters a bridge across disciplines

    CERN Document Server

    Jena, Purusottam

    2010-01-01

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

  4. Family Medicine: Bridge to Life.

    Science.gov (United States)

    Luz, Clare

    2016-01-01

    Reflecting on the suicide of a close friend, this essay explores what comprises, and inspires a will to live, and how those in Family Medicine can address suicide risk even in the face of debilitating or terminal illness. Research indicates that the will to live is a measurable indicator of general well-being, distinct from depression, and an important predictor of a person's motivation to "hold on to life". As such, understanding what is at the heart of a desire to live should alter clinical practice. This essay offers ideas for ways in which to create bridges for patients that could help sustain life.

  5. A bridge to advanced mathematics

    CERN Document Server

    Sentilles, Dennis

    2011-01-01

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

  6. Myocardial bridges: morphological and functional aspects.

    OpenAIRE

    A.G. Ferreira; Trotter, S E; König, B; Décourt, L V; Fox, K; Olsen, E G

    1991-01-01

    OBJECTIVE--To assess the arrangement of myocardial bridges. DESIGN--A necropsy study of 90 consecutive hearts (56 male, 34 female). RESULTS--Myocardial bridges, either single or multiple, were seen in 50 (55.6%) of the 90 hearts. The left anterior descending artery was the most commonly affected artery. Thirty five of the 50 hearts which contained in total 41 muscle bridges were dissected further with a magnifying glass. Two different types of muscle bridges could be identified. Thirty one of...

  7. 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.

  8. Review of Energy Harvesters Utilizing Bridge Vibrations

    Directory of Open Access Journals (Sweden)

    Farid Ullah Khan

    2016-01-01

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

  9. Gust loading on streamlined bridge decks

    DEFF Research Database (Denmark)

    Larose, Guy; Mann, Jakob

    1998-01-01

    The current analytical description of the buffeting action of wind on long-span bridges is based on the strip assumption. However, recent experiments on closed-box girder bridge decks have shown that this assumption is not valid and is the source of an important part of the error margin of the an......The current analytical description of the buffeting action of wind on long-span bridges is based on the strip assumption. However, recent experiments on closed-box girder bridge decks have shown that this assumption is not valid and is the source of an important part of the error margin...

  10. 淦河桥梁方案设计研究%Design and Research on Bridge Scheme of Gan River

    Institute of Scientific and Technical Information of China (English)

    蔡忠华

    2016-01-01

    Following the principal of applicable,economical,safe and beautiful and taking the bridge crossing Gan River in Jingui west road in Xianning City as the engineering background,four types of bridge design schemes are introduced,namely simple supported girder bridge,continuous girder bridge,through tied-arch bridge,and cable-stayed bridge without backstays.The tied arch bridge is chosen as the recommended proposal by taking bridge design,landscape feature,construction feasibil-ity and economy into comprehensive consideration.%遵循“适用、经济、安全、美观”的桥梁设计基本原则,以咸宁市金桂西路跨淦河大桥为工程背景,提供了4种桥梁设计方案:无背索斜拉桥,预应力混凝土连续梁桥、预应力混凝土简支 T梁桥、下承式系杆拱桥。综合考虑论证桥梁构造设计、景观特色、施工可行性和经济性等因素,选取下承式系杆拱桥作为推荐方案。

  11. A bridge between conceptual frameworks sciences, society and technology studies

    CERN Document Server

    2015-01-01

    This book analyzes scientific problems within the history of physics, engineering, chemistry, astronomy and medicine, correlated with technological applications in the social context. When and how is tension between disciplines explicitly practised? What is the conceptual bridge between science researches and the organization of technological researches in the development of  industrial applications?  The authors explain various ways in which the sciences allowed advanced modelling on the one hand, and the development of new technological ideas on the other hand. An emphasis on the role played by mechanisms, production methods and instruments bestows a benefit on historical and scientific discourse: theories, institutions, universities, schools for engineers, social implications as well.  Scholars from different traditions discuss the emerging style of thinking in methodology and, in theoretical perspective, aim to gather and re-evaluate the current thinking on this subject. It brings together contribution...

  12. 49 CFR 237.101 - Scheduling of bridge inspections.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Scheduling of bridge inspections. 237.101 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.101 Scheduling of bridge inspections. (a) Each bridge management program shall include a provision for scheduling...

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  14. Engineer Ethics

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dae Sik; Kim, Yeong Pil; Kim, Yeong Jin

    2003-03-15

    This book tells of engineer ethics such as basic understanding of engineer ethics with history of engineering as a occupation, definition of engineering and specialized job and engineering, engineer ethics as professional ethics, general principles of ethics and its limitation, ethical theory and application, technique to solve the ethical problems, responsibility, safety and danger, information engineer ethics, biotechnological ethics like artificial insemination, life reproduction, gene therapy and environmental ethics.

  15. Engineer Ethics

    International Nuclear Information System (INIS)

    This book tells of engineer ethics such as basic understanding of engineer ethics with history of engineering as a occupation, definition of engineering and specialized job and engineering, engineer ethics as professional ethics, general principles of ethics and its limitation, ethical theory and application, technique to solve the ethical problems, responsibility, safety and danger, information engineer ethics, biotechnological ethics like artificial insemination, life reproduction, gene therapy and environmental ethics.

  16. The Bridge of Mandolin County

    Science.gov (United States)

    Lantz, Juliette M.; Feindt, Jenny E.; Lewellyn, Eric P. B.; Walczak, Mary M.

    1999-12-01

    The Bridge of Mandolin County is a case designed to teach the general chemistry principles of molar mass, ions and aqueous reactions, solubility rules, and inorganic nomenclature. Through the instructor-facilitated class discussion, students consider the options before the Mandolin Town Council regarding deicing the newly constructed bridge connecting Mandolin with a large nearby city. The students must decipher contradictory claims made on behalf of sodium chloride, the traditional deicer, and calcium magnesium acetate, a new environmentally friendly deicer, to arrive at the most cost-effective and environmentally appropriate deicing product. As they work through the analysis they raise questions that can be addressed in a laboratory setting. Four optional role-playing experiments are included, which can be used by the students to gather information helpful to resolution of the case. The case is intended to be used over two class periods, with a laboratory period in between, though suggestions for other models are provided. Laboratory procedures include an EDTA titration for Ca2+ and Mg2+, a gravimetric analysis, a qualitative examination of ions and solubility, an introduction to freezing point depression and measurement, and an experimental design activity. This case can also successfully be used without alteration in non-majors chemistry or environmental chemistry courses, or upper-level analytical or environmental chemistry courses.

  17. Study on complexity of Sutong Bridge's objectives system and its meta-synthesis management

    Institute of Scientific and Technical Information of China (English)

    Fa Yueping; Li Zhen

    2009-01-01

    Objectives define the boundaries of complex engineering system. It is a hard work to identify the specific objectives of a complex engineering system. The objectives system development needs a complicated process, from nix to prototype, and to final definition. The total process will cover the following course: from chaos to well-ordered; from qualitativeness to combination of quantitativeness and qualitativenss, then from qualitativeness to quantitativeness (a recurrent process), expert experience and theoretical science, rationality and sensibility, synthesis analysis and meta-synthesis, routinization and non-routinization. Such process is explicit in phase development yet overlapped; mutually confined yet mutuaLly independent; permeated conflicts yet pregnant in harmony. This article explores the complexity of Sutong Bridge's objectives development and the process of meta-synthesis in the Sutong Bridge engineering.

  18. Structural Performance of Light Weight Multicellular FRP Composite Bridge Deck Using Finite Element Analysis

    Institute of Scientific and Technical Information of China (English)

    Woraphot Prachasaree; Pongsak Sookmanee

    2012-01-01

    Fiber reinforced polymer (FRP) composite materials having advantages such as higher strength to weight than conventional engineering materials,non-corrosiveness and modularization,which should help engineers to obtain more efficient and cost effective structural materials and systems.Currently,FRP composites are becoming more popular in civil engineering applications.The objectives of this research are to study performance and behavior of light weight multi-cellular FRP composite bridge decks (both module and system levels) under various loading conditions through finite element modeling,and to validate analytical response of FRP composite bridge decks with data from laboratory evaluations.The relative deflection,equivalent flexural rigidity,failure load (mode) and load distribution factors (LDF) based on FE results have been compared with experimental data and discussed in detail.The finite element results showing good correlations with experimental data are presented in this work.

  19. Static and fatigue investigation of second generation steel free bridge decks

    International Nuclear Information System (INIS)

    This paper outlines the static and fatigue behavior of two different cast-in-place second generation steel-free bridge decks, which are: hybrid carbon fiber reinforced polymer (CFRP); and glass fiber reinforced polymer (GFRP) and steel strap design. Although cast monolithically, the first deck slab was divided into three segments with different reinforcement configurations. All three segments were tested under a 222kN cyclic loading to investigate fatigue behavior. The second bridge deck comprised an internal panel and two cantilevers and was equipped with a civionics system. The internal panel static test that this paper deals with is useful in the development of fatigue theory derived from fatigue testing of the first bridge deck. Test results form the cyclic loading of the first bridge deck indicated that the cross-sectional area of the reinforcement used in the test bridge deck can be reduced by 40% based on the reinforcement provided in the deck under service loads. The hybrid system also reduced the development of longitudinal crack widths to approximately 0.4 mm under service conditions, compared to the cracks that occurred approximately halfway between adjacent bridge girders that were determined to be roughly 1 mm in several first generation steel-free bridge decks constructed in Canada. Civionics, also discussed in the paper, is a new term coined from Civil-Electronics, which is the application of electronics to civil structures. The Civionics Specifications (2004) developed by ISIS Canada researchers are a helpful design tool for engineers and contractors to develop civionics and structural health monitoring systems for civil infrastructure that will last the lifetime of a structure. The use of civionics for the second test bridge deck ensured the survival of 100% of the 63 internal sensors throughout the rigors of the construction and casting of the deck. (author)

  20. Monitoring the dynamic behaviors of the Bosporus Bridge by GPS during Eurasia Marathon

    Science.gov (United States)

    Erdoǧan, H.; Akpınar, B.; Gülal, E.; Ata, E.

    2007-08-01

    Engineering structures, like bridges, dams and towers are designed by considering temperature changes, earthquakes, wind, traffic and pedestrian loads. However, generally, it can not be estimated that these structures may be affected by special, complex and different loads. So it could not be known whether these loads are dangerous for the structure and what the response of the structures would be to these loads. Such a situation occurred on the Bosporus Bridge, which is one of the suspension bridges connecting the Asia and Europe continents, during the Eurasia Marathon on 2 October 2005, in which 75 000 pedestrians participated. Responses of the bridge to loads such as rhythmic running, pedestrian walking, vehicle passing during the marathon were observed by a real-time kinematic (RTK) Global Positioning System (GPS), with a 2.2-centimeter vertical accuracy. Observed responses were discussed in both time domain and frequency domain by using a time series analysis. High (0.1-1 Hz) and low frequencies (0.00036-0.01172 Hz) of observed bridge responses under 12 different loads which occur in different quantities, different types and different time intervals were calculated in the frequency domain. It was seen that the calculated high frequencies are similar, except for the frequencies of rhythmic running, which causes a continuously increasing vibration. Any negative response was not determined, because this rhythmic effect continued only for a short time. Also when the traffic load was effective, explicit changes in the bridge movements were determined. Finally, it was seen that bridge frequencies which were calculated from the observations and the finite element model were harmonious. But the 9th natural frequency value of the bridge under all loads, except rhythmic running could not be determined with observations.

  1. Monitoring the dynamic behaviors of the Bosporus Bridge by GPS during Eurasia Marathon

    Directory of Open Access Journals (Sweden)

    H. Erdoğan

    2007-08-01

    Full Text Available Engineering structures, like bridges, dams and towers are designed by considering temperature changes, earthquakes, wind, traffic and pedestrian loads. However, generally, it can not be estimated that these structures may be affected by special, complex and different loads. So it could not be known whether these loads are dangerous for the structure and what the response of the structures would be to these loads. Such a situation occurred on the Bosporus Bridge, which is one of the suspension bridges connecting the Asia and Europe continents, during the Eurasia Marathon on 2 October 2005, in which 75 000 pedestrians participated. Responses of the bridge to loads such as rhythmic running, pedestrian walking, vehicle passing during the marathon were observed by a real-time kinematic (RTK Global Positioning System (GPS, with a 2.2-centimeter vertical accuracy. Observed responses were discussed in both time domain and frequency domain by using a time series analysis. High (0.1–1 Hz and low frequencies (0.00036–0.01172 Hz of observed bridge responses under 12 different loads which occur in different quantities, different types and different time intervals were calculated in the frequency domain. It was seen that the calculated high frequencies are similar, except for the frequencies of rhythmic running, which causes a continuously increasing vibration. Any negative response was not determined, because this rhythmic effect continued only for a short time. Also when the traffic load was effective, explicit changes in the bridge movements were determined. Finally, it was seen that bridge frequencies which were calculated from the observations and the finite element model were harmonious. But the 9th natural frequency value of the bridge under all loads, except rhythmic running could not be determined with observations.

  2. Determine of velocity field with PIV and CFD during the flow around of bridge piers

    Directory of Open Access Journals (Sweden)

    Picka D.

    2013-04-01

    Full Text Available The article describes the processing of specific junior research FAST-J-11-51/1456 which dealt with physical and CFD of the velocity field during the flow around of bridge piers. Physical modelling has been carried out in Laboratory of water management research in Institute of Water Structures in Brno University of Technology – Faculty of Civil Engineering. To measure of the velocity field in profile of bridge piers were used laser measuring method PIV (Particle Image Velocimetry. The results of PIV served as a basis for comparing experimental data with CFD results of this type of flow in the commercial software ANSYS CFX.

  3. WAVE CURRENT FORCES ON THE PILE GROUP OF BASE FOUNDATION FOR THE EAST SEA BRIDGE, CHINA

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    On the basis of the two structures of the bridge foundation designed for the East Sea Bridge, the wave current forces on four types of oblique piles, the pile group and the single piles at different positions in the pile group considering the effect of the super structures were experimentally investigated. The relationship between the wave current forces and the associated wave parameters, and the comparison of the wave current forces on the pile groups and the single piles were systematically analyzed. The group effectiveness and the reduction coefficient for the wave current forces on the group were examined for engineering design.

  4. Four Engineers...

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    There are four engineers traveling in a car;a mechanical engineer,a chemical engi-neer,an electrical engineer and a comput-er engineer.The car breaks down.“Sounds to me as if the pistons have seized.We ll have to strip down the engine before we canget the car working again,”says the mechanical

  5. Characterization of material for civil engineering

    OpenAIRE

    Cappelletto, Elisa

    2014-01-01

    Materials are the heart of engineering, which can be defined as the creative and rational use of materials for practical purposes. Materials have had an essential role in the development of civil engineering: from the beginning of human evolution, man has used many different materials to build houses, bridges, roads and countless other structures to make his life easier. Ancient populations used the raw materials at their disposal, such as stone, clay and timber. Over the centuries, the searc...

  6. 20 Engineering Technologies Which Changed The World

    Energy Technology Data Exchange (ETDEWEB)

    Lee, In Sik; Shin, Dong Won; Mun, Jung Yang and others

    2004-07-15

    This book deals with 20 engineering technologies which changed the world, these are about a, compass, papermaking, a lens, gunpowder, machine watch, printing technique, vaccine, a suspension bridge, a railroad, a loom, photograph, petroleum, automobile, electricity, wireless communications, synthetic medicine, a jet engine and a rocket, nuclear bombs, ENIAC, and polymerase chain reaction method. Each skill is introduced with history and the detailed reports by other persons.

  7. Bridge Lock-up Device System

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    The Colebrand Lock-up Device (LUD) provides additional substructure strength to resist seismic forces as a structural shock transmission unit for highway bridges. This system can provide a temporary rigid link between bridge structural members under seismic, braking, or other fast-acting type loads, while permitting slow thermal movements.

  8. Paul Dirac:. Building Bridges of the Mind

    Science.gov (United States)

    Brown, Laurie M.

    2003-12-01

    Paul Dirac was a brilliant and original thinker. He used his physical intuition and his ideal of mathematical beauty to construct bridges between major areas of physics. This article discusses several such important works, including the bridge between quantum mechanics and relativity that led to his prediction of the existence of antimatter.

  9. History of cable-stayed bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

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

  10. COUPLING VIBRATION OF VEHICLE-BRIDGE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    陈炎; 黄小清; 马友发

    2004-01-01

    By applying the sinusoidal wave mode to simulate the rugged surface of bridge deck,accounting for vehicle-bridge interaction and using Euler-Bernoulli beam theory, a coupling vibration model of vehicle-bridge system was developed. The model was solved by mode analyzing method and Runge-Kutta method, and the dynamic response and the resonance curve of the bridge were obtained. It is found that there are two resonance regions, one represents the main resonance while the other the minor resonance, in the resonance curve. The influence due to the rugged surface, the vibration mode of bridge, and the interaction between vehicle and bridge on vibration of the system were discussed. Numerical results show that the influence due to these parameters is so significant that the effect of roughness of the bridge deck and the mode shape of the bridge can't be ignored and the vehicle velocity should be kept away from the critical speed of the vehicle.

  11. A STUDY OF BARRIERS IN BRIDGING COMMUNICATION

    OpenAIRE

    Niteen V. Dandekar

    2014-01-01

    The main objective of this paper is to make a thought provoking discussion on the role barriers in bridging communication. It focuses on the concept of communication, process and the role of language related barriers in bridging communication. It studies the significance of communication in modern human life.

  12. General framework for bridge life cycle design

    Institute of Scientific and Technical Information of China (English)

    Junhai MA; Airong CHEN; Jun HE

    2009-01-01

    Based on a detailed illustration for bridge life cycle design which comprises the processes of service life design, aesthetics design, performance design, environ-mental and ecological design, inspection, maintenance and repair design as well as cost analysis, this paper presented a general framework for bridge life cycle design comprising three design phases and six design processes.

  13. Active aerodynamic stabilisation of long suspension bridges

    DEFF Research Database (Denmark)

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

    2004-01-01

    The paper describes the addition of actively controlled appendages (flaps) attached along the length of the bridge deck to dampen wind-induced oscillations in long suppension bridges. A novel approach using control systems methods for the analysis of dynamic stability is presented. In order to ma...

  14. Lifetime Reliability Assessment of Concrete Slab Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  15. Re-Assessment of Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  16. Optimum Maintenance Strategies for Highway Bridges

    DEFF Research Database (Denmark)

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

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

  17. The I-35W bridge Project Website

    DEFF Research Database (Denmark)

    Kampf, Constance

    How can websites be used to rebuild trust?  In August 2007, the Interstate Highway 35-W bridge in Minneapolis, MN collapsed during rush hour.  Although many people were rescued and casualties were as limited as could be expected due to quick and effective intervention, the image of a major bridge...... 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......, and the use of multimodal features.  This paper looks at the I35-W bridge reconstruction project in Minneapolis through web-based communication by the Minnesota Department of Transportation (MnDOT) about the project. The MnDOT bridge reconstruction website will be examined using a combination of 1). Weick...

  18. Translational Approaches in Tissue Engineering and Regenerative Medicine

    CERN Document Server

    Mao, Jeremy J

    2007-01-01

    This landmark book identifies the current and forthcoming roadblocks to scientific research and technological development in stem cell research, tissue engineering, wound healing, and in-vivo animal models. The book is the first to focus on the translational aspect of tissue engineering and regenerative medicine and bridges the gap between laboratory discovery and clinical applications.

  19. Desirable engineering features of the next-generation tokamak device

    International Nuclear Information System (INIS)

    Recent scoping studies examined a series of superconducting, long-pulse Driven Current Tokamak (DCT) devices. One class of options is an ignited, D-T burning device designated DCT-8. It was concluded that the DCT-8 is a most attracttive engineering option to adequately bridge the gap between the Tokamak Fusion Test Reactor (TFTR) and the Engineering Test Reactor

  20. Engineering Special

    OpenAIRE

    Duca, Edward

    2013-01-01

    Smart phones, supersonic planes, Formula 1 cars, green cities, the Internet; engineers built them all. Engineers are everywhere. The world needs them and so do you. http://www.um.edu.mt/think/engineering-special-feature-editorial/

  1. Modified Geometry of Transition Slabs for Integral Bridges

    OpenAIRE

    Dreier, Damien

    2010-01-01

    Over the past decades, an increasing number of integral bridges have been built. This type of bridge offers various advantages in comparison with standard bridges equipped with expansion joints and bearings. In particular, integral bridges require less maintenance since they require less mechanical elements. Transition slabs, which are used in integral bridges, are directly connected to the bridge deck and therefore they are subjected to large displacements caused by creep, shrinkage and temp...

  2. Building bridges … and accelerators

    CERN Multimedia

    2009-01-01

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

  3. Root coverage with bridge flap

    Directory of Open Access Journals (Sweden)

    Pushpendra Kumar Verma

    2013-01-01

    Full Text Available Gingival recession in anterior teeth is a common concern due to esthetic reasons or root sensitivity. Gingival recession, especially in multiple anterior teeth, is of huge concern due to esthetic reasons. Various mucogingival surgeries are available for root coverage. This case report presents a new bridge flap technique, which allows the dentist not only to cover the previously denuded root surfaces but also to increase the zone of attached gingiva at a single step. In this case, a coronally advanced flap along with vestibular deepening technique was used as root coverage procedure for the treatment of multiple recession-type defect. Here, vestibular deepening technique is used to increase the width of the attached gingiva. The predictability of this procedure results in an esthetically healthy periodontium, along with gain in keratinized tissue and good patient′s acceptance.

