WorldWideScience

Sample records for bridge design

  1. 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.

  2. 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.

  3. Salt bridges: geometrically specific, designable interactions.

    Science.gov (United States)

    Donald, Jason E; Kulp, Daniel W; DeGrado, William F

    2011-03-01

    Salt bridges occur frequently in proteins, providing conformational specificity and contributing to molecular recognition and catalysis. We present a comprehensive analysis of these interactions in protein structures by surveying a large database of protein structures. Salt bridges between Asp or Glu and His, Arg, or Lys display extremely well-defined geometric preferences. Several previously observed preferences are confirmed, and others that were previously unrecognized are discovered. Salt bridges are explored for their preferences for different separations in sequence and in space, geometric preferences within proteins and at protein-protein interfaces, co-operativity in networked salt bridges, inclusion within metal-binding sites, preference for acidic electrons, apparent conformational side chain entropy reduction on formation, and degree of burial. Salt bridges occur far more frequently between residues at close than distant sequence separations, but, at close distances, there remain strong preferences for salt bridges at specific separations. Specific types of complex salt bridges, involving three or more members, are also discovered. As we observe a strong relationship between the propensity to form a salt bridge and the placement of salt-bridging residues in protein sequences, we discuss the role that salt bridges might play in kinetically influencing protein folding and thermodynamically stabilizing the native conformation. We also develop a quantitative method to select appropriate crystal structure resolution and B-factor cutoffs. Detailed knowledge of these geometric and sequence dependences should aid de novo design and prediction algorithms.

  4. 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...

  5. 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...

  6. Non-Flutter Design Principle for long Span Bridges

    DEFF Research Database (Denmark)

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

    velocity for a thin airfoil shows an asymptotical behavior. In traditional bridge design the torsional-to-vertical frequency ratio is increased to obtain higher flutter wind velocities. In the present study, we investigate, what we will label the non-flutter design principle, in which the torsional...

  7. Bridging CALL & HCI: Input from Participatory Design

    Science.gov (United States)

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

    2010-01-01

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

  8. Research on Multidisciplinary Optimization Design of Bridge Crane

    Directory of Open Access Journals (Sweden)

    Tong Yifei

    2013-01-01

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

  9. Design and Construction of Operation Bridge for Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kwangsub; Choi, Jinbok; Lee, Jongmin; Oh, Jinho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The operation bridge contains a lower working deck mounted on a saddle that travels on rails. Upright members are mounted on the saddle to support the upper structure and two hoist monorails. The saddle contains an anti-derail system that is composed of seismic lugs and guide rollers. The operation bridge travels along the rails to transport the fuel assembly, irradiated object, and reactor components in the pools by using tools. Hoists are installed at the top girder. The hoist is suspended from the monorail by means of a motor driven trolley that runs along the monorail. Movements of hoist and trolley are controlled by using the control pendant switch. Processes of design and construction of the operation bridge for the research reactor are introduced. The operation bridge is designed under consideration of functions of handling equipment in the pool and operational limits for safety. Structural analysis is carried out to evaluate the structural integrity in the seismic events. Tests and inspections are also performed during fabrication and installation to confirm the function and safety of the operation bridge.

  10. Inclusive design: Bridging theory and practice

    NARCIS (Netherlands)

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

    2013-01-01

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

  11. Determination of design axle loads for bridges from measurements

    NARCIS (Netherlands)

    Steenbergen, R.D.J.M.; Morales Napoles, O.

    2010-01-01

    Recently, the new Eurocode 1 was introduced dealing with traffic load on bridges. In order to establish the National Annex for the design traffic load, measurements of the traffic load were carried out in several highways in The Netherlands using the Weigh In Motion system. The goal was to assure th

  12. A bridge for accelerating materials by design

    Science.gov (United States)

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

    2015-11-01

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

  13. THE DESIGN OF VMEBUS BRIDGE CONTROLLER WITH SHARC BUS

    Institute of Scientific and Technical Information of China (English)

    Wang Min; Wu Shunjun; Su Tao

    2005-01-01

    Targeting at the high expense and inflexibility to realize VMEbus bridge controller by professional Integrated Circuit (IC), this paper presents a scheme of adopting CPLD/FPGA (Complicated Programmable Logic Device/Field Programmable Gate Array) to design bridge controller between VMEbus and local bus. SHARC DSP (Digital Signal Processor) bus is an example. It has functions of nearly entire master/slave interface of VMEbus, and can act as DMA (Direct Memory Access) controller and perform block transfer in DMA or master processor initiative way without length limit. External circuit of the design is very simple. In comparison with special ICs, it has high performance to price ratio and can be easily applied to local buses of other processors with quite a little modification.

  14. Vulnerability analysis for design of bridge health monitoring system

    Science.gov (United States)

    Sun, L. M.; Yu, G.

    2010-03-01

    The recent engineering implementation of health monitoring system for long span bridges show difficulties for precisely assessing structural physical condition as well as for accurately alarming on structural damages, although hundreds of sensors were installed on a structure and a great amount of data were collected from the monitoring system. The allocation of sensors and the alarming algorithm are still two of the most important tasks to be considered when designing the structural health monitoring system. Vulnerability, in its original meaning, is the system susceptibility to local damage. For a structural system, the vulnerability can thus be regarded as structural performance susceptibility to local damage of structure. The purpose of this study is to propose concepts and methods of structural vulnerability for determining monitoring components which are more vulnerable than others and the corresponding warning threshold once the damages occur. The structural vulnerability performances to various damage scenarios depend upon structural geometrical topology, loading pattern on the structure and the degradation of component performance. A two-parameters structural vulnerability evaluation method is proposed in this paper. The parameters are the damage consequence and the relative magnitude of the damage scenarios to the structural system, respectively. Structural vulnerability to various damage scenarios can be regarded as the tradeoff between the two parameters. Based on the results of structural vulnerability analysis, the limited structural information from health monitoring can be utilized efficiently. The approach of the design of bridge health monitoring system is illustrated for a cable-stayed bridge.

  15. Life cycle and performance based seismic design of major bridges in China

    Institute of Scientific and Technical Information of China (English)

    FAN Lichu

    2007-01-01

    The idea of life cycle and performance based seismic design of major bridges is introduced.Based on the key components and non-key components of a bridge and the consideration of the inspectability,replaceability,reparability,controllability and retrofitability of the bridge components,different seismic design levels and expected performance objectives are suggested for the major bridges in China.The vulnerability analysis and progressive collapse analysis,as well as risk assessment,are also proposed to be the important issues to study in order to guide the seismic design of major bridges in the future.

  16. Preliminary design and parametric study of 1400 m partially earth-anchored cable-stayed bridge

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The preliminary design and parametric study of 1400 m partially earth-anchored cable-stayed bridge are described. Static per-formance of this new type of bridge is discussed. Compared with fully self-anchored cable-stayed bridge, its advantages in fin-ished state are summarized. Based on numerical calculation, effects of several structural parameters on static performance are presented.

  17. Bridging the gap between building science and design studios

    Energy Technology Data Exchange (ETDEWEB)

    Papamichael, Konstantinos; Pal, Vineeta

    2002-02-06

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

  18. Photoelastic stress analysis in perforated (Rochette) resin bonded bridge design.

    Science.gov (United States)

    Ziada, H M; Orr, J F; Benington, I C

    2000-05-01

    Rochette described the perforated cast metal bonded design for splinting periodontally compromised teeth. The design was later used for replacing missing teeth. The main causes of failure of the perforated (Rochette) type design were attributed to inappropriate case selection and erosion of the composite from perforations. The aim of this study was to analyse the effect of stress magnitude and direction on failure of perforated resin bonded bridges (RBBs). The objective was to compare stress magnitudes in this design with those reported on the non-perforated RBBs. Photoelastic modelling materials were selected to represent the relative stiffnesses of a posterior mandibular and an anterior maxillary perforated (Rochette) type design. The sizes of the models were scaled to x 2.5 in order to enhance visual analysis of the stress patterns. Stress magnitudes were quantified from isochromatic fringes and stress directions were evaluated from stress trajectories. These revealed a high-stress concentration around the perforations, particularly for those at the proximo-lingual/palatal (connector) areas. This experimental study revealed that the main reason for failure of Rochette designs is deformation at the perforations.

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

    OpenAIRE

    Wenping Liu; Hongling Guo; Heng Li; Yan Li

    2014-01-01

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

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

    Science.gov (United States)

    Ramanathan, Karthik Narayan

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

  1. Design of unballasted track bridges on Beijing--Tianjin intercity railway%Design of unballasted track bridges on Beijing--Tianjin intercity railway

    Institute of Scientific and Technical Information of China (English)

    Sun Shuli; Zhang Wenjian; Wang Zhaohu; Su Wei; Wu Cailan; Bu Qinghao

    2011-01-01

    Beijing--Tianjin intercity railway is the first newly-built passenger dedicated line with operating speed of 350 km/h in our country. During design, new ideas of bridge construction were carried out to ensure the requirements of safety, comfort and stability of the train under high-speed condition. At the same time, concepts of environmental adaptability, service to transportation and comprehensive benefits were observed. On the whole line, long-bridge schemes were adopted and the most advanced technologies of unballasted track were utilized on bridges, the length of which accounts for 87.7 % of the total line. The success of design and construction of the bridges on this rail has accu- mulated valuable experience for high-speed railway construction on a large scale in the future, and made it a marking, demonstrating, and model project to follow.

  2. Fiber-Reinforced Polymer Bridge Design in the Netherlands: Architectural Challenges toward Innovative, Sustainable, and Durable Bridges

    OpenAIRE

    Joris Smits

    2016-01-01

    This paper reviews the use of fiber-reinforced polymers (FRPs) in architectural and structural bridge design in the Netherlands. The challenges and opportunities of this relatively new material, both for the architect and the engineer, are discussed. An inventory of recent structural solutions in FRP is included, followed by a discussion on architectural FRP applications derived from the architectural practice of the author and of other pioneers.

  3. Fiber-Reinforced Polymer Bridge Design in the Netherlands: Architectural Challenges toward Innovative, Sustainable, and Durable Bridges

    Directory of Open Access Journals (Sweden)

    Joris Smits

    2016-12-01

    Full Text Available This paper reviews the use of fiber-reinforced polymers (FRPs in architectural and structural bridge design in the Netherlands. The challenges and opportunities of this relatively new material, both for the architect and the engineer, are discussed. An inventory of recent structural solutions in FRP is included, followed by a discussion on architectural FRP applications derived from the architectural practice of the author and of other pioneers.

  4. 景桥设计初探%On Landscape Bridge Design

    Institute of Scientific and Technical Information of China (English)

    卞慧媛; 陆艳伟

    2009-01-01

    我国的桥梁建设者们开始关注桥梁视觉景观,作为景观设计师有幸参与其中,而可参考的传统园桥有其形式和功能范围的局限,本文提出了景桥一说,主要介绍在景桥设计和营造实践方面的初步探索心得.%Bridge designers in our country pay more attention to visual landscape bridges. As a landscape architect involved in honor, and Traditional Garden Bridge as reference has its limilation on scope of form and function. The conceptt" Landscape Bridge is introduced. This thesis introduced a preliminary study on design and construction about the Landscape Bridge.

  5. 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.

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

    DEFF Research Database (Denmark)

    Bertelsen, Olav Wedege; Kramp, Gunnar

    2012-01-01

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

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

    Science.gov (United States)

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

    2016-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Wenping Liu

    2014-08-01

    Full Text Available More and more mega-complex bridge projects are being or will be built worldwide. At the same time, the design and construction of such projects involve more and more challenges, e.g., complex structural designs, complicated construction environments, etc. This research study aims to apply BIM (Building Information Modelling to bridge projects to improve the efficiency and effectiveness of design and construction. Through the analysis of the characteristics of bridge projects and relevant, associated problems, a BIM-based solution to improving design and construction is developed, including conceptual design optimization, detailed design optimization, the optimization of construction sequences, construction scheduling, construction management, and construction process monitoring. Furthermore, a real-life bridge project is presented to demonstrate the feasibility and validity of the BIM-aided approach to design and construction. It is shown that BIM has the potential to improve the design and construction of bridge projects. It is expected that this research could contribute to the extensive application of BIM in mega-complex bridge projects to aid in design and construction in the future.

  9. The design philosophy and bridge's technical innovation of Hong Kong- Zhuhai-Macao Bridge

    Institute of Scientific and Technical Information of China (English)

    Meng Fanchao; Liu Minghu; Wu Weisheng; Zhang Gejun; Zhang Liang

    2014-01-01

    This article introduces the project overview, construction goal and design philosophy of Hong Kong- Zhuhai-Macao Bridge. Based on large scale, factory production, standardization and assemble line, the innova- tive concept is taken as the general principle for design with the emphasis on description of the new material, new technology, new construction method and new equipment used in the design. The application of innovative technology has provided a solid foundation and favorable guarantee for project quality and design service life

  10. 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.

  11. Designing a second language bridging course for university students

    Directory of Open Access Journals (Sweden)

    Carol A. Puhl

    2013-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Ahmed Shamel Fahmy

    2016-12-01

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

  13. An Optimization Index to Identify the optimal Design Solution of Bridges

    OpenAIRE

    Feng, Yue

    2014-01-01

    Structural optimization has become an important tool for structural designers, since it allows a better exploitation of material, thus decreasing structure self-weight and saving material costs. Moreover, it helps the designer to find innovative design solutions and structural forms that not only better exploit material but also give the structure higher aesthetic value from an architectural point of view. When applied to real scale structures like bridges, this approach leads to the definiti...

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

    DEFF Research Database (Denmark)

    Zhang, Zhe; Andersen, Michael A. E.

    2016-01-01

    The dual active bridge (DAB) converter is an isolated bidirectional dc-dc topology which is the most critical part for the power conversion systems such as solid-state transformers (SST). This paper focuses on analysis and design of high frequency ac inductors which are the power interfacing...

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

    Directory of Open Access Journals (Sweden)

    Dezhang Sun

    2015-01-01

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

  16. Damage investigation of girder bridges under the Wenchuan earthquake and corresponding seismic design recommendations

    Institute of Scientific and Technical Information of China (English)

    Li Jianzhong; Peng Tianbo; Xu yan

    2008-01-01

    An investigation of girder bridges on National Highway 213 and the Doujiangyan-Wenchuan expressway after the Wenchuan earthquake showed that typical types of damage included:span collapses due to unseating at expansion joints;shear key failure;and damage of the expansion joint due to the slide-induced large relative displacement between the bottom of the girder and the top of the laminated-rubber bearing.This slide,however,can actually act as a form of isolation for the substructure,and as a result,the piers and foundation of most of the bridges on state route 213 suffered minor damage.The exception was the Baihua Bridge,which suffered severe damage.Corresponding seismic design recommendations are presented based on this investigation.

  17. 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...... influences the accretion of ice to an extent that the aerodynamic forces differ significantly amongst the designs. The experiments were conducted in a wind tunnel facility capable amongst others to simulate in-cloud icing conditions....

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  19. Get synchronized: bridging the gap between design and volume production

    NARCIS (Netherlands)

    Smulders, F.E.H.M.

    2006-01-01

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

  20. Bridging the gap in constraint-based design

    OpenAIRE

    Veliz, A; Medjdoub, B; Kocaturk, T

    2011-01-01

    Mass customization is one of the most promising computational developments in the AEC industry. Despite recent advances in the production of research-based knowledge, the professional practices lack of a consistent and permanent technology adoption scheme and remain as a very resilient and fragmented industry. This work is a part of an ongoing research project developing guidelines for improving both physical and virtual modeling processes within an architectural design context. Here, we pres...

  1. Bridging Translation by Improving Preclinical Study Design in AKI.

    Science.gov (United States)

    de Caestecker, Mark; Humphreys, Ben D; Liu, Kathleen D; Fissell, William H; Cerda, Jorge; Nolin, Thomas D; Askenazi, David; Mour, Girish; Harrell, Frank E; Pullen, Nick; Okusa, Mark D; Faubel, Sarah

    2015-12-01

    Despite extensive research, no therapeutic interventions have been shown to prevent AKI, accelerate recovery of AKI, or reduce progression of AKI to CKD in patients. This failure in translation has led investigators to speculate that the animal models being used do not predict therapeutic responses in humans. Although this issue continues to be debated, an important concern that has not been addressed is whether improvements in preclinical study design can be identified that might also increase the likelihood of translating basic AKI research into clinical practice using the current models. In this review, we have taken an evidence-based approach to identify common weaknesses in study design and reporting in preclinical AKI research that may contribute to the poor translatability of the findings. We focused on use of N-acetylcysteine or sodium bicarbonate for the prevention of contrast-induced AKI and use of erythropoietin for the prevention of AKI, two therapeutic approaches that have been extensively studied in clinical trials. On the basis of our findings, we identified five areas for improvement in preclinical study design and reporting. These suggested and preliminary guidelines may help improve the quality of preclinical research for AKI drug development.

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

    DEFF Research Database (Denmark)

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

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

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

    Directory of Open Access Journals (Sweden)

    Raymond E. Levitt

    2012-08-01

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

  4. The design philosophy and bridge’s technical innovation of Hong Kong-Zhuhai-Macao Bridge

    Institute of Scientific and Technical Information of China (English)

    Meng Fanchao; Liu Minghu; Wu Weisheng; Zhang Gejun; Zhang Liang

    2014-01-01

    This article introduces the project overview,construction goal and design philosophy of Hong Kong-Zhuhai-Macao Bridge. Based on large scale,factory production,standardization and assemble line,the innova-tive concept is taken as the general principle for design with the emphasis on description of the new material, new technology,new construction method and new equipment used in the design. The application of innovative technology has provided a solid foundation and favorable guarantee for project quality and design service life.

  5. Hybrid design tools for conceptual design and design engineering processes: bridging the design gap: towards an intuitive design tool

    NARCIS (Netherlands)

    Wendrich, Robert Eric

    2016-01-01

    Hybrid Design Tools; Representation; Computational Synthesis. Non-linear, non-explicit, non-standard thinking and ambiguity in design tools has a great impact on enhancement of creativity during ideation and conceptualization. Tacit-tangible representation based on a mere idiosyncratic and individu

  6. Design and Construction of a 50m Single Span Ultra High Performance Ductile Concrete Composite Road Bridge

    Directory of Open Access Journals (Sweden)

    Voo - Yen Lei

    2012-04-01

    Full Text Available A single span 50m long prestressed road bridge was constructed under Public Works Department in the State of Negeri Sembilan, Malaysia contract recently. The bridge was constructed at a small village, Kampung Linsum, crossing a river, Sungai Linggi. To date, this bridge is the Malaysia first and may also be the world longest composite road bridge which made from ultra-high performance ductile concrete (UHPdC. This paper presents the feature of the UHPdC precast girder; brief in-sight of the manufacturing of the girder; the construction sequence of the bridge; the design method and lastly the environmental impact calculation. The midspan deflections of the bridge at different construction history were compared against the collected field data and it showed that the calculated values generally agree well with the field data.

  7. Simulation and Reasonable Design of Bridge Steel Fenders to Reduce Ship Impacts

    Institute of Scientific and Technical Information of China (English)

    OU Bifeng; WANG Junjie

    2006-01-01

    Steel fenders are increasingly used for ship-impact resistance structures in the design of navigable bridges.As an important approach to investigating this anti-impact structure effectiveness to reduce influences of vessel impact,simulation analyses are still not perfect yet.So this paper is intended to discuss several issues related to ship collision simulations,including steel constitutive relationship,connections between steel box and pile cap,contacts definition and friction consideration,and the determination of impact waterlines and angles.Consequently based on two examples of ship-steel fender-bridge structure systems,some conclusions about effectiveness and design of fenders to reduce ship impact are drawn.

  8. SFC Inverter Bridge Drive Circuit Design%SFC逆变桥驱动电路设计

    Institute of Scientific and Technical Information of China (English)

    赵鑫

    2016-01-01

    本文介绍了SFC静止变频器逆变桥部分晶闸管组驱动触发电路的设计。首先简介了SFC的组成结构和工作原理,由整流桥的工作状况及两组桥合作工作的状况,从而提出驱动逆变桥存在要与整流桥同步触发的问题。而后利用分立元件搭建了一个简易驱动电路,并使用Multisim电路仿真软件验证了其有效性,进而给出装置应用的集成电路驱动电路,最后给出触发脉冲实验结果。%The article introduces thyristor trigger circuit design of inverter bridge of SFC static frequency converter. At first it describes the composition and working principle,talks from the working status of rectifier to the cooperating status of two bridges,thereby proposes a question about synchronous trigger between inverter bridge and rectifier bridge. It uses individual device to build a simple drive circuit,and validates the effect by Multisim simulation software,furthermore issues the inverter drive circuit which is consisted of integrated circuit. Final y,it shows the results of pulse generating experiment.

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

    Energy Technology Data Exchange (ETDEWEB)

    Husemoen, Mette Suzanne

    1997-12-31

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

  10. The Principle of the Micro-Electronic Neural Bridge and a Prototype System Design.

    Science.gov (United States)

    Huang, Zong-Hao; Wang, Zhi-Gong; Lu, Xiao-Ying; Li, Wen-Yuan; Zhou, Yu-Xuan; Shen, Xiao-Yan; Zhao, Xin-Tai

    2016-01-01

    The micro-electronic neural bridge (MENB) aims to rebuild lost motor function of paralyzed humans by routing movement-related signals from the brain, around the damage part in the spinal cord, to the external effectors. This study focused on the prototype system design of the MENB, including the principle of the MENB, the neural signal detecting circuit and the functional electrical stimulation (FES) circuit design, and the spike detecting and sorting algorithm. In this study, we developed a novel improved amplitude threshold spike detecting method based on variable forward difference threshold for both training and bridging phase. The discrete wavelet transform (DWT), a new level feature coefficient selection method based on Lilliefors test, and the k-means clustering method based on Mahalanobis distance were used for spike sorting. A real-time online spike detecting and sorting algorithm based on DWT and Euclidean distance was also implemented for the bridging phase. Tested by the data sets available at Caltech, in the training phase, the average sensitivity, specificity, and clustering accuracies are 99.43%, 97.83%, and 95.45%, respectively. Validated by the three-fold cross-validation method, the average sensitivity, specificity, and classification accuracy are 99.43%, 97.70%, and 96.46%, respectively.

  11. Salt bridges destabilize a leucine zipper designed for maximized ion pairing between helices.

    Science.gov (United States)

    Phelan, Paul; Gorfe, Alemayehu A; Jelesarov, Ilian; Marti, Daniel N; Warwicker, James; Bosshard, Hans Rudolf

    2002-03-05

    Interhelical salt bridges are common in leucine zippers and are thought to stabilize the coiled coil conformation. Here we present a detailed thermodynamic investigation of the designed, disulfide-linked leucine zipper AB(SS) whose high-resolution NMR structure shows six interhelical ion pairs between heptad positions g of one helix and e' of the other helix but no ion pairing within single helices. The average pK(a) value of the Glu side chain carboxyl groups of AB(SS) is slightly higher than the pK(a) of a freely accessible Glu in an unfolded peptide [Marti, D. N., Jelesarov, I., and Bosshard, H. R. (2000) Biochemistry 39, 12804-12818]. This indicates that the salt bridges are destabilizing, a prediction we now have confirmed by determining the pH +/- stability profile of AB(SS). Circular dichroism-monitored unfolding by urea and by heating and differential scanning calorimetry show that the coiled coil conformation is approximately 5 kJ/mol more stable when salt bridges are broken by protonation of the carboxyl side chains. Using guanidinium chloride as the denaturant, the increase in the free energy of unfolding on protonation of the carboxyl side chains is larger, approximately 17 kJ/mol. The discrepancy between urea and guanidinium chloride unfolding can be ascribed to the ionic nature of guanidinium chloride, which screens charge-charge interactions. This work demonstrates the difficulty of predicting the energetic contribution of salt bridges from structural data alone even in a case where the ion pairs are seen in high-resolution NMR structures. The reason is that the contribution to stability results from a fine balance between energetically favorable Coulombic attractions and unfavorable desolvation of charges and conformational constraints of the residues involved in ion pairing. The apparent discrepancy between the results presented here and mutational studies indicating stabilization by salt bridges is discussed and resolved. An explanation is

  12. Design of Main Bridge of Guizhou Wujiang River Bridge%贵州乌江大桥主桥设计

    Institute of Scientific and Technical Information of China (English)

    张伟; 曹洪武; 易伦雄

    2013-01-01

    The main bridge of Guizhou Wujiang River Bridge is a 325 m single-span suspension bridge of simply-supported concrete slab stiffening girder. The cross section of the stiffening girder is the dumbbell section, the towers are the portal frame structures of rectangular solid sections and are supported on the dug pile foundations. The anchorage of the bridge on the Xifeng bank is the gravity anchorage while on the Jinsha bank is the tunnel-type anchorage. The main cables consist of the ψ5. 1 mm high-strength galvanized steel wires and the suspenders are made up of the #3. 0 mm low-relaxation and high-strength galvanized parallel steel wires. The software MIDAS Civil 2006 was used to analyze the spatial global force conditions of the bridge and the software FLAC3D was used as well to carry out the three-dimensional elastoplastic numerical calculation and analysis of the tunnel-type anchorage and its surrounding rock. The results of the analysis showed that the various checking calculations of the bridge could meet the relevant requirements in the codes.%贵州乌江大桥主桥为325m单跨简支混凝土板式加劲梁悬索桥.该桥加劲梁采用哑铃形截面;桥塔采用门形框架结构,矩形实心截面,采用挖孔灌注桩基础;息烽岸采用重力锚碇,金沙岸采用隧道锚碇;主缆采用φ5.1 mm镀锌高强钢丝,吊索采用φ5.0 mm低松弛镀锌高强平行钢丝.采用MIDAS Civil 2006软件对该桥进行空间整体受力分析,并采用FLAC3D软件对隧道锚及围岩进行三维弹塑性数值计算分析,结果表明该桥各项检算均满足规范要求.

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

    Science.gov (United States)

    2011-08-01

    crash tested system. Combination railing: A bicycle or pedestrian railing system added to a crashworthy bridge vehicular railing or barrier system...Devices) (Title 23 CFR Part 655 Subpart F): National standard for all traffic control devices installed on any street, highway, or bicycle trail open... trailer unit, and 36,000T is a tractor/tank trailer unit. The numeric portion of the test vehicle designation is the vehicle’s mass in kilograms. Tests

  14. The effect of sprue design and alloy type on the fit of three-unit metal/ceramic bridges.

    Science.gov (United States)

    Johnson, A

    1995-12-01

    This study was designed to compare the effect of three sprue designs and three types of metal alloy/ceramic on the accuracy of fit of three unit bridges. A sprue design which has straight sprues attached directly to the pattern but does not have a button of excess metal connecting the sprues together after casting, produced the best marginal accuracy, irrespective of the alloy type used. Of the three alloys used (gold, palladium and nickel/chromium based alloys) the gold alloy produced better fitting bridges with each sprue design used.

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

    Directory of Open Access Journals (Sweden)

    Weiss Mathieu

    2015-01-01

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

  16. Design of Non-Navigable Span Bridges of Hutong Changjiang River Bridge%沪通长江大桥非通航孔桥设计

    Institute of Scientific and Technical Information of China (English)

    梅新咏; 侯健; 刘琳杰

    2015-01-01

    沪通长江大桥设计通行4线铁路、6车道高速公路,其非通航孔桥为简支钢桁梁结构 ,桥梁跨度112 m ,全长2 912 m ,其中跨南岸大堤桥梁3跨共336 m、跨北岸大堤桥梁2跨共224 m、跨水中横港沙区段桥梁21跨共2 352 m.非通航孔桥主桁为三片钢主桁结构 ,上层公路桥面由钢纵横梁与混凝土桥面板结合而成 ,下层铁路桥面由下弦各节点处的钢横梁与混凝土槽形梁结合而成.桥墩采用钻孔灌注桩基础 ,墩身采用单箱三室的空心钢筋混凝土结构.%The Hutong Changjiang River Bridge is designed to carry 4-track railways and 6-lane expressways .The non-navigable span bridges of the bridge are the simply-supported steel truss girder structures with span length of 112 m .The bridges are totally 2 912 m long ,of which the part of the bridges to cross the river dyke on the south bank has 3 spans and is 336 m long ,to cross the river dyke on the north bank has 2 spans and is 224 m long and to cross the section of the Henggang Islet in the river has 21 spans and is 2 352 m long .T he main trusses of the bridges are the three steel main truss structures .The upper highway decks are the structures composited by the steel stringers ,steel cross beams and concrete deck slabs while the lower railway decks are the ones composited by the steel cross beams at the panel points at the lower chords and the concrete channel girders .T he foundations for the piers of the bridges are all the bored piles and the pier shafts are the reinforced concrete three-cell single-box hollow structures .

  17. 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.

  18. Overall Design of Baitanhu Lake Bridge%白潭湖大桥总体设计

    Institute of Scientific and Technical Information of China (English)

    张全阳

    2014-01-01

    基于城市桥梁的景观要求,白潭湖大桥主桥采用纵向对称布置的(150+150) m混凝土独塔斜拉桥的设计方案。桥塔以拱为形态元素,采用椭圆形拱塔结构;主梁采用预应力混凝土单箱三室斜腹板箱梁,人行道置于斜拉索锚固区外侧;斜拉索采用扇形空间双索面布置,主梁上锚固采用混凝土齿块锚固形式,塔上锚固采用混凝土锚块+隔板的锚固形式;过渡墩采用花瓶形板式墩。桥塔采用爬模施工,桥塔横梁采用分节段浇筑,设置2 m合龙段;主梁采用分节段支架现浇施工,共分13个施工节段。有限元计算结果表明,结构受力满足规范要求。%Given the demands of landscape effect of city bridges ,the design scheme of a (150+150) m concrete single pylon cable-stayed bridge that is symmetrically arranged in the longitudinal direction is chosen for the main bridge of Baitanhu Lake Bridge .The pylon which is basically an arch is designed as an elliptic arched pylon structure .The main girder is the prestressed concrete three-cell single box structure with inclined webs .The sidewalk is arranged along the outer side of the anchorage zone of the stay cables . The stay cables are fanned out in spatial double cable planes ,which are anchored to the main girder via concrete teeth ,but anchored to the pylon with the assistance of concrete blocks and bulkheads .T he transitional piers are vase-shaped plate piers . The pylon is constructed by climbing formwork and the pylon cross beam is cast in segments with a 2 m long closure section .The main girder is cast in segments on scaffoldings and a total of 13 construction segments are made .The results of the finite element calculation indicate that the force conditions of the structure can meet the code requirements .

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

    Directory of Open Access Journals (Sweden)

    Guido Poli

    2012-05-01

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

  20. 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...

  1. 乌苏大桥主桥上部结构设计与计算%Design and Calculation of Superstructure of Main Bridge of Wusu Bridge

    Institute of Scientific and Technical Information of China (English)

    康晋; 肖海珠; 徐伟

    2011-01-01

    The main bridge of the Wusu Bridge is a single pylon and single cable plane cablestayed bridge with span arrangement (140+140) m and with a structural system of rigid fixity of the pylon, pier and girder. A summarized account of the design and calculation of the superstructure of the bridge is presented herewith. The main girder of the bridge is a composite girder with long cantilevers, the central part of the girder is designed as a two-cell and single-box steel girder and the steel cantilever at each side of the girder is the variable depth I-beam and is provided wiht a trough stringer at the far side, which are all topped with 25 cm thick concrete deck slabs connected with the girder via shearing studs. The part of the main girder close to the pylon is designed as a prestressed concrete box girder to facilitate the fixity of the girder with the pylon. The pylon is the single column pylon, 117 m in height. The stay cables, made up of low relaxation galvanized high strength parallel steel wire strands, are of the harp pattern cable plane arranged in the central alignment of the bridge deck. The finite element software MIDAS Civil 2006 and the SCDS programme are employed to calculate and analyze structure of the bridge. The results of the calculation and analysis indicate that the static, stability and dynamic characteristics of the bridge can meet the requirements in the relevant codes.%乌苏大桥主桥为独塔单索面斜拉桥,跨径布置为(140+140) m,采用塔、墩、梁固结体系,综述该桥上部结构设计与计算.主梁为带大挑臂的钢箱结合梁,中间钢箱梁采用单箱双室截面,两侧钢挑臂为变高度工字形梁,挑臂端部设槽形小纵梁;混凝土桥面板厚25 cm,与钢梁通过剪力钉连接;塔根部主梁采用预应力混凝土箱梁,以方便与桥塔固结;桥塔采用独柱式塔,高117 m;斜拉索为竖琴形中央平行索面布置,采用低松弛镀锌高强度平行钢丝束.采用有限元软件MIDAS Civil

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

    NARCIS (Netherlands)

    Li, J.

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Rizal Sebastian

    2013-01-01

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

  4. 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.

  5. Reliability Design and Electro-Thermal-Optical Simulation of Bridge-Style Infrared Thermal Emitters

    Directory of Open Access Journals (Sweden)

    Peng Zhou

    2016-09-01

    Full Text Available Designs and simulations of silicon-based micro-electromechanical systems (MEMS infrared (IR thermal emitters for gas sensing application are presented. The IR thermal emitter is designed as a bridge-style hotplate (BSH structure suspended on a silicon frame for realizing a good thermal isolation between hotplate and frame. For investigating the reliability of BSH structure, three kinds of fillet structures were designed in the contact corner between hotplate and frame. A 3-dimensional finite element method (3D-FEM is used to investigate the electro-thermal, thermal-mechanical, and thermal-optical properties of BSH IR emitter using software COMSOLTM (COMSOL 4.3b, COMSOL Inc., Stockholm, Sweden. The simulation results show that the BSH with oval fillet has the lowest stress distribution and smoothest flows of stress streamlines, while the BSH with square fillet has the highest temperature and stress distribution. The thermal-optical and thermal-response simulations further indicate that the BSH with oval fillet is the optimal design for a reliable IR thermal emitter in spite of having slight inadequacies in emission intensity and modulation bandwidth in comparison with other two structures.

  6. Highway bridge seismic design: summary of FHWA/MCEER project on seismic vulnerability of new highway construction

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Federal Highway Administration (FHWA) sponsored a large, multi-year project conducted by theMultidisciplinary Center for Earthquake Engineering Research (MCEER) titled "Seismic Vulnerability of New HighwayConstruction" (MCEER Project 112), which was completed in 1998. MCEER coordinated the work of many researchers, whoperformed studies on the seismic design and vulnerability analysis of highway bridges, tunnels, and retaining structures.Extensive research was conducted to provide revisions and improvements to current design and detailing approaches andnational design specifications for highway bridges. The program included both analytical and experimental studies, andaddressed seismic hazard exposure and ground motion input for the U.S. highway system; foundation design and soil behavior;structural importance, analysis, and response; structural design issues and details; and structural design criteria.

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

    Science.gov (United States)

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

    2016-06-01

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

  8. A miniature MRE isolator for lateral vibration suppression of bridge monitoring equipment: design and verification

    Science.gov (United States)

    Zhao, Lujie; Yu, Miao; Fu, Jie; Zhu, Mi; Li, Binshang

    2017-04-01

    The testing accuracy and service life of long-span bridge monitoring equipment declines over time due to the adverse effects of environmental vibration during its operation. Therefore, it is essential to use effective methods to reduce the vibration of these devices. In this paper, inspired by the controllable and field-dependent properties of magnetorheological elastomer (MRE), a miniature laminated MRE isolator is designed and manufactured to provide a relatively stable working environment for the monitoring equipment. The method and process of its specific design are elaborated in detail based on the shape factor, allowable seismic displacement, lateral stiffness, allowable vertical load and analysis of magnetic circuit. Besides, a series of dynamic tests are conducted to obtain the characteristics of the MRE isolator under various loading conditions. The experimental results show that the maximum increase of the effective stiffness is 114.12% with the current increasing from 0 A to 3 A. Consequently, the validity of its design is confirmed by a fuzzy control experiment.

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

    DEFF Research Database (Denmark)

    Du, Guangli; Karoumi, Raid

    2011-01-01

    Railway bridges currently encounter the challenges of increasing the load capacity while the environmental sustainability should be achieved. However, it has been realised that the environmental assessment of railway bridges has not been integrated into the decision-making process, the standard...... guideline and criterion is still missing in this field. Therefore, the implementation of life cycle assessment (LCA) method is introduced into railway bridges. This article provides a systematic bridge LCA model as a guideline to quantify the environmental burdens for the railway bridge structures...... and material transportations are ignorable. Sensitivity analysis illustrates the maintenance scenario planning and steel recycling have the significant influence on the final results other than the traffic disturbances....

  10. 重庆寸滩长江大桥主桥设计%Design of Main Bridge of Cuntan Changjiang River Bridge in Chongqing

    Institute of Scientific and Technical Information of China (English)

    唐贺强; 曹洪武; 万田保

    2013-01-01

    The main bridge of Cuntan Changjiang River Bridge in Chongqing is a single-span simply-supported steel box girder suspension bridge with span arrangement 250 m+880 m+250 m.The bridge has two main cables that are the structures of prefabricated parallel high-strength steel wire strands.There are totally 57 pairs of the suspenders arranged for the whole bridge,the suspenders are the structures of prefabricated parallel steel wire strands and are connected with the cable bands by way of pin connection.The tower saddles are the fully cast structures and under a tower saddle,the base plate is arranged and is used as the sliding set.The splay saddles are the base structures and under a splay saddle,the cylindrical steel bearing is arranged.The anchoring systems for the main cables are the shaped steel anchoring systems.The stiffening girder of the bridge is designed as the streamlined flat closed steel box girder that is 3.5 m deep and 42 m wide.The anchorage on both the south and north banks are the gravity anchorage,the foundation for each anchorage is the cast-in-situ enlarged foundation and the body of the anchorage is in U shape in plan.The towers are the reinforced concrete portal frame structures.The two columns of a tower are arranged vertically and the foundation of the tower is the pile foundation with separated pile caps.%重庆寸滩长江大桥主桥为250m+880m+250m的单跨简支钢箱梁悬索桥.该桥设2根主缆,主缆采用预制平行高强钢丝索股结构.全桥共布置57对吊索,吊索采用预制平行钢丝束,与索夹采用销接式连接方式.主索鞍为全铸式结构,鞍底设置座板作为滑动副.散索鞍为底座式结构,底部设置柱面钢支座.主缆锚固系统采用型钢锚固系统.加劲梁采用流线型扁平式封闭钢箱梁,梁高3.5m,宽42 m.南、北锚碇均为重力式锚碇,现浇扩大基础,锚体在平面均呈U形.桥塔为钢筋混凝土门式框架结构,两塔柱竖直布置,基础为分离式承台桩基础.

  11. Design and experimental verification of a new multi-functional bridge seismic isolation bearing

    Institute of Scientific and Technical Information of China (English)

    Chen-xi XING; Hao WANG; Ai-qun LI; Ji-rong WU

    2012-01-01

    A new multi-functional bridge seismic isolation bearing (MFBSIB) is designed and its mechanical model is developed in this paper.Combining an upper sliding device and a lower energy dispassion isolation device effectively,the new MFBSIB can adjust the deformation caused by temperature,vehicle breaks,and concrete creep,etc.,in addition to dissipating energy.The switch of ‘slide-isolation' is achieved and the efficiency of both upper and lower parts is validated through experiment with a model.The shear performance curve established in this paper is verified to be efficient in describing the mechanical characteristics of the bearing through experiment.It is proved through both numerical calculation and experimental analysis that the new MFBSIB is endowed with enough vertical rigidity,good energy dissipation ability,stable overall performance,and good realization in expected goals.Its performance is slightly influenced by shear stress,while affected by vertical pressure,loading frequency,slide limit,etc.,diversely.The results could provide reference for study and application of the new MFBSIB.

  12. Design and construction of the lawnmower, an artificial burnt-bridges motor.

    Science.gov (United States)

    Kovacic, Suzana; Samii, Laleh; Curmi, Paul M G; Linke, Heiner; Zuckermann, Martin J; Forde, Nancy R

    2015-04-01

    Molecular motors of the cell are protein-based, nanoscale machines, which use a variety of strategies to transduce chemical energy into mechanical work in the presence of a large thermal background. The design and construction of artificial molecular motors is one approach to better understand their basic physical principles. Here, we propose the concept of a protein-based, burnt-bridges ratchet, inspired by biological examples. Our concept, the lawnmower, utilizes protease blades to cleave peptide substrates, and uses the asymmetric substrate-product interface arising from productive cleavage to bias subsequent diffusion on the track (lawn). Following experimental screening to select a protease to act as the motor's blades, we chemically couple trypsin to quantum dots and demonstrate activity of the resulting lawnmower construct in solution. Accompanying Brownian dynamics simulations illustrate the importance for processivity of correct protease density on the quantum dot and spacing of substrates on the track. These results lay the groundwork for future tests of the protein-based lawnmower's motor performance characteristics.

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

    CERN Document Server

    Ruan, Xinbo

    2014-01-01

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

  14. 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

  15. 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

  16. Design and parametric study on energy harvesting from bridge vibration using tuned dual-mass damper systems

    Science.gov (United States)

    Takeya, Kouichi; Sasaki, Eiichi; Kobayashi, Yusuke

    2016-01-01

    A bridge vibration energy harvester has been proposed in this paper using a tuned dual-mass damper system, named hereafter Tuned Mass Generator (TMG). A linear electromagnetic transducer has been applied to harvest and make use of the unused reserve of energy the aforementioned damper system absorbs. The benefits of using dual-mass systems over single-mass systems for power generation have been clarified according to the theory of vibrations. TMG parameters have been determined considering multi-domain parameters, and TMG has been tuned using a newly proposed parameter design method. Theoretical analysis results have shown that for effective energy harvesting, it is essential that TMG has robustness against uncertainties in bridge vibrations and tuning errors, and the proposed parameter design method for TMG has demonstrated this feature.

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

    DEFF Research Database (Denmark)

    Makda, Ishtiyaq Ahmed; Nymand, M.

    2013-01-01

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

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

    Science.gov (United States)

    Scott, Elaine P.; Lee, Kasey M.

    1994-01-01

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

  19. 数字技术在路桥设计中的运用%The application of digital technology in road and bridge design

    Institute of Scientific and Technical Information of China (English)

    庞元浩

    2016-01-01

    This paper simply discussed the application present situation and significance of digital technology in road and bridge design,from the information acquisition,3D modeling,design programs and other aspects,illustrated the method application of digital technology for road and bridge design,pointed out that application of digital technology in road and bridge design improved the work efficiency of road and bridge design.%简述了数字技术在路桥设计中的应用现状及意义,从信息采集、三维建模、设计程序等方面,说明了应用数字技术进行路桥设计的方法,指出数字技术运用在路桥设计中提高了路桥设计的工作效率。

  20. Study on wind resistant design of long-span bridges based on field observation result; Dotai kansoku kekka ni motozuku chodaikyo no taifu sekkei ni kansuru kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Katsuchi, H.; Tada, K.; Kitagawa, M.

