WorldWideScience

Sample records for weathering steel bridges

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

    Science.gov (United States)

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

    2017-09-01

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

  2. Experimental investigation of the effect of surface markings on the mechanical integrity of weathering bridge steels : [summary].

    Science.gov (United States)

    2014-11-01

    High-strength low-alloy steel (HSLA) weathering : steels are the conventional choice for fracture-critical members in bridge construction. HSLA : weathering steels offer superior corrosion : resistance, important in Floridas humid and : coastal en...

  3. Assessment of weathering steel bridge performance in Iowa and development of inspection and maintenance techniques.

    Science.gov (United States)

    2013-02-01

    Weathering steel is commonly used as a cost-effective alternative for bridge superstructures, as the costs and environmental : impacts associated with the maintenance/replacement of paint coatings are theoretically eliminated. The performance of : we...

  4. Experimental investigation of the effect of surface markings on the mechanical integrity of weathering bridge steels.

    Science.gov (United States)

    2014-11-01

    High-strength low-alloy (HSLA) weathering steels are the conventional material used for non-redundant fracture-critical members in bridge construction. Guidelines have been put in place by state : Departments of Transportation (DOTs) to prevent mater...

  5. Elevated temperature properties of weathering steel.

    Science.gov (United States)

    2014-01-01

    In recent decades, bridge fires have become a major concern in the U.S. Fire hazard in bridges can result in significant economic and public losses. New construction of bridges often use Weathering Steel (also known as Corten Steel), whic...

  6. Aesthetic coatings for steel bridge components.

    Science.gov (United States)

    2013-11-01

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

  7. Existing Steel Railway Bridges Evaluation

    Directory of Open Access Journals (Sweden)

    Vičan Josef

    2016-12-01

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

  8. Steel-soil composite bridge

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2017-01-01

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

  9. Strengthening steel bridge girders using CFRP.

    Science.gov (United States)

    2010-06-01

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

  10. Steel plate reinforcement of orthotropic bridge decks

    NARCIS (Netherlands)

    Teixeira de Freitas, S.

    2012-01-01

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

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

    NARCIS (Netherlands)

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

    2013-01-01

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

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

    Science.gov (United States)

    2010-12-01

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

  13. Acoustic emission health monitoring of steel bridges

    NARCIS (Netherlands)

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

    2014-01-01

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

  14. Atmospheric corrosion data of weathering steels. A review

    OpenAIRE

    Morcillo, Manuel; Chico, Belén; Cano, H.; Fuente, Daniel de la

    2013-01-01

    Extensive information on the atmospheric corrosion of weathering steel has been published in the scientific literature. The contribution of the present work is to provide a bibliographic review of the reported information, which mostly concerns the weathering steel ASTM A-242. This review addresses issues such as rust layer stabilisation times, steady-state steel corrosion rates, and situations where the use of unpainted weathering steel is feasible. It also analyses the effect of exposure co...

  15. Buckling Instability Behavior of Steel Bridge under Fire Hazard

    OpenAIRE

    Ying Wang; Muyu Liu

    2016-01-01

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

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

    DEFF Research Database (Denmark)

    Du, Guangli; Karoumi, Raid

    2013-01-01

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

  17. Cross-frame connection details for skewed steel bridges.

    Science.gov (United States)

    2010-10-30

    This report documents a research investigation on connection details and bracing layouts for stability : bracing of steel bridges with skewed supports. Cross-frames and diaphragms play an important role in stabilizing : steel girders, particularly du...

  18. Fatigue-Prone Details in Steel Bridges

    Directory of Open Access Journals (Sweden)

    Mohsen Heshmati

    2012-11-01

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

  19. Renovation techniques for fatigue cracked orthotropic steel bridge decks

    NARCIS (Netherlands)

    de Jong, F.B.P.

    2007-01-01

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

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

    Science.gov (United States)

    2014-09-01

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

  1. Optimal, Generic Planning of Maintenance and Inspection of Steel Bridges

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Faber, Michael Havbro

    2002-01-01

    Fatigue damage is an important deterioration mechanism for steel bridges. This paper describes a simplified and generic approach for reliability and risk based inspection planning of fatigue sensitive structural details. Fatigue sensitive details are categorized according to their loading charact...

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

    OpenAIRE

    Ma Wei-long

    2015-01-01

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

  3. Buckling Instability Behavior of Steel Bridge under Fire Hazard

    Directory of Open Access Journals (Sweden)

    Ying Wang

    2016-01-01

    Full Text Available Failure of buckling instability will most likely occur before the displacement reaches the allowable value of the code when a tanker burns under the steel bridge. This research focuses on critical buckling stress of bridge under fire hazard and a thermal analysis model of a steel bridge is established by FDS (Fire Dynamics Simulator. Thermal parameters of the steel are determined by the polynomial fitting method. Temperature field and elastic modulus of the bridge changing with time are calculated by determining the heat release rate function of tanker. Critical buckling stress of the bridge web and bottom floor changing with time is calculated according to steel floor buckling theory. Finite element software ANSYS is used to verify the result. Results show that when a tanker is burning for 17 minutes, critical buckling stress of steel web will be reduced to τcrl,lw(T = 19.1 MPa and σcrl,lw(T = 38.8 MPa, which is less than the web stress (τ = 19.6 MPa, σ = 39.8 MPa caused by dead and live load. So steel web will be the first to show shear flexural bending buckling failure. Displacement in the midspan will reach 35.4 mm at this time, which was less than the allowable displacement (50 mm set by standard. The best rescue time of the bridge under fire hazard is within 15 minutes.