  4. Scour and Scour Countermeasures at Bridge Sites

    Institute of Scientific and Technical Information of China (English)

    CHIEW Yee-Meng

    2008-01-01

    This paper examines scour and scour countermeasures at bridge piers and abutments.Abutment scour is by far more complex than its counterpart associated with piers because of the possibility of the presence of a floodplain. Notwithstanding this, the mechanism of scour at both piers and abutments is very similar; moreover, the failure mechanisms associated with both armor-ing and flow-altering countermeasures are not very different. In rivers with a floodplain, abutment scour becomes much more complex. In cases where the abutment ends at or near to the flood-plain, it can initiate bank erosion, which clearly is an important erosion problem that is quite distinct from the customary scour at either an abutment in rivers without a floodplain or a pier. For this rea-son, abutment scour can be very site-specific while pier-scour is more generic in nature. To this end, the ability to identify the type of abutment scour that may form in a particular channel is closely related to an engineer's ability to propose devices for effective scour countermeasure.By summarizing research efforts on using riprap as a pier or abutment countermeasure over the past few decades, this paper highlights the deficiencies of riprap in arresting pier scour. To this end,different failure mechanisms are identified. They are shear failure, winnowing failure, edge failure,bedform-induced failure and bed-degradation induced failure. Each failure mechanism can singly or, more likely, combine to cause the eventual breakdown of the riprap layer. The study shows that a riprap layer is vulnerable to other failure mechanisms even though it is adequately designed against shear failure, rendering it ineffective in arresting scour.

  5. A comparative study between China and U.S. on seismic design philosophy and practice of a long span arch bridge

    Institute of Scientific and Technical Information of China (English)

    Xu Yan; George C Lee; Fan Lichu; Hu Shide

    2006-01-01

    This paper presents the first of a series of case studies on the seismic design of long span bridges (cablestayed bridges, suspension bridges and arch bridges) under a cooperative research project on seismic behavior and design of highway bridges between the State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University and the Multidisciplinary Center for Earthquake Engineering Research, University at Buffalo. The objective of this series of case studies is to examine the differences and similarities on the seismic design practice of long span bridges in China and the U.S., to identify research needs and to develop design guidelines beneficial to bridge engineers in both countries. Unlike short to medium span bridges, long span bridges are not included in most seismic design specifications, mainly because they are location dependent and structurally unique. In this paper, an available model of a steel tied half through arch bridge with a main span of 550m in China is discussed. Analysis is focused on comparisons of the seismic responses due to different ground motions. Seismic design criteria and seismic performance requirements for long span bridges in both countries were first introduced and compared, and then three near field earthquake records with large vertical components were selected as the excitations to examine the seismic behavior and seismic vulnerability of the bridge. Results show that (1) the selected near field ground motions cause larger responses to key components (critical sections) of the bridge (such as arch rib ends) with a maximum increase of more than twice those caused by the site specific ground motions; (2) piers, longitudinal girders and arch crowns are more vulnerable to vertical motions, especially their axial forces; and (3) large vertical components of near field ground motions may not significantly affect the bridge's internal forces provided that their peak acceleration spectra ordinates only appear at periods

  6. Engineering Ethics In Islam: An Evaluative And Comparative Study Between Code Of Ethics Of Institution Of Engineers, Bangladesh (Ieb) And Code Of Professional Conduct Of Board Of Engineers Malaysia (BEM)

    OpenAIRE

    Muhammad Amanullah

    2012-01-01

    During the past two centuries or so a number of buildings and bridges had been structurally failed and collapsed all over the world. Some of these incidents caused a sizeable number of human casualties. For instance, collapse of Tay Bridge in 1879 killed at least sixty persons. Beside the problems related to their design and construction, probably the failure to follow engineering ethics properly was partially responsible for these incidents. Growing engineering professionalism during the ni...

  7. Multi-objective optimization design of bridge piers with hybrid heuristic algorithms

    Institute of Scientific and Technical Information of China (English)

    Francisco J. MARTINEZ-MARTIN; Femando GONZALEZ-VIDOSA; Antonio HOSPITALER; Victor YEPES

    2012-01-01

    This paper describes one approach to the design of reinforced concrete (RC) bridge piers,using a three-hybrid multiobjective simulated annealing (SA) algorithm with a neighborhood move based on the mutation operator from the genetic algorithms (GAs),namely MOSAMO1,MOSAMO2 and MOSAMO3.The procedure is applied to three objective functions:the economic cost,the reinforcing steel congestion and the embedded CO2 emissions.Additional results for a random walk and a descent local search multi-objective algorithm are presented.The evaluation of solutions follows the Spanish Code for structural concrete.The methodology was applied to a typical bridge pier of 23,97 m in height.This example involved 110 design variables.Results indicate that algorithm MOSAMO2 outperforms other algorithms regarding the definition of Pareto fronts.Further,the proposed procedure will help structural engineers to enhance their bridge pier designs.

  8. Vibration monitoring of long bridges and their expansion joints and seismic devices

    Directory of Open Access Journals (Sweden)

    Islami Kleidi

    2015-01-01

    Full Text Available This paper presents a number of recently installed Structural Health Monitoring (SHM systems: a on a 2km double suspension bridge; b on a long railway viaduct that has experienced cracking; and c on a steel arch bridge in a seismically active area. Damage detection techniques have been applied based on high-frequency measurements of vibrations, pressure and strain, enabling a proper understanding of the structures’ behaviour to be gained. The diverse range of applications presented, designed in collaboration with structure owners and design engineers, includes damage detection on expansion joints of suspension bridges, crack analysis and correlation with accelerations of high-speed trains, and high-frequency performance monitoring of seismic devices. These case studies, based on both static and dynamic approaches, demonstrate the usefulness and ease of use of such systems, and the enormous gains in efficiency they offer.

  9. Real-time visualization of bridge structural response through wireless MEMS sensors

    Science.gov (United States)

    Chung, Hung-Chi; Enomoto, Tomoyuki; Loh, Kenneth; Shinozuka, Masanobu

    2004-07-01

    This study investigates the reliability and accuracy of wireless micro-electromechanical-system (MEMS)-type sensors in application of bridge structural vibration monitoring. With wireless capabilities added onto the developed sensors, it becomes unnecessary for engineers to connect enormous lengths of cables in order to measure vibration on bridges for instance. We investigated two types of MEMS accelerometers: the ADXL 202E and the Silicon Design 2210. To prove the validity of measuring acceleration by using these devices with wireless communication, we succeeded on measuring a pedestrian bridge's vibration under excitation loads in the center of span. The result had been compared with the traditional cabled sensor, PCB 393C. The wireless sensors were showed to be effective and much affordable to carry out the monitoring missions in situ.

  10. Engineering and Software Engineering

    Science.gov (United States)

    Jackson, Michael

    The phrase ‘software engineering' has many meanings. One central meaning is the reliable development of dependable computer-based systems, especially those for critical applications. This is not a solved problem. Failures in software development have played a large part in many fatalities and in huge economic losses. While some of these failures may be attributable to programming errors in the narrowest sense—a program's failure to satisfy a given formal specification—there is good reason to think that most of them have other roots. These roots are located in the problem of software engineering rather than in the problem of program correctness. The famous 1968 conference was motivated by the belief that software development should be based on “the types of theoretical foundations and practical disciplines that are traditional in the established branches of engineering.” Yet after forty years of currency the phrase ‘software engineering' still denotes no more than a vague and largely unfulfilled aspiration. Two major causes of this disappointment are immediately clear. First, too many areas of software development are inadequately specialised, and consequently have not developed the repertoires of normal designs that are the indispensable basis of reliable engineering success. Second, the relationship between structural design and formal analytical techniques for software has rarely been one of fruitful synergy: too often it has defined a boundary between competing dogmas, at which mutual distrust and incomprehension deprive both sides of advantages that should be within their grasp. This paper discusses these causes and their effects. Whether the common practice of software development will eventually satisfy the broad aspiration of 1968 is hard to predict; but an understanding of past failure is surely a prerequisite of future success.

  11. Engineering ceramics

    CERN Document Server

    Bengisu, Murat

    2001-01-01

    This is a comprehensive book applying especially to junior and senior engineering students pursuing Materials Science/ Engineering, Ceramic Engineering and Mechanical Engineering degrees. It is also a reference book for other disciplines such as Chemical Engineering, Biomedical Engineering, Nuclear Engineering and Environmental Engineering. Important properties of most engineering ceramics are given in detailed tables. Many current and possible applications of engineering ceramics are described, which can be used as a guide for materials selection and for potential future research. While covering all relevant information regarding raw materials, processing properties, characterization and applications of engineering ceramics, the book also summarizes most recent innovations and developments in this field as a result of extensive literature search.

  12. Assessing potential scour using the South Carolina bridge-scour envelope curves

    Science.gov (United States)

    Benedict, Stephen T.; Feaster, Toby D.; Caldwell, Andral

    2016-09-30

    SummaryBridge-scour equations presented in the Federal Highway Administration Hydraulic Engineering Circular No. 18 reflect the current state-of-the practice for predicting scour at bridges. Although these laboratory-derived equations provide an important resource for assessing scour potential, there is a measure of uncertainty when applying these equations to field conditions. The uncertainty and limitations have been acknowledged by laboratory researchers and confirmed in field investigations.Because of the uncertainty associated with bridge-scour equations, HEC-18 recommends that engineers evaluate the computed scour depths obtained from the equations and modify the resulting data if they appear unreasonable. Perhaps the best way to evaluate the reasonableness of predicted scour is to compare it to field measurements of historic scour. Historic field data show scour depths resulting from high flows and provide a reference for evaluating predicted scour. It is rare, however, that such data are available at or near a site of interest, making the evaluation of predicted scour as compared to field data difficult if not impossible. Realizing the value of historic scour measurements, the U.S. Geological Survey (USGS), in cooperation with the South Carolina Department of Transportation (SCDOT), conducted a series of three field investigations to collect historic scour data with the goal of understanding regional trends of scour at riverine bridges in South Carolina.Historic scour measurements, including measurements of clear-water abutment, contraction, and pier scour, as well as live-bed contraction and pier scour, were made at more than 200 bridges. These field investigations provided valuable insights into regional scour trends and yielded regional bridge-scour envelope curves that can be used as supplementary tools for assessing all components of scour at riverine bridges in South Carolina.The application and limitations of these envelope curves were documented in

  13. Oscillations in a sunspot with light bridges

    CERN Document Server

    Yuan, Ding; Huang, Zhenghua; Li, Bo; Su, Jiangtao; Yan, Yihua; Tan, Baolin

    2014-01-01

    Solar Optical Telescope onboard Hinode observed a sunspot (AR 11836) with two light bridges (LBs) on 31 Aug 2013. We analysed a 2-hour \\ion{Ca}{2} H emission intensity data set and detected strong 5-min oscillation power on both LBs and in the inner penumbra. The time-distance plot reveals that 5-min oscillation phase does not vary significantly along the thin bridge, indicating that the oscillations are likely to originate from the underneath. The slit taken along the central axis of the wide light bridge exhibits a standing wave feature. However, at the centre of the wide bridge, the 5-min oscillation power is found to be stronger than at its sides. Moreover, the time-distance plot across the wide bridge exhibits a herringbone pattern that indicates a counter-stream of two running waves originated at the bridge sides. Thus, the 5-min oscillations on the wide bridge also resemble the properties of running penumbral waves. The 5-min oscillations are suppressed in the umbra, while the 3-min oscillations occupy...

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

    Directory of Open Access Journals (Sweden)

    Rong Chen

    2013-01-01

    Full Text Available Taking arch bridges, including deck, half-through, and through arch bridges (short for DAB, HTAB, and TAB as examples, mechanics analysis models of longitudinal interaction between continuously welded rails (short for CWRs and arch bridges are established. Based on the finite element method (FEM, the longitudinal interaction calculation software of CWR on arch bridges has been developed. Focusing on an HTAB, the tension, compression, and deflection conditions are calculated and analyzed. The results show that the mechanics analysis models of three types of arch bridges can truly reflect the real state of the structure; the calculation software can be used for systematic research of the CWR on arch bridge; as for HTAB, temperature difference of arch rib has a small effect on rail tension/compression, and arch bridge can be simplified as a continuous beam for rail tension/compression additional force calculation; in calculation of deflection conditions of HTAB, it is suggested that train loads are arranged on half span and full span and take the direction of load entering bridge into account. Additionally, the deflection additional force variation of CFST basket handle arch bridge is different from that of ordinary bridge.

  15. Probabilistic Corrosion Service Life Model of Concrete Bridge Exposed to Chloride Deicer Salts

    Directory of Open Access Journals (Sweden)

    Cristian-Claudiu Comisu

    2005-01-01

    Full Text Available A model to determine the time till first repair and subsequent rehabilitation of concrete bridge decks exposed to chloride deicer salts that recognizes and incorporates the statistical nature of factors affecting the corrosion process, consists of the following serial phases: diffusion to the depth of the steel that would precipitate first maintenance actions; corrosion of the steel at the first maintenance depth until cracking and spalling occurs; continuous spalling until a damage level is reached which is defined as the end of functional service life for the deck of concrete bridge. The model expands on an existing deterministic model using statistical computing techniques, including resampling techniques such as the parametric and simple bootstrap. Emphasis was placed on the diffusion portion of the diffusion-cracking model, but advances can be readily included for the time for corrosion deterioration after corrosion initiation. The diffusion phase is described by Fick’s law and the boundary conditions define the solution form. The time till cracking model depends upon some factors as concrete strength properties, cover depth and corrosion rate. Corrosion rate has a significant influence on the time to cracking which typically occurs in three to seven years after initiation. Service life model that predict the time to first repair and rehabilitation of concrete bridge decks provide a useful tool for comparing the effectiveness measures and provide bridge engineers with a useful planning tool. A service life model for the corrosion of concrete bridge deck in chloride laden environments is proposed. The aim of this paper is to enhance the awareness among the engineering community to use the model to determine the time till first repair and subsequent rehabilitation of concrete bridge decks exposed to chloride deicer salts in Romania.

  16. Signal and noise in bridging PCR

    Directory of Open Access Journals (Sweden)

    Thaler David S

    2002-07-01

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

  17. 上承式拱梁组合桥设计%Design of combined deck type arch bridge

    Institute of Scientific and Technical Information of China (English)

    严国香

    2012-01-01

    结合某桥的工程地理位置及沿河景观要求,对该桥的结构设计特点、构造与施工要点等进行了简要介绍,目前该桥运营情况良好,并取得了一定的经济、社会效益,为同类型桥梁施工积累宝贵经验。%This paper synthesized the engineering geographic location and river landscape requirements of a bridge,simply introduced the structure design features,structure and construction key points of this bridge,present the bridge was operating in good condition,and achieved certain economic,social effect,accumulated valuable experience for the same type bridge construction.

  18. Traveling wave effect on the seismic response of a steel arch bridge subjected to near fault ground motions

    Institute of Scientific and Technical Information of China (English)

    Xu Yan; George C Lee

    2007-01-01

    In the 1990s, several major earthquakes occurred throughout the world, with a common observation that near fault ground motion (NFGM) characteristics had a distinct impact on causing damage to civil engineering structures that could not be predicted by using far field ground motions. Since then, seismic responses of structures under NFGMs have been extensively examined, with most of the studies focusing on structures with relatively short fundamental periods, where the traveling wave effect does not need to be considered. However, for long span bridges, especially arch bridges, the traveling wave (only time delay considered) effect may be very distinct and is therefore important. In this paper, the results from a case study on the seismic response of a steel arch bridge under selected NFGMs is presented by considering the traveling wave effect with variable apparent velocities. The effects of fling step and long period pulses of NFGMs on the seismic responses of the arch bridge are also discussed.

  19. Human Errors and Bridge Management Systems

    DEFF Research Database (Denmark)

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

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

  20. Building the Clinical Bridge: An Australian Success

    Directory of Open Access Journals (Sweden)

    Marianne Wallis

    2012-01-01

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

  1. Building the clinical bridge: an Australian success.

    Science.gov (United States)

    Wallis, Marianne; Chaboyer, Wendy

    2012-01-01

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

  2. Maxwell Tension Supports the Water Bridge

    OpenAIRE

    Widom, A.; Srivastava, Y. N.; Swain, J.; Sivasubramanian, S.

    2008-01-01

    A cylindrical flexible cable made up of pure fluid water can be experimentally spanned across a spatial gap with cable endpoints fixed to the top edges of two glass beakers. The cable has been called a water bridge in close analogy to iron cables employed to build ordinary span bridges. A necessary condition for the construction of a water bridge is that a large electric field exists parallel to and located within the water cable. Presently, there is no accepted detailed theory which quantita...

  3. Pilot testing of a hydraulic bridge exciter

    OpenAIRE

    Andersson Andreas; Ülker-Kaustell Mahir; Borg Richard; Dymén Olivier; Carolin Anders; Karoumi Raid

    2015-01-01

    This paper describes the development of a hydraulic bridge exciter and its first pilot testing on a full scale railway bridge in service. The exciter is based on a hydraulic load cylinder with a capacity of 50 kN and is intended for controlled dynamic loading up to at least 50 Hz. The load is applied from underneath the bridge, enabling testing while the railway line is in service. The system is shown to produce constant load amplitude even at resonance. The exciter is used to experimentally ...

  4. Field measurement on wind characteristic and buffeting response of the Runyang Suspension Bridge during typhoon Matsa

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; LI AiQun; GUO Tong; XIE Jing

    2009-01-01

    Field measurement on wind characteristic and buffeting response of existing bridge is of great value to the development of bridge wind engineering, and the structural health monitoring system (SHMS) em-ployed in many long-span bridges provide a research basis for the field measurement. In order to pro-vide reliable basis for wind resistant evaluation of Runyang Suspension Bridge (RSB), two anemome-ters and 85 accelerometers were installed in the SliMS of RSB. In August 2005, Typhoon Matsa crossed over Jiangsu, the SHMS timely recorded the typhoon and structural vibration responses. In this paper by using the time-frequency technique and statistical theory, the recorded data were analyzed to obtain the strong wind characteristics, the buffeting response characteristics of the cable and deck, and the variation of buffeting response RMS versus wind speed. Results obtained in this study can be em-ployed to validate the credibility of current buffeting response analysis theory techniques, and provide reference values for wind resistant evaluation of other long-span bridges.

  5. Fatigue Performance Assessment of Composite Arch Bridge Suspenders Based on Actual Vehicle Loads

    Directory of Open Access Journals (Sweden)

    Bin Chen

    2015-01-01

    Full Text Available In the through arch bridges, the suspenders are the key components connecting the arch rib and the bridge deck in the middle, and their safety is an increasing focus in the field of bridge engineering. In this study, various vehicle traffic flow parameters are investigated based on the actual vehicle data acquired from the long-term structural health monitoring system of a composite arch bridge. The representative vehicle types and the probability density functions of several parameters are determined, including the gross vehicle weight, axle weight, time headway, and speed. A finite element model of the bridge structure is constructed to determine the influence line of the cable force for various suspenders. A simulated vehicle flow, generated using the Monte Carlo method, is applied on the influence lines of the target suspender to determine the stress process, and then the stress amplitude spectrum is obtained based on the statistical analysis of the stress process using the rainflow counting method. The fatigue performance levels of various suspenders are analyzed according to the Palmgren-Miner linear cumulative damage theory, which helps to manage the safety of the suspenders.

  6. Field measurement on wind characteristic and buffeting response of the Runyang Suspension Bridge during typhoon Matsa

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Field measurement on wind characteristic and buffeting response of existing bridge is of great value to the development of bridge wind engineering,and the structural health monitoring system(SHMS) em-ployed in many long-span bridges provide a research basis for the field measurement.In order to pro-vide reliable basis for wind resistant evaluation of Runyang Suspension Bridge(RSB),two anemome-ters and 85 accelerometers were installed in the SHMS of RSB.In August 2005,Typhoon Matsa crossed over Jiangsu,the SHMS timely recorded the typhoon and structural vibration responses.In this paper by using the time-frequency technique and statistical theory,the recorded data were analyzed to obtain the strong wind characteristics,the buffeting response characteristics of the cable and deck,and the variation of buffeting response RMS versus wind speed.Results obtained in this study can be em-ployed to validate the credibility of current buffeting response analysis theory techniques,and provide reference values for wind resistant evaluation of other long-span bridges.