    1996-07-21

    Based on records of strong wind and bridge response to the 19th typhoon in 1991 and 13th typhoon in 1993 at the Onaruto Bridge and the Minami Bisan-Seto Bridge as well as results of numerical analysis, the validity of wind resistant design was investigated. The validity of current wind resistant design was confirmed for the intensity of turbulence and the power spectrum among the natural wind properties. The spatial correlation property was expressed better by Karman`s correlation equation than by usual exponential function equation. The bridge response value was evaluated well by using Karman`s correlation equation, as to bridge response properties, and especially the gust response properties. It was more rational to apply Karman`s correlation equation rather than usual exponential equation to the wind resistant design of long-span bridges. It was suggested that the evaluation of the wind load in the wind resistant design can be reduced. Accordingly, the design of long-span bridges, whose structures can be determined by the wind load, can be rationalized. 20 refs., 13 figs., 2 tabs.

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

    Directory of Open Access Journals (Sweden)

    Solazzi L.

    2010-06-01

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

  2. 泥石流地段桥涵设计探讨%Analysis of Bridge Design in Debris Flow District

    Institute of Scientific and Technical Information of China (English)

    郑彩平

    2013-01-01

    Xinjiang is the area that often occurs debris flow. Bridge installed debris flow area is inevitable with the develop-ment of highway traffic in our country. Combining with highway rebuilding project S212 line Tuergate-Wuqia section, the pa-per discussed bridge design for the debris flow section and put forward specific treatment measures.%  新疆属泥石流多发地区,随着我国公路交通事业的发展,泥石流地区桥涵的设置是不可避免的。文章结合S212线吐尔尕特—乌洽段公路改建工程,重点对泥石流地段桥涵设计进行探讨,并提出具体处理措施。

  3. Design of Cable-Stayed Bridge of Caofeidian Industry Zone Bridge No.1%曹妃甸工业区1号桥斜拉桥设计

    Institute of Scientific and Technical Information of China (English)

    陈亮; 卢永成; 周伟翔; 邵长宇

    2011-01-01

    The Caofeidian Industry Zone Bridge No. 1 is composed of navigable span bridge, non-navigable span bridges and approach bridges and is located in the cold and strong earthquake region in the northern part of China. A summarized account of the design of the navigable span bridge of the bridge is presented herewith. In accordance with the construction conditions and landscape requirements, the navigable span bridge is designed as a single pylon and single cable plane cable-stayed bridge with span arrangement 2 X 138 m, the pylon is the column pylon in shape of boat sail. The anchorage zone in the pylon is the steel anchor box exposed outside the pylon. The main girder is the steel and concrete composite girder having three cells and a single box. The stay cables are made up of φ7 mm galvanized parallel steel wires and the foundation of the pylon pier is the group pile foundation. The research of seismic resistance of the bridge show that for a major single pylon cable-stayed bridge located in the strong earthquake region, the rigid fixity system of pylon, girder and pier should be possibly avoided in order to reduce seismic response of the bridge structure.%曹妃甸工业区1号桥位于北方寒冷强震区,由通航孔桥、非通航孔桥及引桥组成,综述该桥通航孔桥设计.根据建设条件及景观要求,通航孔桥为跨径2×138 m独塔单索面斜拉桥;桥塔为独柱形,造型为船帆式;索塔锚固区采用外露式钢锚箱方案;主梁采用单箱三室钢-混凝土箱形结合梁;斜拉索采用φ7 mm镀锌平行钢丝;桥塔墩采用群桩基础.抗震性能研究表明,强震区大型独塔斜拉桥应尽量避免采用塔、梁、墩固结体系,以减小桥梁结构的地震响应.

  4. 路桥过渡段路基路面设计施工探析%Subgrade and Pavement Design and Construction of Bridge Transition Section

    Institute of Scientific and Technical Information of China (English)

    王海峰

    2015-01-01

    主要研究了路桥过渡段路基路面设计施工,总结了路桥过渡段的常见病害,并对路桥过渡段设计和施工中的关键性问题进行了研究。%The main road subgrade transition section of the bridge design and construction, summed up a common disease bridge transition period, and the design and construction of bridge transition section of the key issues were studied.

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

    Directory of Open Access Journals (Sweden)

    Wenxue LIU

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

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

    NARCIS (Netherlands)

    Sebastian, R.

    2013-01-01

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

  7. Design and performance of an EMI filter to reduce conducted EMI in an isolated full bridge buck converter power supply

    Institute of Scientific and Technical Information of China (English)

    Abdolreza Esmaeli; SUN Li; ZHAO Ke; JIANG Bao-jun

    2005-01-01

    EMI Filter Design and Performance for isolated full bridge buck converter is developed in this paper.In order to design a high performance EMI filter, many issues need to be considered beforehand. Some important issues including accurate model of converter components, parasitic elements, its effect on EMI noise and impedance mismatch are included in this paper. A numerical prediction of EMI/EMC has the potential to evaluate EMI performances at the design stage and before prototyping. It can also help reduce the post-prototype EMC cost by minimizing late redesign and modifications of a design implementation. Saber simulator is used to analyze the EMI noises and EMI filter's performance. Conducted EMI noise measurement and EMI filter design of isolated full bridge buck converter has been achieved while successfully satisfying the FCC class B limits in the frequency range from 150 kHz to 30 MHz. Simulation results are compared with experimental data and the effectiveness of the EMI simulation approach is demonstrated.

  8. 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.

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

    Science.gov (United States)

    Sadeghi, H.

    2015-12-01

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

  10. Bridge and steel structures. Wind resistant design and vibration control; Kyoryo kokozobutsu. Taifu seishin gijutsu no kojo wo mezashite

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, M.; Takeuchi, T.; Saito, Y.; Kazama, K. [Sumitomo Heavy Industries, Ltd., Tokyo (Japan)

    1998-08-20

    This paper describes the wind resistant design and vibration control of bridges. For the long span bridges, vibration by wind is worried due to their flexible structures. Wind tunnel tests are conducted, and the shape of bridges is modified on the basis of the test results. On the other hand, tuned mass dampers (TMDs) are often used during the construction with footing for a short period. For the passive TMD which is a general pendulum type, the number of vibration frequency can be variable by changing the position of spring and damper. The restitutive force can be obtained for the vertical Vibration using lever-type weight damper and spring. For the Active TMD, the weight of lever-type damper is driven by the servo-motor using rack pinion. An optimum regulator is used for the control. Sufficient damping performance was obtained by applying this to the main tower, which depended on the gain and vibration amplitude. An aerodynamic damper is used for the vibration of cables by the wind. Especially, the rain vibration is a problem, which is due to the interaction of rain flow and wind. To solve this problem, a U-engrave cable has been developed for preventing the formation of rainwater flow channels on the cable surface. 9 refs., 14 figs., 5 tabs.

  11. Overall Design and Study of South and North Bridges of Xiazhang Sea-Crossing Bridge%厦漳跨海大桥南、北汊桥总体设计与研究

    Institute of Scientific and Technical Information of China (English)

    王福敏; 罗强; 李军

    2013-01-01

    厦漳跨海大桥主要由北汊桥、海门岛立交及收费服务区、南汊桥、海平立交四大部分组成,全长9.333 km.为适应复杂的自然与建设条件,对该桥桥位方案进行比选,并对项目中关键控制性工程(北汊主桥、南汊主桥)的桥型方案进行研究.经研究,最终确定北汊主桥采用主跨780m的五跨连续钢箱梁斜拉桥方案,南汊主桥采用主跨300 m的结合梁斜拉桥方案.针对项目中复杂的地质条件、高地震烈度和恶劣的风环境,分别采取设置适应性强的桩基础,对较差的桩基地质注浆;按抗震要求进行构造设计,在主桥塔梁处设置纵向阻尼器,引桥设置减隔震支座;北汊主桥采用一种翼型扶手栏杆、南汊主桥采用分流板抗风等措施进行处理.%The Xiazhang Sea-Crossing Bridge,totally 9.333 km long,is composed of four major parts of the north bridge,Haimen Island interchange and toll service area,south bridge and Haiping interchange.To accommodate the complicated natural and construction conditions of the bridge,the bridge site schemes were compared and the bridge type schemes for the critical control projects (the north and south main bridges) were studied.According to the study,it was finally determined that the 5-span continuous steel box girder cable-stayed bridge with a main span 780 m would be adopted for the north main bridge and the composite girder cable-stayed bridge with a main span 300 m would be adopted for the south main bridge.In consideration of the complicated geologic conditions,high intensity earthquake and harsh wind environment,the well adaptive pile foundations were respectively utilized.For the pile foundations at the locations with poor geology,the foundations would be grouted.The structures of the bridge were designed in compliance with the seismic resistance requirements.At the connections between the pylons and girders of the main bridges,the longitudinal dampers were arranged and on the piers

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

    Directory of Open Access Journals (Sweden)

    Qiao You-Lin

    2011-05-01

    Full Text Available Abstract Background More than 50% of the worldwide cases of hepatocellular carcinoma occur in China, and this malignancy currently represents the country's second leading cause of cancer death in cities and the leading cause in rural areas. Despite recent advances in the control and management of hepatocellular carcinoma within China, this disease remains a major health care issue. The global HCC BRIDGE study, designed to assess patterns of hepatocellular carcinoma therapy use and associated outcomes across real-world clinical practice, has recently been expanded as a national study in China, allowing a detailed analysis of hepatocellular carcinoma in this important country. Methods/Design The global HCC BRIDGE study is a multiregional longitudinal cohort trial including patients newly diagnosed with hepatocellular carcinoma between January 1, 2005, and June 30, 2011, who are receiving treatment for hepatocellular carcinoma via sites in the Asia-Pacific, European, and North American regions. The HCC BRIDGE China national study comprises the portion of the global HCC BRIDGE study conducted within mainland China. Patients will be followed from time of diagnosis of hepatocellular carcinoma (post-January 1, 2005 to time of death or December 31, 2011, whichever comes first. Data will be collected on demographic/clinical characteristics, relevant laboratory values, hepatocellular carcinoma/underlying liver disease treatment, tumor response, adverse events, hospitalizations, and overall survival. The primary study end point is overall survival; secondary end points are disease progression, treatment-limiting adverse events, and treatment failure. Results At the time of writing, 15 sites have selected for participation across all 7 traditional regions of China (North, North-East, East, South, South-West, North-West, and Central. The anticipated study population from the China national study is approximately 9000 patients. Discussion Findings from the

  13. Design and optimization of micro-semiconductor bridge used for solid propellant microthrusters array

    Science.gov (United States)

    Ru, Chengbo; Dai, Ji; Xu, Jianbing; Ye, Yinghua; Zhu, Peng; Shen, Ruiqi

    2016-06-01

    Igniter is the basic component of MEMS-based solid propellant microthrusters (SPM) array, which should response fast with low dissipated energy. To satisfy the requirements, micro-semiconductor bridge (MSCB) with dual V-angles contributing to the reduction of dissipated energy is introduced into the array. The electrical explosion characteristics of MSCB investigated under constant voltage, in the considerations of the limit of power supply in the micro/nanosatellite, are similar to those under capacitive discharge. The bridge was completely vaporized and burst into the hot plasma under high-level voltage. While under low-level voltage, the bridge was partly vaporized without detected plasma. The 3#SCB (90° V-angle) with the smallest power density resulting in the lowest applied voltage (12.0 V) and the 2#SCB with the smallest narrow width (Wmin) leading to the lowest average power (11.3 W) were chosen to the further optimization. The ignition tests were implemented to examine the ignition reliability of the contractible igniters, which were optimized to satisfy the voltage limitation with sufficient ignition capacity. The results show that the effective SCB with lowest dissipated power is the 3#-3SCB, which function within 100 μ under 7.0 V, and the average power below 5.0 W.

  14. 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.

  15. Steel bridge deck pavement design index analysis of the highway bridge in Maanshan Yangtze River%马鞍山长江公路大桥钢桥面铺装设计指标分析

    Institute of Scientific and Technical Information of China (English)

    詹成根; 王民; 张昭

    2014-01-01

    对马鞍山长江公路大桥钢桥面铺装技术难点进行了分析,并确定了设计要求。参考国内类似结构的多种大跨径悬索桥钢桥面铺装设计指标,从使用条件、工程实践及试验研究等角度出发,对比分析了钢桥面铺装设计指标。结合该桥整体结构变形和荷载响应特性,制定了钢桥面铺装结构层设计指标。该研究成果对改善钢桥面铺装的结构性能和提高钢桥面铺的使用寿命具有重要的意义。%By analyzing technical difficulties of Maanshan Yangtze River highway bridge steel bridge deck pavement,the design requirements are determined.Considering do-mestic similar structures of long-span steel bridge deck pavement design index of sus-pension bridges,the operation conditions,engineering practice and experimental studies are compared.According to the overall structure deformation,load response characteris-tics,design index for steel bridge deck pavement structure layer,research achievements of scientific improvement are obtained,which can improve the performance and increase the service life of the steel bridge deck pavement structure.This work has important significance.

  16. 钢桥面沥青铺装层设计要点分析%Analysis of the Notes about Design of the Steel Bridge Asphalt Pavement

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      本文根据笔者多年的工作经验,从钢桥面沥青铺装设计的技术要求、桥面沥青铺层的结构和大跨径钢桥面沥青铺装三个方面,探讨了钢桥面沥青铺装层的设计要点。%In this article bases on years of work experience, discusses the design points of steel bridge asphalt pavement fr-om three aspects of the technical requirements of steel bridge asphalt pavement design, the structure of bridge asphalt over-lay and the large span steel bridge asphalt pavement.

  17. 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...

  18. APPLICATION OF STEEL PIPE PILE LOADING TESTS TO DESIGN VERIFICATION OF FOUNDATION OF THE TOKYO GATE BRIDGE

    Science.gov (United States)

    Saitou, Yutaka; Kikuchi, Yoshiaki; Kusakabe, Osamu; Kiyomiya, Osamu; Yoneyama, Haruo; Kawakami, Taiji

    Steel sheet pipe pile foundations with large diameter steel pipe sheet pile were used for the foundation of the main pier of the Tokyo Gateway bridge. However, as for the large diameter steel pipe pile, the bearing mechanism including a pile tip plugging effect is still unclear due to lack of the practical examinations even though loading tests are performed on Trans-Tokyo Bay Highway. In the light of the foregoing problems, static pile loading tests both vertical and horizontal directions, a dynamic loading test, and cone penetration tests we re conducted for determining proper design parameters of the ground for the foundations. Design parameters were determined rationally based on the tests results. Rational design verification was obtained from this research.

  19. Optimum design of phase opposition disposition pulse width modulation logic circuit for switching seven level cascaded half bridge inverter

    Directory of Open Access Journals (Sweden)

    Nentawe Y. Goshwe

    2016-06-01

    Full Text Available Theevolution of multilevel inverters (MLIs has made it possible to extract power from direct current (DC sources to alternating current (AC power. This paper presents the design of a novel phase opposition disposition pulse width modulation scheme (PODPWM logic circuit for a conventional single phase seven level cascaded H-Bridge (CHB inverter using Matlab/Simulink. The minimum switching logic circuit for the single phase seven level CHB inverter was obtained by modeling the logic equations that could be used with any number of levels depending on the number of modulating and carrier signals involved. The reduction in total harmonic distortion (THD of the output voltage for the MLI using low switching frequency at different modulation indixes is also investigated. The logic equations have made it easier to design a PODPWM circuit for any CHB inverter and the logic gates designed gave an optimum THD value of 16.73 % at modulation index of 0.20.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    This paper presents a low-cost bidirectional isolated dc–dc converte, derived from dual-active-bridge converter for the power sources with variable output voltage like supercapacitors. The proposed converter consists of push-pull-forward circuit half-bridge circuit (PPFHB) and a high-frequency tr...... by digital signal processor for comparison purpose. Detailed test results verify the theoretical analysis and demonstrate the validity of optimization design method....

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  2. Sustainable Bridge Infrastructure Procurement

    DEFF Research Database (Denmark)

    Safi, Mohammed; Du, Guangli; Simonsson, Peter

    2016-01-01

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

  3. 道路桥梁设计中的隐患及解决措施分析%Hazard analysis and solutions design of roads and bridges

    Institute of Scientific and Technical Information of China (English)

    刘一兵

    2015-01-01

    道路桥梁是重要的基础设施,是公路交通的核心组成部分,道路桥梁建设顺利,经济和社会发展就有了保障,反之,如果道路桥梁出现设计和施工的隐患和问题,那么非但会影响公路交通的畅通,而且还会形成对经济和社会的巨大风险与威胁。本研究以道路桥梁建设中的设计工作为中心,展开了道路桥梁设计隐患的相关研究,在分析道路桥梁设计中存在问题和隐患的基础上,提供了解决道路桥梁设计隐患和问题的措施。%The roads and bridges are important infrastructure is a core component of road traffic, road construction bridge smoothly, economic and social development have security, on the contrary, if there is risk, and the design and construction of roads and bridges, then not only will affect the highway traffic flow, but also the formation of a huge economic and social risks and threats. In this study, road construction, bridge design work for the center, launched a road bridge design risks related research, basic problems and pitfalls in the analysis on the design of roads and bridges, roads and bridges designed to provide a solution measures risks and problems.

  4. Problem Analysis of Pedestrian Bridge Design%人行天桥设计若干问题分析

    Institute of Scientific and Technical Information of China (English)

    晏江; 童琪; 王艳华

    2012-01-01

    文章从使用功能、绿化、照明干扰、舒适度及汽车激振效应等方面入手,对人行天桥景观设计和动力性能设计中存在的主要问题进行了分析,并提出了相应的解决对策与建议。%From the usage function, greening, lighting interference, comfortability and automotive exciting effect etc, the article analyzed the major problems existing in the pedestrian bridge landscape design and dynamic performance design,and proposed some corresponding countermeasures and suggestions.

  5. 活性粉末混凝土人行天桥试设计研究%Trial-design of a reactive powder concrete pedestrian bridge

    Institute of Scientific and Technical Information of China (English)

    黄卿维; 吴永银; 杜任远; 陈宝春; 陈宜言; 吴庆雄

    2012-01-01

    Reactive powder concrete ( RPC) is a cement-based composite material with super-high compressive strength, high toughness and good durability, which could be used to build pedestrian bridge and make the bridge cost-efficient, aesthetic and durable. Taking a pedestrian bridge with a main span of 47 m as the prototype, a trial design of RPC pedestrian bridge was conducted. Analysis results show that the RPC pedestrian bridge has a better cost performance and the material of its girder cost is 39% less than that of the steel pedestrian bridge. Compared with the prestressed concrete (PC) pedestrian bridge, RPC pedestrian bridge has better mechanical performance, and the consumptions of concrete and steel are decreased by 56.4% and 18.2% , respectively, resulting in a reduction of 53.9% of the self-weight. Therefore, RPC pedestrian bridge has considerable application advantages.%活性粉末混凝土(RPC)是一种抗压强度高且韧性、耐久性好的水泥基复合材料,应用于人行天桥,具有经济、美观、耐久性好等特点.以主跨47 m的某人行天桥为原型,进行了RPC人行天桥试设计.分析结果表明,与钢桥相比,RPC桥性价比较高,主梁材料费用为钢桥的61.0%;与预应力混凝土(PC)桥相比,结构受力性能有较大的提高,主梁混凝土和预应力筋用量减少56.4%和18.2%,结构自重减轻53.9%.因此,RPC人行天桥具有较大的应用优势.

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

    Directory of Open Access Journals (Sweden)

    Hanbing Liu

    2016-11-01

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

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

    Science.gov (United States)

    Razak, Rafiza Abdul

    2013-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    The applicability of miniaturized magnetic field sensors is being explored in several areas of magnetic field detection due to their integratability, low mass, and potentially low cost. In this respect, different thin-film technologies, especially those employing magnetoresistance, show great...... potential, being compatible with batch micro- and nanofabrication techniques. For low-frequency magnetic field detection, sensors based on the planar Hall effect, especially planar Hall effect bridge (PHEB) sensors, show promising performance given their inherent low-field linearity, limited hysteresis...... and moderate noise figure. In this work, the applicability of such PHEB sensors to different areas is investigated. An analytical model is constructed to estimate the performance of an arbitrary PHEB sensor geometry in terms of, e.g., sensitivity and detectivity. The model is valid for an ideal case, e...

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

    DEFF Research Database (Denmark)

    Andersen, Kristine

    2007-01-01

    Considering the rapidly growing amount of digital educational materials only few of them bridge the gab between experimental learning environments and computer based learning environments (Gardner, 1991). Observations from two cases in primary school and lower secondary school in the subject......, based on the narrative approach for experimental learning subjects, relying on ideas from Csikszentmihalyis notion of flow (Csikszentmihalyi, 1991), storyline-pedagogy (Meldgaard, 1994) and ideas from Howard Gardner (Gardner, 1991). The model forms the basis for educational games to be used in home...... economics, and thus is a step on the road to produce a learning resource in an area, until now mostly populated with electronic recipe-managers and digital health-tracking ditto....

  10. 谈一座景观人行天桥的设计%Discussion on the design of a landscape-style pedestrian bridge

    Institute of Scientific and Technical Information of China (English)

    王佳

    2015-01-01

    Combining with a practical project,this paper introduces the design for the pedestrian bridge mainly by descrbing the landscape design in such aspects as the structure form,rail,bridge deck pavement,the stress,stiffness and natural vibration frequency of the bridge is analyzed by using finite element software,put forward the construction scheme of the pedestrian bridge. It can be consulted by similar bridge design.%以实际工程为例,简要介绍了天桥结合景观在结构形式、栏杆、桥面铺装等方面的设计手法,并采用有限元软件,对天桥应力、刚度及自振频率进行了分析,据此提出了桥梁施工方案,可为类似工程设计提供参考。

  11. Trialogues: a framework for bridging the gap between people research and design

    NARCIS (Netherlands)

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

    2009-01-01

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

  12. 桥梁与环境相互协调的重要性以及桥梁美学设计的要点%The Importance of Bridge Coordinated with Environment and the Aesthetics Points of Bridge Design

    Institute of Scientific and Technical Information of China (English)

    彭宜强

    2013-01-01

    任何一座桥梁一般都具有使用和欣赏两个方面的功能。建造一座桥是一次工程的专业设计,又是一次艺术的大胆创作。这就需要设计者将技艺和艺术灵感相结合,需要建筑师具备工程师的大脑,同时具备艺术家的心智。%Any bridge general y has two aspects function of use and appreciation. Building a bridge is an engineering pro-fessional design, also an artistic creation. This requires the des-igner's skill and artistic inspiration combining with each other, and architects need to have the brains of the engineer, with art-ist's mind at same time.

  13. 基于可靠度的组合桥梁设计及维护策略%Reliability-Based Design and Maintenance Strategy for Composite Bridges

    Institute of Scientific and Technical Information of China (English)

    张慕圣; 陈锐斌

    2012-01-01

    Currently,the design practice of highway bridges around the world are moving towards limit states design,a reliability-based design procedure.Canadian Highway Bridge Design Code (CHBDC) is the first design code entirely developed based on limit states design philosophy,including foundations and FRP components.However,reliability of a structure decreases in service due to environmental attacks and material deterioration such as fatigue,corrosion and many other reasons.Therefore,the structure should be inspected periodically,and the reliability of the structure should be evaluated according to its age and field data.If its reliability is reduced to a certain level,a repair should be scheduled as well as some preventive maintenance measures should be implemented to prevent further deterioration.Recently,many research works have been conducted to investigate reliability-deterioration mechanisms for each type of infrastructure and its components,optimize the inspection and maintenance strategy,predict remaining service life,estimate its life cycle cost.This paper is focused on the study of reliability-deterioration mechanisms of slab on steel girder bridges due to fatigue and corrosion of steel girders as well as corrosion of reinforcement in the deck slab.Examples will also be given to illustrate the proposed life cycle management strategy for composite slab on steel girder bridges.

  14. Analysis and Design of Bridge Management System%桥梁管理系统的分析与设计

    Institute of Scientific and Technical Information of China (English)

    陈悦

    2012-01-01

    Based on many features of the bridge management system,combined with current computer technology,the technical contents involved in model determination,software analysis and structural design are introduced,providing references for software development in the same industry.%针对桥梁管理系统的诸多特性,结合当前的计算机技术,介绍了在软件开发过程中涉及的模式确定、软件分析以及结构设计方面的技术内容,为同行业软件开发提供借鉴。

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

    DEFF Research Database (Denmark)

    Makda, Ishtiyaq Ahmed; Nymand, Morten

    2015-01-01

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

  16. 郑州市解放路跨线桥主桥设计与施工%Design and Construction of Main Bridge of Jiefang Road Overpass Bridge in Zhengzhou City

    Institute of Scientific and Technical Information of China (English)

    申国朝

    2012-01-01

    The main bridge of the Jiefang Road Overpass Bridge in Zhengzhou City is a cable-stayed bridge with twin pylons, single cable plane and with span arrangement (106 + 248 + 106) m and the bridge employs the structural system of rigid fixity of its pylons and main girder. The main girder of the bridge is of the prestressed concrete triple-cell single box of quasi-triangle section and has a 62 m long variable width portion at the side span on the west side. On both sides of a pylon, 15 pairs of stay cables made up of the low relaxation and high-strength galvanized parallel steel wires are arranged. The pylons are the concrete solid single-column ones of H-shape sections and the main piers are the vase shape hollow reinforced concrete structures supported on the frictional group bored pile foundations. The software Bridge Doctor V3. 03, MIDAS Civil and ANSYS were used to respectively build the plane finite element model for the bridge and the plane link and spatial plate-shell finite element models for the variable width portion. With these models, the global static force of the bridge and the force conditions of the portion were analyzed. In addition, a 1: 4 model for the variable width portion was also designed and made to carry out the model test. The results of the finite element analysis and model test showed that the force conditions of various parts of the bridge could meet the requirements in the codes. The part of the bridge spanning the passenger dedicated railway line on the east side was constructed by the rotation erection while the part of the bridge spanning the freight railway line on the west side was constructed by the covered form traveler.%郑州市解放路跨线桥主桥为双塔单索面斜拉桥,跨径布置为(106+248+106)m,采用塔、梁固结体系.该桥主梁为预应力混凝土单箱三室准三角形截面,西侧边跨设62 m长的变宽段.每个桥塔两侧布置15对斜拉索,斜拉索采用低松弛镀锌高强平行钢丝.桥塔采

  17. 区域性河流桥梁景观规划设计%Planning and Design Discussion on Bridge Landscape of Regional River

    Institute of Scientific and Technical Information of China (English)

    乔云强; 刘国祥; 马汀; 刘安双

    2012-01-01

    The regional river bridge landscape cases at home and abroad were introduced. By taking bridge landscape design as an example, the factors should be considered for the bridge landscape planning were analyzed; the planning principle and design thought were discussed; and some guidance conclusions were summarized.%介绍国内外区域性河流系列桥梁景观案例,并以城市新区内某河流桥梁景观规划设计为例,分析在桥梁景观规划上需考虑的因素,探讨同河流上桥梁景观规划原则和设计思想,总结出有指导意义的结论.

  18. Seismic Design of Japanese Portal Frame Bridge%日本单跨门式刚架桥的抗震设计

    Institute of Scientific and Technical Information of China (English)

    张春轶; 施立鑫; 李岩

    2011-01-01

    简要介绍日本单跨门式刚架桥的特点,通过抗震性能,解析方法,解析步骤,设计水平震度,地震土压系数等几方面对抗震设计进行了阐述.最后介绍了单跨门式刚架桥的适用条件.%This paper introduces the characteristics of Japanese portal frame bridge, and seismic design of bridge are described by the seismic performance, analytical methods and procedures, the design level of seismic intensity, seismic pressure coefficient. Finally, it introduces application conditions of portal frame bridge.

  19. Design of Main Bridge of Xi′nan Bridge in Guigang City,Guangxi%广西贵港西南大桥主桥设计

    Institute of Scientific and Technical Information of China (English)

    李翠霞; 张巨生

    2015-01-01

    广西贵港市西南大桥主桥为(46+88+280+88+46) m双塔双索面预应力混凝土边主梁斜拉桥。主梁采用等高度带悬臂的矩形混凝土边主梁与“工”字形钢横梁相结合的形式,整幅桥面宽36.5m,设双向2.0%横坡。桥塔采用“鱼”状流线弧形框架钢筋混凝土结构,塔柱高102.5 m,采用外侧为“D”形圆弧段的箱形截面。桥塔设上、下横梁,均采用预应力混凝土单箱单室结构。全桥共设136根斜拉索,斜拉索采用φs 15.2 m m镀锌钢绞线索,空间双索面扇形布置。桥塔墩采用分离式基础,上、下游分离式基础中心距34.7 m ,其下各设9根φ2.5 m钻孔桩。承台为正方形钢筋混凝土结构。4号墩顶面设一圆端形塔座。%The main bridge of the Xi′nan Bridge in Guigang City ,Guangxi is a prestressed concrete edge main girders cable‐stayed bridge with double pylons ,double cable planes and with span arrangement (46+88+280+88+46) m .T he main girders of the bridge are of the structural type combining the rectangular concrete edge main girders having constant depth and cantilevers with the I‐shape steel cross beams .The width of the whole bridge deck is 36 .5 m and the deck is provided with dual 2 .0% transverse slopes .A pylon of the bridge is the“fish”‐shape streamlined arc frame reinforced concrete structure that is 102 .5 m in height and the outer side of the pylon is of the“D”‐shape round arc box section .The upper and lower cross beams of the pylon are all the prestressed concrete single‐cell single‐box structures .There are totally 136 stay cables arranged for the whole bridge .The stay cables are the φs 15 .2 mm galvanized steel wire strand cables and are arranged in fan shape and spatial double cable planes .The pylon pier is supported on the sep‐arated foundations .T he center‐to‐center distance of the foundations on the upstream and dow n‐stream sides is 34 .7

  20. Bridging the Planning Gap: Linking Conceptual Army Design to Military Decision-Making

    Science.gov (United States)

    2011-05-19

    art, French postmodern philosophy, social sciences, psychology, architecture , urban planning, and…ancient Chinese military thinking.” For this...bringing two “separate but closely related” activities together is not limited to architecture alone. 2 Understanding the history of detailed and...Design,” 10. 96 Bryan Lawson, How Designers Think: The Design Process Demystified, 4th Ed., (Boston MA: Architectural Press, 2006), 109. 44 If

  1. 基于GIS的桥梁管理系统的设计与研究%Design and Research of Bridge Management System Based on GIS

    Institute of Scientific and Technical Information of China (English)

    王翔

    2016-01-01

    In our country, the bridge construction and management of the existing problems, traditional bridge management mode has been unable to meet the needs of modernization, which requires the related departments and the management development for the high quality of bridge management information system. Firstly brielfy on the GIS technology and the bridge management system were basic overview, and then introduce the application of GIS technology in bridge management information system, based on GIS bridge management system overview of the design of the system structure design and bridge information query and analysis functions.%在我国,对桥梁的建设管理上存在诸多问题,传统的桥梁管理模式已无法满足现代化的工作需求,这就要求相关管理部门及管理者开发出高质量的桥梁管理信息系统。文章首先简要地对GIS技术和桥梁管理系统进行了基本概述,然后介绍了GIS技术在桥梁管理信息系统中的实际应用,最后基于GIS的桥梁管理系统的设计概述了系统结构设计和桥梁的信息查询以及系统分析的功能。

  2. 桥梁设计过程中仿生理念的应用研究%Application research of bio-inspired concept in bridge design

    Institute of Scientific and Technical Information of China (English)

    周翠芳

    2014-01-01

    对桥梁设计中的仿生理念,微观仿生和宏观仿生三方面的内容进行了详细的分析和探讨,论述了仿生理念在我国桥梁工程设计工作中的具体应用情况,指出在桥梁设计中应用仿生理念,解决了设计过程中存在的问题,提升了桥梁设计方案的创新性。%The paper analyzes and explores bridge design contents including bio-inspired concept,micro-bio-inspired and macro-bio-inspired method,discusses its specific application conditions in domestic bridge engineering design,and points out that:the bio-inspired concept applica-tion in bridge design both solves the design problems and improves creativity of bridge design scheme.

  3. Study of Landscape Design of Arch Bridges in Garden%园林中拱桥的景观设计研究

    Institute of Scientific and Technical Information of China (English)

    贾艳敏; 唐军斌; 于广龙

    2013-01-01

    To provided reference for the landscape design of arch bridges in garden, the principles (including the coordinated proportions, proper dimensions, balanced layout, graceful rhythm, rich implications and environmental merging) and procedures of the landscape design of the bridges were summarized and the practicability of the arch bridge types (including the solid spandrel arch bridge, open spandrel arch bridge, rigid-frame arch bridge, composite system arch bridge and irregularly shaped arch bridge) commonly employed for the brides in garden was analyzed. On the basis of the summarization and analysis, a landscape arch bridge for the Xiangfang Park, Harbin was designed. The bridge is a three-span continuous composite arch structure with span arrangement (15 + 30 + 15) m and rise-to-span ratio 1/5. In the transverse direction of the superstructure of the bridge, two arch ribs are employed. The transverse length of an arch rib is 3. 0 m, the spacing distance between the arch ribs is 3. 5 m and in between the arch ribs, the lateral bracings are not provided. The substructure of the bridge is of the bored piles and pile caps. The balustrades are designed into the ones having each vertical plate plus a railing and are configurated into the shape of swan. The bridge after the landscape design has clear force lines, simple and smooth structure and hence becomes a graceful and harmonious scene together with its surrounding environment.%为对园林中拱桥的景观设计提供参考,总结园林中拱桥景观的设计原则(比例协调、尺度恰当;均衡匀称、韵律优美;富于内涵、融于环境)与步骤,并对园林拱桥常见桥型(实腹拱桥、空腹拱桥、刚架拱桥、组合体系拱桥、异型拱桥)的实用性进行分析,以此为基础对哈尔滨香坊公园中的一座景观拱桥进行设计.该桥采用(15+30+15)m三跨连续拱式组合结构,矢跨比为1/5.上部结构横向采用2片拱肋,拱肋横向长度为3.0m,间距3.5m,拱肋

  4. Design of an aluminium bicycle path integrated in a steel bridge

    NARCIS (Netherlands)

    Maljaars, J.; Soetens, F.; Burggraaf, H.G.

    2007-01-01

    This paper describes the design of the aluminium structure of a bicycle path which is mounted on an existing steel brige. The benefits of aluminium, being low self weight, freedom in design obtained by extrusion and good corrosion resistance were maximal utilized. One of the main drawbacks of alumin

  5. Bridging the Gap between Designers and Consumers: The Role of Effective and Accurate Personas

    Science.gov (United States)

    Miaskiewicz, Tomasz

    2010-01-01

    Firms now routinely collect information about the needs of their customers, but this information is not sufficiently considered during product design decisions. This research examines the relationship between designers and consumers to build an understanding of how the consumer should be represented to increase the consumer focus during the…

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

    Science.gov (United States)

    2007-01-01

    scholars from both “inside” and “outside” communities to enrich their dialog and enhance intercommunity research. Further, we explain how C2 applies well...classroom curricula and pedagogy to incorporate the princi- ples and tools associated with enterprise design as a rational, inte- grated design

  7. Design and construction of Sutong Bridge deep-water main-pylon foundations

    Institute of Scientific and Technical Information of China (English)

    Ren Huixing; Ouyang Xiaoyong; He Maosheng; Nie Qinlong; Wang Xiali

    2009-01-01

    This paper, from three aspects including construction conditions, foundation design and construction, introduces some considerations in the designing of main-pylon foundations and some practical measures to deal with certain unfavorable construction conditions, such as deep water, tidal effect, soft stratum and heavy traffic, during the construction of main-pylon foundations.

  8. Design of T-Frame Bridge of Mashui River Bridge%马水河特大桥T形刚构桥设计

    Institute of Scientific and Technical Information of China (English)

    陈晓波

    2011-01-01

    Mashui River Bridge is a long span T-frame bridge with span arrangement (116 +116) m. The main girder of the bridge is a prestressed concrete girder of variable section, having a single cell single box and vertical webs. The top of the girder is 10.7 m in width and the bottom varies in round arc. The main pier of the bridge is 108 m high and the pier shaft is the high-rise rectangular hollow pier that has no solid section close to the top of the pier and is connected with the girder in a way of spatial frame. The foundation for the pier is composed of 24 nos. of φ2.5 m reinforced concrete bored piles, the concrete for the piles is of C30 and a 7.5 m high training dike is set at the footing of the pier. The BSAS and ANSYS are respectively used to conduct the structural static force calculation and spatial static and dynamic force analysis. The results of the calculation and analysis show that the static force, wind resistance, seismic resistance and dynamic response of the vehicle and bridge can all satisfy the relevant requirements in the codes. The pier shaft of the bridge is constructed by the backward inclined cantilever formwork and the main girder is constructed by the free balanced cantilever concreting method.%马水河特大桥为(116+116)m的大跨度T形刚构桥.主梁采用变截面预应力混凝土箱梁,单箱单室直腹板,箱梁顶宽10.7 m,梁底缘按圆弧变化.主墩高108 m,墩身采用矩形空心高墩,墩顶不设实体段,与梁部按空间框架形式相接,桩基采用24-φ2.5 m钢筋混凝土钻孔桩,混凝土强度等级为C30,在墩底设置7.5 m高的导流堤.分别采用BSAS和ANSYS对全桥进行结构静力计算及空间静力和动力分析.分析结果表明:该桥静力、抗风、抗震、车桥动力响应验算结果均满足规范要求.该桥主墩墩身采用后倾式悬臂模板法施工,主梁采用对称悬臂浇筑法施工.

  9. Habitats: A Simple Way to Bridge Artifacts, Professions, and Theories in Ubiquitous Design

    DEFF Research Database (Denmark)

    Brynskov, Martin; Kramp, Gunnar

    2007-01-01

    This paper briefly shows how product designers as well as information system designers may use the habitat framework as a tool to inform their understanding of the pervasive computing systems they are designing. This is done by (1) introducing the basic elements of habitats, (2) analyzing...... and comparing two empirical case-studies, one about life and death (emergency response at major incidents) and one about playfulness (children’s pervasive play and gaming), and (3) discussing the usefulness of using habitats. The result is a number of real-world examples where we argue that using habitats...

  10. Design, Synthesis and Evaluation of Organic Non-linear Optical Chromophores with Configurationally and Conformationally Locked Polyene Bridges

    Science.gov (United States)

    2007-11-02

    A modular, synthetic scheme was developed for versatile variation of donors, acceptors and polyene bridge length of NLO-chromophores. Configurational...and conformational rigidity of the polyene bridges were realized by making each set of adjacent double and single bond pair part of a fused...cylohexene ring. Substituent effects on the reactions leading to the establishment of the donor, elongation of the fused polyene bridge and the final

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    This paper presents the design, modeling, and control of an isolated dc-dc three-port converter (TPC) based on an interleaved-boost full-bridge converter with pulsewidth modulation (PWM) and phase-shift control for hybrid renewable energy systems. In the proposed topology, the switches are driven...

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

    NARCIS (Netherlands)

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

    2011-01-01

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

  13. Bridging user-centered design and requirements engineering with GRL and persona cases

    OpenAIRE

    Faily, Sharmal

    2011-01-01

    Despite the large body of i* research, there has been com- paratively little work on how goal-modelling techniques can help identify usability concerns. Recent work has considered how goal models might better integrate with User-Centered Design. This paper takes an alterna- tive perspective by examining how work in User-Centered Design, specifi- cally Persona Cases, can be re-framed as goal models. We briefly describe an approach for doing this, and present some preliminary results from apply...

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

    Directory of Open Access Journals (Sweden)

    Mona Komeijani

    2016-03-01

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

  15. Design of Concrete Self-Anchored Suspension Bridge of Wusong Bridge in Jilin City%吉林市雾凇大桥混凝土自锚式悬索桥设计

    Institute of Scientific and Technical Information of China (English)

    张伟; 唐贺强; 宁伯伟

    2011-01-01

    The main bridge of the Wusong Bridge in Jilin City is a 5-span continuous concrete self-anchored suspension bridge with span arrangement (35+68+150+68+35) m. A summarized account of the design and calculation of the main bridge is presented herewith. On the bridge, the transverse and vertical bearings and the longitudinal dampers are arranged in between the stiffening girder and towers. The girder is of a concrete 3-cell single box section, the depth of a typical segment of the girder is 2.5 m and towards the anchorage sections at the side spans, the segments of the girder gradually change into a depth of 6.5 m. A tower of the bridge is a concrete portal frame structure that is 54 m in height and the tower columns and the cross beams on the towers are all of rectangular hollow sections. Beneath a tower pier are the pile caps of separation type and each pile cap is supported by 9 nos. of Φ2.0 m bored piles. The main cables are respectively made up of Φ5.1 mm galvanized high strength steel wires and the hanger cables are of Φ7.0 mm low relaxation galvanized high strength parallel steel wires. In the design, the finite element software MIDAS Civil 2006, the nonlinear analysis software BNLAS for suspension bridge and the plane program SCDS are employed to calculate and analyze the bridge. The results of the calculation and analysis indicate that all checking calculation made for the bridge can conform to the relevant requirements in the codes.%吉林市雾凇大桥主桥为(35+68+150+68+35)m五跨连续混凝土自锚式悬索桥,综述该桥主桥设计与计算.该桥塔梁间设置横、竖向支座和纵向阻尼器;加劲梁采用单箱三室混凝土截面,标准段梁高2.5 m,在边跨锚固段渐变至6.5 m;桥塔采用门形框架混凝土结构,高54 m,塔身及横梁均采用矩形空心截面;桥塔墩下部采用分离式承台,单个承台布置9根φ2.0 m钻孔灌注桩;主缆采用φ5.1 mm镀锌高强钢丝,吊索采用φ7.0 mm低松弛镀锌高强

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

    CERN Document Server

    Guenther, Milan

    2012-01-01

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

  17. Structure-Based Design of a Novel SMYD3 Inhibitor that Bridges the SAM-and MEKK2-Binding Pockets.

    Science.gov (United States)

    Van Aller, Glenn S; Graves, Alan P; Elkins, Patricia A; Bonnette, William G; McDevitt, Patrick J; Zappacosta, Francesca; Annan, Roland S; Dean, Tony W; Su, Dai-Shi; Carpenter, Christopher L; Mohammad, Helai P; Kruger, Ryan G

    2016-05-03

    SMYD3 is a lysine methyltransferase overexpressed in colorectal, breast, prostate, and hepatocellular tumors, and has been implicated as an oncogene in human malignancies. Methylation of MEKK2 by SMYD3 is important for regulation of the MEK/ERK pathway, suggesting the possibility of selectively targeting SMYD3 in RAS-driven cancers. Structural and kinetic characterization of SMYD3 was undertaken leading to a co-crystal structure of SMYD3 with a MEKK2-peptide substrate bound, and the observation that SMYD3 follows a partially processive mechanism. These insights allowed for the design of GSK2807, a potent and selective, SAM-competitive inhibitor of SMYD3 (Ki = 14 nM). A high-resolution crystal structure reveals that GSK2807 bridges the gap between the SAM-binding pocket and the substrate lysine tunnel of SMYD3. Taken together, our data demonstrate that small-molecule inhibitors of SMYD3 can be designed to prevent methylation of MEKK2 and these could have potential use as anticancer therapeutics.