  4. Design principles of surfacings on orthotropic steel bridge decks

    NARCIS (Netherlands)

    Medani, T.O.

    2006-01-01

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

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

    NARCIS (Netherlands)

    Kolstein, M.H.

    2007-01-01

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

  6. Special heavy plates and steel solutions for bridge building

    Science.gov (United States)

    Lehnert, Tobias

    2017-09-01

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

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

    OpenAIRE

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

    2016-01-01

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

  8. Acoustic emission source mechanisms for steel bridge material

    Science.gov (United States)

    Hossain, M.; Yu, J.; Ziehl, P.; Caicedo, J.; Matta, F.; Guo, S.; Sutton, M.

    2013-01-01

    Over the past twenty years acoustic emission (AE) has been studied for applications to the structural health monitoring (SHM) of metallic structures. The success of AE for prognosis of in-service steel bridges depends on the reliability of the received AE signals. The emphasis of this paper is on the characterization of acoustic emission source mechanisms for ASTM A572 grade 50 steel. The source characterization was aided by Digital Imaging Correlation (DIC) and Scanning Electronic Microscopy (SEM). The results indicate that both ductile and brittle mechanisms can produce AE during fatigue crack growth in the steel. However, the fracture mechanisms are predominately ductile. A key preliminary finding is that fatigue crack extension does not generally produce AE events in the early stage of fatigue crack growth for the steel bridge material investigated.

  9. Seismic response of steel suspension bridge

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-11-01

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

  10. Examination of Post-Tensioned Steel Bridges in Indiana

    OpenAIRE

    Wu, Hung-I; Bowman, Mark D.

    2000-01-01

    The purpose of the research study is to conduct an investigation to understand the performance of a relatively new type of bridge construction that involves prestressed (post-tensioned) steel-concrete composite bridge members. Strictly speaking, the technical and economical advantages of this type of structure have been understood for several decades. However, the application of this concept to practice is still very limited due to difficulties associated with the post-tensioning anchorage. T...

  11. 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...... have been carried through. The materials that have been used are either conventional structural steel with a yield stress of f(y) similar to 400-410 MPa or high-strength steel with a yield stress of f(y) similar to 810-840 MPa. The fatigue tests have been carried out using load histories, which...

  12. 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...... on welded plate test specimens have been carried through. The materials that have been used are either conventional structural steel with a yield stress of ~ 400-410 MPa or high-strength steel with a yield stress of ~ 810-840 MPa.The fatigue tests have been carried out using load histories, which correspond...

  13. Phase and widening construction of steel bridges.

    Science.gov (United States)

    2014-03-01

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

  14. Progress in the Research of Fatigue of Weathering Steel after Corrosion

    Science.gov (United States)

    Jianyu, Liang; Jian, Yao; Youwu, Xu

    2017-12-01

    Weathering steel has a good corrosion resistance in the atmosphere, and the application of weathering steel in civil structure also reduces the cost of painting and maintenance. It is also possible for the bare weathering steel to bear the fatigue load with a rust layer. This paper summarizes the fatigue researches after corrosion of weathering steel, including the shape of specimens, failure modes of fatigue and the conclusions obtained through experimental investigations. It is also introduced the fatigue model of weathering steel after corrosion, which can be useful for the engineering application or further researches.

  15. 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.

  16. 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...

  17. Dynamic characteristics of old railway steel bridges in Egypt

    Directory of Open Access Journals (Sweden)

    Hassan Maha M.

    2017-01-01

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

  18. Shear Behavior of Corrugated Steel Webs in H Shape Bridge Girders

    OpenAIRE

    Qi Cao; Haibo Jiang; Haohan Wang

    2015-01-01

    In bridge engineering, girders with corrugated steel webs have shown good mechanical properties. With the promotion of composite bridge with corrugated steel webs, in particular steel-concrete composite girder bridge with corrugated steel webs, it is necessary to study the shear performance and buckling of the corrugated webs. In this research, by conducting experiment incorporated with finite element analysis, the stability of H shape beam welded with corrugated webs was tested and three fai...

  19. 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.

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

    Directory of Open Access Journals (Sweden)

    Tan Manjiang

    2015-01-01

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

  1. Failure and fatigue life assessment of steel railway bridges with brittle material

    NARCIS (Netherlands)

    Maljaars, J.