  7. Institute-Industry Interoperation Model: An Industry-Oriented Engineering Education Strategy in China

    Science.gov (United States)

    Wang, Yanqing; Qi, Zhongying; Li, Ziru; Zhang, Lijie

    2011-01-01

    Engineering education has been well implemented in the majority of developed countries such as the USA, Germany, and the United Kingdom so that the gap between engineering science and engineering practice is greatly bridged. However, in China, the gap still exists, and some attempts by Chinese government, even though having made obvious progress,…

  8. Remote Bridge Deflection Measurement Using an Advanced Video Deflectometer and Actively Illuminated LED Targets.

    Science.gov (United States)

    Tian, Long; Pan, Bing

    2016-01-01

    An advanced video deflectometer using actively illuminated LED targets is proposed for remote, real-time measurement of bridge deflection. The system configuration, fundamental principles, and measuring procedures of the video deflectometer are first described. To address the challenge of remote and accurate deflection measurement of large engineering structures without being affected by ambient light, the novel idea of active imaging, which combines high-brightness monochromatic LED targets with coupled bandpass filter imaging, is introduced. Then, to examine the measurement accuracy of the proposed advanced video deflectometer in outdoor environments, vertical motions of an LED target with precisely-controlled translations were measured and compared with prescribed values. Finally, by tracking six LED targets mounted on the bridge, the developed video deflectometer was applied for field, remote, and multipoint deflection measurement of the Wuhan Yangtze River Bridge, one of the most prestigious and most publicized constructions in China, during its routine safety evaluation tests. Since the proposed video deflectometer using actively illuminated LED targets offers prominent merits of remote, contactless, real-time, and multipoint deflection measurement with strong robustness against ambient light changes, it has great potential in the routine safety evaluation of various bridges and other large-scale engineering structures. PMID:27563901

  9. Remote Bridge Deflection Measurement Using an Advanced Video Deflectometer and Actively Illuminated LED Targets

    Science.gov (United States)

    Tian, Long; Pan, Bing

    2016-01-01

    An advanced video deflectometer using actively illuminated LED targets is proposed for remote, real-time measurement of bridge deflection. The system configuration, fundamental principles, and measuring procedures of the video deflectometer are first described. To address the challenge of remote and accurate deflection measurement of large engineering structures without being affected by ambient light, the novel idea of active imaging, which combines high-brightness monochromatic LED targets with coupled bandpass filter imaging, is introduced. Then, to examine the measurement accuracy of the proposed advanced video deflectometer in outdoor environments, vertical motions of an LED target with precisely-controlled translations were measured and compared with prescribed values. Finally, by tracking six LED targets mounted on the bridge, the developed video deflectometer was applied for field, remote, and multipoint deflection measurement of the Wuhan Yangtze River Bridge, one of the most prestigious and most publicized constructions in China, during its routine safety evaluation tests. Since the proposed video deflectometer using actively illuminated LED targets offers prominent merits of remote, contactless, real-time, and multipoint deflection measurement with strong robustness against ambient light changes, it has great potential in the routine safety evaluation of various bridges and other large-scale engineering structures. PMID:27563901

  10. Neural Engineering

    Science.gov (United States)

    He, Bin

    About the Series: Bioelectric Engineering presents state-of-the-art discussions on modern biomedical engineering with respect to applications of electrical engineering and information technology in biomedicine. This focus affirms Springer's commitment to publishing important reviews of the broadest interest to biomedical engineers, bioengineers, and their colleagues in affiliated disciplines. Recent volumes have covered modeling and imaging of bioelectric activity, neural engineering, biosignal processing, bionanotechnology, among other topics.

  11. Mechanical engineering

    CERN Document Server

    Darbyshire, Alan

    2010-01-01

    Alan Darbyshire's best-selling text book provides five-star high quality content to a potential audience of 13,000 engineering students. It explains the most popular specialist units of the Mechanical Engineering, Manufacturing Engineering and Operations & Maintenance Engineering pathways of the new 2010 BTEC National Engineering syllabus. This challenging textbook also features contributions from specialist lecturers, ensuring that no stone is left unturned.

  12. Allegheny County-Owned Bridges Points

    Data.gov (United States)

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

  13. Allegheny County-Owned Bridges Centerlines

    Data.gov (United States)

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

  14. Assessment of the Reliability of Concrete Bridges

    DEFF Research Database (Denmark)

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

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

  15. Pilot testing of a hydraulic bridge exciter

    Directory of Open Access Journals (Sweden)

    Andersson Andreas

    2015-01-01

    Full Text Available This paper describes the development of a hydraulic bridge exciter and its first pilot testing on a full scale railway bridge in service. The exciter is based on a hydraulic load cylinder with a capacity of 50 kN and is intended for controlled dynamic loading up to at least 50 Hz. The load is applied from underneath the bridge, enabling testing while the railway line is in service. The system is shown to produce constant load amplitude even at resonance. The exciter is used to experimentally determine frequency response functions at all sensor locations, which serve as valuable input for model updating and verification. An FE-model of the case study bridge has been developed that is in good agreement with the experimental results.

  16. Practical Approach to Fragility Analysis of Bridges

    Directory of Open Access Journals (Sweden)

    Yasamin Rafie Nazari

    2012-12-01

    Full Text Available Damages during past earthquakes reveal seismic vulnerability of bridge structures and the necessity of probabilistic approach toward seismic performance evaluation of bridges and its interpretation in terms of decision variables such as repair cost, downtime and life loss. This Procedure involves hazard analysis, structural analysis, damage analysis and loss analysis. The purpose of present study is reviewing different methods developed to derive fragility curves for damage analysis of bridges and demonstrating a simple procedure for fragility analysis using Microsoft Office Excel worksheet to reach probability of occurring predefined level of damage due to different levels of seismic demand parameters. The input of this procedure is the intensity of ground motion and the output is an appropriate estimate of the expected damage. Different observed damages of the bridges are discussed and compared the practical definition of damage states. Different methods of fragility analyses are discussed and a practical step by step example is illustrated.

  17. Tensegrity modules for pedestrian bridges

    OpenAIRE

    Rhode-Barbarigos, Landolf; Bel Hadj Ali, Nizar; MOTRO, RENE; Smith, Ian F.C.

    2009-01-01

    p. 2221-2232 Tensegrity systems are spatial structures composed of tensile and compression components in a self-equilibrated state of prestress. The tensegrity concept offers good structural efficiency and results in modular and lightweight structures. Research into tensegrity systems has resulted in reliable techniques for form finding and structural analysis. However, designing tensegrity systems for structural engineering applications is not yet part of mainstream structural design. Ind...

  18. Identifying hidden sexual bridging communities in Chicago.

    Science.gov (United States)

    Youm, Yoosik; Mackesy-Amiti, Mary Ellen; Williams, Chyvette T; Ouellet, Lawrence J

    2009-07-01

    Bridge populations can play a central role in the spread of human immunodeficiency virus (HIV) by providing transmission links between higher and lower prevalence populations. While social network methods are well suited to the study of bridge populations, analyses tend to focus on dyads (i.e., risk between drug and/or sex partners) and ignore bridges between distinct subpopulations. This study takes initial steps toward moving the analysis of sexual network linkages beyond individual and risk group levels to a community level in which Chicago's 77 community areas are examined as subpopulations for the purpose of identifying potential bridging communities. Of particular interest are "hidden" bridging communities; that is, areas with above-average levels of sexual ties with other areas but whose below-average AIDS prevalence may hide their potential importance for HIV prevention. Data for this analysis came from the first wave of recruiting at the Chicago Sexual Acquisition and Transmission of HIV Cooperative Agreement Program site. Between August 2005 through October 2006, respondent-driven sampling was used to recruit users of heroin, cocaine, or methamphetamine, men who have sex with men regardless of drug use, the sex partners of these two groups, and sex partners of the sex partners. In this cross-sectional study of the sexual transmission of HIV, participants completed a network-focused computer-assisted self-administered interview, which included questions about the geographic locations of sexual contacts with up to six recent partners. Bridging scores for each area were determined using a matrix representing Chicago's 77 community areas and were assessed using two measures: non-redundant ties and flow betweenness. Bridging measures and acquired immunodeficiency syndrome (AIDS) case prevalence rates were plotted for each community area on charts representing four conditions: below-average bridging and AIDS prevalence, below-average bridging and above

  19. Inspection Based Evaluation of a Danish Road Bridge

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  20. TMACS test procedure TP012: Panalarm software bridge

    International Nuclear Information System (INIS)

    This Test Procedure addresses the testing of the functionality of the Tank Monitor and Control System (TMACS) Panalarm bridge software. The features to be tested are: Bridge Initialization Options; Bridge Communication; Bridge Performance; Testing Checksum Errors; and Testing Command Reject Errors. Only the first three could be tested; the last two have been deferred to a later date

  1. Assessment of a Bridge WIM System on Integral Concrete Bridges and on Steel Orthotropic Decks

    OpenAIRE

    Ieng, Sio Song; SCHMIDT, Franziska; ROMBONI, Frédéric; Jacob, Bernard

    2011-01-01

    Bridge-Weigh-In-Motion uses bridges as a scale to weigh vehicles. Practically, this is done by measuring the strains in that bridge, and relating them to the weight and dimensions of a truck called “calibration trucks” whose shape and axle weights are well known. This article summarizes different B-WIM experiments the institute IFSTTAR (formerly called LCPC) realized and the lessons drawn from this experience. First, the system has been tested on frame-type bridges with integral s...

  2. Experimental study of single span railway bridges

    OpenAIRE

    Rigueiro, Constança; Rebelo, C.; Silva, L. Simões da

    2007-01-01

    The main purpose of this paper is to present some results concerning the investigation that has been done by the authors regarding the dynamic response of small to médium span railway bridges using response acceleration data colleted during the measurements carried out on single span bridges on the railway track Linz-Wels, in Austria. Using output-only methods in this experimental program, it was possible to have an estimation of the igenfrequencies, mode shapes and the corresponding viscous ...

  3. Active control of vibrations in pedestrian bridges

    OpenAIRE

    Álvaro Cunha; Carlos Moutinho

    1999-01-01

    This paper, apart from making a brief general reference to vibration problems in pedestrian bridges, as well as to the form of modelling of dynamic pedestrian loads, presents the use of a predictive control strategy for the numerical simulation of the dynamic response of actively controlled structures of this type. The consideration of this control strategy permitted the development of a computational model, which was applied to the study of a pedestrian cable-stayed bridge, in order to show ...

  4. Building Organic Bridges: Volume 1, Argentina - France

    OpenAIRE

    Rahmann, Gerold; Aksoy, Uygun

    2014-01-01

    [Foreword ...] The 18th IFOAM Organic World Congress held on 13-15 October, 2014 in Istanbul-Turkey targets to 'build organic bridges'. The Scientific track will contribute to bridging not only scientists but also institutions and disciplines, and to linking more developed and less developed, rural and urban, research to extension, plant to animal, farm practices to world-wide problems and producer and consumers. Organic is a management system that requires a diversity of inputs from differen...

  5. Building Organic Bridges: Volume 2, Germany - India

    OpenAIRE

    Rahmann, Gerold; Aksoy, Uygun

    2014-01-01

    [Foreword ...] The 18th IFOAM Organic World Congress held on 13-15 October, 2014 in Istanbul-Turkey targets to 'build organic bridges'. The Scientific track will contribute to bridging not only scientists but also institutions and disciplines, and to linking more developed and less developed, rural and urban, research to extension, plant to animal, farm practices to world-wide problems and producer and consumers. Organic is a management system that requires a diversity of inputs from differen...

  6. Thermal Bridge Effects in Walls Separating Rowhouses

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

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

  7. External Prestressing Bridge Reinforcement Technology Review

    Directory of Open Access Journals (Sweden)

    Zhu Hanbing

    2015-01-01

    Full Text Available Externally prestressed bridge can not only limit and reduce the cracks and deformation of the structure, improve the rigidity and bearing capacity of structure, improve the stress state of structure, but also have less interference for bridge operation when it is operating and have the good economic efficiency. This paper introduces the advantages and disadvantages of external prestressed strengthening technique, its calculation theory and construction technology described in detail, and finally the paper discusses the deficiency of existing research.

  8. Subscapularis Tendon Repair Using Suture Bridge Technique

    OpenAIRE

    Park, Yong Bok; Park, Young Eun; Koh, Kyoung Hwan; Lim, Tae Kang; Shon, Min Soo; Yoo, Jae Chul

    2015-01-01

    The subscapularis tendon plays an essential role in shoulder function. Although subscapularis tendon tears are less common than other rotator cuff tears, tears of the subscapularis tendon have increasingly been recognized with the advent of magnetic resonance imaging and arthroscopy. A suture bridge technique for the treatment of posterosuperior rotator cuff tears has provided the opportunity to improve the pressurized contact area and mean footprint pressure. However, suture bridge fixation ...

  9. Framework for Bridges Maintenance in Egypt

    Directory of Open Access Journals (Sweden)

    Hesham Abd Elkhalek

    2016-01-01

    Full Text Available The traditional approaches for bridges maintenance is proven to be inefficient as they lead to random way of spending maintenance budget and deteriorating bridge conditions. In many cases, maintenance activities are performed due to user complaints. The objective of this paper is to develop a practical and reliable framework to manage the maintenance and repair activities of Bridges network in Egypt considering performance and budget limits. The model solves an optimization problem that maximizes the average condition of the network given the limited budget using Genetic Algorithm (GA. The main tasks of the system are bridge inventory, condition assessment, deterioration using markov model, and maintenance optimization. The developed model takes into account multiple parameters including serviceability requirements, budget allocation, element importance on structural safety and serviceability, bridge impact on network, and traffic. A questionnaire is conducted to complete the research scope. The proposed model is implemented in software, which provides a friendly user interface. The results of the framework are multi – year maintenance plan for the entire network for up to five years. A case study is presented for validating and testing the model with Data collected from “General Authority for Roads, Bridges and Land Transport” in Egypt.

  10. Precast Pearl-Chain concrete arch bridges

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  11. 76 FR 20807 - Notice of Final Federal Agency Actions on the Sellwood Bridge Project, SE Tacoma Street and...

    Science.gov (United States)

    2011-04-13

    ... Tacoma Street and Oregon Highway 43, Multnomah County, OR AGENCY: Federal Highway Administration (FHWA... project, Sellwood Bridge, SE Tacoma Street and Oregon 43, in Multnomah County, Oregon. This action grants... Graham, Operations Engineer, Federal Highway Administration, 530 Center Street, NE., Suite 100,...

  12. Statistical inference for financial engineering

    CERN Document Server

    Taniguchi, Masanobu; Ogata, Hiroaki; Taniai, Hiroyuki

    2014-01-01

    This monograph provides the fundamentals of statistical inference for financial engineering and covers some selected methods suitable for analyzing financial time series data. In order to describe the actual financial data, various stochastic processes, e.g. non-Gaussian linear processes, non-linear processes, long-memory processes, locally stationary processes etc. are introduced and their optimal estimation is considered as well. This book also includes several statistical approaches, e.g., discriminant analysis, the empirical likelihood method, control variate method, quantile regression, realized volatility etc., which have been recently developed and are considered to be powerful tools for analyzing the financial data, establishing a new bridge between time series and financial engineering. This book is well suited as a professional reference book on finance, statistics and statistical financial engineering. Readers are expected to have an undergraduate-level knowledge of statistics.

  13. Applicability of URANS and DES Simulations of Flow Past Rectangular Cylinders and Bridge Sections

    OpenAIRE

    Claudio Mannini

    2015-01-01

    This paper discusses the results of computational fluid dynamics simulations carried out for rectangular cylinders with various side ratios of interest for many civil engineering structures. A bridge deck of common cross-section geometry was also considered. Unsteady Reynolds-averaged Navier-Stokes (URANS) equations were solved in conjunction with either an eddy-viscosity or a linearized explicit algebraic Reynolds stress model. The analysis showed that for the case studies considered the 2-D...

  14. Response Modification Factors for Concrete Bridges in Europe

    OpenAIRE

    Kappos, A. J.; Paraskeva, T. S.; Moschonas, I. F.

    2013-01-01

    The paper presents a methodology for evaluating the actual response modification factors (q or R) of bridges and applies it to seven concrete bridges typical of the stock found in southern Europe. The usual procedure for analytically estimating the q-factor is through pushover curves derived for the bridge in (at least) its longitudinal and transverse directions. The shape of such curves depends on the seismic energy dissipation mechanism of the bridge; hence, bridges are assigned to two cate...

  15. Six new projects will bridge gap between CERN and society

    CERN Multimedia

    Anaïs Rassat, Knowledge Transfer Group

    2016-01-01

    Knowledge Transfer Fund awarded over six hundred thousand Swiss francs to six projects in 2016.   Computer racks at the CERN Data Centre, the heart of CERN’s entire scientific, administrative, and computing infrastructure. CERN has awarded funding to six new projects with the aim to bridge the gap between technology and society. Over 600,000 CHF (€ 542,766) of capital was granted through its competitive Knowledge Transfer Fund (KT Fund). The fund is issued as part of CERN’s goal to maximize its overall impact on society. The selected projects cover new applications for CERN technology in a broad range of fields beyond high-energy physics, ranging from cancer diagnostics and aerospace applications, to next-generation cloud computing, radiation safety, and digital preservation. The technologies were developed at CERN as part of the variety of high-energy physics needs, and arise from several research departments: Engineering, Information Technology, Be...

  16. Evaluation of seismic damage to bridges and highway systems in Shelby County, Tennessee

    Science.gov (United States)

    Jernigan, John Bailey

    Past earthquakes have demonstrated that bridges are one of the most vulnerable components of highway transportation systems. In addition to bridges, roadways may also be subject to damage, particularly in an area prone to earthquake-induced liquefaction. As a consequence, the highway transportation systems after an earthquake might be impaired and the post-earthquake emergency response might be compromised. Furthermore, the impact on the regional economy might be very significant from the damage to highway systems. Since highway transportation systems are critical lifelines for people living in an urban area, it is important to evaluate the vulnerability of bridges and highway systems in earthquake-prone regions. Memphis and Shelby County, Tennessee are located close to the southwestern segment of the New Madrid seismic zone (NMSZ). This zone produced three of the largest earthquakes in North America in 1811--1812. Presently, the NMSZ is still active and is considered by engineers, seismologists, and public officials as the most hazardous seismic zone in the central and eastern United States. Bridges in the Memphis area were generally not designed for seismic resistance until 1990. Therefore, the majority of existing bridges might suffer damage from earthquakes occurring in the NMSZ. The overall objective of this study is to evaluate the expected damage to bridges and roadways on the major routes in Memphis and Shelby County resulting from New Madrid earthquakes with the aid of geographic information system (GIS) technology. The road network selected for this study includes all the Interstate highway system, all the primary and secondary routes maintained by the state, and most of the major arterial routes. There are 452 bridges on the selected roadway systems and data pertinent to these bridges and roadway systems were collected and implemented as a GIS database. The bridges in the Memphis area were classified into several types and damage states were determined

  17. Governing Engineering

    DEFF Research Database (Denmark)

    Buch, Anders

    2012-01-01

    Most people agree that our world face daunting problems and, correctly or not, technological solutions are seen as an integral part of an overall solution. But what exactly are the problems and how does the engineering ‘mind set’ frame these problems? This chapter sets out to unravel dominant...... perspectives in challenge per-ception in engineering in the US and Denmark. Challenge perception and response strategies are closely linked through discursive practices. Challenge perceptions within the engineering community and the surrounding society are thus critical for the shaping of engineering education...... and the engineering profession. Through an analysis of influential reports and position papers on engineering and engineering education the chapter sets out to identify how engineering is problematized and eventually governed. Drawing on insights from governmentality studies the chapter strives to elicit the bodies...

  18. Governing Engineering

    DEFF Research Database (Denmark)

    Buch, Anders

    2011-01-01

    Abstract: Most people agree that our world faces daunting problems and, correctly or not, technological solutions are seen as an integral part of an overall solution. But what exactly are the problems and how does the engineering ‘mind set’ frame these problems? This chapter sets out to unravel...... dominant perspectives in challenge perception in engineering in the US and Denmark. Challenge perception and response strategies are closely linked through discursive practices. Challenge perceptions within the engineering community and the surrounding society are thus critical for the shaping...... of engineering education and the engineering profession. Through an analysis of influential reports and position papers on engineering and engineering education the chapter sets out to identify how engineering is problematized and eventually governed. Drawing on insights from governmentality studies the chapter...

  19. Industrial Engineering

    DEFF Research Database (Denmark)

    Karlsson, Christer

    2015-01-01

    Industrial engineering is a discipline that is concerned with increasing the effectiveness of (primarily) manufacturing and (occasionally).......Industrial engineering is a discipline that is concerned with increasing the effectiveness of (primarily) manufacturing and (occasionally)....

  20. Engineering Cartilage

    Science.gov (United States)

    ... Research Matters NIH Research Matters March 3, 2014 Engineering Cartilage Artistic rendering of human stem cells on ... situations has been a major goal in tissue engineering. Cartilage contains water, collagen, proteoglycans, and chondrocytes. Collagens ...

  1. Prosthetic Engineering

    Science.gov (United States)

    ... Overview CoE for Limb Loss Prevention and Prosthetic Engineering Menu Menu VA Center of Excellence for Limb ... ZIP code here Enter ZIP code here Prosthetic Engineering - Overview Our aim is to improve prosthetic prescription ...

  2. Role of multiprotein bridging factor 1 in archaea: bridging the domains?

    NARCIS (Netherlands)

    Koning, de B.; Blombach, F.; Wu Hao,; Brouns, S.J.J.; Oost, van der J.

    2009-01-01

    MBF1 (multiprotein bridging factor 1) is a highly conserved protein in archaea and eukaryotes. It was originally identified as a mediator of the eukaryotic transcription regulator BmFTZ-F1 (Bombyx mori regulator of fushi tarazu). MBF1 was demonstrated to enhance transcription by forming a bridge bet

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    The fracture resistance of fibre composites can be greatly enhanced by crack bridging. In situ observations of mixed mode crack growth in a unidirectional carbon-fibre/epoxy composite reveal crack bridging by single fibres and by beam-like ligaments consisting of several fibres. Based on the obse...

  4. Engineering economy

    International Nuclear Information System (INIS)

    This book is written for engineer and manager who is working for analysis of propriety of project. It gives descriptions of basic of engineering economy, compare principle of engineering economy, application of compare principle, evaluation of capital project, value of time of funds and evaluation of investment, engineering economy analysis of an alternative idea, depreciation, determination and principle analysis of uncertain prospect, analysis of propriety of project, profitable plan in product progress, quality, cost and profit and analysis of complex investment project.