  18. 桥梁设计中的安全性影响因素探讨%Exploration of the Safety Influence Factors in the Bridge Design

    Institute of Scientific and Technical Information of China (English)

    陈文阁

    2013-01-01

    With the increasingly rapid development of urbani-zation, the security of bridge design is becoming more and mo-re at ention. In recent years, the construction of bridges has in-creasingly common, while the accidents are also increasing. If not improved, then the safety of the bridge wil have a severe effect on people's normal life.%随着城市化发展的越来越迅速,桥梁设计的安全性也越来越受到关注。近几年来桥梁的建设越来越普遍,发生的事故也越来越多。如果对桥梁的安全不加以改进,则必然会对人们的正常生活带来严重的影响。

  19. A contribution to the hydraulic design of bridges in coastal zones; Una contribucion al diseno hidraulico de puentes en zonas costeras

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Bribiesca, J.L.; Gracia Sanchez, J. [Instituto de Ingenieria, UNAM, Mexico, D.F. (Mexico)

    2004-06-01

    It is proposed a criterion to determine, from the hydraulic point of view, the width and the height of bridges of coastal zones. The criterion uses information of failed and not failed bridges (both in the same current). The criterion allows the design of new bridges and the revision of the existing ones others existent ones. Numerical examples are included. [Spanish] Se presenta un criterio para determinar el ancho y la altura de puentes sobre rios de zonas costeras desde el punto de vista hidraulico. El criterio empleo informacion de puentes fallados y no fallados (sobre una misma corriente); asimismo, permitio tanto el diseno de puentes nuevos, como la revision de otros existentes. Se incluyen ejemplos numericos.

  20. Read To Succeed: MECCA Summer Learning Camp. Manual To Design and Deliver a Summer Bridges Program.

    Science.gov (United States)

    Illinois State Board of Education, Springfield.

    This manual presents information on designing and delivering a summer learning program whose goal is to provide an opportunity for students to experience academic success and positive self-esteem through reading fluency and comprehension. Sections of the manual address background and policies (on student and teacher selection, student promotion,…

  1. Bridging the Gap: A Roadmap to Breaking the Biological Design Barrier

    Directory of Open Access Journals (Sweden)

    Jacob eBeal

    2015-01-01

    Full Text Available This paper presents an analysis of an emerging bottleneck in organism engineering, and paths by which it may be overcome. Recent years have seen the development of a profusion of synthetic biology tools, largely falling into two categories: high-level design tools aimed at mapping from organism specifications to nucleic acid sequences implementing those specifications, and low-level build and test tools aimed at faster, cheaper, and more reliable fabrication of those sequence and assays of their behavior in engineered biological organisms. Between the two families, however, there is a major gap: we still largely lack the predictive models and component characterization data required to effectively determine which of the many possible candidate sequences considered in the design phase are the most likely to produce useful results when built and tested. As low-level tools continue to mature, the bottleneck in biological systems engineering is shifting to be dominated by design, making this gap a critical barrier to progress. Considering how to address this gap, we find that widespread adoption of readily available analytic and assay methods is likely to lead to rapid improvement in available predictive models and component characterization models, as evidenced by a number of recent results. Such an enabling development is, in turn, likely to allow high-level tools to break the design barrier and support rapid development of transformative biological applications.

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  3. Bridging Design and Behavioral Research With Variance-Based Structural Equation Modeling

    NARCIS (Netherlands)

    Henseler, Jörg

    2017-01-01

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

  4. 平行弦钢桁架过街人行天桥设计%The Design of a Parallel Chord Steel Truss Pedestrian Bridge

    Institute of Scientific and Technical Information of China (English)

    董震

    2016-01-01

    分析北京某平行弦桁架人行过街天桥设计,该天桥主体结构由上部两榀钢桁架和下部混凝土柱组成,总长52.5m,单跨最大跨径30m。设计考虑竖向地震、温度效应等荷载作用,并计算结构竖向第一振动频率,避免人群行走时桥身产生共振。设计方法和结构选型可供技术人员作同类设计参考。%The paper describes the design of a parallel chord steel truss pedestrian bridge in Beijing. The main structure of the bridge is composed of above two steel trusses and concrete columns bottom. The most span of the bridge is 30m, and the whole length is 50m. The structure calculation includes of the vertical earthquake, temperature effect and the first natural frequency of vertical vibration for avoiding the resonance of the bridge caused by human walking. The design method and selection of the structure provide reference for similar design.

  5. Design, synthesis, insecticidal activity, and structure-activity relationship (SAR): studies of novel triazone derivatives containing a urea bridge group based on transient receptor potential (TRP) channels.

    Science.gov (United States)

    Yang, Yan; Liu, Yuxiu; Song, Hongjian; Li, Yongqiang; Wang, Qingmin

    2016-11-01

    Numerous compounds containing urea bridge and biurea moieties are used in a variety of fields, especially as drugs and pesticides. To search for novel, environmentally benign and ecologically safe pesticides with unique modes of action, four series of novel triazone analogues containing urea, thiourea, biurea, and thiobiurea bridge, respectively, were designed and synthesized, according to various calcium ion channel inhibitors which act on transient receptor potential protein. Their structures were characterized by [Formula: see text] NMR, [Formula: see text] NMR, and HRMS. The insecticidal activities of the new compounds were obtained. The bioassay results indicated that compounds containing a thiourea bridge and a thiobiurea bridge exhibited excellent insecticidal activities against bean aphid. Specifically, compounds [Formula: see text], [Formula: see text], and [Formula: see text] exhibited 85, 90, and 95 % activities, respectively, at 10 mg/kg. Compounds [Formula: see text] (30 %), [Formula: see text] (35 %), [Formula: see text] (30 %), and [Formula: see text] (40 %) exhibited the approximate aphicidal activity of pymetrozine (30 %) at 5 mg/kg. In addition, some target compounds exhibited insecticidal activities against lepidopteran pests. From a molecular design standpoint, the information obtained in this study could help in the further design of new derivatives with improved insecticidal activities.

  6. Existing Steel Railway Bridges Evaluation

    Science.gov (United States)

    Vičan, Josef; Gocál, Jozef; Odrobiňák, Jaroslav; Koteš, Peter

    2016-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Lisa D. Young

    2003-10-01

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

  8. Design of Bridge Expansion Joints with Perforated Dowels Under Impact Loading

    Institute of Scientific and Technical Information of China (English)

    YODA Teruhiko; AYASHI Mamiko

    2008-01-01

    The expansion joints are expected to have movement capacity.bearing capacity for stahc and dynamic loading,water-tightness,low noise emission and traffic safety.In particular.the tailure due to impact loading is the main reason for the observed damaaes.The problem of dynamic behavior of the expansion joints is so complex that we shall focus our attention on the impact factor for vehicle load that is governed by traffic impact.In order to overcome this difficulty. the cantilever-toothed aluminum joint(finger joint)is one of the promising joints under impact load-ing.In this study,from the viewpoint of design methodology.numerical studies for impact be-havior were conducted for aluminum alloy expansion joints with perforated dowels.The design im-pacf factor for the expansion joints with the perforated dowels against traffic impact loading was examined by using numerical simulations.

  9. 基于UHPC的超大跨径桥梁优化设计%Optimal Design of Ultra-long Span Bridge Based on UHPC

    Institute of Scientific and Technical Information of China (English)

    闫军祥

    2016-01-01

    In order to solve the problems in long span bridge of conventional concrete, such as easily cracking of box girder, limited span (under 300 m), Ultra-high Performance Concrete (UHPC) has been introduced to the design of ultra-long span bridge. A new type structure of continuous box girder contain thin-wall structure and dense diaphragm plates has been design. Obtain the optimal distance is 4m of dense diaphragm plates and optimal span ratio is 0.6 through performance analysis and optimization design. Research finding the UHPC bridge has the advantages of strong sustainability, long service life through contrastive analysis of UHPC bridge design scheme and entity arch bridge. The design of UHPC bridge provide a new method for ultra-long continuous box girder bridge.%为了解决常规混凝土下大跨径桥梁出现的箱梁易开裂,主跨径难以突破300 m等问题,将超高性能混凝土(ultra-high performance concrete,UHPC)引用至超大跨径的桥梁设计当中,形成了一种集薄壁结构、密集横隔板箱梁于一体的新型连续梁结构,并对横隔板参数和跨径比进行优化,确定最佳横隔板间隔为4 m,跨径比为0.6。将UHPC箱体桥梁设计方案与某实体桥梁进行对比分析,发现UHPC桥梁具有可持续性强、使用寿命长等优点,为超大跨径连续箱体桥梁设计提供了一个新的方法。

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

    DEFF Research Database (Denmark)

    Brynskov, Martin

    2007-01-01

    This paper will focus on the challenges in designing pervasive computing technology for children’s play, taking into account current trends in popular culture. In search of theoretical support for this work I have been exploring an activity-based approach called ‘habitats’ to describe the conditi......This paper will focus on the challenges in designing pervasive computing technology for children’s play, taking into account current trends in popular culture. In search of theoretical support for this work I have been exploring an activity-based approach called ‘habitats’ to describe...... the conditions around various design projects, and it seems to have some value. I will present my experiences from a playful pervasive gaming system for children and the problems I faced trying to find a solid theoretical paradigm. The paper argues that habitats with its three perspectives – physical......, informational, and pragmatic – together with the ability to describe their relations are a useful platform for practitioners and theorists who are forced to span a heterogeneous mash-up of technologies, theories, and professions....

  11. 太阳河大桥结构耐久性设计%Structural Durability Design for Taiyanghe River Bridge

    Institute of Scientific and Technical Information of China (English)

    应天益; 袁胜峰

    2014-01-01

    The Taiyanghe River Bridge are composed of a suspended cable-arch structure and a rigid-frame structure with oblique legs ,the former belongs to an elastically supported continuous girder with multiple supports and the latter is a rigid-frame system with V-shaped piers .The main girder is a prestressed concrete structure and the arch ribs are steel and concrete hybrid structures . Because the bridge is exposed in the marine environment ,its structural durability should be given top priority .Based on the existing durability design codes and other documents ,to increase the thickness of the concrete cover and the compactness of concrete are regarded as the fundamental measures in the concrete durability design .The load bearing capacity of the structure was opti-mized and the maintenance condition for the components was improved so as to reduce the impact of minor cracks on the durability of components .Mcreover ,a series of auxiliary measures ,such as using rust inhibitor ,concrete coatings and permeable formwork lining were taken as well .The steel structure is protected using the corrosion prevention technique ,and selectively using the heavy corrosion protection coatings and the thermal spraying composite coatings .Meanwhile ,to further ensure the durability of the structure ,specific requirements for construction technique and construction quality control of the bridge are proposed .%太阳河大桥由拱索支撑结构和斜腿刚构组成,其中拱索支撑结构为多支点弹性支撑连续梁,斜腿刚构部分为V形墩刚构体系,主梁为预应力混凝土结构,主拱为钢-混凝土混合结构。该桥位于近海环境,其结构耐久性问题突出,在现有的耐久性设计规范和其它文献资料的基础上,采取增加混凝土保护层厚度和密实性作为混凝土耐久性设计的根本措施,通过优化结构受力和改善构件养护条件来减小裂缝对构件耐久性的影响,并采取了阻锈剂、混凝

  12. Design of FPGA- Based SPWM Single Phase Full-Bridge Inverter

    Directory of Open Access Journals (Sweden)

    Afarulrazi Abu Bakar

    2009-12-01

    Full Text Available Nowadays power inverters serve as an important emergency power supply system in events of main power supply failure. The AC output voltage of a power electronic inverter is usually non-sinusoidal and hence has a high harmonic content. Sinusoidal Pulse Width Modulation (SPWM scheme is normally used to convert the DC power supply into AC power supply by comparing the reference voltage waveform with the triangular waveform known as carrier. SPWM provides a way to reduce the total harmonic distortion of load current. The objective of this paper is to demonstrate a SPWM switching scheme by using Altera DE2-70 board. In this SPWM technique, a sinusoidal reference voltage waveform is compared with the triangular carrier voltage to generate the on and off switching states. This switching scheme will trigger the gate of the power switch. In this paper, the SPWM switching strategies implemented using Altera DE2-70 (Cyclone II EP2C35F672C6 with 16 bit serial configuration devices. The switching between reference and carrier waveforms of SPWM is obtained by using Matlab software. Simulation on the design waveform is conducted using Quartus II software tools provided by Altera. The output frequency of SPWM is 50 Hz and the design is limited to two values of modulation indices which are 0.5 and 0.75.

  13. Bridging the conservation design and delivery gap for wetland bird habitat maintenance and restoration in the Midwestern United States

    Science.gov (United States)

    Thogmartin, W.E.; Potter, B.; Soulliere, G.

    2011-01-01

    The U.S. Fish and Wildlife Service's adoption of Strategic Habitat Conservation is intended to increase the effectiveness and efficiency of conservation delivery by targeting effort in areas where biological benefits are greatest. Conservation funding has not often been allocated in accordance with explicit biological endpoints, and the gap between conservation design (the identification of conservation priority areas) and delivery needs to be bridged to better meet conservation goals for multiple species and landscapes. We introduce a regional prioritization scheme for North American Wetlands Conservation Act funding which explicitly addresses Midwest regional goals for wetland-dependent birds. We developed decision-support maps to guide conservation of breeding and non-breeding wetland bird habitat. This exercise suggested ~55% of the Midwest consists of potential wetland bird habitat, and areas suited for maintenance (protection) were distinguished from those most suited to restoration. Areas with greater maintenance focus were identified for central Minnesota, southeastern Wisconsin, the Upper Mississippi and Illinois rivers, and the shore of western Lake Erie and Saginaw Bay. The shores of Lakes Michigan and Superior accommodated fewer waterbird species overall, but were also important for wetland bird habitat maintenance. Abundant areas suited for wetland restoration occurred in agricultural regions of central Illinois, western Iowa, and northern Indiana and Ohio. Use of this prioritization scheme can increase effectiveness, efficiency, transparency, and credibility to land and water conservation efforts for wetland birds in the Midwestern United States.

  14. Molecular design of organic dyes based on vinylene hexylthiophene bridge for dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Three donor-(π-spacer)-acceptor(D-π-A) organic dyes,containing different groups(triphenylamine,di(p-tolyl)phenylamine,and 9-octylcarbazole moieties) as electron donors,were designed and synthesized.Nanocrystalline TiO2 dye-sensitized solar cells were fabricated by using these dyes.It was found that the variation of electron donors in the D-π-A dyes played an important role in modifying and tuning photophysical properties of organic dyes.Under standard global AM 1.5 solar condition,the DSSC based on the dye D2 showed the best photovoltaic performance:a short-circuit photocurrent density(Jsc) of 13.93 mA/cm2,an open-circuit photovoltage(Voc) of 0.71 V,and a fill factor(FF) of 0.679,corresponding to solar-to-electric power conversion efficiency(η) of 6.72%.

  15. Molecular design of organic dyes based on vinylene hexylthiophene bridge for dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    LIU DaXi; ZHAO Bin; SHEN Ping; HUANG Hui; LIU LiMing; TAN SongTing

    2009-01-01

    Three donor-(TT-spacer)-acceptor (D-tt-A) organic dyes,containing different groups (triphenylamine,di(p-tolyl)phenylamine,and 9-octylcarbazole moieties) as electron donors,were designed and synthesized. Nanocrystalline TiO2 dye-sensitized solar cells were fabricated by using these dyes. It was found that the variation of electron donors in the D-tt-A dyes played an important role in modifying and tuning photophysical properties of organic dyes. Under standard global AM 1.5 solar condition,the DSSC based on the dye D2 showed the best photovoltaic performance: a short-circuit photocurrent density (Jsc) of 13.93 mA/cm2,an open-circuit photovoltage (Voc) of 0.71 V,and a fill factor (FF) of 0.679,corresponding to solar-to-electric power conversion efficiency (77) of 6.72%.

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

    Directory of Open Access Journals (Sweden)

    Hal A. Lawson

    2016-09-01

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

  17. 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.

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

    Science.gov (United States)

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

    2015-04-01

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

  19. Development of a rapid design procedure for emergency repair of bridge columns using fiber-reinforced polymers

    OpenAIRE

    Slater, Susan E.

    2008-01-01

    Fiber reinforced polymers (FRP) are increasingly used for seismic retrofit of undamaged bridge columns. The addition of a confining jacket increases overall strength and ductility of the column. However, FRPs can also be used for repair of a damaged bridge column after a seismic event. This research project explores the application of FRPs for retrofit of damaged circular columns. A decision tree for the emergency repair of damaged columns is presented. The decision tree aids field engineers ...

  20. Analysis of Highway Bridge Design and New Construction Technology%公路桥梁设计及施工新技术分析

    Institute of Scientific and Technical Information of China (English)

    张生霞

    2015-01-01

    本文结合GPS新技术、计算机技术以及混凝土新技术等,并对我国目前公路桥梁设计中使用的新技术进行了分析,提出了一些完善公路桥梁设计以及施工的建议,以供参考。%Combining with the GPS new technology, computer technology and new concrete technology, this paper analyzes the new technology used in the current design of highway bridges in China, and puts forward some sug⁃gestions for improving the design and construction of highway bridges for reference.

  1. 铂电阻非平衡电桥温度计的设计%Design of the Unbalanced Bridge Thermometer Using Platinum Resistance

    Institute of Scientific and Technical Information of China (English)

    冯叶; 蒋方为; 张宇鹍; 王吉有

    2016-01-01

    利用Matlab和Origin软件,从理论上分析了电压型非平衡电桥铂金属温度计设计中,各种参数对温度线性度的影响。设计了0~100℃范围的温度计,获得电桥的输出电压和测量温度具有很好的线性关系。%The influence of a variety of parameters on the linear of the thermometer in the design of the unbal-anced bridge are theoretically analyzed using Matlab software and Origin software. The thermometer was de-signed to obtain 0~100℃range.It was found that it has a good linear relationship between the output voltage of unbalanced bridge and temperature.

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

    Science.gov (United States)

    Wherton, Joseph; Prendergast, David

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

  3. Building a Straw Bridge

    Science.gov (United States)

    Teaching Science, 2015

    2015-01-01

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

  4. Design and Application of Bridge Safety Monitoring System%桥梁安全监测系统设计与应用

    Institute of Scientific and Technical Information of China (English)

    安庆; 李岩; 张婷婷

    2016-01-01

    Based on GNSS/GIS integration technology,the paper designed a set of bridge safety monitoring system, and took Jianghan Two Bridge as the application demonstrate in Wuhan,it stated the layout scheme of the base station, monitoring station,communication networks and data monitoring center equipment. At the same time, it developed the bridge safety monitoring system. The system can realize a series of functions,such as the all-weather acquisition,and the automatic rapid transmission. and the real-time decoding process of the bridge monitoring data. It also can display the monitoring information in graphic,and support threshold warning and health assessment. The system can provide the de-cision-making basis for bridge managers.%基于GNSS/GIS集成技术,设计了一套桥梁安全监测系统,以武汉江汉二桥为应用示范,阐述了基准站、监测站、通讯网络及数据监测中心设备的布设方案,研发了桥梁安全监测系统。该系统可实现对桥梁监测数据的全天候采集、自动快速传输、实时解算处理、监测信息图形显示、阈值预警以及健康评估,为桥梁的管理者提供了决策依据。

  5. 京沪高速铁路上海段桥梁设计%Design of Bridges in Shanghai Section of Beijing-Shanghai High-speed Railway

    Institute of Scientific and Technical Information of China (English)

    陈裕民

    2011-01-01

    京沪高速铁路上海段除高速正线外,还包括上海站联络线、虹桥站普速客车联络线、虹桥动车组走行线等,设有4个铁路疏解区,各线以高架桥梁为主.简要介绍京沪高速铁路上海段的建设环境、地质条件、各种线路的主要技术标准以及铁路疏解区复杂的平立面关系.结合具体工点阐述本段桥梁设计的主要特点,着重介绍因受城市区域规划、道路、河道、航道等影响而产生的特殊桥梁结构,并对大跨度斜连续梁、道岔区桥梁、门式桥墩等代表性特殊结构进行说明.特殊桥梁结构的创新与应用为枢纽内铁路线形优化创造了条件,使高速铁路建设与城市规划更加融合.%In addition to the high-speed main line, there are also Shanghai Station connection line, Hongqiao Station connection line for ordinary-speed passenger trains, Hongqiao running line of multiple units and four discongesting regions in the Shanghai section of Beijing-Shanghai high-speed railway, on these lines elevated bridges are most common. This paper briefly introduces construction environment, geological conditions, main technical standards of various railway lines and complex plan and elevation relations in discongesting areas, and describes the main characteristics of bridge design including concrete bridges, emphatically the special bridge structures such as large span skew continuous beam bridges, turnout section bridges, portal pears which have been constructed by the requirements of urban and regional planning, roads, rivers and channels in the Shanghai section of Beijing-Shanghai high-speed railway. The innovation and application of special bridge structures create conditions for linear optimization, and enhance to coordinate high-speed railway construction with city planning.

  6. Modular FRP Composite Bridge Deck

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    The bridge infrastructure of the United States is in constant need of repair and rehabilitation. It is reported that 43% of the bridges in the USA have been identified as being structurally deficient or functionally obsolete due to corrosion. SuperdeckTM, a non-corrosive fiber reinforced polymer (FRP) composite bridge deck. The Deck is designed and engineered into a lightweight, strong and rigid structure that will not corrode. The deck sections, composed of hexagon and double-trapezoid profi...

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    This paper presents the design, modelling and control of a three-port (TPC) isolated dc-dc converter based on interleaved-boost-full-bridge with pulse-width-modulation and phase-shift control for hybrid renewable energy systems. In the proposed topology, the switches are driven by phase-shifted PWM...... of the proposed ac inductor based TPC is investigated by performing state-space modelling. Moreover, the derived mathematical models are validated by simulation and measurements. In order to verify the validity of the theoretical analysis, design and power decoupling control scheme, a prototype is constructed...

  8. 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....

  9. Optimal Design of 3-ton Fork-lift Horizontal Style Turning Bridge%三吨叉车横置式转向桥的优化设计

    Institute of Scientific and Technical Information of China (English)

    王彩芹; 何秀彬

    2001-01-01

    叙述了3 t平衡重式叉车横置油缸转向桥的结构设计,主要包括横置油缸式转向桥的结构参数的确定及其转角精度的核定,从而实现转向系统的技术参数的要求。%The paper describes the structure design of horizontal style oil cylinder turnin g bridge of 3-ton balance weight type fork-lift, which mainly includes the det ermining of structural parameters of oil cylinder type turning bridge and of th e rotary angle precision checking. Thus, the technical parameters' requ irements are met with the turning system.

  10. Study on restrainer design method for continuous bridges%连续梁桥缆索限位器设计方法

    Institute of Scientific and Technical Information of China (English)

    张华; 李建中; 彭天波

    2013-01-01

    The method to define the maximum available relative displacement (MARD) of girder bridges is presented first. Based on the existing restrainer design methods for in-span hinges of frame bridges, different simplified mechanical models are proposed according to the different characteristics and positions of the expansions of continuous bridges with laminated rubber bearings. The nonlinear properties of sliding between laminated rubber bearings and main girders, restrainers and expansion gap are included in the simplified models. The restrainer design method for each simplified model is proposed. The effectiveness of the design methods is verified by designing restrainers for an example bridge. The results from nonlinear time history analysis show that restrainers determined by the methods perform well and effectively prevent unseating of the bridge. Meanwhile the seismic demands of the piers with restrainers are increased.%首先提出了梁桥有效搭接长度的确定方法.在参考国外缆索限位器设计方法的基础上,针对采用板式橡胶支座的连续梁桥,根据不同伸缩缝位置的约束特点,提出了对应的简化力学分析模型.简化模型考虑了板式橡胶支座滑动、缆索限位器和伸缩缝约束作用的非线性特性,在此基础上提出了不同伸缩缝位置处相应的缆索限位器设计方法.采用该方法对某桥进行了缆索限位器设计,并用非线性时程分析方法对限位器设计方法的有效性进行了评估.结果表明,所提设计方法能够有效地设计约束伸缩缝处墩梁相对位移的缆索限位器刚度,但设置缆索限位器后过渡墩的抗震要求有一定的增加.

  11. 道路桥梁设计隐患问题及完善措施%On the Problems and Improvement Measures in Road and Bridge Design

    Institute of Scientific and Technical Information of China (English)

    王玲

    2016-01-01

    The problems in road and bridge design are introduced,and the analysis of the causes of these problems is put forward.Combining with engineering examples,measures to improve the design of roads and bridges are put forward in the paper,including ensuring the safety and durability of the structure,improving the material quality,prolonging service life,paying attention to the road and bridge maintenance and condition monitoring and maintenance,and improving the content of construc-tion technology.The practical application shows that the above measures can effectively prevent the safety hazards,ensure the quality of road and bridge engineering,and improve the comprehensive ben-efits.%针对道路桥梁设计存在的安全隐患,分析产生问题的成因。结合工程实例,提出道路桥梁设计的完善措施,包括确保结构安全性与耐久性、提高材料质量、延长工程使用寿命、重视道路桥梁监测维修及养护、改进施工技术等内容。实际应用表明,采取上述措施能有效预防安全隐患,确保道路桥梁工程质量,提高综合效益。

  12. 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...

  13. Research on The Series Resistance in Non-balanced Bridge Thermometer Design%非平衡电桥温度计设计中串联电阻的研究

    Institute of Scientific and Technical Information of China (English)

    王卫星; 冯中营

    2012-01-01

    本文探讨了串联电阻型非平衡电桥温度设计中串联电阻与桥路电流、桥臂电阻的关系,并说明了串联电阻、桥路电流及桥臂电阻间的相互影响。%This article has discussed that the relation of the series resistance and the bridge connection electric current in the series resistance non-balanced bridge thermometer design,and the relation of the series resistance and the bridge arm resistance.The result has showed the mutual influence of the series resistance and the bridge connection electric current,and the mutual influence of the series resistance and the bridge arm resistance.

  14. 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

  15. 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

  16. 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...

  17. 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,...

  18. Explosion on the reinforcement design and construction methods of stone arch bridge%石拱桥加固设计及施工方法探讨

    Institute of Scientific and Technical Information of China (English)

    周勇

    2015-01-01

    结合工程案例,对拱背增大截面加固石拱桥的设计方案进行了介绍,并对拱上建筑拆除、主拱圈加固、更换拱腔填料等施工工艺进行了阐述,通过实践证明,采用该加固方法既可大大减少工程投资,又能提高石拱桥的整体承载能力,具有显著的社会和经济效益,对石拱桥的加固具有积极的推广意义。%Combining with engineering examples,the paper introduces the design scheme of arch enlarging section reinforced stone arch bridge, and describes top arch building demolishment,main arch circle reinforcement,and replacing arch filling materials and other construction technol-ogies. Practice proves that:the reinforcement methods can not only reduce engineering investment,but also improve integral bearing capability of stone arch bridge,and has obvious social and economic benefits,which has positive meaning for reinforcing stone arch bridge.

  19. 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.

  20. 等离子切割机半桥逆变电源的设计%Design of a Half-bridge Inverter for Plasma Cutting Machines

    Institute of Scientific and Technical Information of China (English)

    朱彬若; 江剑锋; 渠浩; 董娅韵; 杨喜军; 唐厚君

    2016-01-01

    相比全桥逆变式DC-DC变换器,半桥逆变式DC-DC变换器具有结构简单、控制方便和成本低廉的优点,适用于中小功率等离子切割机等应用场合。设计了一种采用半桥逆变式DC-DC变换器、短路引弧、闭环电流控制等特征的等离子切割机逆变电源,兼具有过热保护、过压保护和桥臂电压失衡保护功能,实现了输出电流在35 A !115 A之间连续可调的等离子切割机实物样机。切割工件实测结果表明,基于逆变电源等离子切割机的切割质量达到类激光水平。%As compared with the full-bridge DC-DC inverter,the half-bridge DC-DC inverter features a simple structure,easy control and low cost,so it is applicable to small and medium power plasma cutting machines.The prototype plasma cutting machine designed and manufactured adopts a half-bridge DC-DC inverter,short circuit arc strike and closed loop current control and can perform such functions as overheat protection, overvoltage protection and bridge arm voltage unbalance protection. The output current is continuously adjustable in the range of 35A-115A.Results of actual measurements of work-pieces show that the cutting quality of the plasma cutting machine based on the inverter can almost reach the same level of a laser cutter.

  1. Design of Welded Turnout Bridge on Taiyuan-Zhongwei-Yinchuan Railway%太中银铁路无缝线路道岔桥梁设计

    Institute of Scientific and Technical Information of China (English)

    左家强

    2014-01-01

    太原至中卫至银川铁路文水至靖边段位于吕梁山脉及陕北黄土高原,设计速度200 km/h,铺设跨区间无缝线路有砟轨道。为适应复杂的地形,共有3个车站的4座桥上设置了道岔。桥梁设计时结合具体情况,采用了不同的桥式方案及施工方法。各桥的孔跨布置满足无缝线路道岔的布设原则;对道岔梁采用结构设计软件进行分析,各项指标能满足无缝线路道岔的变形要求。并解决了预应力混凝土箱梁顶板大悬臂剪力滞效应、道岔梁桥墩及基础纵向总刚度与无缝线路道岔受力适应性、桥面及底板变宽连续箱梁支座横向布置等技术难题。经实际运营检验,能保证列车通过时的安全性、舒适性和平稳性。%Wenshui-Jingbian line of Taiyuan-Zhongwei-Yinchuan railway,a ballast jointless track with designed speed of 200 km/h,goes through Luliang Mountains and northern Shanxi Loess Plateau.In order to adapt to the complex terrain, turnouts were installed on four bridges near three stations.Combined with the specific circumstances of each project site, the bridges were designed using different structures and construction methods.The arrangement of spans for each bridge meets the laying principles of welded turnout.MIDAS and BSAS software is employed to ensure analysis for each turnout girder.All indexes met the requirements of the deformation of welded turnout while addressing the shear lag effect on top plate large cantilever of pre-stressed concrete box,adaptability of turnout girder piers and the total longitudinal stiffness of base to welded turnout stress,lateral arrangement of bridge floor and continuous box girders with widened baseboard as well as other technical problems.The actual operation indicates the bridges can ensure a safe,comfortable and smooth running.

  2. Design of simplified RLC Bridge Tester%简易RLC电桥测试仪的设计

    Institute of Scientific and Technical Information of China (English)

    朱赣; 徐云龙; 李伟明

    2012-01-01

    RLC测试是电子专业高素质技能型人才培养的一项内容。以AT89S51单片机作为核心控制器件,将电桥电路中的RLC电压参数经过运算放大器放大后进行模数转换,再由单片机处理数据后,RLC测量值液晶显示。%RLC testing is a part of highly skilled electronic professional training. The paper introduces the de- sign of a simplified RLC bridge tester which uses the AT89S51 microcontroller as the core control device. The tester amplifies the bridge voltage of the RLC circuit parameters through the operational amplifier then does the analog - digital conversion, then after the data processing by the mierocontroller; RLC tester liquid crystal screen can display the results.

  3. Bridging the Technological Gap.

    Science.gov (United States)

    Lazow, Robert; And Others

    The aim of "Bridging the Technological Gap" (BTG), a federally funded demonstration project, is to use microcomputer technology in the rehabilitation of the psychiatrically disabled. Through the use of a custom designed microcomputer software package, clients receive remediation in areas of specific cognitive and behavioral deficits. The project…

  4. Design of the Dongjiang River’s Main Bridge on Conghua-Dongguan Highway%从莞高速东江特大桥主桥设计

    Institute of Scientific and Technical Information of China (English)

    戎泽生

    2014-01-01

    The Dongjiang Grand Bridge,1 377 m in length,was built to serve the purpose of allo-wing Conghua-Dongguan Highway to span the Dongjiang River.Its main bridge adopts an 85 m +2 ×138 m +85 m four-span continuous rigid framework.This bridge is regarded as the key project on the line for its complication in formation and difficulty in design and construction.This paper first presents the design of the main bridge’s construction and the structure computation,and then focuses on analysis of the key aspects in terms of the beam bottom line type selection of box girder,prestressed reinforcement’s ar-rangement and mid-span’s deflection before providing strategies for the tailored design.%东江特大桥为从莞高速跨越东江而设,全长1377 m,主桥采用85 m +2×138 m +85 m 4跨连续刚构方案,本桥结构复杂,设计、施工难度大,是全线的重点控制工程。介绍了主桥的构造设计及结构计算,重点对箱梁梁底线型的选取、预应力布置及跨中下挠几个方面进行分析,并提出设计上的对策。

  5. 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

  6. 跨多股道钢箱梁天桥的结构设计%The Structural Design of Steel Box Girder Pedestrian Bridge Crossing Multiple Railways

    Institute of Scientific and Technical Information of China (English)

    沈耀海

    2011-01-01

    结合西部某新建火车站进站人行天桥工程实例,分析了设计和施工的多种控制条件,论证了主梁采用钢箱梁结构的合理性.通过有限元分析和动力特性计算可知,结构设计的控制因素为竖向自振频率,采用中墩与主梁固结的连接方式可以有效地调整结构竖向自振频率.%Based on the project case of one pedestrian bridge in one new constructed railway station at west China, many controlled conditions are analyzed about structural design and engineering construction, and the rationalitles of steel box girder bridge adopted in the design are also demonstrated. It is learned from finite - element analysis and dynamic characteristics calculation that the control factor of structural design is vertical vibration frequency, which can be improved effectively by means of fixed connection between central pier and steel box girder.

  7. 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.

  8. Design of Danyang Road Bridge in Heze City%菏泽市丹阳路大桥设计

    Institute of Scientific and Technical Information of China (English)

    张伟

    2015-01-01

    菏泽市丹阳路大桥为(40+100+240+100+40) m 双塔中央单索面半飘浮体系混凝土斜拉桥。该桥塔、墩固结,主梁与塔、墩间设置横、竖向支座和纵向液压阻尼器;主梁采用单箱三室斜腹板截面,高3.6m。桥塔采用顺桥向人字形的独柱混凝土塔,高68.2m,单箱单室矩形空心截面。人字形塔柱穿过主梁,与墩身顺接,墩身采用十字形空心薄壁截面,矩形承台,布置33根φ2.0m钻孔灌注桩。辅助墩和交接墩均采用花瓶形双柱式框架墩,矩形承台,布置8根φ1.5m钻孔灌注桩。斜拉索采用φ7 mm镀锌高强平行钢丝束。采用MIDAS Civil 2006和SCDS平面程序对该桥进行计算分析,结果表明该桥各项检算均满足规范要求。%T he Danyang Road Bridge in Heze City is a semi‐floating system concrete cable‐stayed bridge with double pylons ,a central single cable plane and with span arrangement (40+100+240+100+40) m .T he pylons and piers of the bridge are rigidly fixed and in betw een the main girder and pylons and piers ,the lateral and vertical bearings and the longitudinal hydraulic damp‐ers are arranged .The cross section of the main girder is the section of triple‐cell single box with in‐clined webs and the girder is 3 .6 m in depth .In the longitudinal direction of the bridge ,a pylon is the single‐column concrete pylon in the shape of inverted Y ,is 68 .2 m in height and the cross sec‐tion of the pylon is the rectangular hollow section of single‐cell single box .The inverted Y‐shape pylon passes through the main girder and is smoothly fixed with the pylon pier .The cross section of the pylon pier is the crisscross hollow thin‐wall section and the pier stands on the rectangular pile cap under w hich 33 nos .of φ2 .0 m bored piles are arranged .T he auxiliary piers and boundary piers are all the vase‐shape double‐column frame piers and respectively stand on each rectangular

  9. Key Techniques for Design of Edong Changjiang River Highway Bridge%鄂东长江公路大桥设计关键技术

    Institute of Scientific and Technical Information of China (English)

    胡明义; 黄冰释; 余俊林; 唐守峰

    2011-01-01

    The main bridge of Edong Changjiang River Highway Bridge is a semi-floating system hybrid girder cable-stayed bridge with double pylons, double cable planes and with a main span 926 m. The main girder of the bridge was designed as the PK (Pasco-Kennewick Bridge) cross section of separated twin boxes, of which the part of the girder for the central span is of the steel box girder, the parts of the girder for the side spans are of the prestressed concrete (PC) box girders and a steel and concrete joint section was set on each side of the central span at a distance of 12. 5 m to the center of a pylon. To ensure a smooth transition between the steel and concrete structure, the multi-cell force transmission structure with PBL shear connectors was used for the joint section. The cable-to-pylon anchorage is the steel anchor box structure built in the column of a pylon. To control the development of concrete cracks in the anchorage zone in the pylon, the prestressing strands of 12φs 15. 24 were set in the concrete pylon wall on the side of the anchorage. To enhance the structural durability and service life, the durability of reinforced concrete and corrosion protection of steel structure were designed and the life cycle cost concept was applide to the design. The inspection and maintenance accesses for all principal components of the bridge were provided and the inspection and maintenance cycles, replacement criteria, workmanship and technical requirements were formulated as well.%鄂东长江公路大桥主桥为主跨926 m的双塔双索面半飘浮体系混合梁斜拉桥,主梁采用分离式双箱PK断面形式,中跨为钢箱梁,边跨为PC箱梁,钢-混凝土结合段设于中跨距桥塔中心12.5m处.为使钢结构与混凝土结构平稳过渡,钢-混凝土结合段采用PBL剪力连接器的多格室传力构造.索塔锚固采用在塔柱内置钢锚箱的构造,为控制锚固区混凝土裂缝开展,在锚固侧混凝土塔壁内设置12(o)s15.24预应力

  10. 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.

  11. 基于 STM32的全桥逆变器的设计%The Design of Full Bridge Inverter Based on STM32

    Institute of Scientific and Technical Information of China (English)

    黎山峰; 黄超龙

    2016-01-01

    The paper introduces a design of the full bridge inverter based on the STM 32 microcontroller as the controlling core in order to design a low power digital sine-inverter, which uses a high resolution SPWM pulse produced by the MCU ’ s high speed timer , and operates the SPWM pulse into chopper inversion by the photoelectric coupler and IR 2111 to amplify power with the help of the full bridge converter made of IRF 840 , with the LC filtering circuit , finally changing high voltage SPWM pulse into AC power .%为设计一种低功耗的数字化正弦逆变器,设计了以STM32单片机为控制核心的全桥逆变器,该逆变器采由单片机的高速定时器产生高分辨率的SPWM脉冲,通过光耦隔离和IR2111驱动芯片把SPWM脉冲信号对由IRF840场效应管构成的全桥电路实现斩波逆变,经过LC滤波电路,最后实现高压SPWM脉冲转换成交流电源。

  12. Design of Hydraulic System for the LTQ-2000Y Passenger Boarding Bridge%LTQ-2000Y型旅客登机桥液压系统设计

    Institute of Scientific and Technical Information of China (English)

    郭会歌; 薛鹏; 杨军宁; 王永利

    2012-01-01

    阐述了旅客登机桥的作用及对液压系统的要求.介绍了LTQ-2000Y型旅客登机桥的液压系统的设计实践,包括油源系统、升降回路、行走回路、转向回路、调平回路、回转回路和应急回路的设计.归纳了该液压系统的主要特点:控制、操作方式多样;油源高效、节能;行走、制动可靠;升降同步、可控;调平自动、及时.这些特点在设备使用中得到了良好的体现.%The passenger boarding bridge's function and its requirement to the hydraulic system were expatiated. The design practices of the LTQ-2000Y passenger boarding bridge's hydraulic system were described, including the design of the oil source system, lifting loop, walking loop, steering loop, leveling loop, rotating loop and emergency loop. The main features of the hydraulic system were generalized; the control and operation modes were varied; oil source was efficient and energy-saving; walking and braking was reliable; up & down lifting was synchronized and controllable; leveling was automatically and timely. These features are well reflected when using the device.

  13. 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.

  14. Modeling and Design of Five Level Cascaded H-Bridge Multilevel Inverter with DC/DC Boost Converter

    Directory of Open Access Journals (Sweden)

    Vinayaka B.C

    2014-06-01

    Full Text Available Power electronic converters, especially DC/AC Sinusoidal Pulse Width Modulation inverters have been extending their range of use in industry because of their numerous advantages. They typically synthesize the stair –case voltage waveform (from several dc sources which has reduced harmonic content. This paper aims to extend the knowledge about the performance of Five level Cascaded H-Bridge MLI topology with DC/DC Boost Converter using SPWM for fixed DC Source. The output voltage is the sum of the voltage that is generated by each bridge. The switching angles can be chosen in such a way that the total harmonic distortion is minimized. This topology incorporates Boost Converter in the input side which magnifies the fundamental output voltage with reduction in total harmonic distortion. It also incorporates LC filter and hence output is drawn near the sine wave because of more levels. Results of experiments proved efficiency of 95%.The performance of the proposed SPWM strategy in terms of output voltage and THD has studied successfully and shown using MATLAB/Simulink.

  15. LLC resonant half-bridge circuit design with DC-DC%LLC谐振半桥DC-DC电路设计

    Institute of Scientific and Technical Information of China (English)

    杨磊; 吴晓光; 羊彦

    2013-01-01

    LED drive power level after the DC-DC constant current circuit using LLC resonant half-bridge topology structure, and through the output current and voltage feedback loop to achieve constant current limiting function.LLC resonant half-bridge DC-DC constant current circuit power part comprises a resonant circuit and the output of the rectifier circuit, the control part chip power supply circuit, the control chip peripheral circuit, an output feedback loop, the test shows that the system has stable output can be good, long time working with high efficiency.%LED驱动电源的后级DC-DC恒流电路采用LLC谐振半桥的拓扑结构,并通过输出的电流电压双环反馈来实现恒流限压功能.LLC谐振半桥DC-DC恒流电路的功率部分包括了谐振电路和输出整流电路,控制部分有芯片供电电路、控制芯片外围电路、输出反馈回路等,经试验证明该系统输出稳定好,能够长时间高效工作.

  16. Design of Cofferdam for Non-Navigable Span Bridge of Hong Kong-Zhuhai-Macau Bridge over Shallow Water Area%港珠澳大桥浅水区非通航孔桥围堰设计

    Institute of Scientific and Technical Information of China (English)

    黄剑锋

    2015-01-01

    The non‐navigable span bridge of the Hong Kong‐Zhuhai‐Macao Bridge over the shallow water area is a 85‐m span continuous composite girder structure ,the foundations for the bridge are the steel pipe composite pile foundations and the pile caps and piers supported on the foundations are the precast structures .The foundations were constructed by the interlocked doub‐le‐wall steel boxed cofferdams with no internal bracings .A cofferdam is 17 .6 m long ,13 .4 m wide ,23 .2 m high and the thickness of the bulkhead of the cofferdam is 0 .75 m .The cofferdam was designed into a removable structure and in plan ,was divided into 8 segments which were inter‐connected by the combination way of tenon locks and bolts .The cofferdam is mainly made up of three parts of the lateral plates ,horizontal ring plates and vertical partition plates and joints .In accordance with the different force conditions of the cofferdam in the construction process ,4 load cases were considered in the design .The software MIDAS Civil 2006 and ANSYS were used to set up the finite element models for the different load cases and the displacement and stress of the cof‐ferdam and its base sealing structure were analyzed .The results of the analysis indicate that the values of the maximum displacement and stress of the cofferdam and the base sealing concrete structure under the different load cases are all less than those as specified in the codes and can meet the requirements ,proving that the force conditions of the cofferdam in the construction are safe and the cofferdam is structurally rational .%港珠澳大桥浅水区非通航孔桥为跨度85 m的连续组合梁结构,其基础采用钢管复合桩基和预制墩台结构,基础采用无内支撑结构的双壁锁口钢套箱围堰施工。围堰长17.6 m、宽13.4m、高23.2m,壁仓厚0.75m。围堰设计成可拆装式结构,平面分为8块,各分块之间采用榫头式锁口与螺栓组合的方式连接。

  17. 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.