  5. Tidal Energy Conversion Installation at an Estuarine Bridge Site: Resource Evaluation and Energy Production Estimate

    Science.gov (United States)

    Wosnik, M.; Gagnon, I.; Baldwin, K.; Bell, E.

    2015-12-01

    The "Living Bridge" project aims to create a self-diagnosing, self-reporting "smart bridge" powered by a local renewable energy source, tidal energy - transforming Memorial Bridge, a vertical lift bridge over the tidal Piscataqua River connecting Portsmouth, NH and Kittery, ME, into a living laboratory for researchers, engineers, scientists, and the community. The Living Bridge project includes the installation of a tidal turbine at the Memorial Bridge. The energy converted by the turbine will power structural health monitoring, environmental and underwater instrumentation. Utilizing locally available tidal energy can make bridge operation more sustainable, can "harden" transportation infrastructure against prolonged grid outages and can demonstrate a prototype of an "estuarine bridge of the future". A spatio-temporal tidal energy resource assessment was performed using long term bottom-deployed Acoustic Doppler Current Profilers (ADCP) at two locations: near the planned deployment location in 2013-14 for 123 days and mid-channel in 2007 for 35 days. Data were evaluated to determine the amount of available kinetic energy that can be converted into usable electrical energy on the bridge. Changes in available kinetic energy with ebb/flood and spring/neap tidal cycles and electrical energy demand were analyzed. The target deployment site exhibited significantly more energetic ebb tides than flood tides, which can be explained by the local bathymetry of the tidal estuary. A system model is used to calculate the net energy savings using various tidal generator and battery bank configurations. Different resource evaluation methodologies were also analyzed, e.g., using a representative ADCP "bin" vs. a more refined, turbine-geometry-specific methodology, and using static bin height vs. bin height that move w.r.t. the free surface throughout a tidal cycle (representative of a bottom-fixed or floating turbine deployment, respectively). ADCP operating frequencies and bin

  6. Engineering Motion

    Science.gov (United States)

    Tuttle, Nicole; Stanley, Wendy; Bieniek, Tracy

    2016-01-01

    For many teachers, engineering can be intimidating; teachers receive little training in engineering, particularly those teaching early elementary students. In addition, the necessity of differentiating for students with special needs can make engineering more challenging to teach. This article describes a professional development program…

  7. Comprehensive Real-Time Bridge Health Monitoring System of Tongtai Bridge

    Directory of Open Access Journals (Sweden)

    Lei Su-su

    2015-01-01

    Full Text Available Tongtai Bridge is the world’s largest suspension curve-girder-skew-arch bridge, which is located in Zhangjiakou, China. The understanding of mechanics characteristics is limited to such complex bridges, so it is necessary to establish reliable health monitoring system to investigate the static and dynamic responses and monitor the safety of the bridge. A comprehensive real-time bridge health monitoring system is establish, which includes four aspects: sensor system, data acquisition and transmission system, data processing and control system, structure early warning and security assessment system. The paper systematically describes the system design principles, sensor layout, and monitoring content, then expounds system integration and function of each subsystem.

  8. Research on Selections of Bridge Site and Type of Hutiaoxia Jinsha River Bridge%虎跳峡金沙江大桥方案研究

    Institute of Scientific and Technical Information of China (English)

    刘伟; 陈克坚; 游励晖

    2013-01-01

    Research purposes:The Hutiaoxia Jinsha River Bridge is the key project of Lijiang-Xianggelila Railway and is located in the sensitive environmental and high seismic intensity region with the active fault.The reasonable bridge site and type should be selected for this bridge on consideration of the railway alignment,environment protection,topography,geological condition and the plan of hydraulic engineering on the midstream of the river.Research conclusions:(1)Using the deck type steel braced arch at the No.8 bridge site(416m) of the Hutaioxia Jinsha River Bridge is the best engineering plan.Using the steel truss suspension bridge at No.27 bridge site (98 + 660 +98 m) can remain the condition for the hydroelectric plan of river and can get the better economic and social benefits.(2) The deck type steel braced arch has features of the good load bearing capacity,good rigidity and nice looking and is suitable for the high mountain and deep valley area,but it produces the impact on the water storage and shipping under bridge because the arch rib is installed on bottom of the structure.(3) The steel truss suspension bridge has the features of the fine anti-seismic performance and good rigidity to meet the train requirement.(4) The research result can provide the reference to the type selection of the large span railway bridge in mountain and deep valley area.%研究目的:虎跳峡金沙江大桥为丽香铁路的重点控制性工程.大桥桥址位于环境敏感区、高烈度地震区及断裂发育带,需要综合线路走线、环保、地形、地质情况及金沙江中游水电开发规划的影响,选择虎跳峡金沙江大桥的合理桥位及桥式方案.研究结论:(1)虎跳峡金沙江大桥的8号桥位416 m上承式钢桁拱桥是最优的工程方案,27号桥位(98+660 +98)m钢桁梁悬索桥可以为规划中的水电开发预留条件,整体上经济、社会效应更好;(2)上承式钢桁拱桥承载能力高、刚度大、造型优美,适用于

  9. A probabilistic bridge safety evaluation against floods.

    Science.gov (United States)

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

    2016-01-01

    To further capture the influences of uncertain factors on river bridge safety evaluation, a probabilistic approach is adopted. Because this is a systematic and nonlinear problem, MPP-based reliability analyses are not suitable. A sampling approach such as a Monte Carlo simulation (MCS) or importance sampling is often adopted. To enhance the efficiency of the sampling approach, this study utilizes Bayesian least squares support vector machines to construct a response surface followed by an MCS, providing a more precise safety index. Although there are several factors impacting the flood-resistant reliability of a bridge, previous experiences and studies show that the reliability of the bridge itself plays a key role. Thus, the goal of this study is to analyze the system reliability of a selected bridge that includes five limit states. The random variables considered here include the water surface elevation, water velocity, local scour depth, soil property and wind load. Because the first three variables are deeply affected by river hydraulics, a probabilistic HEC-RAS-based simulation is performed to capture the uncertainties in those random variables. The accuracy and variation of our solutions are confirmed by a direct MCS to ensure the applicability of the proposed approach. The results of a numerical example indicate that the proposed approach can efficiently provide an accurate bridge safety evaluation and maintain satisfactory variation. PMID:27386269

  10. Natural vibration dynamics of Rainbow Bridge, Utah

    Science.gov (United States)

    Moore, J. R.; Thorne, M. S.; Wood, J. R.; Doyle, S.; Stanfield, E.; White, B.

    2015-12-01

    We measured resonant frequencies of Rainbow Bridge, Utah, one of the world's longest rock spans, during a field experiment recording ambient vibration data. Measurements were generated over 20 hours on March 23-24, 2015 using two broadband three-component seismometers placed on the bridge, and compared to concurrent data from nearby reference stations 20 and 220 m distant. We identified seven distinct modes of vibration for Rainbow Bridge between 1 and 6 Hz. Data for each resonant frequency was then analyzed to determine the frequency-dependent polarization vector in an attempt to clarify mode shapes; e.g. the fundamental mode represents out-of-plane horizontal flexure. We compared experimental data to results of 3D numerical modal analysis, using a new photogrammetric model of Rainbow Bridge generated in this study imported into COMSOL Multiphysics. Results compare well with measured data for seven of the first eight modeled modes, matching vibrational frequencies and polarization orientations generally within 10%. Only predicted mode 6 was not explicitly apparent in our experimental data. Large site-to-reference spectral ratios resolved from experimental data indicate high amplification on the bridge as compared to nearby bedrock.

  11. Bridges in the random-cluster model

    Directory of Open Access Journals (Sweden)

    Eren Metin Elçi

    2016-02-01

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

  12. Computational engineering

    CERN Document Server

    2014-01-01

    The book presents state-of-the-art works in computational engineering. Focus is on mathematical modeling, numerical simulation, experimental validation and visualization in engineering sciences. In particular, the following topics are presented: constitutive models and their implementation into finite element codes, numerical models in nonlinear elasto-dynamics including seismic excitations, multiphase models in structural engineering and multiscale models of materials systems, sensitivity and reliability analysis of engineering structures, the application of scientific computing in urban water management and hydraulic engineering, and the application of genetic algorithms for the registration of laser scanner point clouds.

  13. Documentation for assessment of modal pushover-based scaling procedure for nonlinear response history analysis of "ordinary standard" bridges

    Science.gov (United States)

    Kalkan, Erol; Kwong, Neal S.

    2010-01-01

    The earthquake engineering profession is increasingly utilizing nonlinear response history analyses (RHA) to evaluate seismic performance of existing structures and proposed designs of new structures. One of the main ingredients of nonlinear RHA is a set of ground-motion records representing the expected hazard environment for the structure. When recorded motions do not exist (as is the case for the central United States), or when high-intensity records are needed (as is the case for San Francisco and Los Angeles), ground motions from other tectonically similar regions need to be selected and scaled. The modal-pushover-based scaling (MPS) procedure recently was developed to determine scale factors for a small number of records, such that the scaled records provide accurate and efficient estimates of 'true' median structural responses. The adjective 'accurate' refers to the discrepancy between the benchmark responses and those computed from the MPS procedure. The adjective 'efficient' refers to the record-to-record variability of responses. Herein, the accuracy and efficiency of the MPS procedure are evaluated by applying it to four types of existing 'ordinary standard' bridges typical of reinforced-concrete bridge construction in California. These bridges are the single-bent overpass, multi span bridge, curved-bridge, and skew-bridge. As compared to benchmark analyses of unscaled records using a larger catalog of ground motions, it is demonstrated that the MPS procedure provided an accurate estimate of the engineering demand parameters (EDPs) accompanied by significantly reduced record-to-record variability of the responses. Thus, the MPS procedure is a useful tool for scaling ground motions as input to nonlinear RHAs of 'ordinary standard' bridges.

  14. Bridge over troubled water spanning the energy-efficiency gap

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Agneta (WSP Environmental, Stockholm (Sweden)); Goeransson, Anders (PROFU, Moelndal (Sweden)); Gudbjerg, Erik (LokalEnergi A/S, Viby (Denmark))

    2009-07-01

    The existence or non-existence of cost-efficient energy efficiency measures seems to be a constant argue between engineers and economists. Engineers on the one hand point at major potentials for cost-efficient energy efficiency measures. A recently carried out study shows that merely 15 per cent of all cost efficient measures in the Swedish building sector are likely to be carried out, even when taking currently implemented policy measures into account. Economists on the other hand claim the cost-efficient potential to be low. The engineers simply have forgotten to include transaction costs and other important factors in their calculations is a common comment. Is the main explanation of the energy-efficiency gap the transaction costs? Several studies are available on the existence of transaction costs and various types of such costs. However, only few of these studies manage to quantify them. In an attempt to bridge the energy-efficiency gap, a Swedish study has recently been carried out in joint effort between engineers and economists. The study seeks to quantify to what extent transaction costs, split incentives and other factors can explain the gap. The results of the study indicate that transaction costs only to a surprisingly small part explain the gap. The output from the study provides important knowledge for policy makers. This paper is presenting the results from the Swedish study on quantifying different parts of the energy-efficiency gap. The presentation is focussed on the buildings sector. The paper also discusses calculation inputs used and sensitivity analyses carried out in the Swedish study.

  15. CONTROL ENGINEERING ON BOARD

    Directory of Open Access Journals (Sweden)

    Serghei RADU

    2012-11-01

    Full Text Available Control engineering embraces instrumentation, alarm systems, control of machinery and plant previously known under the misnomer of automation. Control engineering can be applied not only to propelling and auxiliary machinery but also to electrical installations, refrigeration, cargo handling (especially in tankers and deck machinery, e.g. Windlass control. Opinion still vary on such matters as the relative merits of pneumatic versus electronic system and whether the control center should be in the engine room or adjacent to the navigating bridge. Arguments against the exclusion of the engineer officer from close contact with the machinery are countered by the fact that electronic systems are based on changes other than those of human response. Automated ships (UMS operate closer to prescribed standards and therefore operate with greater efficiency. The closer control of machinery operating conditions, e.g. cooling water temperatures and pressures, permits machinery to be run at its optimum design conditions, making for fuel economy and reduced maintenance. Automation can carry out some tasks far more effectively than men. In other areas it is less effective. For example, the monitoring of machinery operating conditions such as the temperatures and pressures can be carried out by a solid state alarm scanning system at the rate of 400 channels/sec., giving a degree of surveillance which would be impossible by human observation. Conversely, the detection of noisy bearing, a leaky gland or cracked pipe is scarcely possible by automatic means. The balance between the possible and the necessary would be achieved in this case by combining automatic monitoring of all the likely fault conditions, with routine machinery space inspection say twice a day.

  16. Fast Hough transform for automatic bridge extraction

    Science.gov (United States)

    Hao, Qiwei; Chen, Xiaomei; Ni, Guoqiang; Zhang, Huaili

    2008-03-01

    In this paper, a new method to recognize bridge in the complicated background is presented. The algorithm takes full advantages of the characteristics of the bridge image. Firstly, the image is preprocessed and the object edges are extracted. Then according to the limitations of traditional Hough transform (HT), the extraction method of the image line segment characteristic of HT is improved, which eliminates spurious peaks on the basis of global and local thresholds, discriminates the position relation between two straight line segments, and merges segments with near endpoints, etc. Experiments show that this algorithm is more precise and efficient than traditional HT, moreover it can provide a complete description of the bridge in a complicated background.

  17. MINERAL BRIDGES OF NACRE AND ITS EFFECTS

    Institute of Scientific and Technical Information of China (English)

    宋凡; 白以龙

    2001-01-01

    Nacre, or mother-of-pearl, is a kind of composites of aragonite platelets sandwiched between organic materials. Its excellent mechanical properties are thought to stem from the microarchitecture that is traditionally described as a "brick and mortar" arrangement. In this paper, a new microstructure, referred to as mineral bridge in the biomineralization, is directly observed in the organic matrix layers (mortar) of nacre. This is an indication that the organic matrix layer of nacre should be treated as a three-dimensional interface and the microarchitecture of nacre ought to be considered as a "brick-bridge-mortar" structure rather than the traditional one. Experiments and analyses show that the mineral bridges not only improve the mechanical properties of the organic matrix layers but also play an important role in the pattern of the crack extension in nacre.

  18. MULTIPHASE BLASTING OF THE BRIDGE ACROSS THE DRENICA RIVER

    OpenAIRE

    Branko Božić

    1989-01-01

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

  19. Bridging radiation policy and science

    International Nuclear Information System (INIS)

    Scientists, regulators, and policy makers from five continents and 20 countries reached consensus on a number of conclusions and recommendations regarding low-level ionizing radiation exposures at an international conference, 'Bridging Radiation Policy and Science,' at the Airlie Center in Warrenton, Virginia, 1-5 December 1999. The goal of the conference was to develop strategies for formulating national and international policy based on current scientific information in the context of economic, political, and social concerns. Specifically, attendees explored how to establish public policies with respect to radiation protection in view of the scientific uncertainties of the effects of low-level radiation [<100 millisievert (mSv)]. Conference participants agreed that science will not likely answer in the near future fundamental questions about the shape of the dose-response curve and mechanisms of effects of radiation at low doses. The conference endorsed the quest for a prudent and coherent radiation policy based on the International Atomic Energy Agency's (IAEA) 'evolving global framework'. The Conference participants agreed upon the following recommendations: Policy discussions on the regulation of radiation sources delivering low-level radiation should include references to natural background radiation. The conference supports the evolving global framework of the International Atomic Energy Agency (IAEA) for the safe use of radiation. The conference supports further development and evaluation of the ideas associated with the proposal on controllable dose. No radiation dose is below regulatory concern but certain levels should be below regulatory action, and appropriate dose levels should be established. Fundamental questions about the shape of the dose-response curve and mechanisms of effects of radiation at low doses are unlikely to be answered in the near future. Scientific research, including molecular and cellular radiobiology studies are critical in order

  20. NDT evaluation of long-term bond durability of CFRP-structural systems applied to RC highway bridges

    Science.gov (United States)

    Crawford, Kenneth C.

    2016-06-01

    The long-term durability of CFRP structural systems applied to reinforced-concrete (RC) highway bridges is a function of the system bond behavior over time. The sustained structural load performance of strengthened bridges depends on the carbon fiber-reinforced polymer (CFRP) laminates remaining 100 % bonded to concrete bridge members. Periodic testing of the CFRP-concrete bond condition is necessary to sustain load performance. The objective of this paper is to present a non-destructive testing (NDT) method designed to evaluate the bond condition and long-term durability of CFRP laminate (plate) systems applied to RC highway bridges. Using the impact-echo principle, a mobile mechanical device using light impact hammers moving along the length of a bonded CFRP plate produces unique acoustic frequencies which are a function of existing CFRP plate-concrete bond conditions. The purpose of this method is to test and locate CFRP plates de-bonded from bridge structural members to identify associated deterioration in bridge load performance. Laboratory tests of this NDT device on a CFRP plate bonded to concrete with staged voids (de-laminations) produced different frequencies for bonded and de-bonded areas of the plate. The spectra (bands) of frequencies obtained in these tests show a correlation to the CFRP-concrete bond condition and identify bonded and de-bonded areas of the plate. The results of these tests indicate that this NDT impact machine, with design improvements, can potentially provide bridge engineers a means to rapidly evaluate long lengths of CFRP laminates applied to multiple highway bridges within a national transportation infrastructure.

  1. Extracorporeal Life Support Bridge to Ventricular Assist Device: The Double Bridge Strategy.

    Science.gov (United States)

    Marasco, Silvana F; Lo, Casey; Murphy, Deirdre; Summerhayes, Robyn; Quayle, Margaret; Zimmet, Adam; Bailey, Michael

    2016-01-01

    In patients requiring left ventricular assist device (LVAD) support, it can be difficult to ascertain suitability for long-term mechanical support with LVAD and eventual transplantation. LVAD implantation in a shocked patient is associated with increased morbidity and mortality. Interest is growing in the utilization of extracorporeal life support (ECLS) as a bridge-to-bridge support for these critically unwell patients. Here, we reviewed our experience with ECLS double bridging. We hypothesized that ECLS double bridging would stabilize end-organ dysfunction and reduce ventricular assist device (VAD) implant perioperative mortality. We conducted a retrospective review of prospectively collected data for 58 consecutive patients implanted with a continuous-flow LVAD between January 2010 and December 2013 at The Alfred Hospital, Melbourne, Victoria, Australia. Twenty-three patients required ECLS support pre-LVAD while 35 patients underwent LVAD implantation without an ECLS bridge. Preoperative morbidity in the ECLS bridge group was reflected by increased postoperative intensive care duration, blood loss, blood product use, and postoperative renal failure, but without negative impact upon survival when compared with the no ECLS group. ECLS stabilization improved end-organ function pre-VAD implant with significant improvements in hepatic and renal dysfunction. This series demonstrates that the use of ECLS bridge to VAD stabilizes end-organ dysfunction and reduces VAD implant perioperative mortality from that traditionally reported in these "crash and burn" patients.

  2. The seismic response of concrete arch bridges (with focus on the Bixby Creek bridge Carmel, California)

    Energy Technology Data Exchange (ETDEWEB)

    Hoehler, M; McCallen, D; Noble, C

    1999-06-01

    The analysis, and subsequent retrofit, of concrete arch bridges during recent years has relied heavily on the use of computational simulation. For seismic analysis in particular, computer simulation, typically utilizing linear approximations of structural behavior, has become standard practice. This report presents the results of a comprehensive study of the significance of model sophistication (i.e. linear vs. nonlinear) and pertinent modeling assumptions on the dynamic response of concrete arch bridges. The study uses the Bixby Creek Bridge, located in California, as a case study. In addition to presenting general recommendations for analysis of this class of structures, this report provides an independent evaluation of the proposed seismic retrofit for the Bixby Creek Bridge. Results from the study clearly illustrate a reduction of displacement drifts and redistribution of member forces brought on by the inclusion of material nonlinearity. The analyses demonstrate that accurate modeling of expansion joints, for the Bixby Creek Bridge in particular, is critical to achieve representative modal and transient behavior. The inclusion of near-field displacement pulses in ground motion records was shown to significantly increase demand on the relatively softer, longer period Bixby Creek Bridge arch. Stiffer, shorter period arches, however, are more likely susceptible to variable support motions arising from the canyon topography typical for this class of bridges.

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

    Index Scriptorium Estoniae

    Hunt, Brian

    1997-01-01

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

  4. Stability of a liquid bridge under vibration

    Science.gov (United States)

    Benilov, E. S.

    2016-06-01

    We examine the stability of a vertical liquid bridge between two vertically vibrating, coaxial disks. Assuming that the vibration amplitude and period are much smaller than the mean distance between the disks and the global timescale, respectively, we employ the method of multiple scales to derive a set of asymptotic equations. The set is then used to examine the stability of a bridge of an almost cylindrical shape. It is shown that, if acting alone, gravity is a destabilizing influence, whereas vibration can weaken it or even eliminate altogether. Thus, counter-intuitively, vibration can stabilize an otherwise unstable capillary structure.

  5. ParB spreading requires DNA bridging

    OpenAIRE

    Graham, Thomas G. W.; Wang, Xindan; Song, Dan; Etson, Candice M.; van Oijen, Antoine M.; Rudner, David Z.; Loparo, Joseph J.

    2014-01-01

    The bacterial parABS system is employed for plasmid partitioning and chromosome segregation. ParB binds to parS sites and associates with broad regions of adjacent DNA, a phenomenon known as spreading. However, the molecular basis for spreading is unknown. Using single-molecule approaches, Graham et al. demonstrate DNA bridging by B. subtilis ParB (Spo0J). Spo0J mutations that disrupt DNA bridging lead to defective spreading and SMC condensin complex recruitment. This study suggests a novel, ...

  6. Germanium-overcoated niobium Dayem bridges

    Science.gov (United States)

    Holdeman, L. B.; Peters, P. N.

    1976-01-01

    Overcoating constriction microbridges with semiconducting germanium provides additional thermal conductivity at liquid-helium temperatures to reduce the effects of self-heating in these Josephson junctions. Microwave-induced steps were observed in the I-V characteristics of an overcoated Dayem bridge fabricated in a 15-nm-thick niobium film; at least 20 steps could be counted at 4.2 K. No steps were observed in the I-V characteristics of the bridge prior to overcoating. In addition, the germanium overcoat can protect against electrical disturbances at room temperature.

  7. Ambient Vibration Test on Reinforced Concrete Bridges

    Directory of Open Access Journals (Sweden)

    Idris Nurul Shazwin

    2016-01-01

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

  8. A Bridge Deflection Monitoring with GPS

    Science.gov (United States)

    Figurski, M.; Gałuszkiewicz, M.; Wrona, M.

    2007-01-01

    This paper introduces results of investigation carried on by The Applied Geomatics Section in Military University of Technology. Research includes possibilities of monitoring dynamic behavior of a bridge using high rate GPS data. Whole event was executed with collaboration of The Road and Bridge Management and The Warsaw Geodesy Company. Interdisciplinary approach with this project allows authors to get reliable information about investigating constructions and their respond for true traffic loading detected by GPS receivers. Way of compute data and used software (TRACK) are also shown in this paper.

  9. Planar Hall effect bridge magnetic field sensors

    DEFF Research Database (Denmark)

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

    2010-01-01

    Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can...... be significantly enhanced by a geometric factor. For the samples in the present study, we demonstrate an enhancement of the sensor output by a factor of about 100 compared to cross-shaped sensors. The presented construction opens a new design and application area of the planar Hall effect, which we term planar...... Hall effect bridge sensors....

  10. Planar Hall effect bridge magnetic field sensors

    Science.gov (United States)

    Henriksen, A. D.; Dalslet, B. T.; Skieller, D. H.; Lee, K. H.; Okkels, F.; Hansen, M. F.

    2010-07-01

    Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can be significantly enhanced by a geometric factor. For the samples in the present study, we demonstrate an enhancement of the sensor output by a factor of about 100 compared to cross-shaped sensors. The presented construction opens a new design and application area of the planar Hall effect, which we term planar Hall effect bridge sensors.

  11. “On a bridge in Berlin”

    DEFF Research Database (Denmark)

    Pihl, Ole Verner

    2013-01-01

    that jumps in time and place: it begins with Martin Heidegger´s quotation “The Bridge gathers to itself in its own way earth and sky, divinities and mortals”, and the bridge is a state of mind, a chronotope, a portal in time between past, present, and future. The methodological approach is based...... on Bachelard and Heidegger. This GN investigates how architecture changes our cities and cultural identity. It merges different narrative time layers as: childhood memories, dreams, hallucinations, fiction, past, present, and future. The findings of this paper explains why a cross disciplinary approach...

  12. Composite timber-concrete road bridge structure

    Directory of Open Access Journals (Sweden)

    Stojić Dragoslav

    2007-01-01

    Full Text Available This work presents preliminary design of the road bridge made of laminated timber. The supporting system of the main bearing elements is made of the laminated timber in the system of arch with three joints; the bridge slab is designed as continuous slab, made of nine equal fields; each pair is made as composite timber-concrete beam, where the road slab is made of concrete and the needle pieces are made of timber. Fundament is based on HW piles. All the elements are designed to Eurocode.

  13. Toward structural mechanics through wooden bridges in France (1716-1841)

    CERN Document Server

    Tardini, Chiara

    2014-01-01

    Early applications of Navier’s beam theory to the rational design of structures are documented in the Annales of the French Ecole des Ponts et Chaussées and refer to the design of three wooden bridges built in France in the 1840's. Revisiting these examples, the book provides documentation on the progressive establishment of the new design approach, based on the theory of structural mechanics rather than empirical knowledge. The bridges concerned were built according to the structural scheme patented by Ithiel Town in the USA, witnessing the diffusion in Europe of the American advancements in bridge design, circulated by the travel reports of French engineers from the Ecole. Through the exam of French treatises discussing the progress of theoretical formulations in parallel with experimental findings in the 18th and 19th centuries, the book retraces as well the long path which led to the formulation of Navier’s theory. The relevant scientific debate dealt mainly with the specific case of wood bridges; th...

  14. A Multimode Adaptive Pushover Procedure for Seismic Assessment of Integral Bridges

    Directory of Open Access Journals (Sweden)

    Ehsan Mohtashami

    2013-01-01

    Full Text Available This paper presents a new adaptive pushover procedure to account for the effect of higher modes in order to accurately estimate the seismic response of bridges. The effect of higher modes is considered by introducing a minimum value for the total effective modal mass. The proposed method employs enough number of modes to ensure that the defined total effective modal mass participates in all increments of the pushover loading. An adaptive demand curve is also developed for assessment of the seismic demand. The efficiency and robustness of the proposed method are demonstrated by conducting a parametric study. The analysis includes 18 four-span integral bridges with various heights of piers. The inelastic response history analysis is employed as reference solution in this study. Numerical results indicate excellent accuracy of the proposed method in assessment of the seismic response. For most bridges investigated in this study, the difference between the estimated response of the proposed method and the inelastic response history analysis is less than 25% for displacements and 10% for internal forces. This indicates a very good accuracy compared to available pushover procedures in the literature. The proposed method is therefore recommended to be applied to the seismic performance evaluation of integral bridges for engineering applications.

  15. ISIS Technologies for Smart Civil Engineering Infrastructure

    Institute of Scientific and Technical Information of China (English)

    Aftab A. Mufti; Kenneth W. Neale

    2004-01-01

    For more than a century, important civil engineering structures such as bridges, high-rise buildings, dams and marine platforms have contained iron or steel as the reinforcement for concrete or wood (ISIS Canada Strategic Plan, 2000). The useful lives of such structures have often been severely limited by the corrosion of this ferrous component. Much thought has been given in recent years to constructing structures that are lighter, stronger and non-corrosive. These innovative structures are new and for these to be accepted by the engineering community monitoring is mandatory. ISIS Canada has been developing such structures and monitoring them. In this paper, innovative bridge decks that have been implemented is described.

  16. Investigations of effects of pilot injection with change in level of compression ratio in a common rail diesel engine

    OpenAIRE

    Gajarlawar Nilesh; Khetan Ajaykumar; Rao Gaddale Amba Prasad

    2013-01-01

    These day diesel engines are gaining lots of attention as prime movers for various source of transportation. It offers better drive ability, very good low end torque and importantly the lower CO2 emission. Diesel engines are bridging the gap between gasoline and diesel engines. Better noise vibration and harshness levels of gasoline engine are realized to great extent in diesel engine, thanks to common rail direct injection system. Common rail injection system is now well known entity. ...

  17. Bridging biomedical basics with practical applications in BME laboratory education.

    Science.gov (United States)

    Giuffrida, J P

    2004-01-01

    A sophisticated biomedical engineering (BME) laboratory course was designed to integrate state-of-the-art technology with a hands on learning approach in a flexible, virtual-based, clinical application setting. The need for biomedical engineers in research and industry has increased rapidly in recent years. This requires that innovative methods for training BME students evolve to meet that need. BME students should be prepared with a skill set for approaching practical problems. BME education requires hands on learning with cutting edge technology to produce students ready to solve clinical problems in research and industry. Exposing students to a wide range of BME applications not only increases interest, but also better prepares them to solve real world problems. A wide range of BME laboratories have been designed to encompass both the basics of physiological signals and how to effectively utilize them in practical applications. These application interfaces are critical for students to understand how physiological signals may be manipulated to produce meaningful benefits for various medical disorders and rehabilitation needs. The laboratory course presented in this paper was implemented and evaluated at several universities. Utilizing the virtual environment for practical applications bridges the gap between fundamentals and real world designs. PMID:17271499

  18. Modelling Blast Effects on a Reinforced Concrete Bridge

    Directory of Open Access Journals (Sweden)

    Markellos Andreou

    2016-01-01

    Full Text Available The detailed investigation of blast phenomena and their catastrophic effects on existing structures are the main objectives of the present paper. It is well known that blast phenomena may be characterized by significant complexity, often involving complicated wave propagation effects as well as distinguishable material behaviors. Considering the above and in an attempt to provide a simplified modelling approach for the simulation of blast effects, a novel procedure is presented herein based on well-established methodologies and common engineering practices. In the above framework, firstly, the “predominant” deformation shape of the structure is estimated based on elastic finite element simulations under blast loads and then the structural response of the system is evaluated as a result of common computational beam-element tools such as displacement-based pushover analysis. The proposed methodology provides an immediate first estimation of the structural behavior under blast loads, based on familiar engineering procedures. A two-span reinforced concrete bridge was thoroughly investigated and the results provide insightful information regarding the damage patterns and localization.

  19. Information engineering

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, D.N.

    1997-02-01

    The Information Engineering thrust area develops information technology to support the programmatic needs of Lawrence Livermore National Laboratory`s Engineering Directorate. Progress in five programmatic areas are described in separate reports contained herein. These are entitled Three-dimensional Object Creation, Manipulation, and Transport, Zephyr:A Secure Internet-Based Process to Streamline Engineering Procurements, Subcarrier Multiplexing: Optical Network Demonstrations, Parallel Optical Interconnect Technology Demonstration, and Intelligent Automation Architecture.

  20. Engineering Electromagnetics

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Se Yun

    2009-01-15

    This book deals with engineering electromagnetics. It contains seven chapters, which treats understanding of engineering electromagnetics such as magnet and electron spin, current and a magnetic field and an electromagnetic wave, Essential tool for engineering electromagnetics on rector and scalar, rectangular coordinate system and curl vector, electrostatic field with coulomb rule and method of electric images, Biot-Savart law, Ampere law and magnetic force, Maxwell equation and an electromagnetic wave and reflection and penetration of electromagnetic plane wave.

  1. Cognitive Engineering

    OpenAIRE

    Wilson, Kyle M.; Helton, William S; Wiggins, Mark W.

    2013-01-01

    Cognitive engineering is the application of cognitive psychology and related disciplines to the design and operation of human–machine systems. Cognitive engineering combines both detailed and close study of the human worker in the actual work context and the study of the worker in more controlled environments. Cognitive engineering combines multiple methods and perspectives to achieve the goal of improved system performance. Given the origins of experimental psychology itself in issues regard...

  2. Reverse Engineering

    International Nuclear Information System (INIS)

    This book gives descriptions of reverse engineering with principle and structure of it, including what reverse engineering is, prospect and concerned laws, basic knowledge for reverse engineering like manual and back to user mode, using tool such as IDA installation, dependency walker and dump bin, network monitoring and universal extractor. It indicates analysis of malignant code, giving explanations of file virus, spy ware, an infection way of malignant code, anti debugging like Find window.

  3. Software engineering

    CERN Document Server

    Sommerville, Ian

    2010-01-01

    The ninth edition of Software Engineering presents a broad perspective of software engineering, focusing on the processes and techniques fundamental to the creation of reliable, software systems. Increased coverage of agile methods and software reuse, along with coverage of 'traditional' plan-driven software engineering, gives readers the most up-to-date view of the field currently available. Practical case studies, a full set of easy-to-access supplements, and extensive web resources make teaching the course easier than ever.

  4. Engineering Knowledge

    OpenAIRE

    Nathan Rosenberg; W. Edward Steinmuller

    2012-01-01

    In historical perspective, both the nature of and arrangements for the generation of engineering knowledge have evolved over the past 150 years. We examine the historical development of the search for ‘useful knowledge’ in agriculture, aeronautics and chemical engineering during the first half of this period and the evolving balance between public and private initiative in supporting this search. During this period, the US was engaged in the engineering knowledge was often empirical, practice...

  5. Engineering Ethics

    OpenAIRE

    Didier, Christelle

    2010-01-01

    In this chapter, the author presents the research field called "engineering ethics" and analyses some ethical issues related to the engineering profession. Ce chapitre dresse un état des lieux du champ de recherche intitulé depuis les années 1980 "engineering ethics"en anglais. Il présente quelques enjeux éthiques que soulève le métier d'ingénieur.

  6. Rehabilitation Engineering: What is Rehabilitation Engineering?

    Science.gov (United States)

    ... Parents/Teachers Resource Links for Students Glossary Rehabilitation Engineering What is rehabilitation engineering? What types of assistive ... the area of rehabilitation engineering? What is rehabilitation engineering? Source: Michael Goldfarb, Vanderbilt University Rehabilitation engineering is ...

  7. Engineering tribology

    CERN Document Server

    Stachowiak, Gwidon; Batchelor, A W; Batchelor, Andrew W

    2005-01-01

    As with the previous edition, the third edition of Engineering Tribology provides a thorough understanding of friction and wear using technologies such as lubrication and special materials. Tribology is a complex topic with its own terminology and specialized concepts, yet is vitally important throughout all engineering disciplines, including mechanical design, aerodynamics, fluid dynamics and biomedical engineering. This edition includes updated material on the hydrodynamic aspects of tribology as well as new advances in the field of biotribology, with a focus throughout on the engineering ap

  8. Diode-quad bridge for reactive transducers and FM discriminators

    Science.gov (United States)

    Harrison, D. R.; Dimeff, J.

    1972-01-01

    Diode-quad bridge circuit was developed for use with pressure-sensitive capacitive transducers, liquid-level measuring devices, proximity deflection sensors, and inductive displacement sensors. It may also be used as FM discriminator and as universal impedance bridge.

  9. Foot force models of crowd dynamics on a wobbly bridge

    CERN Document Server

    Belykh, Igor; Belykh, Vladamir

    2016-01-01

    Modern pedestrian and suspension bridges are designed using industry-standard packages, yet disastrous resonant vibrations are observed, necessitating multi-million dollar repairs. Recent examples include pedestrian induced vibrations during the openings of the Solf\\'erino Bridge in Paris in 1999 and the increased bouncing of the Squibb Park Bridge in Brooklyn in 2014. The most prominent example of an unstable lively bridge is the London Millennium Bridge which started wobbling as a result of pedestrian-bridge interactions. Pedestrian phase-locking due to footstep phase adjustment, is suspected to be the main cause of its large lateral vibrations; however, its role in the initiation of wobbling was debated. In this paper, we develop foot force models of pedestrians' response to bridge motion and detailed, yet analytically tractable models of crowd phase-locking. We use bio-mechanically inspired models of crowd lateral movement to investigate to what degree pedestrian synchrony must be present for a bridge to ...

  10. 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.

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

    Data.gov (United States)

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

  12. 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.

  13. Hydraulic bridges in unsaturated coarse granular media: Influence of bridge size and conductivity on flow through clasts

    Science.gov (United States)

    Jayakody, Jeevan A.; Nicholl, Michael J.

    2016-10-01

    Unsaturated flow in coarse granular media must pass through hydraulic bridges (e.g., pendular water, porous connections) that form a physical connection between adjoining clasts. Previous studies suggest that volumetric flow through a porous clast (Q) will be linearly dependent on the cross-sectional area of the hydraulic bridges, and understate the importance of bridge conductivity. Numerical simulations were performed to explore steady-state flow through a spherical clast with identical bridges located at the top and bottom. The cross-sectional area of the bridges relative to that of the clast (Ar) was varied across six orders of magnitude. The ratio of hydraulic conductivity between bridges and clasts (Kb/Kc) was varied across 12 orders of magnitude to consider resistive, neutral, and conductive bridges. Results show that hydraulic bridges place a primary control on both Q and flux distribution within the clast. For neutral and conductive bridges (Kb/Kc ≥1), Ar is the dominant factor in determining Q, while Kb/Kc is the primary control for resistive bridges (Kb/Kc < 1). For all bridges, Q shows a non-linear dependency on both Ar and Kb/Kc. The intra-clast flow distribution shifts outwards as Ar increases. Conductive bridges promote this process and resistive bridges impede it.

  14. Bridging the digital divide with mobile services

    CERN Document Server

    Yelton, Andromeda

    2013-01-01

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

  15. Circuit bridging of components by smoke

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-01

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

  16. Bridges in Mathematics. WWC Intervention Report

    Science.gov (United States)

    What Works Clearinghouse, 2009

    2009-01-01

    "Bridges in Mathematics," published by the Math Learning Center (MLC), is an elementary school math curriculum covering kindergarten through fifth grade that focuses on problem solving and skill building, and applies a combination of whole-group, small-group, and independent activities. Lessons incorporate visual models, including manipulatives,…

  17. The Memory Bridge Initiative on Service Learners

    Science.gov (United States)

    Wescott, Amy; Healy, Tara C.

    2011-01-01

    This study evaluated the Memory Bridge Initiative (MBI), an educational, experiential program pairing high school students with older adults who have dementia. A qualitative, single group design with baseline and follow-up measures examined whether or not students would have a positive learning experience while gaining newfound appreciation and…

  18. Bridging the Gap: Pracademics in Foreign Policy

    Science.gov (United States)

    Murphy, Ann Marie; Fulda, Andreas

    2011-01-01

    In his seminal work "Bridging the Gap: Theory and Practice in Foreign Policy", Alexander George (1993) lamented the great divide between academia and the foreign policymaking community, arguing that greater interaction between scholars and policymakers would produce better policy. We share George's belief that scholars and practitioners each have…

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

    Science.gov (United States)

    Barrett, Jan; And Others

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

  20. Journaling: A Bridge between School and Home

    Science.gov (United States)

    McGough, Julie

    2013-01-01

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

  1. 75 FR 41281 - Bridge Safety Standards

    Science.gov (United States)

    2010-07-15

    ... Federal Register at 60 FR 20654, the interim statement included a request for comments to be submitted to... of Agency Policy on the Safety of Railroad Bridges (``policy statement''). See 65 FR 52667. With the... amendment. See 74 FR 157. All aspects of the policy statement that are not incorporated into the...

  2. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

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

    The present paper worked out as a part of a research project on "Dynamic amplification factor of vehicle loadings on smaller bridges" establishes a two-dimensional spectral description of the road roughness surface based on measurements from a Danish road using so-called Profilograph used by Dani...

  3. Bridging gaps : ten crosscurrents in media studies

    OpenAIRE

    Fornäs, Johan

    2008-01-01

    The final, definitive version of this paper has been published in: Media, Culture and Society, (30), 6, 895-905, 2008.Johan Fornäs, Bridging Gaps: Ten Crosscurrents in Media Studies.http://dx.doi.org/10.1177/0163443708096811. by SAGE Publications Ltd, All rights reserved. http://www.sagepub.com/

  4. Steel plate reinforcement of orthotropic bridge decks

    NARCIS (Netherlands)

    Teixeira de Freitas, S.

    2012-01-01

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

  5. Aeroelastic Stability of Suspension Bridges using CFD

    DEFF Research Database (Denmark)

    Stærdahl, Jesper Winther; Sørensen, Niels; Nielsen, Søren R.K.

    2007-01-01

    In recent years large span suspension bridges with very thin and slender profiles have been built without proportional increasing torsional and bending stiffness. As a consequence large deformations at the mid-span can occur with risk of aeroelastic instability and structural failure. Analysis...

  6. The mechanics of ship impacts against bridges

    DEFF Research Database (Denmark)

    Pedersen, Preben Terndrup; Zhang, Shengming

    1998-01-01

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

  7. Bridging the Gap Between Theory and Practice

    Directory of Open Access Journals (Sweden)

    Roy H.M. Sembel

    2015-05-01

    Full Text Available Some concerns in the field of Business Management regarding the gap between theory and practice have been raised by practitioners and academicians. This keynote speech describes some lessons learned from the academic literature regarding this gap (whether the gap really exists, and if it exists, whether it needs to be bridged or closed, and how to bridge or close this gap, and shares the author's personal and professional experiences of living as both an academician and a practitioner. The main findings of this article are: (1 Yes the gap exists, however, it has to be viewed in a wider perspective to really understand the situation; (2 The gap in a specific area is bad and should become our concern, but in other areas it should not; (3 There are some ways to bridge or close the negative gap; (4 There exists hybrid career opportunities to become professionals that work both as an academician and a practitioner; (5 This new breed of hybrid professionals has a huge potential to bridge the bad theory-practice gap.

  8. Thermal Bridge Effects in Window Grooves

    DEFF Research Database (Denmark)

    Rose, Jørgen

    1997-01-01

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

  9. Propagation Engineering in Wireless Communications

    CERN Document Server

    Ghasemi, Abdollah; Ghasemi, Farshid

    2012-01-01

    Wireless communications has seen explosive growth in recent decades, in a realm that is both broad and rapidly expanding to include satellite services, navigational aids, remote sensing, telemetering, audio and video broadcasting, high-speed data communications, mobile radio systems and much more. Propagation Engineering in Wireless Communications deals with the basic principles of radiowaves propagation for frequency bands used in radio-communications, offering descriptions of new achievements and newly developed propagation models. The book bridges the gap between theoretical calculations and approaches, and applied procedures needed for advanced radio links design. The primary objective of this two-volume set is to demonstrate the fundamentals, and to introduce propagation phenomena and mechanisms that engineers are likely to encounter in the design and evaluation of radio links of a given type and operating frequency. Volume one covers basic principles, along with tropospheric and ionospheric propagation,...