  18. Analysis of Highway Concrete Beam Bridge Life Cycle Design Method and Application%公路混凝土梁式桥全寿命设计方法及应用分析

    Institute of Scientific and Technical Information of China (English)

    陈锦辉

    2012-01-01

    目前国内外虽然进行了大量针对桥梁生命周期的专项研究,但关于桥梁全寿命设计体系、各设计过程及相应方法的研究依然匮乏。现阐明了全寿命设计方法的概念、设计原则和设计目标,将桥梁的设计和需求拓展到结构的整个使用寿命期,建立了公路混凝土梁式桥全寿命设计方法的总体框架。同时以一座钢筋混凝土简支梁桥作为背景工程,从桥梁时变可靠性和周期成本优化两个方面入手,将所研究的全寿命设计框架和设计方法进行了具体阐述,并应用于实际混凝土梁式桥项目中,为工程实践提供一定的参考借鉴和设计思路。%Although a great deal of special research on the bridge life cycle has been done at home and abroad, the life cycle design system and the corresponding design methods for bridge are still scarce. The concept of life cycle design methods, design principles and design objectives are clarified. The design of the bridge and needs are expanded to the entire life of the structure. The overall framework of the life cycle design of the highway concrete beam bridge is created in this paper. An example is studied based on simply supported reinforced concrete beam bridge engineering. A life cycle design framework and design method for the life cycle design system of bridge are specifically addressed, according to the two methods including the time-variant reliability and cycle cost optimization for the bridge. The theory is applied to actual concrete beam bridge project for engineering practice to provide references and design ideas.

  19. Military Beam Temporary Bridge Design Crossing over Railway in Electrification Innovation of Existing Line%铁路电气化改造中上跨军用梁公路便桥设计

    Institute of Scientific and Technical Information of China (English)

    肖念婷

    2014-01-01

    In electrification Innovation of existing railways, some road bridges crossing over railway need be demolished and re-constructed because of the insufficient clearance under the bridges, it introduces the analysis and check-calculation of temporaty bridge design by the 64-type military beam,which could be for technical assurance on temporaty bridge operation safety.%结合某铁路电气化改造中既有上跨公路桥因净空不足需拆除重建,介绍采用64军用梁架设公路便桥的设计方案,并进行分析和检算,为便桥运营安全作出技术上的保证。

  20. Visual Storyboarding Provides a Conceptual Bridge from Research to Development: Students Can Imagine the Results of Their Decision Making, and Their Prioritization of the Many Facets of the Design Problem Will Facilitate the Development of a Strong Final Solution

    Science.gov (United States)

    Reeder, Kevin

    2005-01-01

    In order to facilitate the selection/prioritization process and bridge the gap of design research to design conceptualization, students need to visualize the big picture that describes how the research categories such as "user," "marketing," "functional/mechanical research" are related. This is achieved through the use of a visual storyboard. The…

  1. 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...... Belgrade), Leo Pekkala (Finnish Centre for Media Education and Audiovisual Media/MEKU), Julie Uldam (Network on Civic Engagement and Social Innovation) and Gabriella Velics (Community Media Forum Europe)....

  2. Mathematical bridges

    CERN Document Server

    Andreescu, Titu; Tetiva, Marian

    2017-01-01

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

  3. Plastic Bridge

    Institute of Scientific and Technical Information of China (English)

    履之

    1994-01-01

    Already ubiquitous in homes and cars, plastic is now appearing inbridges. An academic-industrial consortium based at the University ofCalifornia in San Diego is launching a three-year research program aimed atdeveloping the world’s first plastic highway bridge, a 450-foot span madeentirely from glass-,carbon,and polymer-fiber-reinforced composite mate-rials, the stuff of military aircraft. It will cross Interstate 5 to connect thetwo sides of the school’s campus.

  4. Structure Design of Basket Handle Arch Bridge of Zhengzhou-Xi'an High-speed Railway%郑州至西安铁路客运专线提篮拱桥结构设计特点

    Institute of Scientific and Technical Information of China (English)

    李义发

    2015-01-01

    尼尔森体系提篮拱桥造型美观,可一孔简支,主桥短,建筑高度低,跨越能力强,结构的竖、横向刚度大,适应整体桥面,造价经济,施工养护方便,设计成系列孔跨应用到铁路客运专线前景广阔,经济和社会效益显著。文中从国内外拱桥的现状出发,介绍了尼尔森提篮拱特征,并结合工程实例介绍了尼尔森提篮拱的构造设计。%Nielsen system basket arch bridge has attractive appearance and can be designed as a single-span bridge that will be simply supported.The length of main bridge of the type of the arch bridge is short,building height is low,spanning capacity is great,vertical and lateral stiffness of the structure is strong,and the bridge is also adapt to the overall bridge deck,cost-effectiveness,easy construction and maintenance.If the bridge is designed to have series of span of different length for selection and applied to the passenger dedicated railway line,it will have wide vista of application and the economic and social benefits will be significant.From the present situation of the arch bridge at home and a-broad,this paper introduces the characteristics and structure of nelson basket handle arch combined with an engineering example.

  5. Structural criteria for the rational design of selective ligands. 2. Effect of alkyl substitution on metal ion complex stability with ligands bearing ethylene-bridged ether donors

    Energy Technology Data Exchange (ETDEWEB)

    Hay, B.P.; Zhang, D.; Rustad, J.R. [Pacific Northwest National Laboratory, Richland, WA (United States)

    1996-04-24

    A novel approach is presented for the application and interpretation of molecular methanics calculations in ligand structural design. The methodology yields strain energies that (i) provide a yardstick for the measurements of ligand binding site organization for metal ion complexation and (ii) allow the comparison of any two ligands independent of either the number and type of donor atoms or the identity of the metal ion. Application of this methodology is demonstrated in a detailed examination of the influence of alkyl substitution on the structural organization of ethylene-bridged, bidentate, ether donor ligands for the alkali and alkaline earth cations. Nine cases are examined, including the unsubstituted ethylene bridge (dimethoxyethane), all possible arrangements of individual alkyl groups (monoalkylation, gem-dialkylation, meso-dialkylation, d,l-dialkylation, trialkylation, and tetraalkylation), and both cis and trans attachments of the cyclohexyl group. The calculated degree of binding site organization for metal ion complexation afforded by these connecting structures is shown to correlate with known changes in complex stability caused by alkyl substitution of crown ether macrocycles.

  6. 跨接在两个网络间的语音记录仪设计%Design of audio recording system bridged on two network

    Institute of Scientific and Technical Information of China (English)

    徐智敏; 颜浩洋; 王建兵; 喻德茂

    2015-01-01

    设计了语音记录仪。该语音记录仪桥接在通信设备之间,同时提供3种桥接接口:以太网接口,支持在 IP 通信方式下的各通话组的直通及录音功能;二线接口,支持模拟二线方式下的直通及录音功能;音频接口,支持模拟音频方式下的直通及录音功能。同时话音记录仪提供 FTP 服务器,可以通过局域网对语音记录仪保存的语音文件进行下载和管理。此外,该设备支持语音回放功能。%An audio recording system was designed in this article which was bridged on the communication device. It provided three bridge means. Ethernet: the audio record and voice call over IP was supplied. 2-wire: voice call on the 2-wire and the audio record was supplied. Audio: the analog audio and the audio record was supplied. The FTP server was supplied. The audio document could be downloaded and managed through the LAN. The device also has the audio replay function.

  7. Design, Synthesis and Antitumor Activity of Novel link-bridge and B-Ring Modified Combretastatin A-4 (CA-4) Analogues as Potent Antitubulin Agents

    Science.gov (United States)

    Duan, Yong-Tao; Man, Ruo-Jun; Tang, Dan-Jie; Yao, Yong-Fang; Tao, Xiang-Xiang; Yu, Chen; Liang, Xin-Yi; Makawana, Jigar A.; Zou, Mei-Juan; Wang, Zhong-Chang; Zhu, Hai-Liang

    2016-01-01

    A series of 12 novel acylhydrazone, chalcone and amide–bridged analogues of combretastatin A-4 were designed and synthesized toward tubulin. All these compounds were determined by elemental analysis, 1H NMR, and MS. Among them, compound 7 with acylhydrazone-bridge, bearing a benzyl at the indole-N position, was identified as a potent antiproliferative agent against a panel of cancer cell lines with IC50 values ranging from 0.08 to 35.6 μM. In contrast, its cytotoxic effects on three normal human cells were minimal. Cellular studies have revealed that the induction of apoptosis by compound 7 was associated with a collapse of mitochondrial membrane potential, accumulation of reactive oxygen species, alterations in the expression of some cell cycle-related proteins (Cyclin B1, Cdc25c, Cdc2, P21) and some apoptosis-related proteins (Bax, PARP, Bcl-2, Caspase3). The docking mode showed the binding posture of CA-4 and compound 7 are similar in the colchicine-binding pocket of tubulin, as confirmed by colchicine-tubulin competitive binding assay, tubulin polymerization inhibitory activity, extracellular protein expression determination assay and confocal immunofluorescence microscopy. In vivo study, compound 7 effectively inhibited A549 xenograft tumor growth without causing significant loss of body weight suggesting that compound 7 is a promising new antimitotic agent with clinical potential. PMID:27138035

  8. Bridge Wire Electric Ignition Drive Circuits Design%桥丝电点火器的驱动电路设计∗

    Institute of Scientific and Technical Information of China (English)

    张宪国; 曹红松; 赵捍东; 白松

    2015-01-01

    Pulse jet engines are often ignited by gunpowder wrapped bridge wire electric igniter and widely used in aircraft attitude control. The electric igniter needs short-pulse current driving for rapid initiation. In this paper,opto-isolated constant current source and capacitor discharge mode driving circuits are designed for the demand of micro-bridge wire electric igniter. Two kinds of detonating circuit designs implemente the ignition driving of brige wire e-lectric igniter wtih resistance fluctuations. The constant current source mode is capable of long storage life,compact spatial structure and high safety, and the reservoir capacitor mode demonstrates high energy efficiency and fast-acting for quick initiation. Two methods provide reference designs for the pulse jet engines of different engineering requirements.%用于飞行器姿态控制的脉喷发动机常采用火药包裹的桥丝电点火器进行点火,电点火器需要短时脉冲电流驱动。本文针对微小型桥丝电点火器驱动需求,设计了光耦隔离恒流源方式及电容储能脉冲放电驱动电路,均实现了对阻值波动桥丝电点火器的点火驱动。试验证明,光耦隔离恒流源方式可靠性高,安全稳定,电容储能放电方式效率高、作用迅速。该两种设计方法可为脉喷发动机的工程实践提供参考。

  9. Design and construction of scour protection for deep-water group pile foundation structures of two pylons in the Sutong Bridge project

    Institute of Scientific and Technical Information of China (English)

    He Ping; Guan Yijun; Zhang Xiongwen; Zhang Qun; Zhou Jianhua

    2009-01-01

    Sutong Bridge, as a world-record cable-stayed bridge with its main span exceeding 1 000 m constructed in Yangtze River estuary region in China, is located at a site with complicated hydrologic conditions and poor geotechnical conditions and therefore, scour protection will be a decisive factor for ensuring smooth and successful construction of this bridge. This paper, starting from structural description of deep-water group pile foundation, analyzes impact to the bridge safety introduced by scour and its protection and further presents different solutions of scour protection for foundation structures of this bridge.

  10. Design of Norway HAKRDANGER Steel Box Girder Bridge Coating Process%挪威HAKRDANGER大桥钢箱梁涂装工艺设计

    Institute of Scientific and Technical Information of China (English)

    李连缀; 李敏风

    2011-01-01

    The anti-corrosion matching scheme and performance of the Norwegian HAKRDANGER bridge steel box girder inside and outside were introduced. The design of coating process including surface treatment, arc spraying zinc process, spray construction process equipment and related technical parameters requirements were introduced in detail.%介绍了挪威HAKRDANGER大桥钢箱梁内外侧防腐配套方案及性能。着重介绍了涂装工艺设计,包括表面处理、电弧喷锌工艺、喷漆施工等工艺设备及相关技术参数要求等。

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-03-15

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

  12. 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...... scenarios outlined. LCA study is performed with the ReCiPe methodology with life cycle inventories data from public database. Five selected mid-point level impact categories and the energy consumption are presented. The result shows that the steel bridge has a better environmental performance due...... to the recycling strategy, while the initial material manufacture is the most dominant phase that contributes large environmental impact in both design solutions....

  13. 重载交通公路桥梁设计中关于车辆载荷的分析%Heavy Traffic Highway Bridge Design Analysis of Vehicle Load

    Institute of Scientific and Technical Information of China (English)

    刘星亮

    2014-01-01

    在设计公路桥梁时,最重要的参考依据是车辆的载荷,它与公路桥梁的具体承载能力和经济价值有直接关系。基于此,在设计重载交通公路桥梁的过程中,分析了其与车辆载荷相关的内容。%In the design of roads and bridges, the most important reference is the load of the vehicle, which has a direct relationship with the specific carrying capacity and economic value of highway bridges. Based on this, the process of designing heavy traffic roads and bridges, the analysis of its relevant content and vehicle load.

  14. 重庆两江大桥交通安全设施优化设计%Optimal Design of Traffic Safety Facilities on Chongqing Two-river Bridges

    Institute of Scientific and Technical Information of China (English)

    张政委

    2014-01-01

    This paper analyzes the problems in traffic safety of urban bridges at present, expatiates design of traffic safety facilities of Two-river Bridges from the aspects of layout of marks, layout of marked lines, protruding signs, delineators, anti-collision drums and TPU columns as well as safety guarantee measures for special sections, etc. in allusion for Chongqing Dongshuimen Yangtze River Bridge and Qiansimen Jialing River Bridge ( Two-river Bridges for short) project, and performs structural check computation and comparative analysis for mark layout, common hot melt marked lines and double-component marked lines, respectively so as to propose an optimal design scheme for traffic safety facilities of Two-river Bridges to satisfy the need of safe operation of bridges.%分析目前城市桥梁交通安全存在的问题,针对重庆东水门长江大桥、千厮门嘉陵江大桥(简称两江大桥)项目,从标志布设、标线布设、突起路标、轮廓标、防撞桶及TPU柱和特殊段落的安全保障措施等方面阐述两江大桥交通安全设施设计,并对标志版面、普通热熔型标线及双组份标线分别进行结构验算和比较分析,提出两江大桥交通安全设施优化设计方案,以满足桥梁安全运营的需要。

  15. 泉州湾跨海大桥工程南岸陆地区引桥及北岸接线设计重点分析%Analysis of Design Focus on Southern District Bridge and North Shore Connection Route of Quanzhou Bay Sea-Crossing Bridge Project

    Institute of Scientific and Technical Information of China (English)

    刘正祥; 苗家武; 朱忠明; 苗瑞坤; 孙楠

    2013-01-01

    泉州湾跨海大桥工程位于福建省东部经济发达地区,是福建省境内的重点工程.文中从南岸引桥顺河道布置、路线与规划区的结合、秀涂互通方案优化、填海路基防护、桥梁耐久性等方面,对泉州湾跨海大桥工程南岸陆地区引桥及北岸接线的设计重点进行分析.%Quanzhou Bay Sea-Crossing Bridge Project is located in the economically developed eastern area, in Fujian Province. It is a key project in Fujian Province. The design focus on Southern District Bridge and North Shore Connection Route of Quanzhou Bay Sea-Crossing Bridge Project are analyzed from Southern Bridge arrangement along the river, route and planning area combination, Xiutu Interchange scheme optimization, reclamation embankment protection, bridge durability etc.

  16. Unseating Damage to Simply Supported Bridges during Wenchuan Earthquake and Design Countermeasures%汶川大地震简支梁桥落梁震害与设计对策

    Institute of Scientific and Technical Information of China (English)

    王东升; 王吉英; 孙治国; 李晓莉

    2011-01-01

    The unseating damage to simply supported bridges and their main influencing factors during the Wenchuan earthquake are summarized. It is found that excepting the earthquake-induced landslide hazard, the earthquake surface rupture, near fault ground motion, punching shear failure of the abutment breast wall, the invalidity of the devices for preventing unseating damage to the bridges and the complex bridge types are main influencing factors leading to the unseating damage to the simply supported bridges. Basic seismic design idea and method to prevent unseating damage to simply supported bridges are presented in this paper, which include: (1) sliding between bridge girders and cap beams is allowed to reduce the seismic actions concentrated on the bridge piers; (2) cap beams with enough seating length are recommended for sliding between girder and pier to avoid unseating damage; (3) shear keys or cable restrainers should be used as added measures to prevent unseating damage. The design method for simply supported bridges with cable restrainers is illustrated in detail by using current seismic design code for bridges.%总结了5· 12汶川大地震中简支梁桥落梁震害及主要影响因素,发现除地震山体滑坡等地质灾害外,断层地表破裂、近断层地震动效应、桥台胸墙冲切破坏、防落梁构造措施单一及桥梁体型复杂等因素都是引起简支梁桥落粱震害的重要原因.提出了简支梁桥防落梁设计的基本理念及相关技术方案要点为允许墩梁间发生滑移,以降低桥墩承受的地震惯性力,以及盖梁提供允许的最大滑移长度及支座支承宽度,再辅助挡块或拉索限位器等共同防止落粱发生.最后结合现行规范,以拉索限位器为例给出了简支梁桥防落梁设计方法.

  17. 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...

  18. 南平闽江大桥斜拉桥挂篮设计与施工技术%The Design and Construction Technology of Suspension Cradle of Nanping Minjiang Cable-stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    李向海

    2011-01-01

    Based on the practical construction experience of Minjiang Bridge of Nanping City Fujian Province,this paper refers to the main technical solutions and application of front-fulcrum suspension cradle in cable-stayed bridge and the design and construction technology of the suspension cradle.%结合福建省南平市闽江大桥工程实际情况,主要介绍了前支点挂篮在斜拉桥施工中的应用、挂篮的设计与施工技术,以及关键技术问题的解决。

  19. 新抗震规范在高速公路典型桥梁设计中的应用%Application of New Earthquake Resistant Code in Typical Bridge Design for Expressway

    Institute of Scientific and Technical Information of China (English)

    罗波; 李峰

    2012-01-01

    对新桥梁抗震规范在高速公路典型桥梁设计中的应用进行了计算分析,以期达到经济合理和相当安全的抗震目的。%Computational analysis on application of new earthquake resistant code for bridge in typical bridge design for expressway is made so as to achieve the economic and reasonable and comparatively safe earthquake re-sistant aim.

  20. Bridging the gap between selection decisions of facade systems at the early design phase: Issues, challenges and solutions

    Directory of Open Access Journals (Sweden)

    Mohamad Kassema

    2015-11-01

    Full Text Available Building facade has a significant impact on the environmental and economic performance of buildings and projects. The specification of their elements at the early design phase depends on numerous technical, environmental and economic factors and involves several stakeholders. The procurement and delivery of the facade work package from the early design phase, through detailed design and manufacture, to installation is a process with several inherent risk factors due to the involved cost, technical and engineering complexities and its position on the critical path in all projects. This research investigates the process of selection and specification of building facade elements at the early design phases with the overarching aim of identifying the issues affecting specification decisions, their root causes and impact on projects. The research utilizes a mixed research approach which combines a retrospective case study and an industry survey as two research methods that build on each other. The findings suggest that the complexity of specification at the early design phases is exacerbated by factors such as the inadequate technical knowledge of stakeholders involved in the decision making process, the non-involvement of building facade consultants, the late involvement of specialist facade subcontractors, and in a few cases by some commercial exclusivity agreements that restricts specification decisions. 

  1. Seismic Performance of Multi-Span RC Railway Bridges

    DEFF Research Database (Denmark)

    Georgakis, Christos; Barrau, Xavier

    2008-01-01

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

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

    Science.gov (United States)

    Ahmad, Javaid; Cheng, Shaohong; Ghrib, Faouzi

    2016-02-01

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

  3. 京石客运专线重点桥渡设计综述%The Summary of Important Bridge Design for Beijing-Shijiazhuang Passenger Dedicated Railway

    Institute of Scientific and Technical Information of China (English)

    牛远志

    2015-01-01

    With reference to the design of bridges on Beijing-Shijiazhuang passenger dedicated line, the focus is placed on the end thorn rigid frame, the Liu Xinzhuang rotating continuous beam, the Fifth Ring Road basket arch, the high pier large span rigid turnout beam and the high frame pier. A brief introduction is made to the four kinds of important pier design. The related results may provide references for future high-speed railway construction in China.%结合京石客运专线桥梁设计,着重介绍端刺刚构梁、柳辛庄转体连续梁、五环路提篮拱、高墩大跨刚构道岔梁、高框架墩等5项重点桥渡设计,简要介绍4项重点桥墩设计。相关成果可为今后的中国高速铁路建设提供借鉴。

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-01

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

  5. Building bridges between theory and practice in medical education using a design-based research approach: AMEE Guide No. 60.

    Science.gov (United States)

    Dolmans, Diana H J M; Tigelaar, D

    2012-01-01

    Medical education research has grown enormously over the past 20 years, but it does not sufficiently make use of theories, according to influential leaders and researchers in this field. In this AMEE Guide, it is argued that design-based research (DBR) studies should be conducted much more in medical education design research because these studies both advance the testing and refinement of theories and advance educational practice. In this Guide, the essential characteristics of DBR as well as how DBR differs from other approach such as formative evaluation are explained. It is also explained what the pitfalls and challenges of DBR are. The main challenges deal with how to insure that DBR studies reveal findings that are of a broader relevance than the local situation and how to insure that DBR contributes toward theory testing and refinement. An example of a series of DBR studies on the design of a teaching portfolio in higher education that is aimed at stimulating a teacher's professional development is described, to illustrate how DBR studies actually work in practice. Finally, it is argued that DBR-studies could play an important role in the advancement of theory and practice in the two broad domains of designing or redesigning work-based learning environments and assessment programs.

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

    Science.gov (United States)

    Roehl, Amy

    2013-01-01

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

  7. River ice jams at bridges

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, D. [New Brunswick Dept. of Transportation, Fredericton, NB (Canada); Beltaos, S. [National Water Research Institute, Burlington, ON (Canada)

    2000-12-01

    Ice jamming, known to cause high water levels at even moderate river flows, is described as both the main and least understood source of ice-related bridge damages. This paper describes a joint study by the New Brunswick Department of Transportation, the Department of the Environment, local governments, and the National Water Research Institute, designed to address problems associated with the interaction of ice jams and bridges. The study consists of collecting information at each of four sites in New Brunswick including: historical data on ice jam locations, causes, and water levels; channel bathymetry, width and slope within each study centred at the respective bridge; and documentation of ice conditions throughout the ice season, including measurement of ice cover thickness, observation of breakup mechanisms, times, causes, characteristics and possible impacts of ice jam release. Data analysis will include determination of high stages due to ice jams or surges caused by upstream ice jam releases, scour potential of surges, and quantification of the structure's capacity to restrain ice movement and to cause jams. The principal objective of the study is to advance beyond empiricism and to develop rational design criteria for bridges by anticipating the effects of climate changes and by incorporating local meteorological and hydrometric records into bridge design for added safety.

  8. 新疆恰尔巴哈特桥设计流量的计算%Calculation of the Design Flow of Xinjiang QiaErBaHaTe Bridge

    Institute of Scientific and Technical Information of China (English)

    李杨; 高秋华

    2011-01-01

    Bridge design flood flow calculation in the design of the bridge site has a very important position, in order to avoid the bridge dam age , bridge design standards to ensure that flood frequency safe operation, the design process must be given to the calculation of adequate knowledge of hydrology. However, because uncertain hydrological system is a complex system of hydrological data informed of relatively limit ed. Especially in the Xinjiang Uyghur Autonomous Region, the land in the small mountain rivers, canals numerous low, and most of the hydrological record is not measured continuously, how to use the existing, adjacent to the hydrological data, inquire design flow of the basin is particularly important. Combining with the design experience of QiaErBaHaTe bridge of Highway 315, the design flow of small watershed bridge and flood design were discussed.%桥梁洪水设计流量的计算在桥位设计中有非常重要的地位,为避免桥梁水毁,保证桥梁在设计标准的洪水频率下安全运营,必须在设计过程中对水文计算给子足够的认识.但由于水文系统是一个复杂不确定的系统,水文资料的获知相对有限.尤其是在新疆维吾尔族自治区,该地中低山区小河流沟渠数不胜数,且多数没有实测连续的水文记录,如何利用现有的、邻近的水文资料,推求该流域的设计流量就尤为重要.结合参加省道315公路的恰尔巴哈特桥设计工作的经验,探讨了新疆小流域桥梁洪水设计流量的确定.

  9. 昌平钢-混凝土结合连续刚构桥的设计与施工%Design and Construction of Steel and Concrete Continuous Composite Rigid Frame of Changping Overpass Bridge

    Institute of Scientific and Technical Information of China (English)

    马立芬; 王冰

    2012-01-01

    The Changping Overpass Bridge is a steel and concrete continuous composite rigid-frame bridge arranged in two continuous units, each being (37 + 60 + 79 + 42. 5) m and (42. 5 + 79 + 42. 5) m. The main girder of the bridge is designed as a steel and concrete composite one, of which the steel box girder is of the single-cell, single-box and vertical web section and the deck slabs are the reinforced concrete structure. The box girder is rigidly fixed with the concrete pier shaft at the intermediate pier and all pier columns of the bridge are the rectangular ones. The fi-nite element program MIDAS Civil was used to establish the calculation model for spatial struc-ture of the whole bridge, the static force of the bridge was calculated and analyzed and the results of the calculation and analysis proved that the stress and structural strength of the box girder could meet the relevant requirements in the codes. To minimize the interference of construction to the traffic under the bridge, the box girder was fabricated in shop and lifted in place at the bridge site. The precast deck slabs were installed by the discontinuous method in the sequence of the parts of the bridge at the midspan first and the parts close to the supports late.%昌平跨线桥采用两联跨度为(37+60+79+42.5)m及(42.5+79+42.5)m的钢-混凝土结合连续刚构型式.该桥主梁为钢-混凝土结合梁,钢箱梁采用单箱单室直腹板截面,桥面板为钢筋混凝土结构,钢箱梁在中墩处与混凝土墩身固结,下部结构墩柱均采用矩形桥墩.采用有限元程序MIDAS Civil建立全桥空间结构计算模型,对该桥进行静力计算分析,结果表明钢箱应力及结构强度均满足规范要求.为减少对桥下交通的影响,该桥钢箱梁采用工厂预制、现场吊装的方法施工,预制桥面板按先跨中后支点的顺序施工,采用间断法安装.

  10. The Design and Analysis of Long-Span and Low-Depth Prestressed Composite Steel-Concrete Beam Bridge

    Institute of Scientific and Technical Information of China (English)

    张俊平; 黄海云; 黄道沸

    2002-01-01

    The design scheme of long-span and low-depth composite steel-concrete beams is introduced, and the methods of avoiding the cracking of concrete deck in the negative moment regions are proposed. Moreover, significant exploration for problems of the composite beams has been made, such as optimizing construction steps to regulate the stress, applying jacking technique to exert prestress on the concrete deck, investigating the uplifting force principle of the shear connectors by means of model test and non-linear finite element analysis, and pointing out the countermeasure to reduce tension force of the shear connectors.

  11. Assessment of the Reliability of Concrete Bridges

    DEFF Research Database (Denmark)

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

    a significant shift in emphasis for the highways authorities around the world away from the design of new structures over to maintaining the existing infrastructure. As a result, bridge owners are seeking improved ways of inspecting, assessing, maintaining and repairing their existing stock of bridges...... 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...

  12. Regulation Design of Xiakou Regulating Locks ~Guanlong Bridge River Reach%峡口节制闸~莞龙桥河段整治设计

    Institute of Scientific and Technical Information of China (English)

    蔡碧红

    2014-01-01

    近几年来,东引运河流域城市化水平加快,水文水情发生改变,洪涝灾害更为严重。为保障东莞市人民生命财产安全以及社会稳定的持续发展,对东引运河、寒溪水进行全面综合整治十分必要。根据峡口节制闸~莞龙桥不同河段实际情况,因地制宜,分别采用不同的堤身结构形式进行设计。%As the urbanization of the Dongyin canal basin accelerated , the hydrological situation has changed and the flood hazards became more serious .In order to ensure the lives and property's safety, as well as the social stability and sustainable development of Dongguan .It is necessary to implement a comprehensive regulation for Dongyin canal and Hanxi River .According to the local reality and the geological conditions of the Xiakou regulating locks ~Guanlong Bridge , the levee's structures have been designed respectively.

  13. 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.

  14. Bridging worlds

    DEFF Research Database (Denmark)

    Rose, Jeremy; Memon, Saifullah Hassan

    2012-01-01

    (and implemented) through comparison with another university in Denmark which is well supported by computer systems. An action design research approach with an interpretative epistemology/ontology was adopted. Though the single comparison experience is difficult to generalise, we conclude that SSM...... (with some adaptations) can enable a socio-technical comparison and design effort and offer a prototype process. The comparison stimulates forward-looking design, but great care must be taken to accommodate cultural differences, and further research is necessary to integrate more sophisticated cultural...

  15. 港珠澳大桥浅水区非通航孔桥组合梁设计%Design of Composite Girders for Non-Navigable Span Bridge of Hong Kong-Zhuhai-Macau Bridge in Shallow Water Area

    Institute of Scientific and Technical Information of China (English)

    罗扣; 王东晖; 张强

    2013-01-01

    The main part of the Hong Kong-Zhuhai-Macau Bridge is a part of the combined bridge and tunnel,of which the non-navigable span bridge in the shallow water area is the 85 m span continuous composite girder bridge that totally has 64 spans of the composite girders and is 5 440 m in length.The span arrangement of the bridge mainly includes two kinds of arrangement of 6)× 85 m and 5)× 85 m.The composite girders are the separated continuous single-cell singlebox girders with constant depth and specifically are composed of the open steel box girders and the concrete deck slabs that are connected each other via shear studs.A steel box girder is the inverted trapezoid structure,a concrete deck slab is the precast full slab in the transverse direction and the grooves are pre-reserved at the locations of the shear studs.To improve the transverse mechanical behavior of the deck slabs,the stringers are set in the sections of the composite girders and to keep the integrity of the slabs,the shear studs are arranged in a way of clustering.The composite girders are erected and installed in each full span by the large transportation and erection floating crane and the girders are closed span by span.%港珠澳大桥主体工程采用桥隧组合方案,其中浅水区非通航孔桥采用85 m连续组合梁桥形式,全长5 440m,共64孔,跨径布置主要采用6×85 m和5×85m2种形式.组合梁采用单箱单室分幅等高连续梁,由开口钢箱梁和混凝土桥面板通过剪力钉联结而成.钢箱梁为倒梯形结构;混凝土桥面板为横向整块预制,在剪力钉处设置预留槽.为改善混凝土桥面板的横向受力性能,该桥组合梁截面设置小纵梁;为保持桥面板的整体性,剪力钉采用集束式布置方式.组合梁采用大型运架一体浮吊整孔安装架设,逐孔合龙.

  16. Structural Design of Multi-Pylon Cable-Stayed Bridge with Corrugated Steel Webs for Chaoyang Bridge in Nanchang%南昌朝阳大桥波形钢腹板多塔斜拉桥结构设计

    Institute of Scientific and Technical Information of China (English)

    陈水生; 钟志斌; 桂水荣; 刘旭政; 钟汉清

    2014-01-01

    The PC composite box girder with corrugated steel webs is applicable to bridges with a variety of structural types ,which exhibits superior durability and economic features as com‐pared with the common concrete box girder .The cable‐stayed bridge with corrugated steel webs is regarded as the type of structure where composite box girder with corrugated steel webs is ingen‐iously used ,making better use of the properties of the two structures . The main navigational bridge of the Chaoyang Bridge in Nanchang is a (79+ 5 × 150+79) m continuous composite box girder cable‐stayed bridge with corrugated steel webs .The bridge has six pylons and the stay ca‐bles are arranged in single cable plane .In addition ,the bridge has two layers of decks ,on the up‐per deck ,dual eight vehicle lanes (four lanes each side) are arranged and pedestrian and non‐mo‐torized vehicle lanes are arranged on the lower deck .Based on the analysis and study undertaken , small side span‐to‐main span ratio was chosen .Due to the multiple pylons ,the load path from the intermediate pylons to the side pylons is long and the effect of ancillary piers in the side spans is minimal ,as a result ,no ancillary piers are installed .In the structural system ,the pylons and the main girder are fixed while the girder and piers are separated .The box girder is 43 .84 m wide , with transverse steel diaphragms .The stay cables are fanned out in single cable plane .The pylon looks like the Chinese character“合“ ,and double bearings are installed at the pylons .T he stay vi‐bration mitigation bearings are used as the vibration mitigation and isolation devices of the super‐structure ,which are installed below the two side pylons .%波形钢腹板PC组合箱梁适用于不同结构形式的桥梁,相比普通混凝土箱梁具有显著的耐久性和经济性,波形钢腹板斜拉桥将波形钢腹板组合箱梁应用到斜拉桥中,充分发挥了2种结构的特点。南昌朝

  17. Design of Bus-bridge Between CAN and Profibus Based on singlechip processor%基于单片机的CAN-PROFIBUS-DP总线桥的设计

    Institute of Scientific and Technical Information of China (English)

    胡永红; 丁璐; 楚亚菲

    2009-01-01

    Aiming at the problem of incompatible protocols between CAN and Profibus, an implementing strategy of CAN-Proflbus-DP (Decentralized Periphery) bus-bridge based on singleehip processor, SPC3 and SJA1000 is proposed. The design method of the hardware and software for the interconnecting communication between a CAN node and ap rofibus- DP slave node is described emphatically. The design is able to connect a CAN bus and ap rofobus-DP bus to form a united measuring and control network. The scheme features low cost,fast speed and high stability. It can be applied in a multi-level station or multi-station servo control system in the industry.%针对目前自动化领域两种流行的现场总线CAN和Profibus通信协议标准互不相容的问题,提出了一种基于单片机、SPC3和SJA1000组建CAN-Profihus-DP总线桥的设计方案,以解决各总线协议标准相互协调与兼容的问题;文中重点阐述了单个CAN节点和单个Profibus-DP从站节点之间通信的硬件和软件设计与实现;该方法能很好地将CAN总线和Prof.bus-DP总线形成统一的多点测控网络,具有通信速度快,稳定的性高、低成本等特点,可应用于具有一站多级或多站伺服机构的工业控制系统中.

  18. 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.

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

    Science.gov (United States)

    van Manen, S. M.

    2013-12-01

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

  20. 低速风洞全模TPS试验空气桥的设计与优化%Design and optimization of the air bridge for low speed full-span TPS test

    Institute of Scientific and Technical Information of China (English)

    章荣平; 王勋年; 黄勇; 冯治

    2012-01-01

    TPS(Turbofan Powered Simulator)technology is the most advanced engine simulation in wind tunnel test. The air bridge is a key technology of TPS tests. This paper presents the design of the air bridge for low speed full-span TPS test. Optimum designs are made for the key beams of the air bridge by using FEM (finite-element method). Layout and the dimension of bellows are also optimized. According to the computation results, the key law of air bridge design is concluded. The air bridge is finally designed according to the space of the model, the inside e-quipments and the requirement of the TPS test. The final design has little effect on force measurement and has little pressure and temperature effect. The success in low speed full-span TPS test indicates that the air bridge meet the requirement of TPS test.%TPS试验技术是目前风洞试验中最先进的涡扇发动机模拟技术,空气桥是TPS试验技术的关键技术之一.介绍了低速全模TPS试验空气桥的设计.通过有限元数值模拟对空气桥关键受力梁进行了优化设计,并进一步对空气桥进行了整体优化,掌握了关键参数影响空气桥性能的规律.综合考虑模型内部空间、内部设备及空气桥的技术要求,完成了空气桥的设计,优化后空气桥对天平测力的影响较小,且同时具有较好的克服高压空气的内力、温度效应的能力.试验结果表明,空气桥性能满足TPS试验的要求.

  1. Bridges in Complex Networks

    CERN Document Server

    Wu, Ang-Kun; Liu, Yang-Yu

    2016-01-01

    A bridge in a graph is an edge whose removal disconnects the graph and increases the number of connected components. We calculate the fraction of bridges in a wide range of real-world networks and their randomized counterparts. We find that real networks typically have more bridges than their completely randomized counterparts, but very similar fraction of bridges as their degree-preserving randomizations. We define a new edge centrality measure, called bridgeness, to differentiate the importance of a bridge in damaging a network. We find that certain real networks have very large average and variance of bridgeness compared to their degree-preserving randomizations and other real networks. Finally, we offer an analytical framework to calculate the bridge fraction and average bridgeness for uncorrelated random networks with arbitrary degree distributions.

  2. 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.

  3. 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...

  4. 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

  5. Design of Half-through Anomalistic Arch Bridge on Changsha-Kunming Passenger-dedicated Line%长昆客运专线铁路中承式异型拱桥设计研究

    Institute of Scientific and Technical Information of China (English)

    施威; 孙大斌

    2015-01-01

    为解决长昆客运专线斜跨潭韶高速公路的问题,通过桥式方案比选,结构构造优化,结构静力、动力计算分析,设计研究出拱肋沿桥轴线非对称错位布置、吊杆扇形布设、无风撑拱肋的中承式斜置拱桥。该桥已投入实际运营,应用良好。%To resolve the problem in design to allow Changsha-Kunming passenger dedicated railway to cross over Xiangtan-Shaoshan highway, this paper, on the basis of bridge scheme comparison, construction structure optimization, calculation and analysis of structural statistics and dynamics, comes to the conclusion that the half-through anomalistic arch bridge is recommended and arranged unsymmetrically and misplaced with its arch ribs along the bridge axial line, with its suspenders placed in fan-shape and its arch ribs without wind bracing. This bridge has been put into use with good results.

  6. 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...... with the minimum acceptable surface temperature regarding surface condensation or mold growth, implemented in the Danish Building Regulations in 2010, and the calculation method for this temperature based on international standards is discussed. The introduction of the minimum acceptable surface temperature has...

  7. CONDITION RATING SYSTEM FOR THAILAND'S CONCRETE BRIDGES

    Directory of Open Access Journals (Sweden)

    Bonaventure H.W. Hadikusumo

    2010-06-01

    Full Text Available The Bridge Management System is designed to maximise use of available data and determine the optimal strategy to perform necessary improvements to bridges in the most cost-effective manner. This paper provides a condition rating system to meet the requirements of Thailand’s Department of Highways (DOH. A rating system to assess the existing condition of bridges is proposed. Segmental inspection is developed to execute efficient element-level evaluations and collect data that demonstrate deterioration patterns in bridge elements. The paper also describes inspection procedures for field survey execution, which enables observed distresses at the level of sub-elements or members to be allocated. Recommendations from bridge experts reveal that the proposed rating system is robust, implementable in actual practice, and suitable for efficient application in evaluating the nation’s concrete highway bridges. Although the bridge condition rating was developed in response to the specific characteristics of Thailand’s bridges, the proposed methodology can easily be extended to other bridge agencies.

  8. 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.

  9. 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.

  10. 贵港市同济大桥自锚式悬索桥总体设计%Overall Design of Self-Anchored Suspension Bridge of Tongji Bridge in Guigang City

    Institute of Scientific and Technical Information of China (English)

    薛雄; 高宝峰

    2016-01-01

    The main bridge of the Tongji Bridge in Guigang City ,with span arrangement of (50+140+280+140+50) m ,is a self‐anchored suspension bridge that has a main span of 280 m and bridge deck width of 37 .5 m .The main suspended girders are the multiple cells single box steel structures ,erected by incremental launching method with maximum launching spans of 2 × 85 m .The two end spans adopt the prestressed concrete structures .The towers are lotus‐shaped sin‐gle‐column towers without cross beam above the deck .The tower looks like an H‐shaped frame structure in plan ,quite elegant aesthetically ,and the minimum stable and safe coefficient of the bridge structure is 6 .4 .The main cables are composed of prefabricated parallel steel wire strands , the standard tensile strength of the steel wires is no less than 1 670 MPa .The strength safety coef‐ficient of the main cable is 2 .71 ,greater than the prescribed 2 .5 ,which meet the code require‐ments .T he hanger cables and the cable clamps are linked by pin connection .T he main cable sad‐dles are fully‐cast structures ,between the saddle base and the saddle pedestal plate ,sliding friction sets are installed .%贵港市同济大桥主桥为主跨280 m的自锚式悬索桥,桥跨布置为(50+140+280+140+50) m ,桥面宽37.5 m。悬吊跨主梁为单箱多室钢箱梁,采用顶推法施工,最大顶推跨径2×85 m。两端锚跨采用预应力混凝土结构。桥塔采用独柱式“荷花”造型,桥面以上塔柱不设置横梁,横向呈“H”形框架结构,景观造型新颖美观,桥塔结构最小稳定安全系数6.4。主缆采用预制平行钢丝索股,钢丝抗拉强度标准值为1670MPa,主缆强度安全系数2.71大于2.5,满足规范要求;吊索及索夹为销接式结构,主索鞍为全铸式结构,鞍底与底座座板间设滑动摩擦副。

  11. 金沙江白鹤滩水电站葫芦口大桥主桥设计%Design of Main Bridge of Hulukou Bridge Crossing Chin-sha River at Baihetan Hydropower Station

    Institute of Scientific and Technical Information of China (English)

    康晋; 舒思利; 徐恭义

    2015-01-01

    葫芦口大桥主桥为(158+656+145) m的单跨双铰钢桁梁悬索桥。该桥设2根主缆,主缆采用预制平行高强钢丝索股结构。全桥共布置71对吊索,吊索采用预制平行钢丝束,与索夹采用销轴连接方式。主索鞍为全铸式结构,鞍底设置滑动副。散索鞍为底座式结构,下设滚轴支座。主缆锚固系统采用型钢锚固系统。加劲梁采用钢桁梁,桁高4.5m,宽17m,采用钢混组合桥面系。两岸锚碇均采用重力式锚、现浇扩大基础,其中巧家侧锚碇采用明挖嵌岩基础。桥塔为钢筋混凝土门式框架结构,塔柱竖直布置,基础采用直径2.5 m的钻孔灌注桩。采用有限元软件BNLAS及MIDAS对该桥进行计算分析,结果表明该桥的静力、动力特性均满足规范要求。%The main bridge of the Hulukou Bridge is a single span double‐hinge steel truss girder suspension bridge with span arrangement of(158+656+145) m .The bridge has two main cables made up of prefabricated parallel high‐strength steel wires .A total of 71 hanger cables , which are composed of prefabricated parallel steel wire strands and are connected with the cable clamps by pin connection ,are installed .The tower saddles are fully‐cast structures ,on the base of w hich sliding pairs are added ,and the spray saddles are pedestal‐like structures resting on roller bearings .The anchoring systems for the main cables are the section steel anchoring system .The stiffening girder adopts the steel truss girder which is 4 .5 m high and 17 m wide ,covered by the steel‐concrete composite deck .The anchorages on the two banks of the river are gravity anchors , the foundation of one anchor is the cast‐in‐situ spread foundation ,w hile the other on the Qiaojia side the open‐cut foundation embedded in rocks .The towers are reinforced concrete portal frame structures with vertical columns ,the foundations of which are formed of 2 .5 m diameter

  12. 基于两水平设防的连续梁桥抗震性能分析%Seismic Performance Analysis of Continuous Girder Bridge Based on Two-level Design Approach

    Institute of Scientific and Technical Information of China (English)

    邓小伟

    2012-01-01

    According to the new ideas and new methods by guidelines for seismic design of highway bridges (JTG / T B02-01-2008) , with the background of a continuous girder bridge in the area of 7 degree earthquake intensity, an elastic-plastic finite element model is established for dynamic characteristics analysis, seismic response spectrum analysis and nonlinear time history analysis, to reveal the force and deformation under earthquake action of two levels. Furthermore, the seismic performance is evaluated to provide a reference for seismic design of bridges.%根据《公路桥梁抗震设计细则》(JTG/T B02—01—2008)中的抗震设防新理念和新方法,以Ⅶ度区某连续梁桥为工程背景,建立了弹塑性有限元模型,依次进行了动力特性分析、地震反应谱分析和非线性时程分析,揭示了两级地震作用下桥梁的受力及变形情况,并对桥梁的抗震性能进行了评价,可供桥梁抗震设计参考.