  10. Noise Reduction of Fractional Source in Cryogenic Current Comparator Bridge

    OpenAIRE

    C. Jassadajin; Kurupakorn, C.; N. Khumthukthit; A. Pruksanubal

    2013-01-01

    In this work, a resistance measurement is done at both high accuracy and precision using Cryogenic Current Comparator (CCC) bridge system [1]. A CCC bridge circuit consists of three parts: coil, current source and detector parts. There are electronic components in the current source of the system. They generate thermal noise in the measurement system. This paper shows the noise reduction in a fractional source of CCC Bridge which is a ramp generator. The bridge receives the voltage signal, wh...

  11. RISK LEVEL ANALYSIS ON THE PREVENTIVE EROSION CAPACITY OF BRIDGES

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Deficiency of the Preventive Erosion Capacity (PEC) of a bridge pier is the main factor leading to bridge failures. In this paper, the PEC of bridge piers was analyzed using the stochastic analysis method. The definitions of the reliability and risk level of a bridge pier subjected to water erosion were proposed and a computational model for erosion depth and risk level in was suggested.

  12. The detection of an older population in the Magellanic Bridge

    OpenAIRE

    Bagheri, Gemma; Cioni, Maria-Rosa; Napiwotzki, Ralf

    2012-01-01

    The Magellanic system comprises the Large Magellanic Cloud (LMC), the Small Magellanic Cloud (SMC), and the less frequently observed Magellanic Bridge and Magellanic Stream. The Bridge is traced by neutral gas and has an observed stellar component, while the Stream consists of gas only, with no observed stellar counterpart to date. This study uses catalogues created in the direction of the Bridge from 2MASS and WISE to investigate the stellar content of the Magellanic Bridge. Catalogues were ...

  13. Rupture of an Evaporating Liquid Bridge between Two Grains

    OpenAIRE

    Mielniczuk, Boleslaw; El Youssoufi, Moulay Saïd; Sabatier, Laurent; Hueckel, Tomasz

    2014-01-01

    The study examines rupture of evaporating liquid bridges between two glass spheres. Evolution of the bridge profile has been recorded with the use of high-speed camera. Geometrical characteristics of the bridge were then used to calculate evolution of the variables during the process: Laplace pressure, capillary force, and surface tension force. For the purpose of reference, the bridge evolution is followed also during kinematic extension. During both processes the diameter of the neck decrea...

  14. TorBricks: Blocking-Resistant Tor Bridge Distribution

    OpenAIRE

    Zamani, Mahdi; Saia, Jared; Crandall, Jedidiah

    2016-01-01

    Tor is currently the most popular network for anonymous Internet access. It critically relies on volunteer nodes called bridges for relaying Internet traffic when a user's ISP blocks connections to Tor. Unfortunately, current methods for distributing bridges are vulnerable to malicious users who obtain and block bridge addresses. In this paper, we propose TorBricks, a protocol for distributing Tor bridges to n users, even when an unknown number t < n of these users are controlled by a malicio...

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

    Data.gov (United States)

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

  16. Nondestructive evaluation inspection of the Arlington Memorial Bridge using a robotic assisted bridge inspection tool (RABIT)

    Science.gov (United States)

    Gucunski, Nenad; Boone, Shane D.; Zobel, Rob; Ghasemi, Hamid; Parvardeh, Hooman; Kee, Seong-Hoon

    2014-04-01

    The information presented in this report provides a detailed assessment of the condition of the Arlington Memorial Bridge (AMB) deck. The field-data collection was obtained by both the RABIT™ Bridge Inspection Tool and a number of semi-automated non-destructive evaluation (NDE) tools. The deployment of the semi-automated NDE tools was performed to inspect the AMB deck condition and also to validate data obtained by the RABIT™ Bridge Inspection Tool. Data mining and analysis were accomplished through enhanced data interpretation and visualization capabilities using advanced data integration, fusion, and 2D rendering. One of the major challenges that the research team had to overcome in assessing the condition of the AMB deck was the presence of an asphalt overlay on the entire bridge deck.

  17. Advances in Structural Control in Civil Engineering in China

    Directory of Open Access Journals (Sweden)

    Hongnan Li

    2010-01-01

    Full Text Available In the recent years, much attention has been paid to the research and development of structural control techniques with particular emphasis on alleviation of wind and seismic responses of buildings and bridges in China. Structural control in civil engineering has been developed from the concept into a workable technology and applied into practical engineering structures. The aim of this paper is to review a state of the art of researches and applications of structural control in civil engineering in China. It includes the passive control, active control, hybrid controland semiactive control. Finally, the possible future directions of structural control in civil engineering in China are presented.

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

    Science.gov (United States)

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

    2015-12-01

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

  19. Building water bridges in air: Electrohydrodynamics of the Floating Water Bridge

    OpenAIRE

    Marin, Alvaro G.; Lohse, Detlef

    2010-01-01

    The interaction of electrical fields and liquids can lead to a phenomenon that defies intuition. Some famous examples can be found in electrohydrodynamics as Taylor cones, whipping jets, or noncoalescing drops. A less famous example is the floating water bridge: a slender thread of water held between two glass beakers in which a high voltage difference is applied. Surprisingly, the water bridge defies gravity even when the beakers are separated at distances up to 2 cm. In this paper, experime...

  20. Spectroscopic Studies of Bridge Contributions to Electronic Coupling in a Donor-Bridge-Acceptor Biradical System

    OpenAIRE

    Kirk, Martin L.; Shultz, David A.; Depperman, Ezra C.; Habel-Rodriguez, Diana; Schmidt, Robert D.

    2012-01-01

    Variable temperature electronic absorption and resonance Raman spectroscopies are used to probe the excited state electronic structure of TpCum,MeZn(SQ-Ph-NN) (1) – a donor-bridge-acceptor (D-B-A) biradical complex and a ground state analog of the charge-separated excited state formed in photoinduced electron transfer reactions. Strong ferromagnetic exchange coupling that is mediated by the para-phenylene bridge stabilizes the triplet ground state of this molecule. Detailed spectroscopic and ...

  1. 49 CFR 237.31 - Adoption of bridge management programs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Adoption of bridge management programs. 237.31 Section 237.31 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Adoption of bridge management programs. Each track owner shall adopt a bridge safety management program...

  2. Ambient Response Analysis of the Great Belt Bridge

    DEFF Research Database (Denmark)

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

    2000-01-01

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

  3. 23 CFR 650.409 - Evaluation of bridge inventory.

    Science.gov (United States)

    2010-04-01

    ... BRIDGES, STRUCTURES, AND HYDRAULICS Highway Bridge Replacement and Rehabilitation Program § 650.409... establishing eligibility and priority for replacement or rehabilitation of bridges; in general the lower the... State program. After evaluation of the inventory and assignment of sufficiency ratings, the...

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  5. 21 CFR 872.3770 - Temporary crown and bridge resin.

    Science.gov (United States)

    2010-04-01

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

  6. Resin-Bonded Bridges in vitro and in vivo

    NARCIS (Netherlands)

    Veen, Johannes Hilbrandt van der

    1988-01-01

    In this thesis in vitro and in vivo studies on the clinical application of resin-bonded bridges are described and discussed. The development of different types of resin-bonded bridges is described in chapter 1. The bridges are often made by boding a cast metal retainer fitted with and artificial too

  7. Bridged Quaterphenyls as Flashlamp-Pumpable Laser Dyes

    OpenAIRE

    Kauffman, Joel M; Kelley, Charles J.; Ghiorghis, Alem; Neister, Edward; Armstrong, Lorne; Prause, Paul R.

    1987-01-01

    Partial bridging of the o,o′ positions of the aromatic rings in quaterphenyl gave superior flashlamp-pumpable laser dyes. Alkyl-substituted carbon bridges gave superior dyes to those containing oxygen or alkyl-substituted nitrogen or silicon bridges. Dyes lasing in the 365–390 nm region with improved energy output, lifetime and solubility were discovered.

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

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  9. Renovation techniques for fatigue cracked orthotropic steel bridge decks

    NARCIS (Netherlands)

    de Jong, F.B.P.

    2007-01-01

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

  10. Road Bridges and Culverts, Bridges layers located in GIS and Transportation database., Published in unknown, City of Roswell, GA.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Road Bridges and Culverts dataset as of unknown. It is described as 'Bridges layers located in GIS and Transportation database.'. Data by this publisher are...

  11. Nonlinear Stability Analysis of Long-Span Continuous Rigid Frame Bridge with Thin-Wall High Piers

    Institute of Scientific and Technical Information of China (English)

    Li Li; Peng Yuancheng; Long Xiaohong; Liao Ping

    2005-01-01

    By utilizing the current finite element program ANSYS, two types of finite element models (FEM), the beam model (BM) and shell model (SM), are established for the nonlinear stability analysis of a practical rigid frame bridge-Longtanhe Great Bridge. In these analyses, geometrical and material nonlinearities are simultaneously taken into account. For geometrical nonlinearity, updated Lagrangian formulations are adopted to derive the tangent stiffness matrix. In order to simulate the nonlinear behavior of the plastic hinge of the piers, the multi-lines spring element COMBIN39 is used in the SM while the bilinear rotational spring element COMBIN40 is employed in the BM. Numerical calculations show that satisfying results can be obtained in the stability analysis of the bridge when the double coupling nonlinearity effects are considered. In addition, the conclusion is significant for practical engineering.

  12. Biomedical Engineering

    CERN Document Server

    Suh, Sang C; Tanik, Murat M

    2011-01-01

    Biomedical Engineering: Health Care Systems, Technology and Techniques is an edited volume with contributions from world experts. It provides readers with unique contributions related to current research and future healthcare systems. Practitioners and researchers focused on computer science, bioinformatics, engineering and medicine will find this book a valuable reference.

  13. Corrosion Engineering.

    Science.gov (United States)

    White, Charles V.

    A description is provided for a Corrosion and Corrosion Control course offered in the Continuing Engineering Education Program at the General Motors Institute (GMI). GMI is a small cooperative engineering school of approximately 2,000 students who alternate between six-week periods of academic study and six weeks of related work experience in…

  14. Genetic Engineering

    Science.gov (United States)

    Phillips, John

    1973-01-01

    Presents a review of genetic engineering, in which the genotypes of plants and animals (including human genotypes) may be manipulated for the benefit of the human species. Discusses associated problems and solutions and provides an extensive bibliography of literature relating to genetic engineering. (JR)

  15. Systems Engineering

    Science.gov (United States)

    Pellerano, Fernando

    2015-01-01

    This short course provides information on what systems engineering is and how the systems engineer guides requirements, interfaces with the discipline leads, and resolves technical issues. There are many system-wide issues that either impact or are impacted by the thermal subsystem. This course will introduce these issues and illustrate them with real life examples.

  16. Biosystems engineering

    OpenAIRE

    P. Ulger; E. Gonulol

    2015-01-01

    Higher agricultural education system has been getting multidiscipline as a result of the level oftechnology, recently. Biosystems Engineering has become popular in developed countries particularly afterelectronic and information technologies has been getting to be a part of agriculture and accompanied ofbiology. In this study definition of Biosystems Engineering discipline, working areas, research, publicationand job opportunities were discussed meticulously. Academic organization of Biosyste...

  17. GEOTECHNICAL MODELS OF THE ARCH FOUNDATIONS OF THE MASLENICA BRIDGE

    Directory of Open Access Journals (Sweden)

    Tomislav Novosel

    1998-12-01

    Full Text Available On the site of Maslenica bridge structural tectonic, geophysical and engineering geological investigations, geotechnical drilling and laboratory sample testings were performed. Maslenica anticline is characteristic for the investigated area. It is built from the limestone of Cretaceous age. The anticline has an asymmetrical form with the vergence of the axial plane towards the north. Reverse faults with recent activities are present. The recent activity was proved by the discovery of the broken stalactite with the displacement of 11 cm, whose age is 36000 years. On quite young stalactites (stalagmites in the cave on the west side, no displacements were noticed. For the next period of 500 years the maximal possible displacement of 2.0 cm is foreseen. Smaller caves with the dimensions of 1 m3, were formed on the intersections of the reverse faults and greater joints. The canyon Novsko ždrilo was formed in the fault shear zone with tectonic transport to the right. According to the range of fracture, three characteristic types of rock masses were separated by engineering geological investigations. According to »Geomechanical classification« (RMR the first type corresponds to II to III class, while the second type corresponds to IV class, and the third type corresponds to V class (mylonite. Because of the complexity of the terrain structure, original engineering geological bases of design have not enabled the direct application of the analysis of stress-strain behaviour. Because of that the simplified geotechnical models were done. They enabled the projecting of foundation in the rock mass and renewal of poor quality rock mass.

  18. Engineering surveying

    CERN Document Server

    Schofield, W

    2001-01-01

    The aim of Engineering Surveying has always been to impart and develop a clear understanding of the basic topics of the subject. The author has fully revised the book to make it the most up-to-date and relevant textbook available on the subject.The book also contains the latest information on trigonometric levelling, total stations and one-person measuring systems. A new chapter on satellites ensures a firm grasp of this vitally important topic.The text covers engineering surveying modules for civil engineering students on degree courses and forms a reference for the engineering surveying module in land surveying courses. It will also prove to be a valuable reference for practitioners.* Simple clear introduction to surveying for engineers* Explains key techniques and methods* Details reading systems and satellite position fixing

  19. Emotional engineering

    CERN Document Server

    In an age of increasing complexity, diversification and change, customers expect services that cater to their needs and to their tastes. Emotional Engineering vol 2. describes how their expectations can be satisfied and managed throughout the product life cycle, if producers focus their attention more on emotion. Emotional engineering provides the means to integrate products to create a new social framework and develops services beyond product realization to create of value across a full lifetime.  14 chapters cover a wide range of topics that can be applied to product, process and industry development, with special attention paid to the increasing importance of sensing in the age of extensive and frequent changes, including: • Multisensory stimulation and user experience  • Physiological measurement • Tactile sensation • Emotional quality management • Mental model • Kansei engineering.   Emotional Engineering vol 2 builds on Dr Fukuda’s previous book, Emotional Engineering, and provides read...

  20. A study on building an experimental system of PVDF sensor for structural local monitoring on a bridge model

    Science.gov (United States)

    Yu, Yan; Wang, Yang; An, Yonghui; Ou, Jinping

    2010-04-01

    Smart material structure originated from aerospace area has been a research hotspot in the application of civil engineering, shipping, and so on. For structural health monitoring of civil engineering, the research about highperformance sensing unit of smart material structure is very important, and this will possibly push further the development of health monitoring and diagnosis technique. As one of the piezoelectric materials belonging to smart materials, PVDF (Polyvinylidene Fluoride) film is widely concerned for its property advantages of low cost, good mechanical ability, high sensibility, resistance of corrosion. In this paper, for the validation of using PVDF for sensing unit for structural local monitoring of civil engineering, an experimental system of PVDF sensor for structural local monitoring on a bridge model is built. Based on the operating mechanism of PVDF, its measure circuit and characteristics(quasi-static and dynamic strain responding) are introduced. A bridge model is designed, and experiments have also been done for structural local health monitoring using PVDF. The experimental results show that, PVDF can finish impact response monitoring and damage detection of a bridge model, and the developed experimental system with simple and easy implement can be used for practical monitoring engineering.

  1. Digimarc MediaBridge: the birth of a consumer product from concept to commercial application

    Science.gov (United States)

    Perry, Burt; MacIntosh, Brian; Cushman, David

    2002-04-01

    This paper examines the issues encountered in the development and commercial deployment of a system based on digital watermarking technology. The paper provides an overview of the development of digital watermarking technology and the first applications to use the technology. It also looks at how we took the concept of digital watermarking as a communications channel within a digital environment and applied it to the physical print world to produce the Digimarc MediaBridge product. We describe the engineering tradeoffs that were made to balance competing requirements of watermark robustness, image quality, embedding process, detection speed and end user ease of use. Today, the Digimarc MediaBridge product links printed materials to auxiliary information about the content, via the Internet, to provide enhanced informational marketing, promotion, advertising and commerce opportunities.

  2. Stability Analysis of Long-Span Continuous Rigid Frame Bridge with Thin-Wall Pier

    Institute of Scientific and Technical Information of China (English)

    HE Bo; SHI Ya-nan; ZHU Hong-ping; GUO Wen-zeng; CHEN Yong

    2008-01-01

    During cantilever cast in construction of high-pier and large-span continuous rigid frame bridges, structural stability in the longest cantilevered stage is very important. Based on a practical design case of a large-span continuous rigid frame bridge in Wuhan, the longest span stability coefficient is calculated with linear-buckling and nonlinear-buckling methods, respectively. The influences of both geometrical nonlinearity and the dual nonlinearity of material and geometry are considered. Numerical results indicate that the nonlinear solution is necessary to stability analysis because linear buckling loads axe much higher than those of nonlinear buckling. Thus, the edge fiber yield criterion is more convenient and faster than ultimate loading criterion when estimating nonlinear stability of structure, and can be used easily in the initial engineering design.

  3. Application of discrete model in analyzes of built and tested composite bridge construction

    Directory of Open Access Journals (Sweden)

    Tarić Mirsad

    2011-01-01

    Full Text Available Designing problem and theoretical analyses of steel-concrete composite structures are especially emphasized in bridge engineering. Method of modelling composite constructions developed and established by standards had been improved by use of finite element method and modern software. By this paper authors wanted to point out the importance of adequate structure modelling assuming all features of steel-concrete bond, and comparing results of experimental research with results of software calculation based on FEM and calculation based on plane theory approach with certain simplifications. Because of research tests necessities the bridge was loaded with four heavy test vehicles. Results, which are represented graphically and numerically were essence for suggestion of giving advantages to area element discretization of composite section over the other one.

  4. Numerical analysis of ultimate strength of concrete filled steel tubular arch bridges

    Institute of Scientific and Technical Information of China (English)

    XIE Xu; CHEN Heng-zhi; Li Hui; SONG Shi-rui

    2005-01-01

    The calculation of ultimate bearing capacity is a significant issue in the design of Concrete Filled Steel Tubular (CFST)arch bridges. Based on the space beam theory, this paper provides a calculation method for determining the ultimate strength of CFST structures. The accuracy of this method and the applicability of the stress-strain relationships were validated by comparing different existing confined concrete uniaxial constitutive relationships and experimental results. Comparison of these results indicated that this method using the confined concrete uniaxial stress-strain relationships can be used to calculate the ultimate strength and CFST behavior with satisfactory accuracy. The calculation results are stable and seldom affected by concrete constitutive relationships. The method is therefore valuable in the practice of engineering design. Finally, the ultimate strength of an arch bridge with span of 330 m was investigated by the proposed method and the nonlinear behavior was discussed.

  5. Comprehensive Detection and Analysis of Defects in Foundation Pile of Bridge

    Institute of Scientific and Technical Information of China (English)

    WANG Qi-ren; HE Ji-shan; YANG Tian-chun

    2003-01-01

    In the process of piling ,there are many various defects in foundation pile of bridge such as mud-bearing,sediment-bearing, isolation, honeycomb, broken piles, and so on, showing physical and mechanical features of low-density and low-intensity. In fact, by using the comprehensive detection of acoustic transmission method, the reflected wave method as well as drill coring sample method, and the rational utilization of engineering geological condition in field, the characteristics, size and location of common defects of foundation pile of bridge can be accurately detected and judged and the integrity of piles and the quality of concrete can be impersonally estimated.comprehensive detecting and analyzing methods on this kind of piles are introduced briefly. The physical characters of defects and basic features of detecting curves and their corresponding relation are emphasized, and causes are analyzed in in detail in this paper.

  6. Advances in Structural Control in Civil Engineering in China

    OpenAIRE

    Hongnan Li; Linsheng Huo

    2010-01-01

    In the recent years, much attention has been paid to the research and development of structural control techniques with particular emphasis on alleviation of wind and seismic responses of buildings and bridges in China. Structural control in civil engineering has been developed from the concept into a workable technology and applied into practical engineering structures. The aim of this paper is to review a state of the art of researches and applications of structural control in civil enginee...

  7. International Conference on Emerging Trends in Science, Engineering and Technology

    CERN Document Server

    Caroline, B; Jayanthi, J

    2012-01-01

    The present book is based on the research papers presented in the International Conference on Emerging Trends in Science, Engineering and Technology 2012, held at Tiruchirapalli, India. The papers presented bridges the gap between science, engineering and technology. This book covers a variety of topics, including mechanical, production, aeronautical, material science, energy, civil and environmental energy, scientific management, etc. The prime objective of the book is to fully integrate the scientific contributions from academicians, industrialists and research scholars.

  8. A nature-inspired approach to reactor and catalysis engineering

    OpenAIRE

    Coppens, M-O

    2012-01-01

    Mechanisms used by biology to solve fundamental problems, such as those related to scalability, efficiency and robustness could guide the design of innovative solutions to similar challenges in chemical engineering. Complementing progress in bioinspired chemistry and materials science, we identify three methodologies as the backbone of nature-inspired reactor and catalysis engineering. First, biology often uses hierarchical networks to bridge scales and facilitate transport, leading to broadl...