  13. Closure technique for the hybrid girder cable stayed bridge of Edong Bridge

    Institute of Scientific and Technical Information of China (English)

    Liu Minghu; Tan Hao; Xu GuoPing; Zhao Canhui

    2012-01-01

    Based on Edong Yangtze River Bridge, which is the second longest hybrid girder cable stayed bridge with 926 m long main span, the influencing factors and crucial techniques of the main span closure method for long span hybrid girder cable stayed bridge are studied. After theoretical analysis, numerical evaluation and practical test, the loading assistant closure method is employed in Edong Yangtze River Bridge. The loading assistant closure method, with better thermal adaptability and less influence on bridge line and the forced status, can meet the requirements of the unstressed state control method. Based on the mentioned advantages, the loading assistant closure method is applicable to long span hybrid girder cable stayed bridges. The conclusion can provide a reference for the further design of the similar brid~es.

  14. Environmental Design for Bridges in Protection Zone of Water Sources at Guangdong Section of Daqing-Guangzhou Expressway%大广高速公路粤境段水源保护区桥梁环保设计

    Institute of Scientific and Technical Information of China (English)

    张建文; 曾鹏; 陈玉刚

    2013-01-01

    The D3 contract section line at Guangdong section of Daqing-Guangzhou Expressway crosses 24km long class Ⅱ protection zone of centralized drinking water sources.The environmental design for bridges in this project faces large range,big scale and big difficulty.In order to guarantee water quality in protection zone free of pollution during construction and operation of project,this paper expatiates setup of rainwater collecting system on decks of 33 bridges and double-layer bridge handrails for 10 important bridges in protection zone of water sources,and meanwhile takes other multiple environmental design measures so as to promote degree of safety of water quality in protection zone of water sources effectively.%大广高速公路粤境段D3合同段路线跨越24km长的集中式饮用水源2级保护区.该项目桥梁环保设计范围广、规模及难度大.为保证项目建设和运营期间水源保护区内水质不受污染,对水源保护区内33座桥梁设置桥面雨水收集系统,对其中10座重要桥梁设置双层桥梁护栏,同时采取了其他多种环保设计措施,使水源保护区内水质的安全度得到有效提升.

  15. 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.

  16. 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 ...

  17. Salt-bridge energetics in halophilic proteins.

    Directory of Open Access Journals (Sweden)

    Arnab Nayek

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

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

    Directory of Open Access Journals (Sweden)

    Aksoy Aysegul Ozgenc

    2017-03-01

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

  19. 弹塑性钢减隔震支座在桥梁抗震设计中的应用%Application of Elasto-Plastic Steel Seismic Isolators to Bridge Anti-Seismic Design

    Institute of Scientific and Technical Information of China (English)

    高山; 彭泽友; 史春娟; 王永祥

    2015-01-01

    为了给桥梁抗震设计提供参考,以减轻桥梁结构在地震中遭受的损伤,介绍一种弹塑性钢减隔震支座(NDQZ)的结构特点及其减隔震原理,并以(83+140+83) m双塔双索面预应力混凝土斜拉桥为实例进行减隔震分析。采用有限元分析软件SAP2000建立全桥有限元模型,在E2地震状态下分别进行非减隔震支座桥梁和NDQZ支座桥梁地震动力时程分析。结果表明:NDQZ支座可实现全桥协同抗震,减隔震效果良好;采用NDQZ支座后,桥梁前3阶自振周期平均延长133%,在顺桥向和横桥向墩底弯矩分别减小了40%和83%,墩底剪力分别减小了39%和70%;承台底弯矩分别减小了39%和74%,承台底剪力分别减小了34%和60%;弯矩和剪力分布均匀。%To provide reference for bridge anti‐seismic design and reduce the damage that bridge suffers in earthquakes ,the structural features and principles of vibration mitigation and iso‐lation of a kind of elasto‐plastic steel seismic isolators (NDQZ)is introduced .A two‐pylon pres‐tressed concrete cable‐stayed bridge with span arrangement of (83+140+83) m and with double cable planes is cited as an example to conduct vibration mitigation and isolation analysis .T he finite element software SAP2000 was used to establish the finite element model of the whole bridge ,to carry out time‐history analysis of the bridge with bearings incapable of vibration mitigation and iso‐lation effect and the bridge with NDQZ under the E2 earthquake condition respectively .The re‐sults of the analysis indicate that the NDQZ bearings can realize the effect of the w hole‐bridge col‐laborative vibration resistance ,displaying sound vibration mitigation and isolation effect .When the NDQZ bearings are used ,the first three orders of bridge natural vibration period averagely ex‐tends 133% .The bending moments in the base of the piers along the bridge length

  20. Design of Main Arch of Hutiaomen Bridge on Guangzhou-Zhuhai Railway%广珠铁路虎跳门特大桥主拱设计

    Institute of Scientific and Technical Information of China (English)

    王鹏宇; 刘振标; 罗世东; 王新国

    2012-01-01

    广珠铁路虎跳门特大桥主桥为(120+248+120)m的连续刚构柔性拱组合桥.拱肋采用钢管混凝土结构,由上、中、下弦管组成,弦管内采用C50混凝土,每片拱肋由两管平行管和提篮内倾单管组成,由直腹杆和斜腹杆连接成三肢桁架拱;三角形直腹杆采用矩形钢箱截面,斜腹杆采用圆钢管;全桥拱肋共布置19道横撑;拱座采用实体截面.主桥采用先梁后拱的施工方案.采用MIDAS Civil 2006检算拱肋承载力、结构强度、稳定性等性能,计算结果表明拱肋的静力、动力性能均满足规范要求.%The main bridge of the Hutiaomen Bridge on Guangzhou-Zhuhai Railway is a hy-brid bridge of continuous rigid frame structure and flexible arch with span arrangement (120 + 248 + 120) m. The arch ribs of the bridge employ the concrete-filled steel tube structure formed by the upper, middle and lower chord tubes that are filled in with C50 concrete. Each of the arch ribs is composed of two parallel tubes and an inward inclined tube of basket handle and these tubes are connected into a three-leg (triangular) truss arch by the vertical and inclined web mem-bers, of which a vertical member is the rectangular steel box section while an inclined member is the round steel tube section. The arch ribs of the whole bridge have totally 19 cross bracings, the arch seats are the solid sections and the bridge is constructed by way of erecting the girder first and the arch late. The calculation of the bearing capacity, structural strength and stability behav-ior of the arch ribs is checked by the MIDAS Civil and the results of the checking prove that the static and dynamic behavior of the arch ribs can meet the relevant requirements in the codes.

  1. 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....

  2. Bridge Crossing Simulator

    Science.gov (United States)

    2014-10-07

    Requirement BCS Computer-controlled hydraulic actuation system to impart simulated crossing loads on an entire bridge structure undergoing fatigue test ...structure. Bridge test site with prepared embankments corresponding to the span and bank condition requirements of the bridge under test Conduct real...Center (AEC). (5) Sample size and number of crossings required. The number of required simulated crossings to conduct fatigue testing per the

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

    DEFF Research Database (Denmark)

    Park, Kiwoo; Chen, Zhe

    2013-01-01

    This paper presents a parallel-connected Single Active Bridge (SAB) dc-dc converter for high-power applications. Paralleling lower-power converters can lower the current rating of each modular converter and interleaving the outputs can significantly reduce the magnitudes of input and output current...... requirements, this modular converter concept is expected to be highly beneficial especially for the offshore wind farm application....

  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. 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....

  6. 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.

  7. 三岔双向挤扩灌注桩在桥梁设计中的应用%Application of Cast-in-place Pile with Expanded Branches and Bells by 3-way Extruding Arms in Bridge Design

    Institute of Scientific and Technical Information of China (English)

    张睿

    2016-01-01

    Through the design analysis of a bridge project pile,the cast-in-place piles with expanded branches and bells by 3-way extruding arms in the basic principle and design method are described in this paper and their vertical bearing capacity are calculated.The economic advantage and vertical bear-ing capacity advantage are verified,and the problems of its application in bridge engineering design are presented.%通过对某桥梁项目灌注桩的设计分析,阐述了三岔双向挤扩灌注桩的基本原理和设计方法,分别计算了三岔双向挤扩灌注桩与普通钻孔灌注桩的单桩竖向承载力,验证了三岔双向挤扩灌注桩在经济性及桩基竖向承载力等方面的优势,并提出了该桩基在桥梁工程设计中需要注意的问题。

  8. Design of (2í64)m T Shaped Rigid Frame Bridge on Huangling-Hancheng-Houma Railway%黄韩侯铁路2×64m T形刚构桥设计

    Institute of Scientific and Technical Information of China (English)

    鄢玉胜

    2014-01-01

    This paper studies the design main points of T shaped rigid frame bridge with double thin-wall pier. Relying on the design of 2í64m T shaped rigid frame bridge on the Huangling-Hancheng-Houma Railway, using finite element analysis, this paper introduces the characteristics of internal forces of the cross-brace. The study shows that arc shaped pre-stressed cross-brace can a better solution for the design of the cross-brace reinforcement for double thin wall piers.%重点研究双薄壁桥墩T形刚构桥的设计要点。依托黄韩侯铁路2×64m T形刚构桥,采用有限元分析方法,建立全桥模型进行计算,研究桥墩横撑内力特性,采用圆弧形预应力横撑能较好地解决双薄壁桥墩横撑配筋设计。

  9. 大跨度连续下承式钢箱拱桥设计%Design of Long-Span Continuous Through Type Steel Box Arch Bridge

    Institute of Scientific and Technical Information of China (English)

    李国普; 李斐然

    2016-01-01

    为满足桥梁的景观和功能要求,小浪底坝后保护区交通桥上部结构采用(95+152+95) m三跨连续下承式钢箱拱结构。主梁为预应力混凝土π形梁,采用钢管桩+贝雷梁法施工。拱肋为钢箱提篮拱,结构用钢采用Q345D钢板,先工厂预制再现场焊接成型。吊索采用7根φ15.2环氧喷涂无粘结钢绞线,缠包后热挤HDPE ,抗拉强度标准值1860 M Pa。下部结构采用柱式台、倒V形实体薄壁墩、高桩承台、钻孔灌注桩基础。采用非线性程序TDV进行计算分析,结果表明,该桥的强度、刚度和稳定性以及抗震性能均满足规范要求。%To meet the landscape and function requirements proposed , the transportation bridge in the conservation area behind the Xiaolangdi Dam adopts a three‐span continuous through type steel box arch bridge structure with span arrangement of (95+152+95) m .The main girder is the prestressed concrete π‐shaped girder ,constructed by the combined use of steel tube piles and bailey truss .T he arch ribs are the steel box basket handle arches .T he predominant material used for the structure is the Q345D steel plate ,and all the components are prefabricated in the factory and transported to the bridge site for welding to take shape .Each hanger consists of 7φ15 .2 epoxy non‐binding steel strands ,extruded with HDPE after wrapping .The hanger has a standard tensile strength of 1 860 MPa .The substructure of the bridge incorporates column‐type abutments ,in‐versed V‐shaped solid thin‐wall piers ,high‐rise pile caps and bored piles .The non‐linear program TDV was used to do calculation .The results of the calculation demonstrate that the strength ,ri‐gidity ,reliability and anti‐seismic performance of the bridge all meet the code requirements .

  10. 东莞东江大桥防腐涂装设计%Design of Corrosion Protection Coating for Dongguan Dongjiang River Bridge

    Institute of Scientific and Technical Information of China (English)

    傅战工; 徐恭义

    2011-01-01

    Dongguan Dongjiang River Bridge is a continuous steel truss girder bridge stiffened by rigid suspension members and the site where the bridge is located is in the severe corrosion environment. Through comparison of the performance indices of the epoxy zinc rich premier, alcohol-soluble inorganic silicate zinc rich premier, water-base inorganic silicate zinc rich premier and spraying metal that have been commonly used as the corrosion protection systems for the exterior surfaces of steel structure, in the light of the characteristics of the different structural parts of the bridge and also in comprehensive consideration of the durability, environmental protection, costsaving and maintainability, it was determined that the epoxy zinc rich coating system was to be used for the corrosion protection of the exterior surfaces and high-strength bolt heads of the main trusses, the water-base inorganic silicate zinc rich coating system for the stringers, cross beams and inspection trolley, the electric arc spraying aluminum for the frictional surfaces of the bolts,the light color modified epoxy asphalt for the interior surfaces ofthe box members, the galvanization layer and sealing paint for the steel crush barriers, the resin coating for the balustrades on the sidewalks and the hot-dipped galvanization for the drainage steel pipes of the bridge.%东莞东江大桥为刚性悬索加劲连续钢桁梁桥,桥位处于较严重的腐蚀环境.通过对环氧富锌底漆、醇溶性无机硅酸富锌底漆、水性无机硅酸富锌底漆和喷涂金属等钢结构外表面常用防腐体系的性能指标比较,针对不同结构部位的特点,综合考虑耐久性、环保性、经济性和可维护性,主桁外表面和螺栓头采用环氧富锌体系防腐;纵、横梁和检查车采用水性无机富锌体系防腐;高强螺栓摩擦面采用电弧喷铝防腐;箱形杆件内表面采用淡色改性环氧沥青漆防腐;钢防撞栏采用镀锌层加封闭漆防腐;人

  11. Probabilistic FE analysis of a cable stayed composite bridge

    NARCIS (Netherlands)

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

    1999-01-01

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

  12. Review of Research of Bridge Design Based on Life Cycle Cost Analysis%基于全寿命周期成本分析的桥梁设计研究综述

    Institute of Scientific and Technical Information of China (English)

    谷音; 黄威; 卓卫东

    2011-01-01

    为系统阐述全寿命周期成本分析的桥梁设计的研究现状,介绍了全寿命周期成本分析的研究背景、基本概念和原理,综述了寿命周期成本分析方法在桥梁结构全寿命设计方案决策的研究现状、关键技术和使用前景.总结国外全寿命周期成本基本理论体系,对全寿命周期成本模型和框架的研究进行了介绍,将两种最具代表性的模型进行了对比.归纳了近年国内桥梁全寿命周期成本的构成以及计算方法的研究概况,指出寿命周期成本主要由管理单位成本、用户成本和社会成本组成,分析了计算成本各组成部分中的困难,总结目前基于全寿命周期成本的桥梁设计中存在的问题.为基于全寿命周期成本的桥梁全寿命设计、维护、投资方案决策以及桥梁管理系统开发提供必要的研究背景.%In order to systematically expound the research situation of bridge design based on concept of life cycle cost (LCC) analysis, the research background, basic concept and principle of LCC analysis were introduced. The research status, the appropriate key technologies, and the prospects of LCC analysis for bridge design were illustrated. The study of basic theoretical system of LCC on board was summarized. The models of LCC and the study of framework were showed. The two most representative models were compared.The composition and calculation method of the bridge life cycle cost (BLCC) at home were introduced as well. LCC consists of per-unit cost of management, cost of users and social cost. The difficulties and obstacles encountered in calculation of the components were analyzed, and the existing problems in bridge design based on LCC were summarized. The study presented a necessary background for bridge design,maintenance, investment decision-making and the development of bridge management system based on LCC.

  13. Ergonomic aspects of automation in navigation bridges.

    Science.gov (United States)

    Lazet, A; Walraven, P L

    1971-06-01

    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 efficient, good ergonomic design is essential. A series of designs of navigation bridges is used to illustrate typical problems and situations. The building of full scale mock-ups of complete bridges is essential in order to handle the design as an integrated problem and to simulate the work situation. Such static mock-ups have been shown to be extremely useful in the discussion between builder, future user and adviser. An extension to dynamic simulation is necessary in order to study the actual work conditions in a new design.

  14. Implementation and Non-Destructive Evaluation of Composite Structural Shapes in the Tom's Creek Bridge

    OpenAIRE

    Hayes, M. D.; J. Haramis; Lesko, John J.; Cousins, Thomas E.; J.C.Duke; Weyers, Richard E.

    2000-01-01

    A bridge rehabilitation utilizing a hybrid fiber reinforced polymeric composite has been completed in Blacksburg, Virginia. This project involved replacing the superstructure in the Tom's Creek Bridge, a rural short-span traffic bridge with a timber deck and corroded steel girders, with a glue-laminated timber deck on composite girders. In order to verify the bridge design and to address construction issues prior to the rehabilitation, a full-scale mock-up of the bridge was built and tested i...

  15. Design method and homogeneity control of bridge fair-faced concrete%桥梁清水混凝土设计方法与匀质性控制

    Institute of Scientific and Technical Information of China (English)

    周孝军; 牟廷敏; 丁庆军; 聂传振

    2015-01-01

    According to the structural characteristics of bridge engineering , the mix optimization design method of bridge fair‐faced concrete was presented , and C30 ~ C50 concrete with high cohesion and package ,outstanding fluidity and excellent mechanical properties were prepared .Through the test of air content of fresh concrete , micro hardness and micro structure in different parts of hardened concrete specimens ,effects of viscosity‐modifying admixtures on homogeneity of concrete were discussed . The results showed that the composition of bridge fair‐faced concrete were relatively homogeneous ,and the microstructure were relatively dense .When C30 concrete mixed with 5 × 10-5 cellulose ether or 6% silica fume (mass fraction of cementitious material ) ,air content of fresh concrete were less than 2% ,and slurry viscosity values were between 1 900 and 2 000 MPa · s .Also ,the micro hardness values in different parts of hardened concrete specimens were closed . The results were applied in practical bridge engineering , w hich generally meets the apparent quality requirements of bridge fair faced concrete .%根据桥梁工程结构特点,提出了桥梁清水混凝土的配合比优化设计方法,制备出粘聚性与包裹性好、流动度佳,且具有优良力学性能的C30~C50高性能清水混凝土。通过对混凝土拌合物含气量、硬化试件不同部位显微硬度与微观结构的测试,分析了增粘剂对其匀质性的影响规律。试验表明:对于C30桥梁清水混凝土,掺5×10-5的纤维素醚或掺6%的硅灰时,混凝土的含气量不超过2%,浆体旋转粘度值在1900~2000 M Pa · s之间,试件不同部位显微硬度值接近,匀质性好,结构密实。

  16. 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.

  17. 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...

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

    Directory of Open Access Journals (Sweden)

    Chinh Luong Minh

    2016-01-01

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

  19. Solving Topological and Geometrical Constraints in Bridge Feature Model

    Institute of Scientific and Technical Information of China (English)

    PENG Weibing; SONG Liangliang; PAN Guoshuai

    2008-01-01

    The capacity that computer can solve more complex design problem was gradually increased.Bridge designs need a breakthrough in the current development limitations, and then become more intelli-gent and integrated. This paper proposes a new parametric and feature-based computer aided design (CAD) models which can represent families of bridge objects, includes knowledge representation, three-dimensional geometric topology relationships. The realization of a family member is found by solving first the geometdc constraints, and then the topological constraints. From the geometric solution, constraint equations are constructed. Topology solution is developed by feature dependencies graph between bridge objects. Finally, feature parameters are proposed to drive bridge design with feature parameters. Results from our implementation show that the method can help to facilitate bridge design.

  20. Aerodynamic stability of cable-stayed-suspension hybrid bridges

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin-jun; SUN Bing-nan

    2005-01-01

    Three-dimensional nonlinear aerodynamic stability analysis was applied to study the aerodynamic stability of a cable-stayed-suspension (CSS) hybrid bridge with main span of 1400 meters, and the effects of some design parameters (such as the cable sag, length of suspension portion, cable plane arrangement, subsidiary piers in side spans, the deck form, etc.) on the aerodynamic stability of the bridge are analytically investigated. The key design parameters, which significantly influence the aerodynamic stability of CSS hybrid bridges, are pointed out, and based on the wind stability the favorable structural system of CSS hybrid bridges is discussed.

  1. Rational design of two bpy-bridged 3D and 2D Co(II) open frameworks with similar amino-acid-based Schiff bases.

    Science.gov (United States)

    Li, Zong-Ze; Du, Lin; Zhou, Jie; Zhu, Ming-Rong; Qian, Fen-Hua; Liu, Jing; Chen, Peng; Zhao, Qi-Hua

    2012-12-21

    Two novel bpy-bridged Co(II) Schiff base complexes have been synthesized by the hydro(solvo)thermal reactions of corresponding amino-acid-based Schiff bases, bpy and Co(NO(3))(2)·6H(2)O. The following formulae identify the two complexes: {[Co(napala)(bpy)(0.5)]·H(2)O}(n) (1) and [Co(napgly)(bpy)(0.5)](n) (2) [H(2)napala = N-(2-hydroxy-1-naphthylmethylidene)-D/L-alanine, H(2)napgly = N-(2-hydroxy-1-naphthylmethylidene)-glycine and bpy = 4,4'-bipyridine]. These two compounds have been characterized using single-crystal X-ray diffraction, infrared, powder X-ray diffraction, thermogravimetric analysis, optical spectra analysis, and magnetic measurement. Complex 1 features an unprecedented threefold interpenetrated diamond network based on the fan-shaped Co(II)(4)(μ(2)-napala)(4) molecular square node and bpy linker, which represents the first example of 3D framework among the amino-acid-based Schiff base complexes with salicylaldehyde or its derivatives. In 2, adjacent Co(II) ions are bridged by μ(2)-napgly(2-) to form left- and right-handed [Co(II)(μ(2)-napgly)](n) helical chains. These two types of helical chains are sustained alternately by a symmetrical bpy co-ligand into a 2D grid-based layer. The solid-state fluorescence of complexes 1 and 2 are quenched almost completely compared with free mixed-ligands at room temperature. Moreover, magnetic studies show the dominant antiferromagnetic coupling between the Co(II) centers mediated by the syn-anti-COO(-)-bridges in both complexes.

  2. Optimal design of initative horizontal bracing structure of middle tower column of southern cable stayed bridge of Xiazhang sea-crossing bridge%厦漳跨海大桥南汊斜拉桥索塔中塔柱主动横撑的设计计算

    Institute of Scientific and Technical Information of China (English)

    林寅

    2011-01-01

    本文介绍了厦漳跨海大桥南汊斜拉桥索塔施工中,为消除中塔柱倾斜塔柱根部混凝土的不良应力状态所采用的主动横撑结构的构造特点,以及考虑了施工因素的该结构的设计计算方法,确保中塔柱根部在施工过程中不开裂。该计算方法对类似工程具有一定的指导意义。%This paper intensively introduces the structural characteristics of the adoption of initiative horizontal bracing structure in order to eliminate the bad stress of concrete in the root of leaned tower column during the cable tower construction of Southern Cable Stayed Bridge of Xia Zhang Sea-crossing Bridge,as well as the structural design calculation method considering the construction factors,which can make sure that the root of leaned tower would not cracked during the construction process,and thie could be a reference for similar engineering.

  3. Active Control of Long Bridges Using Flaps

    DEFF Research Database (Denmark)

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

    The main problem in designing ultra-long span suspension bridges is flutter. A solution to this problem might be to introduce an active flap control system to increase the flutter wind velocity. The investigated flap control system consists of flaps integrated in the bridge girder so each flap...... is the streamlined part of the edge of the girder. Additional aerodynamic derivatives are shown for the flaps and it is shown how methods already developed can be used to estimate the flutter wind velocity for a bridge section with flaps. As an example, the flutter wind velocity is calculated for different flap...... configurations for a bridge section model by using aerodynamic derivatives for a flat plate. The example shows that different flap configurations can either increase or decrease the flutter wind velocity. for optimal flap configurations flutter will not occur....

  4. Research on Cultural Landscape Renewal Design of Historical Bridges in Rural and Urban Areas%城乡历史桥梁文化景观更变设计研究

    Institute of Scientific and Technical Information of China (English)

    李绪洪

    2012-01-01

    Based on the urgent need of studying cultural landscape renewal of historical bridges in the process of rural-urban modernization, this paper makes use of appropriate design methods of landscape renewal to explore the fundamental changes of the function and pattern of historical bridges in disrepair and to implement the landscape renewal from the perspective of optimization, integration, management and development. Furthermore, by recombining the historical districts and designing the intensive and interactive transportation function it is realized to make them be the leisure and recreation places for urban and rural residents.%针对目前城乡现代化迫切需要研究历史桥梁文化景观更变的特点,利用相应的景观更变设计方法,探索历史桥梁退役之后,功能、格局发生根本性改变,从优化、整合、经营、发展的角度来实施景观更变,与历史街区空间复合,交通功能集约一体化设计,成为适合城乡人民休闲游憩的场所.

  5. Design of Swinged Continuous Beam of Super-large Bridge Crossing Wuhan-Guangzhou High-speed Railway%跨武广特大桥转体连续梁设计

    Institute of Scientific and Technical Information of China (English)

    涂杨志

    2012-01-01

    Research purposes: The super-large bridge of the Wuhan-Xianning intercity railway is the bridge crossing the Wuhan-Guangzhou High-speed Railway, with main span of 48 + 80 + 48 m continuous beam structure. The construction method of grouting cantilever first and then grouting the swing body was conducted to the beam. In this paper, the introduction is given to the beam construction, including the beam structure, the beam construction method and erection by swing method. Research conclusions: The erection by swing method is a good way for construction of the bridge above-crossing the busy existing railway. This method has the features of money-saving, practice, safety, reliability, cutting the influence of the construction on traffic and reducing the construction risk, and has a wide applicable prospecting. The design and construction of the swinged continuous beam presented in this paper can provide the important reference to the similar works, especially to the bridge design for passenger dedicated line.%研究目的:跨武广特大桥是武咸城际铁路上跨武广客运专线一座特大桥,主跨采用(48 +80 +48)m连续梁结构,该梁采用先悬臂浇注,后转体的施工方法.本文从梁体构造、梁体施工方法、转体施工等方面对本桥连续梁进行介绍.研究结论:上跨繁忙既有线铁路施工,转体施工可谓一种较好方法选择,该方法经济实用、安全可靠、减少上跨桥梁施工对既有线的影响,降低风险,并有广阔的应用前景.本文为转体连续梁的设计与施工提供一实例,为今后同类型桥,特别是上跨客运专线的桥梁设计提供重要的参考价值.

  6. Design of cable-girder anchorage system scheme in self-anchored suspension bridge%自锚式悬索桥缆-梁锚固系统方案设计

    Institute of Scientific and Technical Information of China (English)

    凌云

    2015-01-01

    本文根据已建以及待建自锚式悬索桥工程实例,将自锚式悬索桥工程中主缆在加劲梁梁端的锚固方案进行了总结分析,从施工方面、经济性以及美观性等方面指出了各种锚固方式的优缺点以及适应性。按照锚体材料的不同将现有锚固方式重新进行了分类,综合现有的分类方式提出了一套锚固系统方案设计流程。这种设计流程条理清楚、直观易理解,为今后的自锚式悬索桥主缆锚固系统设计提供指导,快速的形成锚固系统方案,提高设计效率,并获得更好的经济性和美观性。%According to the engineering examples of the self -anchored suspension bridges built and to be built , the cable -girder an-chored projects are summarized and analyzed.From the construction , economy and aesthetics aspects , the advantages adaptability of vari-ous ways of anchoring and are pointed out.According to the different materials of the existing anchorage , the way of anchoring is re -clas-sified and a set of anchor system design process is put forward based on the classification of the existing anchorage systems .This design process is clear , intuitive and easy to understand and can provide guidance for the design of self -anchored suspension bridge main cable anchorage system in the future.Using this design process , anchorage system scheme will be quickly put forward , the design efficiency can be improved and the bridge will be more economic and more beautiful.

  7. Design, fabrication, and characterization of bridge-type micro-hotplates with an SU-8 supporting layer for a smart gas sensing system

    Science.gov (United States)

    Iwata, T.; Soo, W. P. C.; Matsuda, K.; Takahashi, K.; Ishida, M.; Sawada, K.

    2017-02-01

    In this study, bridge-type micro-hotplates (MHP) with an SU-8 supporting layer were proposed for smart gas sensor applications. The proposed MHP consisted of a heating membrane with an area of 140 µm  ×  140 µm, and a 33 µm-thick SU-8 layer deposited on its bridges. Finite element method based simulation confirmed that the proposed MHP displayed good thermal isolation properties. The proposed MHP was successfully fabricated, and the properties of the MHP were characterized. Current-voltage characteristics revealed that the MHP temperature can reach 550 °C at 5 V. The temperature of the MHP was calculated from changes in the resistance of the heater. Power consumption of the MHP approximately corresponded to 13.9 mW for heating to 300 °C. This was comparable to the power consumption reported in the previous studies. Furthermore, a stable operation under a constant voltage was observed for 100 min. The properties of the MHP indicated that it could potentially be utilized for applications related to integrated gas sensors.

  8. 49 CFR 237.131 - Design.

    Science.gov (United States)

    2010-10-01

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

  9. 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.

  10. 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

  11. 考虑残余位移影响的梁式桥基于性能的抗震设计%Study on performance-based seismic design for beam bridges considering residual displacement

    Institute of Scientific and Technical Information of China (English)

    李宇; 车艳阳; 王森

    2015-01-01

    According to the current Chinese code of bridge seismic design,320 strong motion records of four sites are selected to establish elastic-plastic displacement spectra,residual displacement spectra. Normalized parameters of cumulative dissipation energy are improved and equivalent ductility coefficients based on damage indexes are obtained. Furthermore,developed seismic damage models are discussed. Performance-based seismic design for bridges considering residual displacement is proposed and specific examples are provided to show the detailed design procedures. The nonlinear time-history analysis results show that both deformation capacity and energy dissipation capacity of bridge can be considered by the proposed method and the maximal displacement, plastic cumulative damage and residual displacement can be controlled well. The proposed method can be applied in design of low and medium-height piers with short natural period and low ductility.%以我国现行的桥梁抗震设计规范为依据,合理地选取4类场地320条强震记录,统计出适用于我国梁式桥抗震设计的弹塑性位移谱和残余位移谱,并改进正规化累积耗能参数,得到基于损伤性能指标的等效位移延性系数,并以此对桥梁的地震损伤模型进行探讨。在此基础上,提出考虑残余位移影响的梁式桥基于性能的抗震设计方法,并给出具体算例,其非线性时程分析的结果表明:该方法综合考虑了结构的变形和耗能能力,可有效地控制桥墩的首超破坏、塑性累积损伤以及震后残余位移,适用于我国短周期、低延性的一般规则梁式桥的中、低矮桥墩的抗震设计。

  12. Multivariate Feature Selection for Predicting Scour-Related Bridge Damage using a Genetic Algorithm

    Science.gov (United States)

    Anderson, I.

    2015-12-01

    Scour and hydraulic damage are the most common cause of bridge failure, reported to be responsible for over 60% of bridge failure nationwide. Scour is a complex process, and is likely an epistatic function of both bridge and stream conditions that are both stationary and in dynamic flux. Bridge inspections, conducted regularly on bridges nationwide, rate bridge health assuming a static stream condition, and typically do not include dynamically changing geomorphological adjustments. The Vermont Agency of Natural Resources stream geomorphic assessment data could add value into the current bridge inspection and scour design. The 2011 bridge damage from Tropical Storm Irene served as a case study for feature selection to improve bridge scour damage prediction in extreme events. The bridge inspection (with over 200 features on more than 300 damaged and 2,000 non-damaged bridges), and the stream geomorphic assessment (with over 300 features on more than 5000 stream reaches) constitute "Big Data", and together have the potential to generate large numbers of combined features ("epistatic relationships") that might better predict scour-related bridge damage. The potential combined features pose significant computational challenges for traditional statistical techniques (e.g., multivariate logistic regression). This study uses a genetic algorithm to perform a search of the multivariate feature space to identify epistatic relationships that are indicative of bridge scour damage. The combined features identified could be used to improve bridge scour design, and to better monitor and rate bridge scour vulnerability.

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

    Science.gov (United States)

    Putnam, Cynthia

    2010-01-01

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

  14. 高架桥薄壁空心高墩施工%Construction Organizational Design for High Hollow Thin-wall Pier of Viaduct Bridge

    Institute of Scientific and Technical Information of China (English)

    冯世敏

    2014-01-01

    PJ-200 Cantilever formwork ( climbing formwork ) and big steel formwork lifted with tower crane ( turnover formwork construction) have been adopted for the construction of high hollow thin-wall pier of Hewei Bridge at Km:253+353 of Lechang-Guangzhou Expressway, which has achieved good economic benefits.%乐昌至广州高速公路K253+353河尾大桥薄壁空心高墩施工组织设计采用PJ-200悬臂模板(即爬模施工)和塔吊提升大块钢模的方法施工(即翻模施工)相结合的方式,取得了较好的经济效益。

  15. Molecular Design of Crown Ethers. 191. Synthesis of Novel Disulfide- and Diselenide-Bridged Bis (benzo-12-crown-4)s and their Ag+ Selective Electrode Properties

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Two novel heteroatom-bridged bis (benzo-12-crown-4 ether)s, i.e. bis [2-nitro-4,5-(1,4,7,10-tetraoxadecamethylene)phenyl] disulfide 1 and diselenide 2, have been synthesized. X-ray crystallographic structure was obtained for 1. Ion selective electrodes (ISE) for Ag+, containing 1 and 2 in PVC membrane as neutral carriers, were prepared, and their selectivity coefficients for Ag+ (KpolAg,M) were determined against other heavy metal ions, alkali and alkaline-earth metal ions, and ammonium ion. These ISEs showed excellent Ag+ selectivities, log (KpolAg,M) -3.8, against most of the interfering cations examined, except for Hg+.

  16. 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...

  17. Bridging Humanism and Behaviorism.

    Science.gov (United States)

    Chu, Lily

    1980-01-01

    Humanistic behaviorism may provide the necessary bridge between behaviorism and humanism. Perhaps the most humanistic approach to teaching is to learn how certain changes will help students and how these changes can be accomplished. (Author/MLF)

  18. I-5/Gilman advanced technology bridge project

    Science.gov (United States)

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

    2000-04-01

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

  19. 基于qtopia的桥梁检测车防侧翻监控系统的设计与实现%The design and realization of anti-rollover monitoring systerm of bridge-detection vehicle based on qtopia

    Institute of Scientific and Technical Information of China (English)

    杨世华; 王秀敏; 李世忠

    2011-01-01

    针对桥梁检测车在检测过程中存在的安全隐患,设计了一款基于qtopia的防侧翻监控系统,该系统以ARM9处理器为硬件核心,采取串口通信的方式,对来自传感器的信号经过处理,把机械臂的动作以动态图形显示在LCD屏上,克服了视频监控系统无法全角度监控的弊端.经过安装测试,证明该系统响应快速,运行稳定,具有实用价值.%In order to overcoming the hidden danger in the process of bridge-detection vechile detecting the bridge, a new anti-rollover monitoring systerm based qtopia is designed. In the systerm, ARM9 is adopted as the hard ware-core, and serial communication is taken as the way of data communication. After being processed, the signals from the sensors can display and simulate the robot arm movements in the LCD screen by dynamic graphic. It's better than video monitoring system, which can not give the whole view of arm movements. After being installed and tested, the systerm has been proved to be high-speed response, stable and functional.

  20. 大桥深水基础方案设计与施工及经济性研究%Study of Design Solutions, Construction and Economy of Deepwater Foundations for Major Bridges

    Institute of Scientific and Technical Information of China (English)

    杨进

    2011-01-01

    大桥深水基础方案设计在技术上如能很好地与环境相适应,可以达到经济上更合理,现以2座大桥基础工程实例进行分析.肇庆西江公铁两用大桥水中4号墩基础外形与高承台管柱基础基本相似,采用全钢外壳,由于在施工中无需承受震动打桩机的强力冲击,所以结构截面比较轻型,用钢量并不高,且有相当一部分系使用后可以回收的常备式杆件,故在经济上更具优势而且工期也短.泰州长江公路大桥中塔沉井基础高76 m,分为12节,沉井平面布置12个大井孔,与当时在长江中习惯采用的大直径深钻孔集群桩基础方案相比,该沉井基础在材料上更节省,工艺上更简单,且在受力性能和经济性方面明显占优,具有明显的技术优势.%If the design solutions of deepwater foundations for major bridges can technically accommodate very well the environment where the foundations are located, the solutions will be economically still more rational. The practical examples of the foundations of two major bridges are cited herewith and analyzed. The outline of the foundation for in-water Pier No. 4 of Zhaoqing Xijiang River Rail-cum-Road Bridge, used with complete steel shell, is basically similar to the foundation of the cylindrical shafts with elevated pier base. The structural cross section of the foundation for the pier is rather light and the usage amount of steel is not great because the foundation does not have to sustain strong impact from vibro-pile driver in the construction and moreover, a considerable part of the common members for the foundation is recyclable after usage and the foundation therefore is economically advantageous and the working time schedule is short as well. The caisson foundation, 76 m in height, for intermediate tower of Taizhou Changjiang River Highway Bridge is composed of 12 lifts and has 12 big wells arranged in plan of the caisson. In comparison to the large diameter and deep hole group

  1. Germ Cell Intercellular Bridges

    Science.gov (United States)

    Greenbaum, Michael P.; Iwamori, Tokuko; Buchold, Gregory M.; Matzuk, Martin M.

    2011-01-01

    Stable intercellular bridges are a conserved feature of gametogenesis in multicellular animals observed more than 100 years ago, but their function was unknown. Many of the components necessary for this structure have been identified through the study of cytokinesis in Drosophila; however, mammalian intercellular bridges have distinct properties from those of insects. Mammalian germ cell intercellular bridges are composed of general cytokinesis components with additional germ cell–specific factors including TEX14. TEX14 is an inactive kinase essential for the maintenance of stable intercellular bridges in gametes of both sexes but whose loss specifically impairs male meiosis. TEX14 acts to impede the terminal steps of abscission by competing for essential component CEP55, blocking its interaction in nongerm cells with ALIX and TSG101. Additionally, TEX14-interacting protein RBM44, whose localization in stabile intercellular bridges is limited to pachytene and secondary spermatocytes, may participate in processes such as RNA transport but is nonessential to the maintenance of intercellular bridge stability. PMID:21669984

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

  3. 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.

  4. 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.

  5. Research on Local Scour at Bridge Pier under Tidal Action

    Directory of Open Access Journals (Sweden)

    Wang Jianping

    2015-01-01

    Full Text Available Through the local scour test at bridge pier under tidal action in a long time series, this paper observes the growing trend of the deepest point of local scour at bridge pier under tidal conditions with different characteristic parameters, analyzes the impact of repeat sediment erosion and deposition in the scouring pit caused by reversing current on the development process of the scouring pit, and clarifies the relation between the tide and local scouring depth at bridge pier under steady flow conditions, so as to provide a scientific basis for bridge design and safe operation of estuary and harbor areas.

  6. 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.

  7. Very High Frequency Half Bridge DC/DC Converter

    DEFF Research Database (Denmark)

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

    2014-01-01

    This paper presents the first, off chip, class DE (resonant half bridge) converter working in the Very High Frequency (VHF) range. The benefits of using half bridge circuits both in the inverter and rectifier part of a VHF resonant dc/dc converter are analyzed and design equations for all...

  8. Bridging the Educational Research-Teaching Practice Gap: Curriculum Development, Part 1--Components of the Curriculum and Influences on the Process of Curriculum Design

    Science.gov (United States)

    Anderson, Trevor R.; Rogan, John M.

    2011-01-01

    This article summarizes the major components of curriculum design: vision, operationalization of the vision, design, and evaluation. It stresses that the relationship between these components is dynamic, and that the process of curriculum design does not proceed via a linear application of these components. The article then summarizes some of the…

  9. Designing dinuclear iron(II) spin crossover complexes. Structure and magnetism of dinitrile-, dicyanamido-, tricyanomethanide-, bipyrimidine- and tetrazine-bridged compounds.

    Science.gov (United States)

    Batten, Stuart R; Bjernemose, Jens; Jensen, Paul; Leita, Ben A; Murray, Keith S; Moubaraki, Boujemaa; Smith, Jonathan P; Toftlund, Hans

    2004-10-21

    In order to expand the few known examples of dinuclear iron(II) compounds displaying (weak) intradinuclear exchange coupling and spin-crossover on one or both of the iron(II) centres, various dinuclear compounds have been synthesised and assessed for their spin-crossover and exchange coupling behaviour. The key aim of the work was to prepare and structurally characterise 'weakly linked' and 'covalently bridged' systems incorporating bridging ligands such as alkyldinitriles (e.g.NC(CH(2))(4)CN), bipyrimidine (bpym), dicyanamide (dca(-)), tricyanomethanide (tcm(-)), 3,6-bis(2-pyridyl)tetrazine (bptz) and 3,6-bis(2-pyridyl)2,5-dihydrotetrazine (H(2)bptz). The 'end groups', which complete the Fe(ii)N(6) chromophores, include tris(2-pyridylmethyl)amine (tpa), di(2-pyridylethyl)(2-pyridylmethyl)amine (tpa'), 3-(2-pyridyl)pyrazole (pypzH), 1,10-phenanthroline (1,10-phen), tris(pyrazolyl)methane (tpm) and NCX(-)(X = S, Se). It was quite difficult to achieve the spin-crossover condition, many ligand combinations yielding high-spin/high-spin (HS-HS) Fe(II)Fe(II) spin states at all temperatures (300-2 K) with very weak antiferromagnetic coupling (J spin-crossover beginning above 300 K. 'Half crossover' examples, yielding HS-LS states below the spin transition, similar to those noted by Real and coworkers in some mu-bpym systems, were noted for [(1,10-phen)(NCS)(2)Fe(mu-bpym)Fe(NCS)(2)(1,10-phen)], 2, [(pypzH)(NCSe)(2)Fe(mu-bpym)Fe(NCSe)(2)(pypzH)], 4, and [(tpa)Fe(mu-H(2)bptz)Fe(tpa)](ClO(4))(4), 8. Interestingly, the mu-bptz analogue, 7, remained LS-LS at all temperatures with the start of a broad spin crossover evident above 300 K. No thermal hysteresis was evident in the spin transitions of these new dinuclear crossover species indicating a lack of intra- or interdinuclear cooperativity.