  9. Multiscale computer modeling in biomechanics and biomedical engineering

    CERN Document Server

    2013-01-01

    This book reviews the state-of-the-art in multiscale computer modeling, in terms of both accomplishments and challenges. The information in the book is particularly useful for biomedical engineers, medical physicists and researchers in systems biology, mathematical biology, micro-biomechanics and biomaterials who are interested in how to bridge between traditional biomedical engineering work at the organ and tissue scales, and the newer arenas of cellular and molecular bioengineering.

  10. Towards Model Driven Tool Interoperability: Bridging Eclipse and Microsoft Modeling Tools

    Science.gov (United States)

    Brunelière, Hugo; Cabot, Jordi; Clasen, Cauê; Jouault, Frédéric; Bézivin, Jean

    Successful application of model-driven engineering approaches requires interchanging a lot of relevant data among the tool ecosystem employed by an engineering team (e.g., requirements elicitation tools, several kinds of modeling tools, reverse engineering tools, development platforms and so on). Unfortunately, this is not a trivial task. Poor tool interoperability makes data interchange a challenge even among tools with a similar scope. This paper presents a model-based solution to overcome such interoperability issues. With our approach, the internal schema/s (i.e., metamodel/s) of each tool are explicited and used as basis for solving syntactic and semantic differences between the tools. Once the corresponding metamodels are aligned, model-to-model transformations are (semi)automatically derived and executed to perform the actual data interchange. We illustrate our approach by bridging the Eclipse and Microsoft (DSL Tools and SQL Server Modeling) modeling tools.

  11. Claude Claremont's Contribution to the History of Science and Engineering.

    Science.gov (United States)

    Hallenberg, Harvey R.

    1995-01-01

    Discusses the contributions of Claude Claremont to science education for children and his 1937 book, "Spanning Space," which outlines the building of models of bridges and other structures out of paper. Also describes how children and their teachers can build a model strut tower and a steam engine. (MDM)

  12. Small-strain measurement in bridge connections using the digital image correlation (DIC) technique

    Science.gov (United States)

    Desai, Niranjan

    2016-04-01

    Structural health monitoring (SHM) is emerging as a vital tool to help civil engineers improve the safety, maintainability, and reliability of critical structures and assists infrastructure owners with timely information for the continued safe and economic operation of their structure. SHM involves implementing a strategy that identifies and characterizes damage or undesirable performance in engineering structures. The goal of this research project was to determine the smallest strains measurable using standard digital image correlation (DIC) based SHM equipment. This practical investigation that had strong ties to the industry was motivated by damage observed in a real-world bridge, which was initially undetected. Its early detection would have led to reduced repair costs. To accomplish the aforementioned goal, tests were performed on a laboratory specimen that replicated a steel beam-to-column connection of the concerned bridge, involving progressively loading it in a manner in which it was loaded in the actual bridge, while simultaneously measuring the strains that developed in it using the aforementioned DIC-based equipment and software. Under the controlled conditions in the laboratory, the minimum resolution of the state-of-the-art system used in this investigation was determined. Due to the challenges faced in making these small-strain measurements even under highly controlled laboratory conditions, it was concluded that it is currently unrealistic to use the existing DIC technology in a real-world situation to measure strains as small as those that would need to be measured to detect the onset of damage in bridge connections. More work needs to be done in this area.

  13. 高速公路桥梁加固后评价技术%Post Evaluation of Expressway Bridge Reinforcement Technology

    Institute of Scientific and Technical Information of China (English)

    孙卫民

    2014-01-01

    Based on the summarization of current post evaluation technology for highway bridge reinforce-ment project, the article discusses the basic concept, the reinforcement of bridge evaluation objective, con-tent of post evaluation for bridge reinforcement. Combined with the engineering example, the article points out the problems of bridge reinforcement post evaluation and the further research direction.%在对当前高速公路桥梁加固项目后评价技术进行总结分析的基础上,重点论述了桥梁加固后评价的基本概念、目的、内容,并结合具体工程实例指出了当前桥梁加固后评价存在的问题以及进一步的研究方向。

  14. PARAMETRIC STUDY OF SKEW ANGLE ON BOX GIRDER BRIDGE DECK

    OpenAIRE

    Shrikant D. Bobade *, Dr. Valsson Varghese

    2016-01-01

    Box girder bridge deck, is the most common type of bridges in world and India, it consists of several Slab or girders. The span in the direction of the roadway and connected across their tops and bottoms by a thin continuous structural stab, the longitudinal box girders can be made of steel or concrete. The Simple supported single span concrete bridge deck is presented in present study. Skewed bridges are suitable in highway design when the geometry of straight bridges is not possible. The sk...

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

    DEFF Research Database (Denmark)

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

    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...... 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...

  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

    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...... 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...

  17. 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.

  18. Dynamic analysis of rail transit elevated bridge with ladder track

    Institute of Scientific and Technical Information of China (English)

    He XIA; Yushu DENG; Yongwei ZOU; Guido DE ROECK; Geert DEGRANDE

    2009-01-01

    In this paper, a dynamic analysis model of an elevated bridge with ladder tracks under moving train load is established. The whole process of a train running through an elevated bridge at different speeds is simulated.The dynamic responses of the elevated bridge with ladder track and the running safety and comfort index of train vehicles are evaluated. Compared with the dynamic responses of an elevated bridge with ordinary non-ballasted slab track, the ladder track's effect on reducing the vibration of an elevated bridge is analyzed. The analysis results show that the ladder track has good vibration reduction characteristics as compared to ordinary non-ballasted track.

  19. Suspension Bridge Flutter for Girder with Separate Control Flaps

    DEFF Research Database (Denmark)

    Huynh, T.; Thoft-Christensen, Palle

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

  20. Cross-bridge model of muscle contraction. Quantitative analysis.

    OpenAIRE

    Eisenberg, E.; Hill, T L; Chen, Y.

    1980-01-01

    We recently presented, in a qualitative manner, a cross-bridge model of muscle contraction which was based on a biochemical kinetic cycle for the actomyosin ATPase activity. This cross-bridge model consisted of two cross-bridge states detached from actin and two cross-bridge states attached to actin. In the present paper, we attempt to fit this model quantitatively to both biochemical and physiological data. We find that the resulting complete cross-bridge model is able to account reasonably ...

  1. Excitation of Arch and Suspension Bridges by Subwires

    Directory of Open Access Journals (Sweden)

    Noriaki Hiwatashi

    1993-01-01

    Full Text Available A force generation method using a subwire for arch and suspension bridges is proposed. The subwire is connected to the arch or the cable of the bridge through rollers. The uniform force produced by pulling and releasing the pretensioned subwires acts on the bridge as an externalforce. A new device called “the resonance force generator” is also developed to excite the bridges by applying a small force. To verify the proposed concept, a stress ribbon bridge was excited with the resonance force generator.

  2. Excitation of Arch and Suspension Bridges by Subwires

    OpenAIRE

    Noriaki Hiwatashi; Yoji Mizuta; Yutaka Ishihara; Itio Hirai

    1993-01-01

    A force generation method using a subwire for arch and suspension bridges is proposed. The subwire is connected to the arch or the cable of the bridge through rollers. The uniform force produced by pulling and releasing the pretensioned subwires acts on the bridge as an externalforce. A new device called “the resonance force generator” is also developed to excite the bridges by applying a small force. To verify the proposed concept, a stress ribbon bridge was excited with the resonance force ...

  3. Violin Bridge Mobility Analysis under In-Plane Excitation

    OpenAIRE

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

    2013-01-01

    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 frequen...

  4. 道路桥梁设计隐患分析%Analysis of Road and Bridge Design Hazard

    Institute of Scientific and Technical Information of China (English)

    崔巍

    2015-01-01

    作为道路桥梁工程施工建设过程中最关键的环节,道路桥梁的设计质量直接影响其施工建设的整体质量。道路桥梁的设计问题可从耐用性和安全性考虑,设计时,应充分考虑桥梁设计、建设和使用中各类影响道路桥梁安全的因素,同时对道路桥梁设计中存在的问题提出解决对策。注重设计的合理性和科学性,在保证工期进度的同时,充分保证道路桥梁的整体质量。%As the roads and bridges,the most crucial steps in the process of engineering construction, road and bridge design quality directly affect the overall quality of construction.Road and bridge design problems from the durability and safety consideration,the design,should give full consideration to bridge design,construction and use of all kinds of factors affecting the safety of roads and bridges,as well as the problems of road and bridge design countermeasures are put forward. Pay attention to the rationality and scientific nature of design,during the guarantee period of progress at the same time,fully guarantee the overall quality of the roads and bridges.

  5. Engineering mathematics

    CERN Document Server

    Bird, John

    2014-01-01

    A practical introduction to the core mathematics required for engineering study and practiceNow in its seventh edition, Engineering Mathematics is an established textbook that has helped thousands of students to succeed in their exams.John Bird's approach is based on worked examples and interactive problems. This makes it ideal for students from a wide range of academic backgrounds as the student can work through the material at their own pace. Mathematical theories are explained in a straightforward manner, being supported by practical engineering examples and applications in order to ensure

  6. Engineering mathematics

    CERN Document Server

    Stroud, K A

    2013-01-01

    A groundbreaking and comprehensive reference that's been a bestseller since it first debuted in 1970, the new seventh edition of Engineering Mathematics has been thoroughly revised and expanded. Providing a broad mathematical survey, this innovative volume covers a full range of topics from the very basic to the advanced. Whether you're an engineer looking for a useful on-the-job reference or want to improve your mathematical skills, or you are a student who needs an in-depth self-study guide, Engineering Mathematics is sure to come in handy time and time again.

  7. Bridge health assessment system with fatigue analysis algorithm

    Science.gov (United States)

    Wang, Xuan; Wang, M. L.; Zhao, Yang

    2005-05-01

    A modern bridge is such a complicated system that is difficult to analyze by conventional mathematic tools. A rational bridge monitoring requires a good knowledge of the actual condition of various structural components. Fatigue analysis of concrete bridges is one of the most important problems. Concrete bridges are often undergoing a fatigue deterioration, starting with cracking and ending with large holes through the web. There is a need for the development of efficient health assessment system for fatigue evaluation and prediction of the remaining life. This information has clear economical consequences, as deficient bridges must be repaired or closed. The goal of this research is to provide a practical expert system in bridge health evaluation and improve the understanding of bridge behavior during their service. Efforts to develop a functional bridge monitoring system have mainly been concentrated upon successful implementation of experienced-based machine learning. The reliability of the techniques adopted for damage assessment is also important for bridge monitoring systems. By applying the system to an in-service PC bridge, it has been verified that this fuzzy logic expert system is effective and reliable for the bridge health evaluation.

  8. A Review of Indirect Bridge Monitoring Using Passing Vehicles

    Directory of Open Access Journals (Sweden)

    Abdollah Malekjafarian

    2015-01-01

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

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

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2016-01-01

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

  10. 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.

  11. Bridge Condition Assessment Using D Numbers

    Directory of Open Access Journals (Sweden)

    Xinyang Deng

    2014-01-01

    Full Text Available Bridge condition assessment is a complex problem influenced by many factors. The uncertain environment increases more its complexity. Due to the uncertainty in the process of assessment, one of the key problems is the representation of assessment results. Though there exists many methods that can deal with uncertain information, however, they have more or less deficiencies. In this paper, a new representation of uncertain information, called D numbers, is presented. It extends the Dempster-Shafer theory. By using D numbers, a new method is developed for the bridge condition assessment. Compared to these existing methods, the proposed method is simpler and more effective. An illustrative case is given to show the effectiveness of the new method.

  12. Tacoma Bridge Failure-- a Physical Model

    CERN Document Server

    Green, D; Green, Daniel; Unruh, William G.

    2004-01-01

    The cause of the collapse of the Tacoma Narrows Bridge has been a topic of much debate and confusion since the day it fell. Many mischaracterizations of the observed phenomena have limited the widespread understanding of the problem. Nevertheless, there has always been an abundance of evidence in favour of a negative damping model. Negative damping, or positive feedback, is responsible for many large amplitude oscillations observed in many applications. In this paper, we will explain some well-known examples of positive feedback. We will then present a feedback model, derived from fundamental physics, capable of explaining a number of features observed in the instabilities of many bridge decks. This model is supported by computational, experimental and historical data.

  13. Fatigue-Prone Details in Steel Bridges

    Directory of Open Access Journals (Sweden)

    Mohsen Heshmati

    2012-11-01

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

  14. A liquid bridge connecting moving porous surfaces

    Science.gov (United States)

    Gharib, Morteza; Gat, Amir; Navaz, Homayun

    2011-11-01

    We study the coupled problem of a liquid bridge connecting two porous surfaces where the gap between the surfaces is an externally controlled function of time. The relative motion between the surfaces affects the geometry and the pressure distribution of the liquid bridge, thus influencing the diffusion speed and penetration topology within the porous material. Utilizing the lubrication approximation and Darcy's phenomenological law we obtain a relation between the diffusion into the porous surface and the relative motion between the surfaces. A scheme to control the diffusion topology is presented and illustrated for the case of conical penetration topology with an arbitrary cone opening angle. Analytic expressions describing the penetration topology for the case of constant speed of the surfaces and the relative motion between the surfaces required to create a conical penetration topology are obtained and compared to experimental and numerical data. This project was supported by the Defense Threat Reduction Agency (DTRA), Award Number: 330233-A.

  15. Bridging the Divide between Science and Journalism

    OpenAIRE

    Marincola Francesco M; Van Eperen Laura; Strohm Jennifer

    2010-01-01

    Abstract There are countless reasons nearly every scientist should learn how to communicate effectively with the media, including increased understanding of critical research findings to attract or sustain funding and build new professional partnerships that will further propel forward research. But where do scientists begin? Bridging the Divide between Science and Journalism offers practical tips for any scientist looking to work with the media. Given the traditional and internet-based sourc...

  16. Fatigue-Prone Details in Steel Bridges

    OpenAIRE

    Mohsen Heshmati; Mohammad Al-Emrani; Reza Haghani

    2012-01-01

    This paper reviews the results of a comprehensive investigation including more than 100 fatigue damage cases, reported for steel and composite bridges. The damage cases are categorized according to types of detail. The mechanisms behind fatigue damage in each category are identified and studied. It was found that more than 90% of all reported damage cases are of deformation-induced type and generated by some kind of unintentional or otherwise overlooked interaction between different load-carr...

  17. Bridge Inspections and Being an ERC

    OpenAIRE

    Hoernschemeyer, Keith; Miller, Jessica

    2015-01-01

    This presentation will discuss recent changes to the County Bridge Inspection Program from the perspective of both the FHWA and INDOT. We will also discuss the responsibilities of the local public agency’s (LPA’s) employee in responsible charge (ERC) with respect to managing this program. As this course is a yearly requirement, all county ERCs are encouraged to attend. Pre-registering is strongly encouraged by e-mailing your contact information to .

  18. Liquid bridge simulations with OpenFOAM

    OpenAIRE

    Guirao Aguilar, Guillermo

    2011-01-01

    Any liquid-gas interface being under a temperature gradient is subject to a thermocapillary flow generated by the differences in the surface tension. In the particular case of liquid bridges, this flow can evolve into a oscillatory or travelling flow known as hydrothermal wave. This works aims to achieve a better understanding of the formation of this kind of flow by means of computational fluid dynamics techniques using a specific software package. For that, a simplified model of the liquid ...

  19. Legendrian framings for two-bridge links

    CERN Document Server

    Baader, Sebastian

    2009-01-01

    We define the Thurston-Bennequin polytope of a two-component link as the convex hull of all pairs of integers that arise as framings of a Legendrian representative. The main result of this paper is a description of the Thurston-Bennequin polytope for two-bridge links. As an application, we construct non-quasipositive surfaces in $\\R^3$ all whose sub-annuli are quasipositive.

  20. Ether bridge formation in loline alkaloid biosynthesis

    OpenAIRE

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

    2013-01-01

    Lolines are potent insecticidal agents produced by endophytic fungi of cool-season grasses. These alkaloids are composed of a pyrrolizidine ring system and an uncommon ether bridge linking carbons 2 and 7. Previous results indicated that 1-aminopyrrolizidine was a pathway intermediate. We used RNA interference to knock down expression of lolO, resulting in the accumulation of a novel alkaloid identified as exo-1-acetamidopyrrolizidine based on high-resolution MS and NMR. Genomes of endophytes...

  1. Bridging the Gap: Linking Simulation and Testing

    Energy Technology Data Exchange (ETDEWEB)

    Krajewski, Paul E.; Carsley, John; Stoudt, Mark R.; Hovanski, Yuri

    2012-09-01

    The Materials Genome Initiative (MGI) which is a key enabler for the Advanced Manufacturing Partnership, announced in 2011 by U.S. President Barack Obama, was established to accelerate the development and deployment of advanced materials. The MGI is driven by the need to "bridge the gap" between (I) experimental results and computational analysis to enable the rapid development and validation of new mateirals, and (II) the processes required to convert these materials into useable goods.

  2. Software engineering

    CERN Document Server

    Sommerville, Ian

    2016-01-01

    For courses in computer science and software engineering The Fundamental Practice of Software Engineering Software Engineering introduces readers to the overwhelmingly important subject of software programming and development. In the past few years, computer systems have come to dominate not just our technological growth, but the foundations of our world's major industries. This text seeks to lay out the fundamental concepts of this huge and continually growing subject area in a clear and comprehensive manner. The Tenth Edition contains new information that highlights various technological updates of recent years, providing readers with highly relevant and current information. Sommerville's experience in system dependability and systems engineering guides the text through a traditional plan-based approach that incorporates some novel agile methods. The text strives to teach the innovators of tomorrow how to create software that will make our world a better, safer, and more advanced place to live.

  3. Coastal Engineering

    NARCIS (Netherlands)

    Van der Velden, E.T.J.M.

    1989-01-01

    Introduction, waves, sediment transport, littoral transport, lonshore sediment transport, onshore-offshore sediment transport, coastal changes, dune erosion and storm surges, sedimentation in channels and trenches, coastal engineering in practice.

  4. Harmonic engine

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Charles L. (Livermore, CA)

    2009-10-20

    A high efficiency harmonic engine based on a resonantly reciprocating piston expander that extracts work from heat and pressurizes working fluid in a reciprocating piston compressor. The engine preferably includes harmonic oscillator valves capable of oscillating at a resonant frequency for controlling the flow of working fluid into and out of the expander, and also preferably includes a shunt line connecting an expansion chamber of the expander to a buffer chamber of the expander for minimizing pressure variations in the fluidic circuit of the engine. The engine is especially designed to operate with very high temperature input to the expander and very low temperature input to the compressor, to produce very high thermal conversion efficiency.

  5. Climate engineering

    OpenAIRE

    Platt, Ulrich

    2014-01-01

    Es klingt wie eine Mischung aus Größenwahn und Science Fiction: Wissenschaftler wollen das Klima mit Hightechverfahren beeinflussen. "Climate engineering" heißt der Fachbegriff. Natürlich geht es dabei nicht um den verregneten Sommer, sondern um den globalen Klimawandel. Campus-Reporter Nils Birschmann hat sich bei den Umweltforschern der Uni Heidelberg umgehört, ob was dran ist am "climate engineering". Der Beitrag erschien in der Sendereihe "Campus-Report" - einer Beitragsreihe, in ...

  6. Microwave engineering

    CERN Document Server

    Pozar, David M

    2012-01-01

    The 4th edition of this classic text provides a thorough coverage of RF and microwave engineering concepts, starting from fundamental principles of electrical engineering, with applications to microwave circuits and devices of practical importance.  Coverage includes microwave network analysis, impedance matching, directional couplers and hybrids, microwave filters, ferrite devices, noise, nonlinear effects, and the design of microwave oscillators, amplifiers, and mixers. Material on microwave and RF systems includes wireless communications, radar, radiometry, and radiation hazards. A large

  7. Engineering liver

    OpenAIRE

    Griffith, Linda G.; Wells, Alan; Stolz, Donna Beer

    2013-01-01

    Interest in “engineering liver” arises from multiple communities: therapeutic replacement; mechanistic models of human processes; and drug safety and efficacy studies. An explosion of micro- and nano-fabrication, biomaterials, microfluidic, and other technologies potentially afford unprecedented opportunity to create microphysiological models of human liver, but engineering design principles for how to deploy these tools effectively towards specific applications, including how to define the e...

  8. Engineering Statistics

    OpenAIRE

    Vardeman, Stephen B.

    2003-01-01

    In this entry we seek to put into perspective some of the ways in which statistical methods contribute to modern engineering practice. Engineers design and oversee the production, operation, and maintenance of the products and systems that under-gird modern technological society. Their work is built on the foundation of physical (and increasingly biological) science. However, it is of necessity often highly empirical, because there simply isn’t scientific theory complete and simple enough to ...

  9. Ecosystems Engineering

    OpenAIRE

    Ernesto Guhl Nannetti

    2015-01-01

    The article begins by referring to the evolution of engineering with the advancement of natural and physical sciences and the resulting specialization, which has blurred the boundaries of its integrating and holistic nature. This process is illustrated through the expansion of the programs and denominations in Colombia. Further on, it attempts to establish a relationship between engineering and sustainability, and it presents the strong impact of development on the planet's ecosystems, which ...

  10. Photoreceptor engineering

    OpenAIRE

    Thea eZiegler; Andreas eMöglich

    2015-01-01

    Sensory photoreceptors not only control diverse adaptive responses in Nature, but as light-regulated actuators they also provide the foundation for optogenetics, the non-invasive and spatiotemporally precise manipulation of cellular events by light. Novel photoreceptors have been engineered that establish control by light over manifold biological processes previously inaccessible to optogenetic intervention. Recently, photoreceptor engineering has witnessed a rapid development, and light-regu...