  10. Bridging the educational research-teaching practice gap. Curriculum development, Part 1: Components of the curriculum and influences on the process of curriculum design.

    Science.gov (United States)

    Anderson, Trevor R; Rogan, John M

    2011-01-01

    This article summarizes the major components of curriculum design: vision, operationalization of the vision, design, and evaluation. It stresses that the relationship between these components is dynamic, and that the process of curriculum design does not proceed via a linear application of these components. The article then summarizes some of the major influences on curriculum design: policy, local context, societal expectations, research trends, and technology. Then, it provides examples of how these influences affect the design of a curriculum and ends with a comprehensive set of questions that instructors could use to guide their curriculum development process.

  11. 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

  12. Smart suspension systems for bridge-friendly vehicles

    Science.gov (United States)

    Chen, Yonghong; Tan, Chin An; Bergman, Larry A.; Tsao, T. C.

    2002-06-01

    In this paper, the effects of using semi-active control strategy (such as MR dampers) in vehicle suspensions on the coupled vibrations of a vehicle traversing a bridge are examined in order to develop various designs of smart suspension systems for bridge-friendly vehicles. The bridge-vehicle coupled system is modeled as a simply supported beam traversed by a two-degree-of-freedom quarter-car model. The surface unevenness on the bridge deck is modeled as a deterministic profile of a sinusoidal wave. As the vehicle travels along the bridge, the system is excited as a result of the surface unevenness and this excitation is characterized by a frequency defined by the speed of travel and the wavelength of the profile. The dynamic interactions between the bridge and the vehicle due to surface deck irregularities are obtained by solving the coupled equations of motion. Numerical results of a passive control strategy show that, when the lower natural frequency of the vehicle matches with a natural frequency (usually the first frequency) of the bridge and the excitation frequency, the maximum response of the bridge is large while the response of the vehicle is relatively smaller, meaning that the bridge behaves like a vibration absorber. This is undesirable from a bridge design viewpoint. Comparative studies of passive and semi-active controls for the vehicle suspension are performed. It is demonstrated that skyhook control can significantly mitigate the response of the bridge, while ground-hook control reduces the tire force impacted onto the bridge.

  13. 双向全桥DC/DC转换器升降压控制系统的设计与实现%Design and realization of Boost-Buck control system for bidirectional full-bridge DC/DC converter

    Institute of Scientific and Technical Information of China (English)

    李宏恩; 周晋阳; 申玉坤

    2016-01-01

    双向DC/DC转换器是实现高低压电能双向传输功能的直流转换器,在各种直流稳压电源设计上应用广泛。通过小信号分析法,将非线性的DC/DC转换器变换为线性的数学模型进行研究,确定了全桥DC/DC转换器在升/降压模式下的传递函数,然后通过离散型PID控制算法,分析了系统控制的稳定性并确定了PID参数,设计了转换器补偿网络。最后通过仿真模型和样机实验验证,证明了双向全桥DC/DC转换器的升/降压控制系统的有效性。%The bidirectional DC/DC converter can realize the high voltage and low voltage bidirectional conversion,and is widely used in the design of various DC voltage⁃stabilized power supply. The nonlinear DC/DC converter is transformed into the linear mathematical model by means of the small signal analysis method for study. The transfer functions of full⁃bridge DC/DC converter in Boost/Buck modes are determined. And then the discrete PID control algorithm is used to analyze the stability of the control system and determine the PID parameters. The compensation network of the converter was designed. The simulation model and prototype experiment were verified,and the results show that the Boost⁃Buck control system of the bidirectional full⁃bridge DC/DC converter is effective.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-01

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

  15. Comparison of aerodynamic characteristics of pentagonal and hexagonal shaped bridge decks

    Science.gov (United States)

    Haque, Md. Naimul; Katsuchi, Hiroshi; Yamada, Hitoshi; Nishio, Mayuko

    2016-07-01

    Aerodynamics of the long-span bridge deck should be well understood for an efficient design of the bridge system. For practical bridges various deck shapes are being recommended and adopted, yet not all of their aerodynamic behaviors are well interpreted. In the present study, a numerical investigation was carried out to explore the aerodynamic characteristics of pentagonal and hexagonal shaped bridge decks. A relative comparison of steady state aerodynamic responses was made and the flow field was critically analyzed for better understanding the aerodynamic responses. It was found that the hexagonal shaped bridge deck has better aerodynamic characteristics as compared to the pentagonal shaped bridge deck.

  16. 武汉鹦鹉洲长江大桥北锚碇新型沉井基础设计%Design of New Type Caisson Foundation for North Anchorage of Yingwuzhou Changjiang River Bridge in Wuhan

    Institute of Scientific and Technical Information of China (English)

    李明华; 杨灿文

    2011-01-01

    The main bridge of Yingwuzhou Changjiang River Bridge in Wuhan is a three-tower and four-span suspension bridge. After comparison of different design proposals, it was determined that a new type caisson structure of circular cross section and with multiple round wells would be used for the north anchorage foundation of the bridge. In the big size well in the center of the caisson, the crisscross diaphragm was set and along the periphery within the caisson, a number of small size wells were uniformly set. The caisson is 43 m high and has totally 8 lifts, of which the first lift is a steel shell concrete caisson and the rest parts of the caisson from the second to the eighth lifts are all of reinforced concrete caissons. In the construction of the caisson, the caisson was sunk down by no dewatering and the air curtain was provided in the caisson wall to reduce sinking difficulty and construction risk. The software FLAC3D was used to conduct numerical simulation and analysis of the construction process of the sinking and to evaluate the construction safety, the environmental effect caused by the construction and the deformation of the foundation to be applied with load after the bridge was put into operation. The results of the a-nalysis show that in the process of sinking the caisson in lifts, the caisson structure and ground deformation can meet the relevant requirements in the codes and the adverse influence of the construction on the ambient buildings and the river dyke can be effectively avoided.%武汉鹦鹉洲长江大桥主桥为三塔四跨悬索桥.该桥北锚碇基础经多方案比选采用多圆孔环形截面新型沉井结构.沉井中间大圆孔内设置十字形隔墙,圆环内沿圆周均布有小直径井孔.沉井总高43 m,共分8节,第1节为钢壳混凝土沉井,第2~8节均为钢筋混凝土沉井.北锚碇施工中采用不排水下沉、井壁增加空气幕等措施减小施工难度及风险.采用软件FLAC3D对沉井施工过程进

  17. The design of bridge crane spreader based on the multi degre e of freedom finite element analysis%基于多自由度的桥起吊具设计及有限元分析

    Institute of Scientific and Technical Information of China (English)

    叶永伟; 叶连强; 任设东; 钱志勤

    2014-01-01

    In view of the bridge crane in the practical operation, the traditional crane spreader can′t achieve much freedom lifting and reduce the efficiency.This paper proposes a new type of bridge crane spreader design scheme.Comparing traditional spreader structure, it designs a multi degree of freedom the rotation mechanism, the spreader implements multiple hoisting.It establishes the finite element model based on ANSYS software, an-alyzes dynamic and static characteristics of the spreader .The static analysis ensures the spreader of stress and deflection according to the design requirements, and dynamic analysis ensures the operation in the process of a-voiding resonance phenomenon.The results show that the spreader conforms to the requirements of the design and the dynamic performance, provide the practical design proof.%针对实际作业中由于传统桥式起重机吊具的单一性导致无法实现多自由度吊装而降低工作效率的问题,提出了一种新型桥式起重机吊具设计方案。通过对比传统吊具结构,设计了多自由度吊具旋转机构,实现了多方位吊装;利用ANSYS软件建立有限元模型,对吊具进行动静态分析,静态分析保证了吊具的应力和挠度符合设计要求,动态分析保证了作业过程中避免发生共振现象。分析结果表明,该吊具符合设计和动态性能要求,为实际的生产设计提供了依据。

  18. 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.

  19. The aesthetic composite bridge.

    Science.gov (United States)

    Feinman, R A

    1997-01-01

    New developments are constantly introduced in the search for the optimal treatment modality to restore a single anterior tooth. The patient attention has shifted to aesthetics of the restoration, biocompatibility of the dental materials utilized, conservative preparation of the teeth to be restored, and the retention of intact adjacent dentition. The learning objective of this article is to review the methods currently utilized and to present a recently introduced treatment modality--the two-component bridge, which combines the strength and resiliency of composite resin with the aesthetic advantages of porcelain. The technology of the material is reviewed, the predominantly lingual tooth preparation procedures are outlined, and the bridge try-in is described. The advantages of the two-component bridge are presented along with the contraindications and suggestions of careful case selection. Three cases with congenitally missing maxillary lateral incisors in youthful patients are presented to supplement the theoretical outline and to describe and illustrate the clinical procedure.

  20. 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...

  1. 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....

  2. 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.

  3. Design of Bridge Deck with Intelligent Temperature Control and Deicing System%智能控温防冻桥面的构思和设计

    Institute of Scientific and Technical Information of China (English)

    谭红霞; 涂莉; 李建男

    2012-01-01

    It is cold winter in China,and the cold weather lasts almost one month in south China and even longer in the north.So,the road surface and bridge deck get iced up easily.The traffic accidents and high-way closures caused by icing will bring huge negative social influence and economic losses,so it is necessary to take effective decicing methods.However,some of the current deicing methods,have both advantages and disadvantages.Accordingly,this paper proposes a new method:replace a row of reinforcement steel bar with steel pipes in the steel mesh and lay heating wires in the pipes to heat up he bridge deck.The entire circuit control system takes the advantage of automatic temperature control.When the deck temperature is lower than 2 ℃,the temperature control system automatically switch on the power,and wires warm up;when the deck temperature is higher than 20 ℃,the temperature control system automatically switch off the power,wires stop warming.In this way,intelligent temperature control is achieved,and at the same time,the deck will not be iced up in low temperature.This system is easy to repair when with a fault,thus ensuring safe transportation.%中国冬季天气寒冷,路面桥面容易结冰,南方结冰期近1个月,北方时间更长.结冰引起的交通事故和高速公路关闭带来巨大的社会影响和经济损失,故急需采取有效的方法防止路面结冰.利用在桥面铺装层中的钢筋网,修改一个方向的钢筋为钢管,钢管中敷设发热丝,对桥面加热,整个电路使用控制系统根据温度变化自动控制.当桥面温度低于2℃时,控温系统自动接通电源,发热丝发热,加热桥面,当桥面温度高于20℃时,控温系统自动断开电源,发热丝停止加热桥面,从而实现温度智能可控,并且低温时路面不会结冰,故障时易于检修,车辆能安全通行.

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

    NARCIS (Netherlands)

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

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Lei Yan

    2016-01-01

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

  6. BUILDING "BRIDGES" WITH QUALITY ASSURANCE

    Science.gov (United States)

    The papr describes how, rather than building "bridges" across centuries, quality assurance (QA) personnel have the opportunity to build bridges across technical disciplines, between public and private organizations, and between different QA groups. As reviewers and auditors of a...

  7. DOE Information Bridge

    CERN Document Server

    United States. Department of Energy. Office of Scientific and Technical Information

    DOE Information Bridge, a component of EnergyFiles, provides free, convenient, and quick access to full-text DOE research and development reports in physics, chemistry, materials, biology, environmental sciences, energy technologies, engineering, computer and information science, renewable energy, and other topics. This vast collection includes over 43,000 reports that have been received and processed by OSTI since January 1995.

  8. Bridging a Cultural Gap

    Science.gov (United States)

    Leviatan, Talma

    2008-01-01

    There has been a broad wave of change in tertiary calculus courses in the past decade. However, the much-needed change in tertiary pre-calculus programmes--aimed at bridging the gap between high-school mathematics and tertiary mathematics--is happening at a far slower pace. Following a discussion on the nature of the gap and the objectives of a…

  9. 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...

  10. 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)

  11. An Easy-To-Use Combination Four-Terminal-Pair/Two-Terminal-Pair AC Transformer Bridge.

    Science.gov (United States)

    Jeffery, A; Shields, J Q; Lee, L H

    1998-01-01

    A new four-terminal-pair bridge, capable of achieving a relative standard uncertainty of 1×10(-9), was constructed at the National Institute of Standards and Technology by converting a two-terminal-pair bridge. The conversion requires only the addition of components which are easily removed if two-terminal-pair measurements are to be made. The design and testing of this bridge is described. The new four-terminal-pair bridge requires fewer auxiliary balances than the present four-terminal-pair bridge employed at NIST, which makes it much easier to use. This new design can be used to compare capacitance, resistance, and inductance standards.

  12. The Bridges of Taishun County

    Institute of Scientific and Technical Information of China (English)

    MaJianhe

    2003-01-01

    The American film The Bridges of Madison County captured the imagination of many Chinese moviegoers with its bittersweet love story and scenes of rustic covered bridges. But the U.S. can't lay sole claim to such spectacular rural sights:China has its own county worldrenowned for unforgettable bridges.

  13. 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....

  14. 浅析公路桥梁中板式橡胶支座设计%Simple Analysis on Laminated Rubber Bearing Design in Highway Bridge Construction

    Institute of Scientific and Technical Information of China (English)

    马少卿

    2015-01-01

    In this paper ,relevant law s and regulations about design methods of laminated rubber bearing are clarified and existing defects in design are further discussed .%本文主要对我国相关法律对公路桥梁中板式橡胶支座设计方法的规定进行了概述,进而探讨了公路桥梁中板式橡胶支座设计存在的漏洞。

  15. 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.

  16. Case Study on 4000 m-span Cable-stayed Suspension Bridge

    Directory of Open Access Journals (Sweden)

    Haijun Wang

    2014-04-01

    Full Text Available This study describes the case studies for a cable-stayed suspension bridges proposed over the Tsugaru Strait, Japan. Center Bridge is designed as a compound bridge of suspension bridges and cable-stayed bridges with 4000 m super-long-span. Case studies about the effects of cable-stayed bridge length, the design of sub-cable, height and stiffness of main tower, type of foundation and length of side span on displacement were carried out. With appropriate design of above parameters, the compound bridge can reduce horizontal displacement of main tower and vertical deflection in the central portion and enhance resistance to partial loading. The study reports the results based on these case studies.

  17. 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. 

  18. Application Study on HEC-RAS Three-dimensional River Hydraulic Calculation and Analysis System for Bridge Design Optimization%HEC RAS三维河道水力分析计算系统在桥梁优化设计的应用研究

    Institute of Scientific and Technical Information of China (English)

    杨磊磊

    2014-01-01

    Based on computational fluid dynamics, and using three-dimensional river hydraulic model HEC-RAS ( River Analyse System) , this paper took the interchange bridge No. 2 as the research object, which is situated on the Bejaia Express Highway in Algeria and was still under construction. Meanwhile, under the same geological condition and with once-in-a-hundred-year flood peak flow, the paper analyzed the influences of different bridge span schemes on the maximum bridge scouring depth. And then in this paper, the calculation results of three-dimensional river hydraulic model under the condition of different bridge span schemes were analyzed and researched, and finally an economical and reasonable bridge design scheme was determined. This paper provides a new research approach of scheme design for similar bridges at home and abroad in future.%基于计算流体动力学的方法,运用三维河道水力学模型HEC-RAS( River Analyse System)分析阿尔及利贝贾亚高速公路在建项目2号互通桥梁在百年一遇的最大洪峰流量下,不同桥梁孔跨方案在相同地质条件下对桥梁最大冲刷深度的影响,对不同桥梁孔跨方案下三维河道水力学模型计算结果进行分析研究,确定经济合理的桥梁设计方案,为今后国内外同类桥梁设计的方案研究提供了新的研究方法。

  19. Simulation of multivariate diffusion bridges

    DEFF Research Database (Denmark)

    Bladt, Mogens; Finch, Samuel; Sørensen, Michael

    We propose simple methods for multivariate diffusion bridge simulation, which plays a fundamental role in simulation-based likelihood and Bayesian inference for stochastic differential equations. By a novel application of classical coupling methods, the new approach generalizes a previously...... proposed simulation method for one-dimensional bridges to the mulit-variate setting. First a method of simulating approzimate, but often very accurate, diffusion bridges is proposed. These approximate bridges are used as proposal for easily implementable MCMC algorithms that produce exact diffusion bridges...

  20. 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...... the averaged spectral densities(ASD). From the ASD the eigenfrequencies of the structure can be identified. This information can be used in the main analysis, where alle modal parameters are extracted from the spectral densities. Due to long cabling and low response levels (small ambient loads) the response...

  1. 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...... the averaged spectral densities(ASD). From the ASD the eigenfrequencies of the structure can be identified. This information can be used in the main analysis, where alle modal parameters are extracted from the spectral densities. Due to long cabling and low response levels (small ambient loads) the response...

  2. Design of High Randomness PUF Circuit Based on Bridge Unbalance Effect%基于电桥失衡效应的高随机性PUF电路设计

    Institute of Scientific and Technical Information of China (English)

    钱浩宇; 汪鹏君; 李刚

    2016-01-01

    通过对物理不可克隆函数(Physical Unclonable Functions, PUF)电路和电桥失衡效应的研究,提出一种高随机性 PUF 电路设计方案.该方案首先利用工艺偏差导致电桥失衡产生随机偏差电压,然后结合电压型灵敏放大器产生随机的、不可克隆的响应信号.在TSMC 65nm CMOS工艺下,采用全定制方法设计PUF电路, PUF单元电路的版图面积为2.23µm×2.43µm.通过Spectre软件,在不同电压下对所设计PUF电路进行Monte Carlo仿真验证,分析其逻辑功能、随机性等特性.实验结果表明:所设计的PUF电路在电源电压1.2 V和温度25℃下随机性可达51.8%.%Through researching on the physical unclonable function (PUF) circuit and bridge unbalance effect, a high randomness PUF circuit is proposed in this paper. In this scheme, random deviation voltages are generated from bridge unbalance caused by process deviation. Then, random deviation voltages are inputted into sense amplifier to obtain response which is random and unclonable. Under TSMC 65nm CMOS process, the full custom design method is adopted. The layout area of PUF circuit is 2.23µm×2.43µm. Using Spectre software, Monte Carlo simulation results verify the designed PUF circuit under different voltage conditions. And also, the logical function and random characteristics are analyzed based on the simulation results. At 1.2V & 25℃, the randomness of the proposed PUF circuit achieves 51.8%.

  3. 一人桥楼窗框节点解决方案%Window Frame Design of Wheel House for One-man Bridge

    Institute of Scientific and Technical Information of China (English)

    徐美芳

    2014-01-01

    The arrangement of wheel house doors and windows for one-man control console was always difficult for the outfitting designer,due to fact that designers from structure and outfitting discipline did not know each other’s disciplines. The paper connected two disciplines to search for the solution. The structure detail was designed especially in order to fulfill the class requirements as much as possible. The article introduced detail design of wheelhouse doors and windows arrangement improvement based on a 400K VLOC ,which fulfill the NAUT-OC requirements. Four solutions for the structure of window ’s frame were demonstrated which could serve as reference.%一人桥楼门窗布置的设计一直以来是舾装设计的难点。追究其原因,主要是舾装和结构对相互的专业细节不甚了解。现将这两专业进行结合探索其解决方案,同时对结构细节进行专门设计以最大限度地满足规范规则对桥楼视线的要求。描述了40万t船满足NAUT-OC要求的驾驶室窗框节点设计的改进,同时着重总结一人桥楼窗框节点的设计及优化,列出四种驾驶室窗框节点方案,供同行参考讨论。

  4. 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.

  5. ANALYTICAL MODELS OF FLOATING BRIDGES SUBJECTED BY MOVING LOADS FOR DIFFERENT WATER DEPTHS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun; MIAO Guo-ping; LIU Jian-xun; SUN Wen-jun

    2008-01-01

    There are two types of floating bridge such as discrete-pontoon floating bridges and continuous-pontoon floating bridges.Analytical models of both floating bridges subjected by moving loads are presented to study the dynamic responses with hydrodynamic influence coefficients for different water depths. The beam theory and potential theory are introduced to produce themodels. The hydrodynamic coefficients and dynamic responses of bridges are evaluated by the boundary element method and by the Galerkin method of weighted residuals, respectively. Considering causal relationship between the frequencies of the oscillation of floating bridges and the added mass coefficients, an iteration method is introduced to compute hydrodynamic frequencies. The results indicate that water depth has little influence upon the dynamic responses of both types of floating bridges, so that the effect of water depth can be neglected during the course of designing floating bridges.

  6. Dynamic Analysis of A Pontoon-Separated Floating Bridge ubjected to A Moving Load

    Institute of Scientific and Technical Information of China (English)

    WANG Cong; FU Shi-xiao; LI Ning; CUI Wei-cheng; LIN Zhu-ming

    2006-01-01

    For the design and operation of a floating bridge, the understanding of its dynamic behavior under a moving load is of great importance. The purpose of this paper is to investigate the dynamic performances of a new type floating bridge, the pontoon-separated floating bridge, under the effect of a moving load. In the paper, a brief summary of the dynamic analysis of the floating bridge is first introduced. The motion equations for a pontoon-separated floating bridge, considering the nonlinear properties of connectors and vehicles' inertia effects, are proposed. The super-element method is applied to reduce the numerical analysis scale to solve the reduced equations. Based on the static analysis, the dynamic features of the new type floating bridge subjected to a moving load are investigated. It is found that the dynamic behavior of the pontoon-separated floating bridge is superior to that of the ribbon bridge by taking the nonlinearity of connectors into account.

  7. Bridging Classroom Language Ethnography

    OpenAIRE

    GRENFELL, MICHAEL JAMES

    2012-01-01

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

  8. 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.

  9. 挪威Hardanger大桥钢箱梁外侧电弧喷锌工艺设计%Design of zinc arc-spraying process for outer steel box girder of Hardanger Bridge in Norway

    Institute of Scientific and Technical Information of China (English)

    仪德强; 钱胜杰; 金树军; 李敏风; 丁祥

    2012-01-01

    在承接挪威Hardanger大桥钢结构制作中,根据业主的要求,以电弧喷锌作为配套涂层底漆.为了适应钢结构涂装流水线以及佐敦公司的重防腐配套涂料,从钢结构缺陷处理等级、磨料拼配方案、喷砂技术条件、电弧喷锌设备及锌丝线材要求、电弧喷锌工艺参数以及喷锌层质量要求等方面对钢箱梁外侧电弧喷锌工艺进行了设计.%Based on the requirement of proprietor, arc zinc spray coating was used as a primer during the manufacturing of the Norwegian Hardanger bridge's steel structure. In order to adapt the steel structure coating flow line and Jotun's heavy corrosion protection accessory coating, the arc zinc spraying process of outer steel box girder was designed from aspects of pretreatment grade of defects in steel structure, composition for abrasives, sandblasting process conditions, arc zinc spraying equipment, zinc wire requirement, arc zinc spraying process parameters, quality requirement of arc sprayed zinc coating, etc.

  10. Anti-wave Design for Independent Drilling Platform of Sea-crossing Bridge in the Typhoon Area%台风区跨海桥梁独立钻孔平台抗风浪设计

    Institute of Scientific and Technical Information of China (English)

    范发财

    2016-01-01

    In connection with the (B0 ~B58)main pier foundation independent drilling platform of the highway and rail-way combined bridge over the Pingtan Strait of newly-built Fuzhou-Pingtan Railway under the complicated typhoon area sea conditions such as strong wind,high wave and urgent flow,we carry out a summary respectively from the aspects of the structure comparison of independent platform,the structure design calculation for drilling platform and its structural analysis during construction.It can provide a reference for similar engineering construction in future.%针对新建福州至平潭铁路平潭海峡公铁两用大桥(B0~B58)主墩基础独立钻孔平台所处风大、浪高、流急等复杂台风区海况下,分别从独立平台结构形式的比选,钻孔平台的结构设计检算以及施工过程中结构分析等方面进行了总结,为以后类似工程施工提供借鉴。

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

    Directory of Open Access Journals (Sweden)

    Yongle Li

    2015-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    -dc converter (IFBBC) designed for this new application focusing on losses analysis. The system topology is briefly discussed and the major concerns related to the system, cells stacks and converter operating points are analyzed. The dc-dc converter losses are modeled and presented in detail; the analysis...... is validated on adc-dc converter prototype rated at 6 kW 30-80 V 0-80 A on the low voltage side and 700-800 V on the high voltage side (for a grid-tie application). The prototype is based on fully planar magnetic, Si MOSFETs, Si IGBTs and SiC diodes; efficiencies up to ~96.5% and ~97.8% were demonstrated...

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

    CERN Document Server

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

    2006-01-01

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

  14. Effect of near-fault earthquake on bridges: lessons learned from Chi-Chi earthquake

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The objective of this paper is to describe the lessons learned and actions that have been taken related to the seismicdesign of bridge structures after the Chi-Chi, Taiwan earthquake. Much variable near-fault ground motion data was collected fromthe rupture of Chelungpu fault during the Chi-Chi earthquake, allowing the seismic response of bridge structures subjected to thesenear-fault ground motions to be carefully examined. To study the near-fault ground motion effect on bridge seismic design codes, atwo-level seismic design of bridge structures was developed and implemented. This design code reflects the near-fault factors in theseismic design forces. Finally, a risk assessment methodology, based on bridge vulnerability, is also developed to assist in decisionsfor reducing seismic risk due to failure of bridges.

  15. Design and Research of Monitoring System for Mechanical Beam of Bridge-detection Vehicle%桥梁检测车机械臂监控系统设计与研究

    Institute of Scientific and Technical Information of China (English)

    王秀敏; 杨世华; 沈建明; 朱烨俊

    2011-01-01

    Current security problem of Bridge-detection Vehicle is hard to be monitored during working period. Combining with dynamic analyses, a monitoring system is designed based on simulation of the movement of manipulator to slove the problem that video monitoring system cannot display the whole point of Meachanical Beam. Firstly, the space motion model of Mechanical Beam is built, using the value of angle and stretching length of Mechanical Beam collected by sensors, and then the Lagrange's equation is built up to estimate the risk through computering the roll moment. Finally, the Mechanical Beam is drawn by Qtopia and the risk rate of rollover is shown according to it' s location information. The experimental results show that this system can estimate the danger level of Bridge-detection Vehicle rollover in real-time and display the whole point of Meachanical Beam realisticly, after the intelligent, reliability and stability of the system are improved.%研究桥梁检测的优化问题,针对目前桥梁检测车工作过程中自身安全难以监控,为解决视频监控系统不能全角度整体显示机械臂姿态的问题,结合动力学分析提出了基于动画模拟机械臂动作的监控系统.通过传感器采集机械臂角度和伸展长度的信息,建立机械臂空间运动学模型,然后利用拉格朗日法计算机械臂的侧翻力矩作为危险估计的依据,根据机械臂定位信息,通过Qtopia实时绘出机械臂的姿态,给出桥检车的侧翻危险等级.经仿真证明,系统能够实时预测桥检车的危险等级和全角度逼真的显示机械臂位置,提高了监控系统的可靠性、智能化和稳定性,具有实际应用价值.

  16. Bridge monitoring using heterogeneous wireless sensor network

    Science.gov (United States)

    Haran, Shivan; Kher, Shubhalaxmi; Mehndiratta, Vandana

    2010-03-01

    Wireless sensor networks (WSN) are proving to be a good fit where real time monitoring of multiple physical parameters is required. In many applications such as structural health monitoring, patient data monitoring, traffic accident monitoring and analysis, sensor networks may involve interface with conventional P2P systems and it is challenging to handle heterogeneous network systems. Heterogeneous deployments will become increasingly prevalent as it allows for systems to seamlessly integrate and interoperate especially when it comes to applications involving monitoring of large infrastructures. Such networks may have wireless sensor network overlaid on a conventional computer network to pick up data from one distant location and carry out the analysis after relaying it over to another distant location. This paper discusses monitoring of bridges using WSN. As a test bed, a heterogeneous network of WSN and conventional P2P together with a combination of sensing devices (including vibration and strain) is to be used on a bridge model. Issues related to condition assessment of the bridge for situations including faults, overloads, etc., as well as analysis of network and system performance will be discussed. When conducted under controlled conditions, this is an important step towards fine tuning the monitoring system for recommendation of permanent mounting of sensors and collecting data that can help in the development of new methods for inspection and evaluation of bridges. The proposed model, design, and issues therein will be discussed, along with its implementation and results.

  17. Dynamic Characterization of an All-FRP Bridge

    Science.gov (United States)

    Casalegno, C.; Russo, S.

    2017-03-01

    The light weight and high deformability of bridges made with pultruded FRP (fiber-reinforced polymer) materials make them very promising, but, at the same time, vulnerable to dynamic loadings. As a consequence, the vibration serviceability limit state can govern their design. There is currently a lack of data about the dynamic characteristics of FRP bridges and of design guidelines for securing their vibration serviceability. The paper presents the results of dynamic testing and characterization of an all-FRP spatial footbridge. The main modal parameters of the bridge are evaluated by an experimental modal analysis and by comparison of experimental data with FE analysis results. The identified flexural and torsional modes of the bridge are characterized by relatively high values of frequencies and damping. Results of the dynamic characterization give useful information about the dynamic characteristics of this kind of structures and can contribute to the elaboration of future guidelines for providing them with the vibration serviceability.

  18. Seismic studies of the San Francisco-Oakland Bay Bridge

    Energy Technology Data Exchange (ETDEWEB)

    Astaneh-Asl, A; Larsen, S; McCallen, D

    1999-08-17

    Computational simulation plays a central role in the engineering analysis and design of major bridge structures and accurate simulations are essential for the development of earthquake resistant and economical structural designs. This paper describes new methodologies and computational tools which have recently been developed for simulating earthquake ground motions and the seismic response of cable supported bridges. The simulation tools are described and an example application for an important long-span suspension bridge is demonstrated. The application portion of the study has particular focus on the potential damaging effects of long period displacement pulses and permanent ground displacements which can occur when a bridge is located in the near-field of a major earthquake fault.

  19. Piezoelectric energy harvesting from traffic-induced bridge vibrations

    Science.gov (United States)

    Peigney, Michaël; Siegert, Dominique

    2013-09-01

    This paper focuses on energy harvesting from traffic-induced vibrations in bridges. Using a pre-stressed concrete highway bridge as a case study, in situ vibration measurements are presented and analysed. From these results, a prototype of a cantilever piezoelectric harvester is designed, tested and modelled. Even though the considered bridge vibrations are characterized by small amplitude and a low frequency (i.e. below 15 Hz), it is shown that mean power of the order of 0.03 mW can be produced, with a controlled voltage between 1.8 and 3.6 V. A simple model is proposed for theoretical prediction of the delivered power in terms of traffic intensity. This model shows good agreement with the experimental results and leads to a simple but effective design rule for piezoelectric harvesters to be used on bridges.

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

    Science.gov (United States)

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

    2015-10-01

    The extent to which current theoretical modeling alone can reveal real-world metallic nanoparticles (NPs) at the atomic level was scrutinized and demonstrated to be insufficient and how it can be improved by using a pragmatic approach involving straightforward experiments is shown. In particular, 4 to 6 nm in size silica supported Au100-xPdx (x = 30, 46 and 58) explored for catalytic applications is characterized structurally by total scattering experiments including high-energy synchrotron X-ray diffraction (XRD) coupled to atomic pair distribution function (PDF) analysis. Atomic-level models for the NPs are built by molecular dynamics simulations based on the archetypal for current theoretical modeling Sutton-Chen (SC) method. Models are matched against independent experimental data and are demonstrated to be inaccurate unless their theoretical foundation, i.e. the SC method, is supplemented with basic yet crucial information on the length and strength of metal-to-metal bonds and, when necessary, structural disorder in the actual NPs studied. An atomic PDF-based approach for accessing such information and implementing it in theoretical modeling is put forward. For completeness, the approach is concisely demonstrated on 15 nm in size water-dispersed Au particles explored for bio-medical applications and 16 nm in size hexane-dispersed Fe48Pd52 particles explored for magnetic applications as well. It is argued that when ``tuned up'' against experiments relevant to metals and alloys confined to nanoscale dimensions, such as total scattering coupled to atomic PDF analysis, rather than by mere intuition and/or against data for the respective solids, atomic-level theoretical modeling can provide a sound understanding of the synthesis-structure-property relationships in real-world metallic NPs. Ultimately this can help advance nanoscience and technology a step closer to producing metallic NPs by rational design.The extent to which current theoretical modeling alone can

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

    Science.gov (United States)

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

    2015-11-14

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

  2. Morphological aspects of myocardial bridges.

    Science.gov (United States)

    Lujinović, Almira; Kulenović, Amela; Kapur, Eldan; Gojak, Refet

    2013-11-01

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

  3. 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.

  4. A Unique Prestressed Concrete Pedestrian Bridge in Spain

    OpenAIRE

    Ivorra Chorro, Salvador; Alvado Bañón, Joaquín; Crespo Zaragoza, Miguel Ángel

    2014-01-01

    This paper describes the so-called Kiss Bridge. This structure resembles a kiss, a subtle touch of structures. The beams have been structurally designed to adapt the Japanese art of paper folding called "origami." The material used for constructing the floating beams is white reinforced concrete in the form of folded shells. The two geometrically different parts have distinct structural behaviors. The length of the main pathway of both structures is over 60 m. The pedestrian bridge crosses an...

  5. Optimization of Dead Load State in Earth-Anchored Cable-Stayed Bridges

    Institute of Scientific and Technical Information of China (English)

    Bin Sun∗; Rucheng Xiao

    2015-01-01

    In order to determine the reasonable completed dead load state in earth⁃anchored cable⁃stayed bridges, a practical method is proposed. The method is based on the rigidly supported continuous beam method and the feasible zone method, emphasizing on the mutual effect between the self⁃anchored structural parts and the earth⁃anchored ones. Three cable⁃stayed bridge models are designed with the main spans of 1 400 m, including a partially earth⁃anchored cable⁃stayed bridge, a cable⁃stayed⁃suspension bridge and a fully self⁃anchored cable⁃stayed bridge, in which the C50 concrete and Q345 steel are adopted. The partially earth⁃anchored cable⁃stayed bridge and the cable⁃stayed⁃suspension bridge secure lower compressive force in the girder than the fully self⁃anchored cable⁃stayed bridge by 25 percent at least. The same is for the material consumption of the whole bridge. Furthermore, the anchor volume is more than 20% lower in the partially earth⁃anchored cable⁃stayed bridge than that in the cable⁃stayed⁃suspension bridge. Consequently, the practical span of cable⁃stayed bridges can be accordingly extended.

  6. Expected damages of retrofitted bridges with RC jacketing

    Science.gov (United States)

    Montes, O.; Jara, J. M.; Jara, M.; Olmos, B. A.

    2015-07-01

    The bridge infrastructure in many countries of the world consists of medium span length structures built several decades ago and designed for very low seismic forces. Many of them are reinforced concrete structures that according to the current code regulations have to be rehabilitated to increase their seismic capacity. One way to reduce the vulnerability of the bridges is by using retrofitting techniques that increase the strength of the structure or by incorporating devices to reduce the seismic demand. One of the most common retrofit techniques of the bridges substructures is the use of RC jacketing; this research assesses the expected damages of seismically deficient medium length highway bridges retrofitted with reinforced concrete jacketing, by conducting a parametric study. We select a suite of twenty accelerograms of subduction earthquakes recorded close to the Pacific Coast in Mexico. The original structures consist of five 30 m span simple supported bridges with five pier heights of 5 m, 10 m, 15 m 20 and 25 m and the analyses include three different jacket thickness and three steel ratios. The bridges were subjected to the seismic records and non-linear time history analyses were carried out by using the OpenSEEs Plataform. Results allow selecting the reinforced concrete jacketing that better improves the expected seismic behavior of the bridge models.

  7. Bridge Pressure Flow Scour at Clear Water Threshold Condition

    Institute of Scientific and Technical Information of China (English)

    GUO Junke; KERENYI Kornel; PAGAN-ORTIZ Jorge E; FLORA Kevin

    2009-01-01

    Bridge pressure flow scour at clear water threshold condition is studied theoretically and experimentally. The flume experiments reveal that the measured scour profiles under a bridge are more or less 2-dimensional; all the measured scour profiles can be described by two similarity equations, where the horizontal distance is scaled by the deck width while the local scour by the maximum scour depth; the maximum scour position is located just under the bridge about 15% deck width from the downstream deck edge; the scour begins at about one deck width upstream the bridge while the deposition occurs at about 2.5 deck widths downstream the bridge; and the maximum scour depth decreases with increas-ing sediment size, but increases with deck inundation. The theoretical analysis shows that: bridge scour can be divided into three cases, i.e. downstream unsubmerged, partially submerged, and totally submerged. For downstream unsubmerged flows, the maximum bridge scour depth is an open-channel problem where the conventional methods in terms of critical velocity or bed shear stress can be applied; for partially and totally submerged flows, the equilibrium maximum scour depth can be described by a scour and an inundation similarity number, which has been confirmed by experiments with two decks and two sediment sizes. For application, a design and field evaluation procedure with examples is presented, including the maximum scour depth and scour profile.

  8. 一种使用H桥和多谐振荡器的无线充电器设计%A Design of Wireless Charger based on H-Bridge and Multivibrator

    Institute of Scientific and Technical Information of China (English)

    耿其炜; 宋宇飞; 陈耀

    2014-01-01

    针对有线充电繁琐的人工操作和线材杂乱的弊端,设计一种无线充电器方案。此设计使用H桥逆变器和基于NE555的多谐振荡器,利用开关电源模块对交流电进行降压和整流,再将直流电逆变为交流电并通过线圈将电能发射,接收端将接收到的交流电能整流滤波后稳压供应给用电器。与大多数一对一无线充电方案相比,本设计可以在一较大范围内对多个移动设备同时供电。该套系统经测试可稳定工作,并可同时给手机、键盘和鼠标三件无线设备供电,达到设计要求。%To avoid tedious manual charging cable and wire clutter drawbacks,this paper develops a scheme for designing a wireless charger by using an H-bridge inverter and a multivibrator based on NE555.Then switch power module is applied to reduce the voltage and rectify the alternating current.Next,direct current is inverted to alternating current,and the power is transmitted via coils.The alternating power,which is filtered and rectified,is provided for electrical appliances. Compared with the mostly used one-to-one wireless chargers,this design is able to simultaneously power multiple mobile devices in a large area.The tests suggest that this system can work stably and charge mobile phone,keyboard and mouse at the same time.The design purpose is achieved.

  9. 基于力学与造价的CFRP-钢组合拉索斜拉桥设计理论%Design of Cable-stayed Bridges with CFRP-steel Composite Stay Cables Based on Mechanical and Economical Behaviors

    Institute of Scientific and Technical Information of China (English)

    熊文; 肖汝诚; CAIC S; 叶见曙

    2012-01-01

    To solve the problem resulting from the low structural stiffness, authors proposed a new design of cable-stayed bridges with composite carbon fiber reinforced polymer (CFRP)-steel stay cables, especially for the cable-stayed bridges with main spans of 1 400 ~ 2 800 m. More specifically, the CFRP stay cables with high strength-to-weight ratio and traditional steel stay cables with high elastic modulus were combined together for application in cable-stayed bridges, which could improve the entire stiffness of bridges. Through a parametric study concerning the equivalent stiffness and economical behavior, three design strategies for the composite cable- stayed bridges were proposed in details: the best equivalent stiffness with equal safety factor, best equivalent stiffness-to-cost ratio with equal safety factor and best equivalent stiffness with equal budget. The design procedure and design chart based on the proposed strategies were also provided. Finally, the feasibility of the proposed cable-stayed bridges was discussed through a case study of a cable-stayed bridge with a main span of 1 400 m. The results indicate that the proposed composite cable-stayed bridges can demonstrate a high equivalent stiffness and can be an excellent selection for the bridges with main spans of 1 400~2 800 m.%针对1400~2800m主跨斜拉桥整体刚度不足的问题,提出一种新型结构方案——碳纤维增强塑料(CFRP)-钢组合拉索斜拉桥。该方案将CFRP斜拉索与传统钢斜拉索同时应用于斜拉桥中,组合2种材料高强轻质及弹性模量高的优点,以:达.到提高斜拉桥整体刚度的设计目的。通过基于力学与造价的参数分析提出该组合拉索斜拉桥的3种设计原则:等安全系数等效刚度最优、等安全系数等效刚度性价比最优、等造价等效刚度最优,并分别给出详细的设计步骤及设计用图。最后,进行了多种方案1400m主跨斜拉桥试设计。结果

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

    Directory of Open Access Journals (Sweden)

    Donghoon Kang

    2013-01-01

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

  11. Design of the DC-DC Converter Control with Phase-Shift Full-Bridge Based on HIP4081%基于HIP4081的移相全桥DC-DC变换器的设计

    Institute of Scientific and Technical Information of China (English)

    钱伟康; 郭形发; 蒋艳; 倪元鸿

    2011-01-01

    随着我国通信、电力系统以及个人数字产品的快速发展,模块电源的应用越来越广泛.高可靠小功率DC-DC变换器已成为电子电源的一个重点发展方向.主要介绍了以H桥驱动芯片HIP4081为主控电路的小功率DC-DC变换器设计.为了进一步改善开关电源的中的磁性元件性能、减小磁件体积,分析了高频变压器的设计要点.结果分析表明:该变换器具有频响快、负载调整率高、输出电压稳定、纹波小的优点,研究具有一定的工程实际意义.%With the rapid development of telecommunications, power systems and personal digital products, the power modules have more and more widespread application. DC-DC converter with high reliable and low-power has become a focus of electronic power research. The low-power DC-DC converters constructed by the H bridge driver IC HIP4081 plus with a number of external components is described, and high-frequency transformer is designed and analyzed in order to further improve magnetic components performance of switching power supply. Finally, the results show by testing that the converter has some advantages of fast frequency response, high load regulation and less output voltage ripple. Research of the project has some practical engineering significance.

  12. Design of Bridge-Detection Vehicle Monitoring System Based on Android%基于Android的桥梁检测车安全监控系统的设计

    Institute of Scientific and Technical Information of China (English)

    张麒; 王秀敏; 任建新

    2012-01-01

    为解决国内桥梁检测车全局监控设备以及碰撞警报设备缺乏的问题,设计并实现了基于Android平台的一套智能监控系统.该系统通过倾角传感器采集的数据,用3D模型实时模拟机械臂的姿态,以达到全局监控的目的.同时可以根据实际情况构建虚拟障碍物,实现机械臂与障碍物碰撞的逼真模拟与警报.结果表明,该系统性能可靠、实用性强,不但解决了传统视频监控无法达到全局监控的问题,还对人工规避障碍物提供了可靠的参考.%To solve the problem of lacking of global monitoring device and collision warning device for domestic bridge-detection vehicle,we design and implement an intelligent monitoring system based on Android. The system uses real-time 3D model to simulate robot arm posture in realtime from tilt sensor, a-chieving global monitoring. The system can also build virtual obstacles based on actual situation,to simulate the collision between robot arm and obstacles vividly. If collision was detected,the system will trigger the alarm. Result shows that the system has reliable performance as well as strong practicability, it not only solve the problems of the traditional video surveillance can not reach the global monitoring, and also provides a reliable reference for avoiding obstacles by labour.

  13. Design and Optimization of an Efficient (96.1% and Compact (2 kW/dm3 Bidirectional Isolated Single-Phase Dual Active Bridge AC-DC Converter

    Directory of Open Access Journals (Sweden)

    Jordi Everts

    2016-10-01

    Full Text Available The growing attention on plug-in electric vehicles, and the associated high-performance demands, have initiated a development trend towards highly efficient and compact on-board battery chargers. These isolated ac-dc converters are most commonly realized using two conversion stages, combining a non-isolated power factor correction (PFC rectifier with an isolated dc-dc converter.This, however, involves two loss stages and a relatively high component count, limiting the achievable efficiency and power density and resulting in high costs. In this paper, a single-stage converter approach is analyzed to realize a single-phase ac-dc converter, combining all functionalities into one conversion stage and thus enabling a cost-effective efficiency and power density increase. The converter topology consists of a quasi-lossless synchronous rectifier followed by an isolated dual active bridge (DAB dc-dc converter, putting a small filter capacitor in between. To show the performance potential of this bidirectional, isolated ac-dc converter, a comprehensive design procedure and multi-objective optimization with respect to efficiency and power density is presented, using detailed loss and volume models. The models and procedures are verified by a 3.7kW hardware demonstrator, interfacing a 400Vdc-bus with the single-phase 230V,50Hz utility grid. Measurement results indicate a state-of-the-art efficiency of 96.1% and power density of 2 kW/dm3, confirming the competitiveness of the investigated single-stage DAB ac-dc converter.

  14. Evaluation of Seismic Performance of Long Span Continuous Girder Bridges Based on Seismic Isolation Design%基于减隔震设计的大跨度连续梁桥抗震性能评价

    Institute of Scientific and Technical Information of China (English)

    李贞新; 刘高

    2011-01-01

    Nonlinear time history analysis method is adopted to analyze dynamic characteristics and seismic performance based on long span continuous girder bridges with spans of 89 m, 170 m and 89 m in high intensity region. The good hysteretic, energy-dissipation characteristics and self-restoring ability of double curvature seismic isolation bearings are simulated as well as the friction energy-dissipation characteristics of sliding bearing and damping energy-dissipation characteristics of dampers. Analytical results indicate that seismic performance can basically meet the expected design goal; seismic isolation device of double curvature spherical supports and dampers can adjust dynamic characteristics, reduce seismic response, dissipate earthquake energy and guarantee the safety of the structure.%基于高烈度区的某大跨度连续梁桥(89 m+170 m+89 m),采用非线性时程分析法进行结构动力特性及抗震性能分析.全桥均采用三维梁单元建立空间模型,对于双曲面球形减隔震支座的滞回耗能特性和自恢复功能,活动支座的摩擦耗能以及固定销剪断后的效应进行了模拟,同时模拟了阻尼器的阻尼耗能作用.研究结果表明:采用双曲面球形减隔震支座及桥台处纵向阻尼器后,结构的反应得到了很好的控制,确保了高烈度区结构的抗震安全性.

  15. 武汉天兴洲公铁两用桥主塔爬模设计及应用%Design and Application of Climbing Slipform Formwork in Pylon Tower of Wuhan Tianxingzhou Yangtze River Highway-railway Bridge

    Institute of Scientific and Technical Information of China (English)

    宁智刚

    2011-01-01

    武汉天兴洲公铁两用桥主塔模板施工采用液压自爬模体系,打破了传统的施工工艺,对施工环境、提高施工工效、安全环保等都有所改善.针对该工程主塔模板施工,施工脚手架采用液压自爬模系统配合木工字梁模板体系,并对爬模体系进行了优化和设计.此外,阐述了模板系统组成及液压自爬架组成,详细介绍了爬模施工方案以及安全规定.体现了液压自爬模及木梁胶合板模板体系用于异型混凝土结构的优越性.%Hydraulic climbing slipform system is used with main tower formwork construction of Wuhan Tianxingzhou Yangtze river highway-railway bridge, the traditional construction technology is changed. The construction environment, construction efficiency, safety and environmental protection is all improved. Based on the construction, construction scaffolding is used with hydraulic climbing slipform system combined with wood H beam formwork system, and auto-climbing formwork system is optimized and designed. In addition, formwork system composition and hydraulic climbing slipform system are expounded. Construction scheme of climbing slipform and safety regulations are introduced in detail. The fact shows that it is reasonable that hydraulic climbing slipform system and timber beam plywood formwork system are used in non-standard concrete structure.

  16. London Bridge Is Shaking Funny

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    Bridges generally don’t fall down without warning;they crack first. Searching for cracks is a tedious business,though, and bridge inspectors bave been known to miss them. Charles Farrar,a civil engineer at Los Alamos Na-

  17. 3 long bridges of dream were realized Opening of West Seto Motorway; Yume no 3 kakyo ga jitsugen/nishiseto jidoshado haitsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-06-10

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

  18. 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.

  19. 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.

  20. Linguistic Barriers and Bridges

    DEFF Research Database (Denmark)

    Thuesen, Frederik

    2016-01-01

    and intercultural communication, this article analyses interviews with 31 employees from two highly ethnically diverse Danish workplaces. The article shows how linguistic barriers such as different levels of majority language competence and their consequent misunderstandings breed mistrust and hostility, whilst......The influence of language on social capital in low-skill and ethnically diverse workplaces has thus far received very limited attention within the sociology of work. As the ethnically diverse workplace is an important social space for the construction of social relations bridging different social...... groups, the sociology of work needs to develop a better understanding of the way in which linguistic diversity influences the formation of social capital, i.e. resources such as the trust and reciprocity inherent in social relations in such workplaces. Drawing on theories about intergroup contact...

  1. Looking Beyond the Bridge

    DEFF Research Database (Denmark)

    Jahn, Elke; Rosholm, Michael

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

  2. 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.

  3. Behavior of FRP Link Slabs in Jointless Bridge Decks

    Directory of Open Access Journals (Sweden)

    Aziz Saber

    2012-01-01

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

  4. Aerodynamic challenges in span length of suspension bridges

    Institute of Scientific and Technical Information of China (English)

    XIANG Haifan; GE Yaojun

    2007-01-01

    The potential requirement of extreme bridge spans is firstly discussed according to horizontal clearances for navigation and economical construction of deep-water foundation. To ensure the technological feasibility of suspen- sion bridges with longer spans, the Static estimation of feasi- ble span length is then made based on current material strength and weight of cables and deck. After the performances of the countermeasures for raising the aerodynamic stability are reviewed, a trial design of a 5 000 m suspension bridge, which is estimated as a reasonable limitation of span length, is finally conducted to respond to the tomorrow's challenge in span length of suspension bridges with the particular aspects, including dynamic stiffness, aerodynamic flutter and aerostatic stability.

  5. Segmental Bridges under Combined Torsion, Bending and Shear

    Institute of Scientific and Technical Information of China (English)

    黄真; 刘西拉

    2003-01-01

    Segmental bridges with unbonded prestressed tendons have some advantages, such as the weather independence and the corrosion protection of prestressing tendons. This paper analyzed the behavior of a prestressed segmental bridge with unbonded tendons under combined loading of torsion, bending and shear. According to the experiment research, a modified skew bending model was developed to calculate the bearing capacity of segmental bridges subjected to combined bending, shear and torsion. The finite element method was used to investigate the deflection behaviors of such structure, also to check the theoretical model. The theoretical and FEM research resuits were compared favorably with the test results from Technical University of Braunschweig, Germany. Finally, suggestion for the design and construction of segmental bridges with external prestressing was made.

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

    Science.gov (United States)

    Lackéus, Martin; Williams Middleton, Karen

    2015-01-01

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

  7. Bridging Cultures: Evaluating Teachers' Understanding of Cross-Cultural Conflicts.

    Science.gov (United States)

    Trumbull, Elise; Greenfield, Patricia; Quiroz, Blanca; Rothstein-Fisch, Carrie

    The Bridging Cultures Project is a collaboration among several researchers and teachers (n=8) to design professional development activities on the topic of cross-cultural understanding. During the fall of 1996, participating teachers will be given a pre-assessment and post-assessment. The assessments are designed to give some information on how…

  8. Study of Nonlinear Seismic Response and TMD Primary Control of the Cable-Stayed Bridge Section of the Third Macao-Taipa Bridge

    Institute of Scientific and Technical Information of China (English)

    Long Xiaohong; Li Li

    2004-01-01

    The practical design of the cable-stayed bridge of the 3rd Macao-Taipa bridge is investigated by the finite element analysis program ANSYS, and 3-D elements BEAM188 and BEAM4 are adopted to create a dynamic calculation model. In order to analyze the material nonlinear seismic response of the cable-stayed bridge, the nonlinear behaviors of the ductile plastic hinges of the bridge towers are taken into account by employing the nonlinear rotational spring element COMBIN40. To simulate a major earthquake, three earthquake records were chosen using a wave-choosing program and input into the bridge structure along longitudinal and transversal directions. Comparisons of the linear and nonlinear seismic responses of the cable-stayed bridge are performed. In addition, a study of TMD primary control is carried out using element MASS21 and element COMBIN14, and it is indicated that the effects of mitigation monitoring are evident.

  9. 240 W全桥移相ZVS变换器的设计%Design of a 240 W full-bridge converter with phase shift control and zero voltage switching

    Institute of Scientific and Technical Information of China (English)

    张本庚; 刘平

    2011-01-01

    The phase-shifted full-bridge zero-voltage-switching (PS-FB-ZVS) PWM converter is widely used in medium and high power levels. However, there are two problems existing in this kind of converter; one is that lagging leg has narrow zero-voltage-switching ranges,and the other is that the output rectifier diodes suffer the parasitic oscillation and voltage spike resulted by the reverse recovery of the rectifier diodes. The converter discussed in the literalure one had wide zero-voltage-switching ranges of lagging leg switches by using the magnetizing current. In addition, the resonance between the leakage inductor of the transformer and the rectifier capacitors could reduce the current stresses of the rectifier diodes and coeduction losses. Based on the principle of the converter, one 240 W zero-voltage-switching (ZVS) soft-switching power supply on the phase shift control was designed The procedures of main circuit design were presented. The experimental waveforms were given in the end.%移相全桥零电压变换器在中大功率场合中得到了广泛的应用,但其滞后臂只能在较窄的负载范围内实现软开关,并且其输出整流二极管反向恢复时产生严重的寄生振荡,二极管上存在很高的尖峰压.而文献[1]中变换器的滞后臂利用励磁电感电流可以在较宽的负载范围内实现软开关.变压器的漏感与电容的谐振可以减小整流管的电流应力和导通损失.基于此变换器的工作原理,设计了一台240 W移相控制零电压软开关电源,给出了主电路的设计过程,最后给出了实验波形.

  10. Acquisition and Analysis of Dynamic Responses of a Historic Pedestrian Bridge using Video Image Processing

    Science.gov (United States)

    O'Byrne, Michael; Ghosh, Bidisha; Schoefs, Franck; O'Donnell, Deirdre; Wright, Robert; Pakrashi, Vikram

    2015-07-01

    Video based tracking is capable of analysing bridge vibrations that are characterised by large amplitudes and low frequencies. This paper presents the use of video images and associated image processing techniques to obtain the dynamic response of a pedestrian suspension bridge in Cork, Ireland. This historic structure is one of the four suspension bridges in Ireland and is notable for its dynamic nature. A video camera is mounted on the river-bank and the dynamic responses of the bridge have been measured from the video images. The dynamic response is assessed without the need of a reflector on the bridge and in the presence of various forms of luminous complexities in the video image scenes. Vertical deformations of the bridge were measured in this regard. The video image tracking for the measurement of dynamic responses of the bridge were based on correlating patches in time-lagged scenes in video images and utilisinga zero mean normalisedcross correlation (ZNCC) metric. The bridge was excited by designed pedestrian movement and by individual cyclists traversing the bridge. The time series data of dynamic displacement responses of the bridge were analysedto obtain the frequency domain response. Frequencies obtained from video analysis were checked against accelerometer data from the bridge obtained while carrying out the same set of experiments used for video image based recognition.

  11. Torsional instability in suspension bridges: The Tacoma Narrows Bridge case

    Science.gov (United States)

    Arioli, Gianni; Gazzola, Filippo

    2017-01-01

    All attempts of aeroelastic explanations for the torsional instability of suspension bridges have been somehow criticised and none of them is unanimously accepted by the scientific community. We suggest a new nonlinear model for a suspension bridge and we perform numerical experiments with the parameters corresponding to the collapsed Tacoma Narrows Bridge. We show that the thresholds of instability are in line with those observed the day of the collapse. Our analysis enables us to give a new explanation for the torsional instability, only based on the nonlinear behavior of the structure.

  12. 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.

  13. 刚构-连续梁桥健康监测系统设计%Design of Health Monitoring System for Rigid-Frame and Continuous-Beam Composite Bridge

    Institute of Scientific and Technical Information of China (English)

    杨雅勋; 郝宪武; 孙磊

    2011-01-01

    In order to solve the problem in the construction of health monitoring system in rigid-frame and continuous-beam composite bridge structure, the Jin Shui Gou Bridge is taken as an object for study. Aiming at the structural environment and the loading characteristics of this bridge, the content of monitoring, composition, functions and principle of the health monitoring system of the rigid-frame and continuous-beam composite bridge are studied. The basis of project selection for the health monitoring system is proposed. The composition, main functions, selection of monitoring insttrument and placement of sensors of the health monitoring system of Jin Shui Gou Bridge are also analyzed. The scientific basis of the health monitoring system for Jin Shui Gou Bridge is provided.%为了解决刚构-连续梁桥结构健康监测系统的建设问题,以金水沟大桥为研究对象进行研究,针对刚构-连续梁桥的结构环境和受力特点,研究了刚构-连续梁桥健康监测系统的监测内容,系统组成、作用及原理,提出了建立健康监测系统项目的选择依据,并对金水沟大桥健康监测系统的构成、主要功能、监测仪器选择以及传感器布置等进行了分析,为金水沟大桥健康监测系统的建立提供科学依据,同时也为此类桥梁健康监测系统的建设提供参考.

  14. 基于桥面铺装技术的城市高架桥梁设计研究%Urban Elevated Bridge Design Based on Deck Pavement Technology

    Institute of Scientific and Technical Information of China (English)

    宋殿峰

    2014-01-01

    This article expounds the deck pavement techn-ology of urban elevated bridge and points out the existing problems, and puts forward pavement construction, joints treatment and other technical processing measures through analyzes the deck pavement technology of urban elevated bridge.%本文对城市高架桥梁桥面铺装工艺进行了阐述,指出面铺装存在的问题,通过对高架桥桥面铺装技术的分析,提出了摊铺施工、接缝处理等技术处理举措。

  15. Earthquake Performance Analysis of Steel Truss-Concrete Continuous Rigid Frame Bridge

    Directory of Open Access Journals (Sweden)

    Li Yuanming

    2014-04-01

    Full Text Available The steel truss-concrete Combination continuous rigid frame bridge is that we use steel truss for Principal stress structure.The seismic performance of a steel truss-concrete Combination continuous rigid frame bridge was studied in this paper. A dynamic spatial finite element model of Qingqiyong Bridge, which is a long span bridge, was created using MIDAS. Its natural frequency and vibration mode can be calculated,the seismic performance and structure stiffness were discussed and analyzed on the basis of calculated results. Design response spectrum and time-history method are used to calculate this bridge, seismic performance is discussed in this paper . Results show that natural frequency of the bridge is small, its period is long, and this kind of bridge is a new kind of earthquake resistant and energy-saving structure. Seismic effect has some effect on the bridge, especially the bending moment Along the bridge. The results of this paper can also provide some references for the design, construction, health monitoring and maintenance of bridges of like.

  16. Experimental study on the width of the turbulent area around bridge pier

    Institute of Scientific and Technical Information of China (English)

    ZHUANG Yuan; LIU Zu-yuan

    2007-01-01

    At present, the method of calculating the turbulent flow width around the bridge pier is not given in the "Standard for Inland River Navigation" (GB50139-2004) in China, and the bridge designer usually increases the bridge span in order to ensure the navigation safety, which increases both of the structural design difficulty and the project investments. Therefore, it is extremely essential to give a research on the turbulent flow width around the bridge pier. Through the experiments of the fixed bed and the mobile bed, the factors influencing the turbulent flow width around the bridge pier have been analyzed, such as the approaching flow speed, the water depth, the angles between the bridge pier and the flow direction, the sizes of bridge pier, the shapes of the bridge pier, and the scouring around the bridge pier, etc. Through applying the dimension analytic method to the measured data, the formula of calculating the turbulent flow width around the bridge pier is then inferred.

  17. Evaluation Behavior of Qing Shan Concrete Bridge under Static Load Test

    Directory of Open Access Journals (Sweden)

    Haleem K. Hussain

    2011-07-01

    Full Text Available This study describes and evaluates the state of Qing Shang Bridge. The deterioration of bridge can be summarized due to increased internal forces may be a result of higher loading or due to the sever climatic and environmental weathers changes, bridges need reinforcement because damage due to external factors which reduced the cross-sectional resistance to external loads. The assessment of traffic loading on bridges is subject to large levels of uncertainty. While some allowance is provided in design codes for variable traffic conditions, they are conservative to allow for generalization at a safe level. Also this article identify the design demands of Qing Shan bridge which is located in China/ Heilongjiang Province, He gang - Nen Jiang Road 303 provincial highway, Wu Da Lian Chi area, is an important bridge in the urban areas. The investigation program was include the observation and evaluate the damage in T-section concrete beams , box girder bridges section in additional evaluate the whole state of bridges under static load test, the use of Finite Element Analysis was preferred method to study the behavior of concrete. Furthermore the load test program includes the main beams of bridge. The test results show that the bridge in general structural condition is good. T beam girder of the span No. 10 was tested for static load and need to be strengthening. The concrete box girder shows good state of condition, and no seriously damage effects.

  18. FBG application in bridge health monitoring system of Wuhan Yangtze River 2nd Bridge

    Science.gov (United States)

    Liu, Jun

    2009-10-01

    For the traditional resistance strain sensor's shortage,for example,their stability,durability and monitoring scorpe could not satisfied the requirement of bridge monitoring system,put forward to adopt advanced fiber-optic bragg grating sensor and its technology to build up the bridge health monitoring system.Analysed the application scope and aim of difference kinds of fiber bragg grating sensors used, including stress strain sensors,temperature sensors,crack sensors and testing force ring sensors.According to the key construction sections as the project designed,expatiated their specific installation methods and construction craftwork in Wuhan Yangtze River 2th bridge.It formed distributed fiber sensing network of bridge with large-scale located fiber-optic bragg grating sensors, and pointed out the becareful prodeeding when to link no more than twenty sensors to one fiber for the demodulator precision.Discussed how to construct the data acquisition system and its function via the sensors and their demodulator.One fiber of the linked sensors connected to one channel of the demodulator and all together reached sixteen channels.The demodulator were connected to the switch through rj45 interface and communicated with the acquisition server.Designed the software program of data acquisition software system and the database,which used the Sqlite of the embed database to storage the configure information and receive the data through the TCP/IP protocol.It has been build a bridge health monitoring system base on fiber bragg grating technology.

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

    Science.gov (United States)

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

    2017-02-01

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

  20. 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...

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

    Data.gov (United States)

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

  2. 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]....

  3. Rational design of azide-bridged bimetallic complexes. Crystal structure and magnetic properties of Fe(III)MFe(III) (M = Ni(II) and Cu(II)) trinuclear species.

    Science.gov (United States)

    Colacio, Enrique; Costes, Jean-Pierre; Domínguez-Vera, José M; Maimoun, Ikram Ben; Suárez-Varela, José

    2005-01-28

    The first examples of azide-bridged bimetallic trinuclear complexes ([M(cyclam)][FeL(N3)(mu1,5-N3)]2) (H2L = 4,5-dichloro-1,2-bis(pyridine-2-carboxamido) benzene) have been structurally and magnetically characterized.

  4. 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...

  5. 海洋环境下预应力混凝土桥梁耐久性分析与设计%Durability Analysis and Design of Prestressed Concrete Girder Bridge in Marine Environment

    Institute of Scientific and Technical Information of China (English)

    李成绩; 陆春华

    2012-01-01

    In order to study the durability behavior of concrete structure caused by chloride attack in marine environment,a calculated model for chloride ingress in prestressed concrete is built,which mainly takes material property,environment,stress level of concrete and surface convection into account.Then,considering the character of durability failure for presstressed concrete bridge structure,the durability limit state is defined as the initiation of prestressing steel's corrosion.Based on the statistic results of relevant random variables,the reliability indexes under various water-binder ratio and cover thickness are studied with Monte-Carlo simulation;and the minimum cover thickness are proposed to satisfy certain target reliability index.Analytical results can provide some reference to engineering durability design.%为了研究海洋环境下氯离子侵蚀引起的混凝土结构耐久性行为,在重点考虑材料、环境、混凝土应力水平以及表层对流区影响的基础上,建立了预应力混凝土氯离子侵入扩散模型;随后,基于预应力混凝土桥梁结构耐久性失效的特点,提出了以预应力筋临界锈蚀作为耐久性极限状态的标志;并在各随机变量统计分析的基础上,采用Monte-Carlo方法研究了不同水胶比、不同保护层厚度时的可靠指标变化情况,得出了给定目标可靠指标下预应力筋的最小保护层厚度。相关研究成果可以为工程设计提供一定参考。

  6. 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.

  7. 大跨桥梁健康监测系统设计构成及其进展%Designed Components and Development of Health Monitoring Systems for Long Span Bridges

    Institute of Scientific and Technical Information of China (English)

    王戒躁; 钟继卫; 王波

    2009-01-01

    With the constant construction of the new types of long span, lightweight and flexible structure bridges, the safety and durability of the bridges in operation state have attracted great concern from engineering circle and the real-time structural health monitoring and the near real-time structural safety evaluation of the bridges have also become the hot research subjects in the engineering and academic circles. The contents and components of the monitoring and evaluation systems are presented herewith, the current research of the monitoring and evaluation systems for some major bridges at home and abroad are reviewed, the state-of-the-art, development tendency and prospecting of the monitoring system and evaluation items are described and the research findings of the monitoring system for Wuhan Yangluo Changjiang River Bridge are particularly analyzed.%随着大跨、轻、柔等新型桥型的不断建造,桥梁结构运营状态的安全性及耐久性受到工程界高度重视.大跨度桥梁的实时结构健康监测和近实时结构安全评估工作也成为工程界及学术界研究的热点问题.介绍桥梁健康监测与评估系统的内容及系统构成,简要回顾国内外大型桥梁健康监测与评估系统的研究现状,阐述桥梁健康监测与评估项目的发展现状、趋势及前景,并重点分析武汉阳逻长江大桥健康监测系统的研究成果.

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    CT. Ramanathan

    2010-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Yongjian Liu

    2015-08-01

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

  11. 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....

  12. Comparison of Temperature Loadings of Bridge Girders

    Directory of Open Access Journals (Sweden)

    J. Římal

    2008-01-01

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

  13. Hydraulic and geomorphic monitoring of experimental bridge scour mitigation at selected bridges in Utah, 2003-05

    Science.gov (United States)

    Kenney, Terry A.; McKinney, Tim S.

    2006-01-01

    Unique bridge scour mitigation designs using concrete A-Jacks were developed by the Utah Department of Transportation and installed at the Colorado River Bridge at State Road 191 and the Green River Bridge at State Road 19. The U.S. Geological Survey monitored stream reaches at these sites by collecting streambed-topography and water-velocity data from 2003 through 2005. These data were acquired annually from a moving boat with an acoustic Doppler current profiler and a differential global positioning system. Raw unordered data were processed and readied for interpolation into organized datasets with DopplerMacros, a set of computer programs. Processed streambed topography data were geostatistically interpolated by using Ordinary Kriging, and inverse distance weighting interpolation was used in the development of the two-dimensional velocity datasets. These organized datasets of topography and velocity were developed for each survey of the two bridge sites. A comparison of the riverbed topography data for each survey was done. An increase in bed elevation related to the installation of the A-Jacks scour countermeasures is evident at the Colorado River Bridge at State Road 191. The three topographic datasets acquired after the installation at the Green River Bridge at State Road 19 show few changes.

  14. 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.

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

    CERN Document Server

    Băncilă, Radu

    2015-01-01

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

  16. Redundancy Evaluation of Fracture Critical Bridges

    OpenAIRE

    Bapat, Amey Vivek

    2014-01-01

    Cases of brittle fractures in major bridges prompted AASHTO to publish its first fracture control plan in 1978. It focused on material and fabrication standards, and required periodic 24-month hands-on inspection of bridges with fracture critical members. The practical result of this plan was to significantly increase the life cycle cost of these bridges, rendering them uneconomical. Apart from the Point Pleasant Bridge that failed in 1967, no other bridge has collapsed in the USA following a...

  17. Aerostatic Stability of Long-Span Cable-Stayed Bridges: Parametric Study

    Institute of Scientific and Technical Information of China (English)

    程进; 江见鲸; 肖汝诚; 项海帆

    2003-01-01

    The increasing span of cable-stayed bridges has focused more attention on the aerostatic stability of the design and construction of such bridges. This paper presents a new method to analyze the nonlinear aerostatic stability of cable-stayed bridges including all three components of the wind load and the geometric nonlinearity. The analysis was used to investigate the effects of the wind angle of incidence, the wind load of individual bridge elements, the sagging of cable elements, the changes of tower height and the changes of side span length on the aerostatic stability of cable-stayed bridges. The results show that the wind angle of incidence and the wind loads on the cables have an important effect on the aerostatic stability of cable-stayed bridges.

  18. Seismic performance evaluation for super-long span cable-stayed bridges

    Institute of Scientific and Technical Information of China (English)

    Ye Aijun; Wu Shouchang

    2009-01-01

    Based on the capacity/demand (C/D) analysis of bridge components, and life cycle and performance based seismic design principles, a practical approach is developed for the seismic performance evaluation of super-long span cable-stayed bridges. According to the approach, the seismic performance evaluation of the Sutong Bridge, which is a cable-stayed bridge with a main span of 1 088 m, is completed, and the practicality of the approach is validated. The earthquake resistance level for super-long span cable-stayed bridges is discussed, including the earthquake level, its corresponding structural performance and check indices. And a set of formula for capacity/demand ratio calculation of bridge components is proposed.

  19. GPS Dynamic Monitoring Experiment and Result Analysis of Long-Span Cable-Stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    For the sake of timely appraising the working condition of the bridge, measuring the dynamic characteristics of the bridge structure is very important and necessary. A GPS dynamic monitoring test was carried out in the Wuhan Baishazhou Bridge, which is one of the longest span cable-stayed bridges having been built in China. This paper introduces the experimental implementing scheme and data processing method. The vibration characteristics of the middle span of cable-stayed bridge are availably obtained by use of the spectral analytic approach. The measuring results are very identical to the theoretical designed values. The research demonstrates that, with GPS receiver of the high sampling rate and suitable data processing method, the vibration characteristics of the bridge structure can be determined with high accuracy.

  20. Nondestructive Evaluation of Railway Bridge by System Identification Using Field Vibration Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Duc Duy; Hong, Dong Soo; Kim, Jeong Tae [Pukyong National University, Busan (Korea, Republic of)

    2010-12-15

    This paper presents a nondestructive evaluation approach for system identification (SID) of real railway bridges using field vibration test results. First, a multi-phase SID scheme designed on the basis of eigenvalue sensitivity concept is presented. Next, the proposed multi-phase approach is evaluated from field vibration tests on a real railway bridge (Wondongcheon bridge) located in Yangsan, Korea. On the steel girder bridge, a few natural frequencies and mode shapes are experimentally measured under the ambient vibration condition. The corresponding modal parameters are numerically calculated from a three-dimensional finite element (FE) model established for the target bridge. Eigenvalue sensitivities are analyzed for potential model-updating parameters of the FE model. Then, structural subsystems are identified phase-by-phase using the proposed model-updating procedure. Based on model-updating results, a baseline model and a nondestructive evaluation of test bridge are identified

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

    Directory of Open Access Journals (Sweden)

    B. Asgari

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    OpenAIRE

    Ali Akbar Ramezanianpour; Seyyed Alireza Tabatabaei; Mahyar Pourlak; Majid Abareshi

    2016-01-01

    The selection of “Structural system” is one of the most important factors in any bridge and infrastructure design. Designers perform the structural calculations for the project determines the priorities as well as design and performance criteria. Further analysis of the structural selection problem and the identification of the bridge desirable capabilities, triggered the consideration of analytic hierarchy process (AHP) as a possible basis for the decision making. The methodology uses the VI...

  4. Design plan and checking calculation for the reinforcement of prestressed continuous box girder bridges%预应力连续箱梁桥加固设计及验算

    Institute of Scientific and Technical Information of China (English)

    张胜

    2016-01-01

    某预应力连续箱梁桥运营15年后,箱梁内外出现了较多的裂缝、钢筋锈蚀和台后填土沉降等病害,已影响桥梁结构的正常使用和安全。根据该桥的质量检测报告,提出了箱梁顶板采用增厚钢筋混凝土、箱室顶板内表面采用粘贴钢板和碳纤维相结合以及箱梁腹板粘贴钢板的加固方法。通过理论计算和荷载试验对加固后的桥梁承载力进行了验算和检测,结果表明,结构承载力和刚度都有明显地提高,能保证桥梁的正常使用。%A prestressed continuous box girder bridge appeared various diseases in fifteen years, for instance, cracks of the inside and outside surface of the box girder, steel corrosion and the obvious settlement of filling at back abutment. The disease has affected the normal use and safety of the bridge structure. Based on the testing reports of the bridge, a feasible strengthening method is put forward: The roof of box girder is strengthened by the thick reinforced concrete;The top plate of the box is strengthened by steel plate and carbon fiber, and box girder webs is strengthened by steel plate. The carrying capacity of the reinforced bridge is checked by the theoretical calculation and the load test. The results show that the bearing capacity and stiffness of the structure are obviously improved and can meet the requirements of normal use.

  5. Design Argumentation in Academic Design Education

    DEFF Research Database (Denmark)

    Dalsgaard, Peter; Dindler, Christian; Fritsch, Jonas

    2013-01-01

    We explore design argumentation as a resource when teaching interaction design in a university setting. We propose that design argumentation can help bridge between practice-based design education and theoretical issues from university curricula. In this paper, we outline the idea of design argum...

  6. The Akashi Kaikyo Bridge and the Storebælt Bridge

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1999-01-01

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

  7. Steel structure (bridge and building); Doboku/kenchiku bun`ya ni okeru yosetsu gijutsu no tenkai

    Energy Technology Data Exchange (ETDEWEB)

    Fukazawa, M. [Yokogawa Bridge Corp., Tokyo (Japan)

    1996-01-05

    In this article, the trends of welding engineering are discussed in two groups, namely bridges and steel frames. First of all, in the field of bridges, as the themes of technical innovation of steel bridges, the challenge to build long span bridges, coping with new structural forms, and rationalization of general bridges are selected. Concerning very long bridges, considerable elongation of its spans and technological development for materials, design, construction and erection relating to improvement of profitability become inevitable. Besides, in addition to the functions of bridges, the bridges playing the roles of environmental and/or artistic structures become many, thereby the cases of using welding for the site joints increase. As the measure for rationalize bridge construction, it is to reduce steel weight and working costs for increasing profitability, and the progress of welding technology therefor has been observed. With regard to the manufacture of bridge portions in a factory, labor saving, automatization and robotization of in-house welding have been made, and bridge maintenance as well as pursuance of attaining the state of maintenance free are also important. The trend that the bridge load is becoming larger and enhancement of earthquake resistance are also important. Regarding steel frames, functionalization of steel, making steel very thick, various automatization of manufacturing, and pursuance of earthquake resistant safety are being made. 14 refs., 7 figs.

  8. 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.

  9. 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...

  10. Analysis of Common Aerodynamic Measures for Wind Resistant Design of Long Span Bridges%大跨度桥梁抗风设计常用气动措施分析

    Institute of Scientific and Technical Information of China (English)

    胡长灿; 詹昊

    2015-01-01

    为提高大跨度桥梁的抗风性能,对该类桥梁抑制涡激共振和提高颤振稳定性的常用气动措施及其机理进行初步分析。桥梁涡激共振和颤振稳定性与旋涡的产生和漂移有关,因此气动优化的一般原则是改善结构迎风面和背风面的气动外形以延缓或避免流动分离、减小分离涡尺度、阻碍旋涡漂移路径。抑制桥梁涡激振动一般采用设置倒角、安装风嘴和优化风嘴形状、安装导流板等气动措施;提高桥梁颤振稳定性一般采用安装风嘴和优化风嘴形状、安装稳定板和气动翼板等气动措施。研究表明采用气动措施后,大跨度桥梁的气动性能得到改善。%To improve the wind resistant performance of long span bridges ,the common aero‐dynamic measures and their mechanism for suppressing the vortex‐induced resonance and for im‐proving the flutter stability of the bridges are preliminarily analyzed .Since the vortex‐induced res‐onance and flutter stability of the bridges are correlated with the vortex generation and vortex drift ,the general principle of optimizing the aerodynamic measures is to improve the windward and leeward structural aerodynamic profiles in order to delay or avoid the flow separation ,reduce the separated vortex scales and impede the vortex drift paths .As regards the aerodynamic measures for suppressing the vortex‐induced vibration of the bridges ,the rounded corners and wind fairings are generally installed ,the shapes of the wind fairings are optimized and the guide vanes are in‐stalled while as regards the measures for improving the flutter stability ,the wind fairings are gen‐erally installed ,the shapes of the wind fairings are optimized and the stabilizers and aerodynamic wing plates are installed .Researches indicate that the aerodynamic performance of the long span bridges can be improved after these measures have been taken .

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

    Science.gov (United States)

    Hodgson, Justin

    2009-01-01

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

  12. Excitation energy transfer in donor-bridge-acceptor systems.

    Science.gov (United States)

    Albinsson, Bo; Mårtensson, Jerker

    2010-07-21

    This perspective will focus on the mechanistic aspects of singlet and triplet excitation energy transfer. Well defined donor-bridge-acceptor systems specifically designed for investigating the distance and energy gap dependencies of the energy transfer reactions are discussed along with some recent developments in computational modeling of the electronic coupling.

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

    Directory of Open Access Journals (Sweden)

    Ali Akbar Ramezanianpour

    2016-10-01

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

  14. Study of the aerostatic and aerodynamic stability of super long-span cable-stayed bridges

    Institute of Scientific and Technical Information of China (English)

    Zhang Xinjun; Sun Hailing

    2014-01-01

    With the increase of span length,the bridge tends to be more flexible,and the wind stability be-comes an important problem for the design and construction of super long-span cable-stayed bridges. By taking a super long-span cable-stayed bridge with a main span of 1 400 m as example,the aerostatic and aerodynamic stability of the bridge are investigated by three-dimensional nonlinear aerostatic and aerodynamic stability analy-sis,and the results are compared with those of a suspension bridge with a main span of 1 385 m,and from the aspect of wind stability,the feasibility of using cable-stayed bridge in super long-span bridge with a main span above 1 000 m is discussed. In addition,the influences of design parameters including the depth and width of the girder,the tower structure,the tower height-to-span ratio,the side-to-main span ratio,the auxiliary piers in the side span and the anchorage system of stay cables,etc on the aerostatic and aerodynamic stability of su-per long-span cable-stayed bridges are investigated numerically;the key design parameters are pointed out,and also their reasonable values are proposed.

  15. An Expert System for Concrete Bridge Management

    DEFF Research Database (Denmark)

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

    1997-01-01

    management systems are presently being implemented by bridge authorities in several countries. The prototype of an expert system for concrete bridge management is presented in this paper, with its functionality relying on two modules. The inspection module relies on a periodic acquisition of field......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...

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

    CERN Document Server

    Moffett, Jack

    2014-01-01

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

  17. Study of displacements of a bridge abutment using FEM

    Directory of Open Access Journals (Sweden)

    Wymysłowski Michał

    2016-06-01

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

  18. 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.

  19. Balanced bridge feedback control system

    Science.gov (United States)

    Lurie, Boris J. (Inventor)

    1990-01-01

    In a system having a driver, a motor, and a mechanical plant, a multiloop feedback control apparatus for controlling the movement and/or positioning of a mechanical plant, the control apparatus has a first local bridge feedback loop for feeding back a signal representative of a selected ratio of voltage and current at the output driver, and a second bridge feedback loop for feeding back a signal representative of a selected ratio of force and velocity at the output of the motor. The control apparatus may further include an outer loop for feeding back a signal representing the angular velocity and/or position of the mechanical plant.

  20. 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.

  1. Geometry control of long-span continuous girder concrete bridge during construction through finite element model updating

    Science.gov (United States)

    Wu, Jie; Yan, Quan-sheng; Li, Jian; Hu, Min-yi

    2016-04-01

    In bridge construction, geometry control is critical to ensure that the final constructed bridge has the consistent shape as design. A common method is by predicting the deflections of the bridge during each construction phase through the associated finite element models. Therefore, the cambers of the bridge during different construction phases can be determined beforehand. These finite element models are mostly based on the design drawings and nominal material properties. However, the accuracy of these bridge models can be large due to significant uncertainties of the actual properties of the materials used in construction. Therefore, the predicted cambers may not be accurate to ensure agreement of bridge geometry with design, especially for long-span bridges. In this paper, an improved geometry control method is described, which incorporates finite element (FE) model updating during the construction process based on measured bridge deflections. A method based on the Kriging model and Latin hypercube sampling is proposed to perform the FE model updating due to its simplicity and efficiency. The proposed method has been applied to a long-span continuous girder concrete bridge during its construction. Results show that the method is effective in reducing construction error and ensuring the accuracy of the geometry of the final constructed bridge.

  2. Simple Evaluation of Load-Carrying Capacity of Multi-Span Folding Bridges based on Floating Supports

    Directory of Open Access Journals (Sweden)

    Jan Marszałek

    2014-12-01

    Full Text Available [b]Abstract[/b]. The papers covers simple evaluation of load-carrying capacity of multi-span folding bridges based on floating supports. Combined bridges built in this approach, could be used as a temporary crossing. The methodology of this evaluation is shown graphically on the basis of designed nomograms for two existing bridge structures i.e. MS-54 and DMS-65, mounted on rigid and floating supports. These nomograms facilitate the simple and fast determination of the impact of changing fixed support into floating support with different bridge length spans on the carrying capacity of the bridge. The paper also presents the influence of long-term use (enlarging the mounting backlash in the joints of these structures on the carrying capacity of the bridge.[b]Keywords[/b]: building, folding bridges, nomograms, assembly clearances

  3. Scale-Bridging Model Development for Coal Particle Devolatilization

    CERN Document Server

    Schroeder, Benjamin B; Smith, Philip J; Fletcher, Thomas H; Packard, Andrew; Frenklach, Michael; Hegde, Arun; Li, Wenyu; Oreluk, James

    2016-01-01

    When performing large-scale, high-performance computations of multi-physics applications, it is common to limit the complexity of physics sub-models comprising the simulation. For a hierarchical system of coal boiler simulations a scale-bridging model is constructed to capture characteristics appropriate for the application-scale from a detailed coal devolatilization model. Such scale-bridging allows full descriptions of scale-applicable physics, while functioning at reasonable computational costs. This study presents a variation on multi-fidelity modeling with a detailed physics model, the chemical percolation devolatilization model, being used to calibrate a scale-briding model for the application of interest. The application space provides essential context for designing the scale-bridging model by defining scales, determining requirements and weighting desired characteristics. A single kinetic reaction equation with functional yield model and distributed activation energy is implemented to act as the scal...

  4. Animal experiments with the microelectronics neural bridge IC.

    Science.gov (United States)

    Li, Wenyuan; Pei, Fei; Wang, Zhigong; Lü, Xiaoying

    2012-01-01

    The combination of the neural science and the microelectronics science offers a new way to restore the function of central nervous system. A neural regeneration module is used to be implanted into body to bridge the damaged nerve. A microelectronics neural bridge IC designed in CSMC 0.5□m CMOS process which can detect the neural signal and stimulate the nerve is presented. The neural regeneration module is composed of the microelectronics neural bridge IC and some discrete devices. An animal experiment has been done to check whether the neural signal can be transmitted with the chip normally or not. The animal experiment results suggest that the neural regeneration module can make the neural signal transmit normally.

  5. Fatigue in Steel Highway Bridges under Random Loading

    DEFF Research Database (Denmark)

    Agerskov, Henning; Nielsen, Jette Andkjær

    1999-01-01

    Fatigue damage accumulation in steel highway bridges under random loading is studied. The fatigue life of welded joints has been determined both experimentally and from a fracture mechanics analysis. In the experimental part of the investigation, fatigue test series on welded plate test specimens...... correspond to one week's traffic loading, determined by means of strain gauge measurements on the orthotropic steel deck structure of the Faro Bridges in Denmark. The test series carried through show a significant difference between constant amplitude and variable amplitude fatigue test results. Both...... the fracture mechanics analysis and the fatigue test results indicate that Miner's rule, which is normally used in the design against fatigue in steel bridges, may give results that are unconservative. The validity. of the results obtained from Miner's rule will depend on the distribution of the load history...

  6. Fatigue in Steel Highway Bridges under Random Loading

    DEFF Research Database (Denmark)

    Agerskov, Henning; Nielsen, J.A.; Vejrum, Tina

    1997-01-01

    In the present investigation, fatigue damage accumulation in steel highway bridges under random loading is studied. The fatigue life of welded joints has been determined both experimentally and from a fracture mechanics analysis.In the experimental part of the investigation, fatigue test series...... to one week's traffic loading, determined by means of strain gage measurements on the orthotropic steel deck structure of the Farø Bridges in Denmark.The test series which have been carried through show a significant difference between constant amplitude and variable amplitude fatigue test results. Both...... the fatigue test results and the fracture mechanics analysis indicate that the linear fatigue damage accumulation formula, which is normally used in the design against fatigue in steel bridges, may give results, which are unconservative. The validity of the results obtained from the linear fatigue damage...

  7. The Damage Effects in Steel Bridges under Highway Random Loading

    DEFF Research Database (Denmark)

    Agerskov, Henning; Nielsen, Jette Andkjær

    1996-01-01

    In the present investigation, fatigue damage accumulation in steel bridges under highway random loading is studied. In the experimental part of the investigation, fatigue test series on welded plate test specimens have been carried through. The fatigue tests have been carried out using load...... histories, which correspond to one week's traffic loading, determined by means of strain gage measurements on the orthotropic steel deck structure of the Farø Bridges in Denmark. Both the results that have been obtained in the test series carried through and the results of fracture mechanics analysis...... indicate that the linear fatigue damage accumulation formula, which is normally used in the design against fatigue in steel bridges, may give results, which are unconservative....