  11. Web Engineering

    OpenAIRE

    Deshpande, Yogesh; Murugesan, San; Ginige, Athula; Hansen, Steve; Schwabe, Daniel; Gaedke, Martin; White, Bebo

    2003-01-01

    Web Engineering is the application of systematic, disciplined and quantifiable approaches to development, operation, and maintenance of Web-based applications. It is both a pro-active approach and a growing collection of theoretical and empirical research in Web application development. This paper gives an overview of Web Engineering by addressing the questions: a) why is it needed? b) what is its domain of operation? c) how does it help and what should it do to improve Web application develo...

  12. Game Engineering

    OpenAIRE

    Aumann, Robert J.

    2009-01-01

    "Game Engineering" deals with the application of game theoretic methods to interactive situations or systems in which the rules are well defined, or where the designer can himself specify the rules. This talk, which addressed a business-school audience with no specific knowledge of game theory, describes five examples of game engineering: two dealing with auctions, two with traffic systems, and one with arbitration. At the end of the talk there was a Q & A session, which, too, is recorded here.

  13. Governing Engineering

    OpenAIRE

    Buch, Anders

    2011-01-01

    Abstract: Most people agree that our world faces daunting problems and, correctly or not, technological solutions are seen as an integral part of an overall solution. But what exactly are the problems and how does the engineering ‘mind set’ frame these problems? This chapter sets out to unravel dominant perspectives in challenge perception in engineering in the US and Denmark. Challenge perception and response strategies are closely linked through discursive practices. Challenge perceptions w...

  14. Bridge concrete deteriorating diagnosis by infrared thermography

    Science.gov (United States)

    Shibata, Hiroki; Fukuyama, Nobuhiro; Sakuma, Joji; Mochizuki, Jun; Kimura, Yukinori

    2006-04-01

    Bridge is indispensable as social overhead capital. In the past, concrete construction was believed to be semi-permanent. Actually, however, concrete is deteriorated by various factors including seawater damage, annual temperature change, etc. Therefore, it is now obvious that maintenance and management are essential to keep performance of the bridge. In Japan, we had many reports of using infrared thermography for diagnosis of building, mainly for delamination of tile and mortar used for surface of the building for more than 10 years. In recent years, infrared thermogrephy is more actively used for delamination of surface of the bridge. Passive method is usually used for open-air concrete structure diagnosis, which utilizes intraday environmental temperature change and/or radiation energy emitted from the sun which create delta-T of delamination portion of the concrete structure. It is very important to take thermal image at right conditions. Otherwise, you may easily fall onto false diagnosis. In our presentation, many case examples and study of thermal data will be shown, which are taken at the right condition.

  15. Building water bridges in air: Electrohydrodynamics of the Floating Water Bridge

    CERN Document Server

    Marin, Alvaro G

    2010-01-01

    The interaction of electrical fields and liquids can lead to phenomena that defies intuition. Some famous examples can be found in Electrohydrodynamics as Taylor cones, whipping jets or non-coalescing drops. A less famous example is the Floating Water Bridge: a slender thread of water held between two glass beakers in which a high voltage difference is applied. Surprisingly, the water bridge defies gravity even when the beakers are separated at distances up to 2 cm. In the presentation, experimental measurements and simple models are proposed and discussed for the stability of the bridge and the source of the flow, revealing an important role of polarization forces on the stability of the water bridge. On the other hand, the observed flow can only be explained due to the non negligible free charge present in the surface. In this sense, the Floating Water Bridge can be considered as an extreme case of a leaky dielectric liquid (J. R. Melcher and G. I. Taylor, Annu. Rev. Fluid Mech., 1:111, 1969).

  16. Engineering Annual Summary 1998

    Energy Technology Data Exchange (ETDEWEB)

    Dimolitsas, S

    1999-05-01

    Unlike most research and development laboratories, Lawrence Livermore National Laboratory (LLNL) is responsible for delivering production-ready designs. Unlike most industry, LLNL is responsible for R and D that must significantly increase the nation's security. This rare combination of production engineering expertise and national R and D agenda identifies LLNL as one of the few organizations today that conducts cutting-edge engineering on grand-scale problems, while facing enormous technical risk and undergoing diligent scrutiny of its budget, schedule, and performance. On the grand scale, cutting-edge technologies are emerging from our recent ventures into ''Xtreme Engineering{trademark}.'' Basically, we must integrate and extend technologies concurrently and then push them to their extreme, such as building very large structures but aligning them with extreme precision. As we extend these technologies, we push the boundaries of engineering capabilities at both poles: microscale and ultrascale. Today, in the ultrascale realm, we are building NIF, the world's largest laser, which demands one of the world's most complex operating systems with 9000 motors integrated through over 500 computers to control 60,000 points for every laser shot. On the other pole, we have fabricated the world's smallest surgical tools and the smallest instruments for detecting biological and chemical agents used by antiterrorists. Later in this Annual Summary, we highlight some of our recent innovations in the area of Xtreme Engineering, including large-scale computer simulations of massive structures such as major bridges to prepare retrofitting designs to withstand earthquakes. Another feature is our conceptual breakthrough in developing the world's fastest airplane, HyperSoar, which can reach anywhere in the planet in two hours at speeds of 6700 mph. In the last few years, Engineering has significantly pushed the technology in structural

  17. The Internet Inter-Orb Protocol Security Bridge

    Directory of Open Access Journals (Sweden)

    Pawel Slowikowski

    1999-01-01

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

  18. The effect of ageing on the mechanical properties of the silk of the bridge spider Larinioides cornutus (Clerck, 1757)

    OpenAIRE

    Emiliano Lepore; Marco Isaia; Stefano Mammola; Nicola Pugno

    2016-01-01

    Spider silk is regarded as one of the best natural polymer fibers especially in terms of low density, high tensile strength and high elongation until breaking. Since only a few bio-engineering studies have been focused on spider silk ageing, we conducted nano-tensile tests on the vertical naturally spun silk fibers of the bridge spider Larinioides cornutus (Clerck, 1757) (Arachnida, Araneae) to evaluate changes in the mechanical properties of the silk (ultimate stress and strain, Young’s modu...

  19. 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.

  20. Aerodynamic stability of cable-supported bridges using CFRP cables

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin-jun; YING Lei-dong

    2007-01-01

    To gain understanding of the applicability of carbon fiber reinforced polymer (CFRP) cable in cable-supported bridges, based on the Runyang Bridge and Jinsha Bridge, a suspension bridge using CFRP cables and a cable-stayed bridge using CFRP stay cables are designed, in which the cable's cross-sectional area is determined by the principle of equivalent axial stiffness.Numerical investigations on the aerodynamic stability of the two bridges are conducted by 3D nonlinear aerodynamic stability analysis. The results showed that as CFRP cables are used in cable-supported bridges, for suspension bridge, its aerodynamic stability is superior to that of the case using steel cables due to the great increase of the torsional frequency; for cable-stayed bridge,its aerodynamic stability is basically the same as that of the case using steel stay cables. Therefore as far as the wind stability is considered, the use of CFRP cables in cable-supported bridges is feasible, and the cable's cross-sectional area should be determined by the principle of equivalent axial stiffness.

  1. 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.

  2. Patterned transgene expression in multiple channel bridges after spinal cord injury

    OpenAIRE

    De Laporte, Laura; Huang, Alyssa; Ducommun, Melissa M.; Zelivyanska, Marina L.; Aviles, Misael O.; Adler, Andrew F.; Shea, Lonnie D.

    2010-01-01

    Patterning of gene delivery on sub-millimeter length scales within tissue engineering scaffolds can provide a fundamental technology to recreate the complex architectures of tissues. Surface-mediated delivery of lipoplexes mixed with fibronectin was investigated to pattern vectors within 250 µm channels on poly (lactide-co-glycolide) (PLG) bridges. Initial studies performed in vitro on PLG surfaces indicated that a DNA density of 0.07 µg/mm2 inside each channel with a weight ratio of DNA to f...

  3. Wheel-Rail Contact Forces in High-Speed Simply Supported Bridges at Resonance

    OpenAIRE

    Museros Romero, Pedro; Castillo-Linares, Alejandro; Alarcón Álvarez, Enrique

    2004-01-01

    The response of high-speed bridges at resonance, particularly under flexural vibrations, constitutes a subject of research for many scientists and engineers at the moment. The topic is of great interest because, as a matter of fact, such kind of behaviour is not unlikely to happen due to the elevated operating speeds of modern rains, which in many cases are equal to or even exceed 300 km/h ( [1,2]). The present paper addresses the subject of the evolution of the wheel-rail contact forces ...

  4. Demonstration of Bridge Type Schemes for Maanshan Changjiang River Bridge Under Condition of Complicated River Pattern%复杂河势条件下的马鞍山长江大桥桥型方案论证

    Institute of Scientific and Technical Information of China (English)

    杨光武

    2013-01-01

    马鞍山长江公路大桥所处河段为分汊河段,其中左汊主桥桥址处河势条件复杂,通过对桥址处河势条件及通航要求等建桥条件的综合分析,对5种左汊主桥桥型方案(主跨2×1080m三塔悬索桥方案、主跨1 388 m两塔悬索桥方案、主跨1 180m两塔斜拉桥方案、主跨2×850m三塔斜拉桥方案、主跨1 760m单跨悬索桥方案)从航道适应性、工程经济性进行比较和论证.经过综合比选,确定马鞍山长江公路大桥左汊主桥采用主跨2×1 080 m三塔两跨悬索桥,较好地解决了深槽左右摆动引起的航道适应性问题,为大桥的顺利立项和获批创造了有利条件.%The river reaches at the site of Maanshan Changjiang River Highway Bridge are the forked reaches, of which the condition of river pattern of the reach at the site of the main bridge of the left bridge is quite complicated. Through the comprehensive analysis of the construction conditions, such as the river pattern and navigation requirements, of the site of the main bridge, five bridge type schemes (i. e. a three-tower suspension bridge with main spans 2×1 080 m, a two-tower suspension bridge with a main span 1 388 m, a two-pylon cable-stayed bridge with a main span 1 180 m, a three-pylon cable-stayed bridge with main spans 2×850 m and a single-span suspension bridge with a main span 1 760 m) put forward for the bridge were compared and demonstrated from aspects of the waterway adaptability and engineering economy. On the basis of the comparison and demonstration, it was finally determined that the scheme of the three-tower and two-span suspension bridge with main spans 2×1080 m should be chosen for the bridge. With the chosen scheme, the problem of the waterway adaptability affected by the left and right swaying of the deep channel was well resolved and the favorable conditions for the successful determining and approval of the bridge project were thus created.

  5. Construction and control technology of the main bridge superstructure of Sutong Bridge

    Institute of Scientific and Technical Information of China (English)

    Zhang Hong; Luo Chenbin; Zhang Yongtao; You Xinpeng

    2009-01-01

    The Sutong Yangtze River Bridge (short as Sutong Bridge) is now the largest span cable-stayed bridge in the world. The construction of the superstructure of the middle bridge covered several stages including erection of the big block girders for the side span, assistant span and tower area, erection of standard girders and closure of the middle span. The big block girders were hoisted by a floating crane, and the standard girders were hoisted by a double crane system on the deck. The pushing assistant method was adopted for the middle span closure construction. Furthermore, key technologies and innovative methods used in the processes of girder erection and cable assemblage in all stages were expatiated systematically. An all-stage self- adaptive geometry control method was used in the construction process. By accurately controlling the unstressed dimensions and shape of all structural components in each step, and realization that the control system and the controlled system adapt to each other, the goal was to make control of the final line shape and inner force of the bridge structure achievable. Two solutions, including GPS based and total station based dynamic geometry monitoring systems, were used to resolve the measure problem under the wide-range of wind-induced vibrations in the long cantilever state. Finally, research on the wind-induced vibration of the superstructure during the construction period was executed. Buffeting response analysis to the longest single and double cantilever states were carried out. The analysis and evaluation of wind resistance safety of the main girders under the longest single cantilever state was made, and corresponding wind resistance measures were suggested. The as-built geometric error and cable force error were controlled in a required design range, and this whole technological achievement can be a benchmark for construction of other large span cable-stayed bridges in the future.

  6. 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

  7. Engineering physics

    CERN Document Server

    Mukherji, Uma

    2015-01-01

    ENGINEERING PHYSICS is designed as a textbook for first year engineering students of a two semester course in Applied Physics according to new revised syllabus. However the scope of this book is not only limited to undergraduate engineering students and science students, it can also serve as a reference book for practicing scientists.Advanced technological topics like LCD, Squid, Maglev system, Electron microscopes, MRI, Photonics - Photonic fibre, Nano-particles, CNT, Quantum computing etc., are explained with basic underlying principles of Physics.This text explained following topics with numerous solved, unsolved problems and questions from different angles. Part-I contains crystal structure, Liquid crystal, Thermo-electric effect, Thermionic emission, Ultrasonic, Acoustics, semiconductor and magnetic materials. Whereas Part-2 contains Optics, X-rays, Electron optics, Dielectric materials, Quantum Physics and Schrodinger wave equation, Laser, Fibre-optics and Holography, Radio-activity, Super-conductivity,...

  8. Engineering Optics

    CERN Document Server

    Iizuka, Keigo

    2008-01-01

    Engineering Optics is a book for students who want to apply their knowledge of optics to engineering problems, as well as for engineering students who want to acquire the basic principles of optics. It covers such important topics as optical signal processing, holography, tomography, holographic radars, fiber optical communication, electro- and acousto-optic devices, and integrated optics (including optical bistability). As a basis for understanding these topics, the first few chapters give easy-to-follow explanations of diffraction theory, Fourier transforms, and geometrical optics. Practical examples, such as the video disk, the Fresnel zone plate, and many more, appear throughout the text, together with numerous solved exercises. There is an entirely new section in this updated edition on 3-D imaging.

  9. ENGINEERING GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20091943 Cao Zubao(Xi’an Branch of China Coal Research Institute,Xi’an 710054,China);Zhu Mingcheng Application of Pipe-Roof Curtain Grouting in Construction of Coal Mine Tunnel Crossing the Fractured Zone(Exploration Engineering,ISSN1672-7428,CN11-5063/TD,35(8),2008,p.79-81,3 illus.,4 refs.,with English abstract)Key words:curtain grouting20091944 Chen Changfu(Civil Engineering College,Hunan University,Changsha 410082,China);Xiao Shujun Application of Weighted Residual Method in Whole Internal Force Calculation of Anti-Slide Pile(Hydrogeology and Engineering Geology,ISSN1000-3665,CN11-2202/P,35(4),2008,p.75-79,3 illus.,9 refs.)Key words:slide-resistant

  10. Engineering surveying

    CERN Document Server

    Schofield, W

    2007-01-01

    Engineering surveying involves determining the position of natural and man-made features on or beneath the Earth's surface and utilizing these features in the planning, design and construction of works. It is a critical part of any engineering project. Without an accurate understanding of the size, shape and nature of the site the project risks expensive and time-consuming errors or even catastrophic failure.Engineering Surveying 6th edition covers all the basic principles and practice of this complex subject and the authors bring expertise and clarity. Previous editions of this classic text have given readers a clear understanding of fundamentals such as vertical control, distance, angles and position right through to the most modern technologies, and this fully updated edition continues that tradition.This sixth edition includes:* An introduction to geodesy to facilitate greater understanding of satellite systems* A fully updated chapter on GPS, GLONASS and GALILEO for satellite positioning in surveying* Al...

  11. On list quotation of bridges%谈桥梁清单报价

    Institute of Scientific and Technical Information of China (English)

    曹建梅

    2012-01-01

    Combining with the compilation experience for the list quotation of bridges,the paper points out some opinions for the list quotation of bridges,indicates and analyzes the rechecking of the engineering amount and the factors which influence the bridge costs,and points out the quota can be accurately budgeted when the design graphs are sufficiently mastered and the construction organization is reasonably designed.%结合桥梁清单报价编制经验,就桥梁工程清单报价提出了一些看法,重点对核对工程量、影响桥梁工程造价的因素等进行了论述和分析,并指出只有熟悉和掌握设计图纸,合理进行施工组织设计,准确套用定额,才能做出准确的预算。

  12. Design of the Long-term Safety Monitoring System of Zhicheng Yangtze River Bridge

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The long-term safety monitoring system of Zhicheng Yangtze River Bridge was established in the principle of open information service and standardized systems engineering.The ADSL dynamic IP communication network established by using VPN technology and application of encryption technology,tunnel technology and user identification accreditation technology have made the system safer and more reliable.The system can fulfill real-time,regular and triggered signal collection according to needs and may give notice or alarm for the discovery of real-time failure.Monitored data can be collected and stored to provide reliable data for stipulating technical indicators for safety operation of the large-span railway bridges.The system,after its completion,can maintain its long-term stable running,take hold of the running condition of all locations of bridge under monitoring,evaluate the overall situation and life cycle,and make available the technical reserves for the Infrastructure Inspection Center of MOR.

  13. Structural safety monitoring for Nanjing Yangtze River Bridge

    Institute of Scientific and Technical Information of China (English)

    黄方林; 何旭辉; 陈政清; 曾储惠

    2004-01-01

    In order to evaluate objectively and accurately the integrity, safety and operating conditions in real time for the Nanjing Yangtze River Bridge, a large structural safety monitoring system was described. The monitoring system is composed of three parts: sensor system, signal sampling and processing system, and safety monitoring and assessment system. Combining theoretical analysis with measured data analysis, main monitoring contents and layout of measuring points were determined. The vibration response monitoring was significantly investigated. The main contents of safety monitoring on vibration response monitoring are vibration of the main body of the Nanjing Yangtze river bridge, collision avoidance of the bridge piers, vibration of girders on high piers for the bridge approach and earthquake. As a field laboratory, the safety monitorying system also provides information to investigate the unknown and indeterminate problems on bridge structures and specific environment around bridges.

  14. Development of a nondestructive evaluation method for FRP bridge decks

    Science.gov (United States)

    Brown, Jeff; Fox, Terra

    2010-05-01

    Open steel grids are typically used on bridges to minimize the weight of the bridge deck and wearing surface. These grids, however, require frequent maintenance and exhibit other durability concerns related to fatigue cracking and corrosion. Bridge decks constructed from composite materials, such as a Fiber-reinforced Polymer (FRP), are strong and lightweight; they also offer improved rideability, reduced noise levels, less maintenance, and are relatively easy to install compared to steel grids. This research is aimed at developing an inspection protocol for FRP bridge decks using Infrared thermography. The finite element method was used to simulate the heat transfer process and determine optimal heating and data acquisition parameters that will be used to inspect FRP bridge decks in the field. It was demonstrated that thermal imaging could successfully identify features of the FRP bridge deck to depths of 1.7 cm using a phase analysis process.

  15. Detection of Subsurface Defects in Concrete Bridge Deck Joints

    Directory of Open Access Journals (Sweden)

    Wonchang Choi

    2011-01-01

    Full Text Available Problem statement: The integrity of deck joints in highway bridges plays a major role to determine overall performance of bridge system. As the bridge maintenance program, the defects in deck joints have historically been detected by conventional non-destructive testing and evaluation methods such as visual inspection, chain-dragging and by the detecting sounds under the traffic. Future bridge maintenance challenges will demand the development of techniques and procedures to detect and monitor such defects before they become apparent. Approach: Two non-destructive methods; namely Ground Penetration Radar (GPR and Seismic Properties Analyzer (SPA were employed to assess the integrity of deck joins installed in North Carolina bridges. Results: The results obtained with the GPR and SPA allows to quantify the subsurface defects in bridge deck joints. Conclusion: The practical application and limitations of each method are discussed in this study.

  16. Dynamic Vehicle Impact for Safety Assessment of Bridges

    DEFF Research Database (Denmark)

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

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

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

    DEFF Research Database (Denmark)

    Hansen, Henriette I.; Thoft-Christensen, Palle

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

  18. Engineering tribology

    CERN Document Server

    Stachowiak, Gwidon

    2013-01-01

    Engineering Tribology, 4th Edition is an established introductory reference focusing on the key concepts and engineering implications of tribology. Taking an interdisciplinary view, the book brings together the relevant knowledge from different fields needed to achieve effective analysis and control of friction and wear. Updated to cover recent advances in tribology, this new edition includes new sections on ionic and mesogenic lubricants, surface texturing, and multiscale characterization of 3D surfaces and coatings. Current trends in nanotribology are discussed, such as those relating to

  19. Biochemistry engineering

    International Nuclear Information System (INIS)

    This deals with biochemistry engineering with nine chapters. It explains bionics on development and prospect, basics of life science on classification and structure, enzyme and metabolism, fundamentals of chemical engineering on viscosity, shear rate, PFR, CSTR, mixing, dispersion, measurement and response, Enzyme kinetics, competitive inhibition, pH profile, temperature profile, stoichiometry and fermentation kinetics, bio-reactor on Enzyme-reactor and microorganism-reactor, measurement and processing on data acquisition and data processing, separation and purification, waste water treatment and economics of bionics process.

  20. Software engineering

    CERN Document Server

    Thorin, Marc

    1985-01-01

    Software Engineering describes the conceptual bases as well as the main methods and rules on computer programming. This book presents software engineering as a coherent and logically built synthesis and makes it possible to properly carry out an application of small or medium difficulty that can later be developed and adapted to more complex cases. This text is comprised of six chapters and begins by introducing the reader to the fundamental notions of entities, actions, and programming. The next two chapters elaborate on the concepts of information and consistency domains and show that a proc