  8. Seismic Retrofitting of an Existing Steel Railway Bridge by Fluid Viscous Dampers

    Science.gov (United States)

    Gangopadhyay, Avijit; Ghosh, Aparna Dey

    2016-06-01

    There are over a lakh of bridges in the Indian Railways, many of which have become seismically deficient, either through aging or due to inadequate seismic design considerations. The extensive damage of bridges all over the world in recent earthquakes has propelled significant advancement in earthquake protection and retrofitting of bridges. Amongst various passive control systems that are reliable as well as cost-effective, Fluid Viscous Dampers (FVDs) are proving to be successful in bridge vibration control. Orificed FVDs, commercially available as Taylor Devices, have already been successfully installed in several bridges worldwide. However, there has been no such application or study related to Indian railway bridges. In this paper, an existing thirty years' old railway bridge in Jharkhand, India, has been analyzed in SAP2000v14 considering reduced stiffness and found deficient when subjected to spectrum-compatible accelerograms. Subsequent retrofitting of the bridge superstructure with FVDs has been carried out and the results indicate substantial reductions in the responses of the bridge deck.

  9. Seismic Retrofitting of an Existing Steel Railway Bridge by Fluid Viscous Dampers

    Science.gov (United States)

    Gangopadhyay, Avijit; Ghosh, Aparna Dey

    2016-09-01

    There are over a lakh of bridges in the Indian Railways, many of which have become seismically deficient, either through aging or due to inadequate seismic design considerations. The extensive damage of bridges all over the world in recent earthquakes has propelled significant advancement in earthquake protection and retrofitting of bridges. Amongst various passive control systems that are reliable as well as cost-effective, Fluid Viscous Dampers (FVDs) are proving to be successful in bridge vibration control. Orificed FVDs, commercially available as Taylor Devices, have already been successfully installed in several bridges worldwide. However, there has been no such application or study related to Indian railway bridges. In this paper, an existing thirty years' old railway bridge in Jharkhand, India, has been analyzed in SAP2000v14 considering reduced stiffness and found deficient when subjected to spectrum-compatible accelerograms. Subsequent retrofitting of the bridge superstructure with FVDs has been carried out and the results indicate substantial reductions in the responses of the bridge deck.

  10. Bridges and Equipment

    Science.gov (United States)

    2009-09-15

    2-80010 and 2-2-80111. These measurements should be accomplished in each system stowage and transport configuration (truck, trailer, and pallet...required embankment conditions including level, longitudinal/side slope, racked , and bank height differential requirements. Each designated crossing...paragraphs or tables. 4.13 Transportability . 4.13.1 Method . a. As listed in TOP 1-2-50023, plan to test all of the system stowage and

  11. Preliminary study to facilitate smart structure systems in bridge girders

    Science.gov (United States)

    Kirkpatrick, Thomas C.; Peterson, Danford O.; Rossi, Peter J.; Ray, Laura R.; Livingston, Richard A.

    1999-05-01

    Sensors are currently available and used to monitor structural performance and loads incurred by bridges already in service. However, there has been limited research concerning the stresses that steel bridge girders endure during transport from the manufacturer to the job site and during the installation process. This paper reports the measured stresses on steel bridge girders during transportation from Lancaster, PA to Hanover, NH and during construction of the Ledyard Bridge on the New Hampshire - Vermont border. Two different monitoring system were developed for this data acquisition in a mobile environment. The first, a fiber optic strain monitoring system, utilizing Bragg grating technology. The second utilized an electrical- resistive foil strain gage network, in conjunction with wireless telemetry equipment. Together, these two systems formed a smart structure system for monitoring bridge girders while confirming the accuracy of data gathered through redundancy. Result conclusively demonstrated for the first time, that stresses in beams during transportation are significant and approach the factor of safety margin in girder design.

  12. Ground-penetrating radar: A tool for monitoring bridge scour

    Science.gov (United States)

    Anderson, N.L.; Ismael, A.M.; Thitimakorn, T.

    2007-01-01

    Ground-penetrating radar (GPR) data were acquired across shallow streams and/or drainage ditches at 10 bridge sites in Missouri by maneuvering the antennae across the surface of the water and riverbank from the bridge deck, manually or by boat. The acquired two-dimensional and three-dimensional data sets accurately image the channel bottom, demonstrating that the GPR tool can be used to estimate and/or monitor water depths in shallow fluvial environments. The study results demonstrate that the GPR tool is a safe and effective tool for measuring and/or monitoring scour in proximity to bridges. The technique can be used to safely monitor scour at assigned time intervals during peak flood stages, thereby enabling owners to take preventative action prior to potential failure. The GPR tool can also be used to investigate depositional and erosional patterns over time, thereby elucidating these processes on a local scale. In certain instances, in-filled scour features can also be imaged and mapped. This information may be critically important to those engaged in bridge design. GPR has advantages over other tools commonly employed for monitoring bridge scour (reflection seismic profiling, echo sounding, and electrical conductivity probing). The tool doesn't need to be coupled to the water, can be moved rapidly across (or above) the surface of a stream, and provides an accurate depth-structure model of the channel bottom and subchannel bottom sediments. The GPR profiles can be extended across emerged sand bars or onto the shore.

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

    Directory of Open Access Journals (Sweden)

    E. Tubaldi

    2015-01-01

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

  14. Design and Analysis of Main Saddle Structure for Self-anchored Suspension Bridge with Spatial Cables%空间缆索悬索桥主鞍座结构设计与分析

    Institute of Scientific and Technical Information of China (English)

    李建慧; 李爱群; 袁辉辉; 李喜平

    2009-01-01

    以南京江心洲大桥为工程背景,对空间缆索自锚式悬索桥主鞍座的相关问题进行研究.以大型通用有限元程序为平台,采用二次开发技术,建立精细化有限元模型,在此基础上采用合理的加载模式对其进行空间受力分析,并阐述与空间主鞍座相匹配的主缆切点简化修正方法.结果表明:空间主缆在成桥状态对主鞍座横向力的作用会造成鞍槽外侧壁应力大于内侧壁的应力;主缆横向体积力会对主鞍座压紧装置和鞍体产生梯度分布的竖向挤压力;自锚式悬索桥体系转换过程中缆索的几何非线性效应显著,体现在空缆到成桥状态主缆与主鞍座空间切点位置会有较大的变化.%Based on the Jianxinzhou Bridge in Nanjing, the issues related to the main saddle of the serf-anchored suspension bridge with spatial cables were studied. Refinement finite element model was established with secondary development technology based on the platform of general finite element program, reasonable load pattern was used for its spatial mechanical analysis, and the spatial main cable tangenty point correction method which matched with the main saddle was also discussed. The result shows that (1) external lateral wall stress of saddle groove is higher than the internal wall stress because of the role of lateral force from the main cable in the ~mished bridge state; (2) horizontal volume force of the main cable can generate a gradient distribution of vertical extrusion pressure on the saddle clamping device and the main saddle body; (3) the geometric nonlinear effect of self-anchored suspension bridge cable system in the constroction process is significant, which reflects from that the spatial tangent point position of main cable with main saddle changes a lot from free cable to finished cable state.

  15. Centrifuge modeling of rocking-isolated inelastic RC bridge piers

    OpenAIRE

    Loli, Marianna; Knappett, Jonathan A; Brown, Michael J.; Anastasopoulos, Ioannis; GAZETAS, George

    2014-01-01

    Experimental proof is provided of an unconventional seismic design concept, which is based on deliberately underdesigning shallow foundations to promote intense rocking oscillations and thereby to dramatically improve the seismic resilience of structures. Termed rocking isolation, this new seismic design philosophy is investigated through a series of dynamic centrifuge experiments on properly scaled models of a modern reinforced concrete (RC) bridge pier. The experimental method reproduces th...

  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. Noise Considerations in Resistance Bridges

    DEFF Research Database (Denmark)

    Diamond, Joseph M.

    1963-01-01

    A signal-to-noise analysis is made of the Wheatstone bridge, where the unknown and standard resistors may be at different temperatures, a situation which occurs in resistance thermometry. The limiting condition is assumed to be dissipation in the unknown resistor. It is shown that the ratio arms ...

  18. Parametric Study on Dynamic Response of Fiber Reinforced Polymer Composite Bridges

    Directory of Open Access Journals (Sweden)

    Woraphot Prachasaree

    2015-01-01

    Full Text Available Because of high strength and stiffness to low self-weight ratio and ease of field installation, fiber reinforced polymer (FRP composite materials are gaining popularity as the materials of choice to replace deteriorated concrete bridge decks. FRP bridge deck systems with lower damping compared to conventional bridge decks can lead to higher amplitudes of vibration causing dynamically active bridge deck leading serviceability problems. The FRP bridge models with different bridge configurations and loading patterns were simulated using finite element method. The dynamic response results under varying FRP deck system parameters were discussed and compared with standard specifications of bridge deck designs under dynamic loads. In addition, the dynamic load allowance equation as a function of natural frequency, span length, and vehicle speed was proposed in this study. The proposed dynamic load allowance related to the first flexural frequency was presented herein. The upper and lower bounds’ limits were established to provide design guidance in selecting suitable dynamic load allowance for FRP bridge systems.

  19. A Train-Bridge Dynamic Interaction Analysis Method and Its Experimental Validation

    Directory of Open Access Journals (Sweden)

    Nan Zhang

    2016-12-01

    Full Text Available The train-bridge dynamic interaction problem began with the development of railway technology, and requires an evaluation method for bridge design in order to ensure the safety and stability of the bridge and the running train. This problem is studied using theoretical analysis, numerical simulation, and experimental study. In the train-bridge dynamic interaction system proposed in this paper, the train vehicle model is established by the rigid-body dynamics method, the bridge model is established by the finite element method, and the wheel/rail vertical and lateral interaction are simulated by the corresponding assumption and the Kalker linear creep theory, respectively. Track irregularity, structure deformation, wind load, collision load, structural damage, foundation scouring, and earthquake action are regarded as the excitation for the system. The train-bridge dynamic interaction system is solved by inter-history iteration. A case study of the dynamic response of a CRH380BL high-speed train running through a standard-design bridge in China is discussed. The dynamic responses of the vehicle and of the bridge subsystems are obtained for speeds ranging from 200 km·h−1 to 400 km·h−1, and the vibration mechanism are analyzed.

  20. 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.

  1. 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 Strömsund Bridge (from 1955) to 890 m in the Tatara Bridge (from 1999)....

  2. Building Bridges One Line at a Time

    Science.gov (United States)

    Grigsby, Cathy Murray

    2012-01-01

    In this article, first-grade students were taught the different kinds of lines that were part of the construction of various bridges--the curved lines of the arches of stone bridges, straight lines connecting the cables of a suspension bridge, vertical lines, horizontal lines, and so on. They gained practice in drawing structures and in fine brush…

  3. Design

    DEFF Research Database (Denmark)

    Volf, Mette

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

  4. Earthquake Response Analysis of Approach Bridge of Suramadu Sea-Crossing Bridge%苏拉马都大桥引桥抗震分析

    Institute of Scientific and Technical Information of China (English)

    郭河; 范轶峰

    2011-01-01

    苏拉马都大桥是印度尼西哑的一座特大型桥梁,其引桥为预应力混凝土连续箱梁结构,通过V形墩与主桥相连.由于桥址处抗震设防烈度较高,又是跨越马都拉海峡的特大型桥梁,其抗震性能尤为重要.采用两水平的抗震设计方法,从地震输入、地震反应谱分析、非线性时程分析、结构的抗震性能验算等方面对苏拉马都大桥引桥的抗震性能进行分析,结果表明,在2 500年1重现期的地震作用下,该桥的抗震性能均满足抗震设防要求.%Surammadu Bridge is an especially large bridge in Indonesia. Its structure style is prestressed concrete continuous box bridge and links with the main bridge by V-style pier. The seismic performance of Suramadu Bridge is particularly important because of the bridge across the Madula Strait and the high seismic intensity at the bridge site. In this paper, based on the antiseismic design of Suramadu Approach Bridge, seismic behavior of cable-stayed bridge is investigated by two-level earthquake-resistance method from the seismic input, the analysis of earthquake response spectrum, the analysis of nonlinear time history and the checking of structural earthquake-resistance performance. It is indicated that, the resistance of Suramadu Approach Bridge is larger than the requirement under the 2 500-year recurrence interval (2% in 50year) earthquake load.

  5. Beginning Course Surveys: Bridges for Knowing and Bridges for Being

    Directory of Open Access Journals (Sweden)

    David Starr-Glass

    2011-06-01

    Full Text Available The use of a participant survey, administered at the outset of an online course, can provide information useful in the management of the learning environment and in its subsequent redesign. Such information can clarify participants’ prior experience, expectations, and demographics. But the very act of enquiring about the learner also signals the instructor’s social presence, relational interest, and desire to enter into an authentic dialogue. This study examines the use of participant surveys in online management courses. The first section discusses the informational bridges that this instrument provides. The second section considers survey responses to open-ended questions dealing with student sentiments. This analysis suggests that the survey plays a valuable part in accentuating social presence and in initiating relational bridges with participants.

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

    Directory of Open Access Journals (Sweden)

    A. A. Lapko

    2008-01-01

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

  7. 33 CFR 115.70 - Advance approval of bridges.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Advance approval of bridges. 115... BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.70 Advance approval of bridges. (a) The General Bridge Act of 1946 requires the approval of the location and plans of bridges...

  8. Performance analysis of LAN bridges and routers

    Science.gov (United States)

    Hajare, Ankur R.

    1991-01-01

    Bridges and routers are used to interconnect Local Area Networks (LANs). The performance of these devices is important since they can become bottlenecks in large multi-segment networks. Performance metrics and test methodology for bridges and routers were not standardized. Performance data reported by vendors is not applicable to the actual scenarios encountered in an operational network. However, vendor-provided data can be used to calibrate models of bridges and routers that, along with other models, yield performance data for a network. Several tools are available for modeling bridges and routers - Network II.5 was used. The results of the analysis of some bridges and routers are presented.

  9. Theoretical and experimental study on shear lag effect of partially cable-stayed bridge

    Institute of Scientific and Technical Information of China (English)

    WU Gao-feng; XU Hong

    2005-01-01

    In order to resolve the traffic congestion problem, many cable-stayed bridges are designed with a large width to span ratio. This results in significant shear lag effect to cause nonuniform stress distribution along the flanges of the beam of bridge.This paper reports study on the shear lag effect of the Lanzhou Xiaoxihu Yellow River Bridge. A 3D finite element model of the bridge was developed and finite element analysis (FEA) was done to obtain the theoretical results. To evaluate the theoretical results, a scaled model was made to conduct static test in laboratory. The experiment results accorded with the results obtained by FEA. It is proved that FEA is an effective method to predict shear lag effect of bridges of this type.

  10. Dynamic Behavior of Tied-Arch Bridges under the Action of Moving Loads

    Directory of Open Access Journals (Sweden)

    Paolo Lonetti

    2016-01-01

    Full Text Available The dynamic behavior of tied-arch bridges under the action of moving load is investigated. The main aim of the paper is to quantify, numerically, dynamic amplification factors of typical kinematic and stress design variables by means of a parametric study developed in terms of the structural characteristics of the bridge and moving loads. The basic formulation is developed by using a finite element approach, in which refined schematization is adopted to analyze the interaction between the bridge structure and moving loads. Moreover, in order to evaluate, numerically, the influence of coupling effects between bridge deformations and moving loads, the analysis focuses attention on usually neglected nonstandard terms in the inertial forces concerning both centripetal acceleration and Coriolis acceleration. Sensitivity analyses are proposed in terms of dynamic impact factors, in which the effects produced by the external mass of the moving system on the dynamic bridge behavior are evaluated.

  11. Dynamic test and finite element model updating of bridge structures based on ambient vibration

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The dynamic characteristics of bridge structures are the basis of structural dynamic response and seismic analysis,and are also an important target of health condition monitoring.In this paper,a three-dimensional finite-element model is first established for a highway bridge over a railroad on No.312 National Highway.Based on design drawings,the dynamic characteristics of the bridge are studied using finite element analysis and ambient vibration measurements.Thus,a set of data is selected based on sensitivity analysis and optimization theory;the finite element model of the bridge is updated.The numerical and experimental results show that the updated method is more simple and effective,the updated finite element model can reflect the dynamic characteristics of the bridge better,and it can be used to predict the dynamic response under complex external forces.It is also helpful for further damage identification and health condition monitoring.

  12. Creep and shrinkage effects on integral abutment bridges

    Science.gov (United States)

    Munuswamy, Sivakumar

    Integral abutment bridges provide bridge engineers an economical design alternative to traditional bridges with expansion joints owing to the benefits, arising from elimination of expensive joints installation and reduced maintenance cost. The superstructure for integral abutment bridges is cast integrally with abutments. Time-dependent effects of creep, shrinkage of concrete, relaxation of prestressing steel, temperature gradient, restraints provided by abutment foundation and backfill and statical indeterminacy of the structure introduce time-dependent variations in the redundant forces. An analytical model and numerical procedure to predict instantaneous linear behavior and non-linear time dependent long-term behavior of continuous composite superstructure are developed in which the redundant forces in the integral abutment bridges are derived considering the time-dependent effects. The redistributions of moments due to time-dependent effects have been considered in the analysis. The analysis includes nonlinearity due to cracking of the concrete, as well as the time-dependent deformations. American Concrete Institute (ACI) and American Association of State Highway and Transportation Officials (AASHTO) models for creep and shrinkage are considered in modeling the time dependent material behavior. The variations in the material property of the cross-section corresponding to the constituent materials are incorporated and age-adjusted effective modulus method with relaxation procedure is followed to include the creep behavior of concrete. The partial restraint provided by the abutment-pile-soil system is modeled using discrete spring stiffness as translational and rotational degrees of freedom. Numerical simulation of the behavior is carried out on continuous composite integral abutment bridges and the deformations and stresses due to time-dependent effects due to typical sustained loads are computed. The results from the analytical model are compared with the

  13. Real-Time Seismic Monitoring of Thenewcape Girardeau (mo) Bridge and Recorded Earthquake Response

    Science.gov (United States)

    çelebi, Mehmet

    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. Design of the bridge accounted for the possibility of a strong earthquake (magnitude 7.5 or greater) during the design life of the bridge. The monitoring network consists of a superstructure and two free-field arrays and comprises a total of 84 channels of accelerometers deployed on the superstructure, pier foundations and free-field in the vicinity of the bridge. The paper also introduces the high quality response data obtained from the network. Such data is aimed to be used by the owner, researchers and engineers to (1) assess the performance of the bridge, (2) check design parameters, including the comparison of dynamic characteristics with actual response, and (3) better design future similar bridges. Preliminary analyses of low-amplitude ambient vibration data and that from a small earthquake reveal specific response characteristics of this new bridge and the free-field in its proximity. There is coherent tower-cabledeck interaction that sometimes results in amplified ambient motions. Also, while the motions at the lowest (tri-axial) downhole accelerometers on both MO and IL sides are practically free-from any feedback from the bridge, the motions at the middle downhole and surface accelerometers are significantly influenced by amplified ambient motions of the bridge.

  14. NASDS- NASTRAN/DISCOS/SAMSAN DMAP BRIDGING PROGRAM

    Science.gov (United States)

    Frisch, H. P.

    1994-01-01

    The design of a controller for a flexible structure requires an ability to obtain flexible body data in a format compatible with design and performance evaluation methods. The control designer may have to work with several different programs to obtain all the data and capabilities he needs. The NASTRAN/DISCOS/SAMSAN bridging program and its associated data file processor provide the flexible structure control designer with a means of tying together the following programs: 1) the NASA Structural Analysis (NASTRAN) system which provides general finite element and matrix manipulation capabilities for the analysis of structures, 2) the Dynamic Interaction Simulation of Controls and Structure (DISCOS) program which provides for the time and frequency domain analysis of any dynamic system that can be modeled as a system of interconnected rigid and flexible bodies, and 3) the SAMSAN library which provides a self-consistent set of algorithms for the support of large-order controls system design and evaluation studies with an emphasis on sampled system analysis. The NASTRAN/DISCOS/SAMSAN bridging program allows the engineer to integrate these three programs into a complete package for the design and analysis of flexible structure controllers. The NASTRAN/DISCOS/SAMSAN bridging program and its associated data file processor may be used to obtain all of the data necessary for defining a flexible body to DISCOS or to any program developed using the SAMSAN library. The bridging program consists of a NASTRAN DMAP sequence which may be used to obtain a variety of different types of modal data including standard, Craig-Bampton, augmented body, and boundary compliance. The user may also request the generation of the following: mass, stiffness, damping, and constraint matrices; data for fine to coarse mesh mass distribution interpolation programs; modal damping, modal observability/ controllability matrices; coarse or fine mesh modal data; and an assortment of matrices useful for

  15. Problems associated with nondestructive evaluation of bridges

    Science.gov (United States)

    Prine, David W.

    1995-05-01

    The US has 542,000 bridges that consume billions of dollars per year in construction, rehabilitation, and maintenance funds and which are the lifelines of US commerce. The 1992 ISTEA (Intermodal Surface Transportation Efficiency Act) mandates the implementation of a quantitative computerized bridge management system by 1996. A prime need of such a system are quantitative bridge inspection methods to feed accurate reliable condition information to the huge database of bridges. Nondestructive evaluation (NDE) will fill a critical need in the implementation of effective bridge management. However, many serious barriers exist to the widespread routine application of this technology to bridges. This paper provides an overview of the typical problems associated with applying NDE to bridges.

  16. Comparison and blend of architectural aesthetics--An art design exploration on the“Bridge School”in Pinghe, Zhangzhou%建筑美学中的对比交融--漳州平和“桥上书屋”艺术设计的探索

    Institute of Scientific and Technical Information of China (English)

    侯郑昕

    2014-01-01

    In Qiling village, Pinghe country, Zhanghou, the“Bridge School”, a Hope Primary School built on a bridge , has won several world-class awards. The structure is modest, it has some original achievements on the design thinking, architectural aesthetics and material decoration. It combines technology and art in one, by using the comparison and blend of artistic expression in the form and structure, building color and so on, to produce a unique effect.%多次获世界级大奖的漳州平和崎岭乡的“桥上书屋”,是一所建在桥上希望小学。建筑本体虽然不大,但其在设计思考、建筑美学和材料装饰的运用上,均有新颖的建树。它融技术和艺术于一体,在形体结构、建材色彩等方面采用对比交融的艺术表现手法,产生出独特效果。

  17. DNA-bridged Chiroplasmonic Assemblies of Nanoparticles

    Science.gov (United States)

    Kotov, Nicholas

    2015-03-01

    Chirality at nanoscale attracts a lot of attention during the last decade. A number of chiral nanoscale systems had been discovered ranging from individual nanoparticles to helical nanowires and from lithographically defined substrates. DNA bridges make possible in-silico engineering and practical construction of complex assemblies of nanoparticles with of both plasmonic and excitonic nature. In this presentation, expected and unexpected optical effects that we observed in chiral plasmonic and excitonic systems will be demonstrated. Special effort will be placed on the transitioning of theoretical and experimental knowledge about chiral nanoscale systems to applications. The most obvious direction for practical targets was so far, the design of metamaterials for negative refractive index optics. The results describing the 3D materials with the highest experimentally observed chiral anisotropy factor will be presented. It will be followed by the discussion of the recent developments in analytical application of chiral assemblies for detection of cancer and bacterial contamination.

  18. Research on Cascaded H-bridge SVG

    Directory of Open Access Journals (Sweden)

    Yannan Yu

    2014-07-01

    Full Text Available Due to the sharp increase of the non-linear loads, the power quality lagged behind the need for an adequate power system. With a fast response, low loss, low output harmonic current, SVG has become the mainstream of dynamic reactive power compensation devices. The paper introduces a multilevel cascaded H-bridge SVG, featured with DSP+FPGA dual-core control unit and fault-tolerant redundant system, which will enhance the reliability and dynamic response, reduce the switching loss and equipment cost, and increase the efficiency of the reactive power compensation. Through instructing the MATLAB simulation model of SVG and testing model machine, the design correction of medium voltage SVG power circuits and parameters is verified. The model machine is working well.

  19. 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.

  20. 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....

  1. Cochleates bridged by drug molecules.

    Science.gov (United States)

    Syed, Uwais M; Woo, Amy F; Plakogiannis, Fotios; Jin, Tuo; Zhu, Hua

    2008-11-03

    A new type of cochleate, able to microencapsulate water-soluble cationic drugs or peptides into its inter-lipid bi-layer space, was formed through interaction between negatively charged lipids and drugs or peptides acting as the inter-bi-layer bridges instead of multi-cationic metal ions. This new type of cochleate opened up to form large liposomes when treated with EDTA, suggesting that cationic organic molecules can be extracted from these cochleates in a way similar to multivalent metal ions from metal ion-bridged cochleates. Cochleates can be produced in sub-micron size using a method known as "hydrogel isolated cochleation" or simply by increasing the ratio of multivalent cationic peptides over negatively charged liposomes. When nanometer-sized cochleates and liposomes containing the same fluorescent labeled lipid component were incubated with human fibroblasts cells under identical conditions, cells exposed to cochleates showed bright fluorescent cell surfaces, whereas those incubated with liposomes did not. This result suggests that cochleates' edges made them fuse with the cell surfaces as compared to edge free liposomes. This mechanism of cochleates' fusion with cell membrane was supported by a bactericidal activity assay using tobramycin cochleates, which act by inhibiting intracellular ribosomes. Tobramycin bridged cochleates in nanometer size showed improved antibacterial activity than the drug's solution.

  2. Modal identification of long-span Runyang Bridge using ambient responses recorded by SHMS

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Runyang Bridge is a newly built cable-supported bridge that crosses the Yangtze River in China.The bridge is composed of one suspension bridge and one cable-stayed bridge.During the construction of the bridge,a structural health monitoring system(SHMS)was installed,which was designed by the Southeast University.Since the bridge was open to traffic,quantities of structural ambient responses have been recorded by the SHMS.And,it’s really important to extract structrural information from these records for health monitoring.This paper presents the study on modal identification of the bridge.The dynamic properites including modal frequencies,mode shapes and damping ratios are extracted from the ambient responses.Two identification methods are employed including the enhanced frequency domain decomposition and the stochastic subspace identification.The identified modal parameters from the two methods are compared.Results show that modal frequencies and mode shapes from the two methods are almost the same while the damping ratios are different.

  3. Modal identification of long-span Runyang Bridge using ambient responses recorded by SHMS

    Institute of Scientific and Technical Information of China (English)

    FEI QingGuo; LI AiQun; HAN XiaoLin; MIAO ChangQing

    2009-01-01

    Runyang Bridge is a newly built cable-supported bridge that crosses the Yangtze River in China.The bridge is composed of one suspension bridge and one cable-stayed bridge.During the construction of the bridge,a structural health monitoring system(SHMS)was installed,which was designed by the Southeast University.Since the bridge was open to traffic,quantities of structural ambient responses have been recorded by the SHMS.And,it's really important to extract structrural information from these records for health monitoring.This paper presents the study on modal identification of the bridge.The dynamic properites including modal frequencies,mode shapes and damping ratios are extracted from the ambient responses.Two identification methods are employed including the enhanced frequency domain decomposition and the stochastic subspace identification.The identified modal parameters from the two methods are compared.Results show that modal frequencies and mode shapes from the two methods are almost the same while the damping ratios are different.

  4. Field dynamic testing on a Cyprus concrete highway bridge using Wireless Sensor Network (WSN)

    Science.gov (United States)

    Votsis, Renos A.; Kyriakides, Nicholas; Tantele, Elia A.; Chrysostomou, Christis Z.; Onoufriou, Toula

    2014-08-01

    The aims of the bridge management authorities are to ensure that bridges fulfil their purpose and functionality during their design life. So, it is important to identify and quantify the deterioration of the structural condition early so that a timely application of an intervention will avoid more serious problems and increased costs at a later stage. A measure to enhance the effectiveness of the existing structural evaluation by visual inspection is instrumental monitoring using sensors. The activities performed in this process belong to the field of Structural Health Monitoring (SHM). The SHM offers opportunities for continuous or periodic monitoring on bridges and technological advances allow nowadays the employment of wireless sensors networks (WSN) for this task. A SHM application using WSN was implemented on a multi-span reinforced concrete (RC) highway bridge in Limassol with the objective to study its dynamic characteristics and performance. Part of the specific bridge will be replaced and this offered a unique opportunity for measurements before and after construction so that apparent changes in the dynamic characteristics of the bridge will be identified after the repairing work. The measurements provided indications on the frequencies and mode shapes of the bridge and the response amplitude during the passing of traffic. The latter enabled the investigation of the dependency of the bridge's structural damping to the amplitude of vibration induced by the passing of traffic. The results showed that as the excitation increases the magnitude of modal damping increases as well.

  5. Human-simulated intelligent control of train braking response of bridge with MRB

    Science.gov (United States)

    Li, Rui; Zhou, Hongli; Wu, Yueyuan; Wang, Xiaojie

    2016-04-01

    The urgent train braking could bring structural response menace to the bridge under passive control. Based on the analysis of breaking dynamics of a train-bridge vibration system, a magnetorheological elastomeric bearing (MRB) whose mechanical parameters are adjustable is designed, tested and modeled. A finite element method (FEM) is carried out to model and optimize a full scale vibration isolation system for railway bridge based on MRB. According to the model above, we also consider the effect of different braking stop positions on the vibration isolation system and classify the bridge longitudinal vibration characteristics into several cases. Because the train-bridge vibration isolation system has multiple vibration states and strongly coupling with nonlinear characteristics, a human-simulated intelligent control (HSIC) algorithm for isolating the bridge vibration under the impact of train braking is proposed, in which the peak shear force of pier top, the displacement of beam and the acceleration of beam are chosen as control goals. The simulation of longitudinal vibration control system under the condition of train braking is achieved by MATLAB. The results indicate that different braking stop positions significantly affect the vibration isolation system and the structural response is the most drastic when the train stops at the third cross-span. With the proposed HSIC smart isolation system, the displacement of bridge beam and peak shear force of pier top is reduced by 53.8% and 34.4%, respectively. Moreover, the acceleration of bridge beam is effectively controlled within limited range.

  6. Investigation of Influence Factors of Wind-Induced Buffeting Response of a Six-Tower Cable-Stayed Bridge

    Directory of Open Access Journals (Sweden)

    Zhi-Qiang Zhang

    2016-01-01

    Full Text Available This paper presents an investigation of the wind-induced buffeting responses of the Jiashao Bridge, the longest multispan cable-stayed bridge in the world. A three-dimensional finite element model for the Jiashao Bridge is established using the commercial software package ANSYS and a 3D fluctuating wind field is simulated for both bridge deck and towers. A time-domain procedure for analyzing buffeting responses of the bridge is implemented in ANSYS with the aeroelastic effect included. The characteristics of buffeting responses of the six-tower cable-stayed bridge are studied in some detail, focusing on the effects including the difference in the longitudinal stiffness between the side towers and central towers, partially longitudinal constraints between the bridge deck and part of bridge towers, self-excited aerodynamic forces, and the rigid hinge installed in the middle of the bridge deck. The analytical results can provide valuable references for wind-resistant design of multispan cable-stayed bridges in the future.

  7. 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.

  8. Bridging Bilingual and Special Education: Opportunities for Transformative Change in Teacher Preparation Programs

    Science.gov (United States)

    Ochoa, Alberto M.; Brandon, Regina R.; Cadiero-Kaplan, Karen; Ramírez, Pablo C.

    2014-01-01

    This article reports on the design and performance of ALAS (Acquisition of Language Skills and Academic Literacy) Teacher Education Project designed to bridge Biliteracy and Special Education teacher preparation. ALAS was designed by faculty in two higher education departments engaged in teacher preparation to respond to California's need for…

  9. Mechanism of Geogrid Reinforced Soil at Bridge Approach

    Institute of Scientific and Technical Information of China (English)

    FENG Guangle; LUO Rong; CHEN Congxin

    2007-01-01

    Using Geogrid-Reinforced Soil (GRS) we studied the working mechanism and design method of GRS at bridge approach with high backfill by field experiment. In a highway section where the height of backfill is 13.5 meters, geogrids were used at two bridge approaches to address the bumping problems. Some soil pressure cells were used to measure the normal and lateral soil pressure at different locations in the roadbed. The experimental results indicate that geogrids in geogrid-reinforced soil (GRS) could produce an uplift force, the closer the location to the abutment, the larger the uplift force, and the reduction of measured soil pressures compared with theoretical values was the largest at the bottom of roadbed, less at the top than at the bottom, and the least in the mid-height of roadbed than at the bottom. These findings are different from those of the traditional greogrid-reinforced subgrade design method.

  10. Bridging Cultures between Home and School: A Guide for Teachers--With a Special Focus on Immigrant Latino Families.

    Science.gov (United States)

    Trumbull, Elise; Rothstein-Fisch, Carrie; Greenfield, Patricia M.; Quiroz, Blanca

    This book focuses on how to meet the challenges of education in a pluralistic society, presenting the Bridging Cultures framework, which is designed for understanding differences and conflicts that arise in situations where school culture is more individualistic than the home value system. Six sections examine: (1) "The Bridging Cultures…

  11. Heat Loss Due To Thermal Bridges In Buildings

    Science.gov (United States)

    Fang, J. B.; tarot, R. A.; Childs, K. W.; Courville, G. E.

    1984-03-01

    Building envelopes often contain numerous highly conductive heat flow paths, called thermal bridges, which are major sources of heat loss and deterioration of building materials due to moisture condensation. Some examples of thermal bridges occurring in office buildings are presented. Infrared thermography was used to identify the locations and magnitudes of thermally defective areas resulting from inadequate construction, design, or substandard workmanship in existing buildings. Due to the large thermal inertia of building components and transient conditions caused by fluctuating outdoor and indoor temperatures, long measurement periods are required. This makes thermography impractical for quantifying the heat loss. In order to estimate the heat loss rate from thermal bridges and to obtain a better understanding of the physical processes involved, a two-dimensional heat flow model has been developed for transient heat conduction within the exterior wall/intermediate floor systems. The calculated results from the mathematical model are compared with available experimental data. An in-situ measurement technique, which is currently under development at NBS for quantifying the energy loss due to thermal bridges, is described.

  12. An innovative steel-concrete joint for integral abutment bridges

    Directory of Open Access Journals (Sweden)

    Bruno Briseghella

    2015-08-01

    Full Text Available Integral abutment bridges are becoming rather common, due to the durability problems of bearings and expansion joints. At the same time, among short- and medium-span bridges, multi-beam steel-concrete composite deck with hot-rolled girder is an economical and interesting alternative to traditional pre-stressed concrete solutions. The two concepts can be linked together to design integral steel-concrete composite bridges with the benefits of two typologies. The most critical aspect for these bridges is usually the joints between deck and piers or abutments. In this paper, an innovative beam-to-pier joint is proposed and a theoretical and experimental study is introduced and discussed. The analyzed connection is aimed at combining general ease of construction with a highly simplified assembly procedure and a good transmission of hogging and sagging moment at the supports in continuous beams. For this purpose, the traditional shear studs, used at the interface between steel beam and upper concrete slab, are also used at the ends of steel profiles welded horizontally to the end plates. To better understand the behaviour of this kind of joints and the roles played by different components, three large-scale specimens were tested and an FE model was implemented. The theoretical and experimental results confirmed the potential of the proposed connection for practical applications and indicated the way to improve its structural behaviour.

  13. Statistical consideration and challenges in bridging study of personalized medicine.

    Science.gov (United States)

    Li, Meijuan

    2015-01-01

    Applications of personalized medicine are becoming increasingly prominent. A well-characterized market-ready companion diagnostic assay (CDx) is often desired for patient enrollment in device-drug pivotal clinical trial(s) so that Food and Drug Administration can ensure that appropriate clinical and analytical validation studies are planned and carried out for CDx. However, such a requirement may be difficult or impractical to accomplish. A clinical trial assay (CTA) instead of CDx may be used for patient enrollment in the clinical trial. A concordance study (or bridging study) will be required to assess the agreement between CDx and CTA in order to bridge the clinical data (e.g. overall survival) from CTA to CDx and to evaluate the drug efficacy in CDx intended use population. In this article, we will discuss statistical challenges in study design and data analysis for bridging study. Particularly, we aimed to provide statistical methods on how to estimate the drug efficacy in CDx intended use population using results from bridging study and CTA-drug pivotal clinical trial.

  14. NSGA - II Optimization on Life-cycle Seismic Design of Single Circular Reinforced Concrete Bridge Piers%基于 NSGA - II 的规则桥梁圆形单柱 RC 桥墩全寿命造价优化设计

    Institute of Scientific and Technical Information of China (English)

    柳春光; 张士博; 柳英洲

    2015-01-01

    以基于抗震性能设计基本原则-“投资-效益”准则为理论支撑,提出了将多目标遗传算法与延性抗震设计、地震风险相结合的抗震结构集成全寿命抗震优化设计的新方法,建立了规则桥梁圆形单柱 RC 桥墩多目标全寿命造价优化设计的通用框架。并应用 NSGA - II 建立了以圆形单柱 RC 桥墩截面直径、纵筋和箍筋的配筋率为决策变量,以初始造价和地震损失期望为多目标的全寿命造价优化设计模型。计算结果表明:RC 桥墩多目标全寿命造价优化设计为投资者提供了更加灵活的初始投资的选择空间,同时 NSGA - II 也为该优化设计提供了一个较好的算法支持。%Based on the cost-effectiveness criterion ,a fundamental principle for performance-based seismic design ,a new method for optimizing total life-cycle seismic design of bridge piers was put forward with the consideration of multi -objec-tive genetic algorithm ,seismic ductility design and earthquake risks .According to which ,the general framework of multi-objective total life-cycle cost optimization design for regular reinforced concrete single circular bridge piers was estab -lished .On the platform of NSGA - II ,a total life-cycle cost optimization model of this pier was constructed with the deci -sion variable as section diameter ;the ratios of the longitudinal reinforcement ,the lateral reinforcement ,the initial cost of the structure and the expectation of earthquake loss as multiple objectives .The calculation results indicate that this method can provide the investors with a more flexible initial investment options ,meanwhile NSGA - II can also equip the designers with a better algorithm support for optimization design .

  15. Solid-state pulsed microwave bridge for electron spin echo spectrometers of 8-mm wavelength range

    Directory of Open Access Journals (Sweden)

    Kalabukhova E. N.

    2012-12-01

    Full Text Available The article presents a construction of a coherent pulsed microwave bridge with an output power up to 10 Wt with a time resolution of 10–8 seconds at a pulse repetition rate of 1 kHz designed for electron spin echo spectrometers. The bridge is built on a homodyne scheme based on IMPATT diodes, which are used for modulation and amplification of microwave power coming from the reference Gunn diode oscillator. The advantages of the bridge are optimal power and minimum pulse width, simple operation, low cost.

  16. Dynamic analysis of coupled vehicle-bridge system with uniformly variable speed

    Science.gov (United States)

    Wei-zhen, Li; Chang-ping, Chen; Yi-qi, Mao; Chang-zhao, Qian

    2016-09-01

    In this paper, a planar biaxial vehicle model with four degrees of freedom is presented based on spring-damping-mass system theory. By using Runge-Kutta method, the dynamic characteristics of a simply support bridge acting by moving vehicle with uniform variable speed are analyzed, and the effects of inertia force, relative acceleration and initial velocity are taken into consideration in the present research. The time-deflection response curves of the bridge under the variation of initial speed and acceleration are analyzed. Some valuable results are found which can provide a theoretical direction for the consideration of dynamical characteristics in design of bridge system.

  17. Experimental Study of Properties of Pervious Concrete used for Bridge Superstructure

    DEFF Research Database (Denmark)

    Lund, Mia Schou Møller; Hansen, Kurt Kielsgaard; Hertz, Kristian Dahl

    2014-01-01

    -Chain Bridges are a new patented bridge technology consisting of a number of Super-Light Deck elements, which are post-tensioned to create an arch bridge used for example for highways. The present study investigates how pervious concrete can be applied as a stabilizing filling materi-al between the arch...... substructure and the wearing course. One pervious concrete mixture contain-ing air entrainment is designed and tested. The tests include investigations of compaction meth-ods, compressive strength, stiffness, frost resistance and permeability....

  18. Rejection of Power Supply Noise in Wheatstone Bridges : Application to Piezoresistive MEMS

    CERN Document Server

    Boujamaa, El Mehdi; Mailly, Frédérick; Latorre, Laurent; Nouet, Pascal

    2008-01-01

    This paper deals with the design of MEMS using piezoresistivity as transduction principle. It is demonstrated that when the sensor topology doesn't allow a perfect matching of strain gauges, the resolution is limited by the ability of the conditioning circuit (typically a Wheatstone bridge) to reject power supply noise. As this ability is strongly reduced when an offset voltage is present at the output of the bridge, the proposed architecture implements a feedback loop to control MOS transistors inserted in the Wheatstone bridge to compensate resistor mismatches. This feedback exhibits a very good offset cancellation and therefore a better resolution is achieved.

  19. Design of Swiveling Construction of Continuous Beam for Yunliang River Extra-long Bridge on Harbin-Dalian Passenger Dedicated Line%哈大客运专线运粮河特大桥连续梁转体施工设计

    Institute of Scientific and Technical Information of China (English)

    盖小红

    2012-01-01

    哈大客运专线运粮河特大桥主桥为跨度(60+ 100+60)m预应力混凝土连续箱梁,为跨越既有哈大铁路而设,与既有哈大铁路夹角为24°,墩高7.5m,桥下净空受限,如果采用传统的悬臂挂篮现浇施工,则施工周期长,对既有铁路正常运营产生干扰,而且施工过程中稍有不慎就会威胁到桥下正在高速运行的列车.而采用连续梁转体施工能有效规避施工过程中与既有铁路干扰,维护既有线路的运营安全,减少既有线加固防护数量.以运粮河特大桥主跨转体为工程背景,对客运专线连续梁跨既有铁路时平行转体的系统组成及其相关构件的设计进行研究.%The Yunliang River extra-long bridge on Harbin-Dalian Passenger Dedicated Line with main span {60+100+60 )m pre-stressed concrete continuous single box beam is designed to cross the existing Harbin-Dalian railway at an angle of 24 degree with pier height 7. 5 m. The limited clearance under the bridge would require long period of construction time, and interfere with normal operation of the existing railway line, imposing potential risks to the running trains underneath during the construction. If construction with swiveling continuous beam is applied, the inference with the existing railway line can be avoided and the protection works for the existing line reduced. This paper, on the basis of the construction of the main span of Yunliang river extra-long bridge, focuses on the composition of the parallel swiveling system to cross passenger dedicated line by continuous beam, and the design of the relevant components.

  20. Instrumentation for durability monitoring of a long-span cable-stayed bridge

    Science.gov (United States)

    Hua, X. G.; Ni, Y. Q.; Zhou, H. F.; Ko, J. M.

    2005-05-01

    This paper outlines the design of an instrumentation system for durability monitoring of the world's longest cable-stayed bridge: the Sutong Bridge with a central span of 1088 m. As part of the Structural Health Monitoring And Safety Evaluation System (SHMASES) for the Sutong Bridge, the durability monitoring system is designed to monitor the corrosion in reinforced concrete structures. The sensors for durability monitoring include two categories. The first category refers to the sensors to monitor the causes leading to corrosion, such as temperature and relative humidity. The second category is electrode assemblies which are used to monitor the end results of corrosion. Data from the sensory system are then periodically collected using a portable or remotely computerized data acquisition system. The collected data from this system will provide useful information on maintenance and repair of concrete structures, and are envisaged to be incorporated into the reliability-based safety evaluation system developed for the Sutong Bridge