    2014-01-01

    Some existing steel bridges have been constructed from steels with a toughness that does not fulfil the requirements in modern standards. In such a case, standards for bridges do not provide an alternative assessment route. Yet such bridges may still be fit for purpose. This paper presents an

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

    Science.gov (United States)

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

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

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

    Science.gov (United States)

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

    2017-07-01

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

  4. Quantitative acoustic emission monitoring of fatigue cracks in fracture critical steel bridges.

    Science.gov (United States)

    2014-01-01

    The objective of this research is to evaluate the feasibility to employ quantitative acoustic : emission (AE) techniques for monitoring of fatigue crack initiation and propagation in steel : bridge members. Three A36 compact tension steel specimens w...

  5. High Performance Steel Development for Highway Bridge Construction: A Cooperative Effort

    Science.gov (United States)

    1997-08-01

    mechanical property requirements of ASTM A709 Grades 70W and 100W. This paper presents the development of the steels produced under the FHWA Program on High Performance Steels for Bridge Construction .

  6. Example of dynamic analysis of orthotropic steel bridge plate

    Directory of Open Access Journals (Sweden)

    Cvijić Radomir

    2015-01-01

    Full Text Available This paper presents brief dynamic analysis of one typical steel bridge orthotropic plate. Geometry and load data are adopted according to recommendations from the literature. Calculation is preformed using the Finite element method where the commercial software package Abaqus is used. Dynamic load due to vehicle crossing is modeled via six weighted rigid plates with dimensions equal to the contact surface between the wheel and the plate. Obtained results suggest that the main impact on the structural response comes from the speed of the vehicle. Influence of the crossing of the second vehicle was negligible in presented analysis.

  7. Effects of fire damage on the structural properties of steel bridge elements.

    Science.gov (United States)

    2011-04-30

    It is well known that fire can cause severe damage to steel bridges. There are documented cases where fire has directly led to the collapse or significant sagging of a steel bridge. However, when the damage is less severe, the effects of the fire, if...

  8. Structural health monitoring in end-of-life prediction for steel bridges subjected to fatigue cracking

    NARCIS (Netherlands)

    Attema, T.; Courage, W.M.G.; Maljaars, J.; Meerveld, H. van; Paulissen, J.H.; Pijpers, R.J.M.; Slobbe, A.T.

    2015-01-01

    This paper presents a monitoring and modelling methodology to assess the current and future conditions of steel bridges subjected to fatigue cracking. Steel bridges are subjected to fatigue cracking as a result of fluctuating stresses caused by the crossing of heavy vehicles. Specifically for

  9. Steel bridge fatigue crack detection with piezoelectric wafer active sensors

    Science.gov (United States)

    Yu, Lingyu; Giurgiutiu, Victor; Ziehl, Paul; Ozevin, Didem; Pollock, Patrick

    2010-04-01

    Piezoelectric wafer active sensors (PWAS) are well known for its dual capabilities in structural health monitoring, acting as either actuators or sensors. Due to the variety of deterioration sources and locations of bridge defects, there is currently no single method that can detect and address the potential sources globally. In our research, our use of the PWAS based sensing has the novelty of implementing both passive (as acoustic emission) and active (as ultrasonic transducers) sensing with a single PWAS network. The combined schematic is using acoustic emission to detect the presence of fatigue cracks in steel bridges in their early stage since methods such as ultrasonics are unable to quantify the initial condition of crack growth since most of the fatigue life for these details is consumed while the fatigue crack is too small to be detected. Hence, combing acoustic emission with ultrasonic active sensing will strengthen the damage detection process. The integration of passive acoustic emission detection with active sensing will be a technological leap forward from the current practice of periodic and subjective visual inspection, and bridge management based primarily on history of past performance. In this study, extensive laboratory investigation is performed supported by theoretical modeling analysis. A demonstration system will be presented to show how piezoelectric wafer active sensor is used for acoustic emission. Specimens representing complex structures are tested. The results will also be compared with traditional acoustic emission transducers to identify the application barriers.

  10. Monitoring steel bridge renovation using lead isotopic tracing.

    Science.gov (United States)

    Salome, Fred; Gulson, Brian; Chiaradia, Massimo; Davis, Jeffrey; Morris, Howard

    2017-05-01

    Monitoring removal of lead (Pb) paint from steel structures usually involves analysis of environmental samples for total lead and determination of blood Pb levels of employees involved in the Pb paint removal. We used high precision Pb isotopic tracing for a bridge undergoing Pb paint removal to determine if Pb in the environmental and blood samples originated from the bridge paint. The paint system on the bridge consisted of an anti-corrosive red Pb primer top-coated with a Micaceous Iron Oxide (MIO) alkyd. Analysis of the red Pb primer gave uniform isotopic ratios indicative of Pb from the geologically-ancient Broken Hill mines in western New South Wales, Australia. Likewise waste abrasive material, as anticipated, had the same isotopic composition as the paint. The isotopic ratios for other samples lay on 2 separate linear arrays on a(207)Pb/(204)Pb versus (206)Pb/(204)Pb diagram, one largely defined by gasoline and the majority of the ambient air data, and the other by data for one sample each of gasoline and ambient air and underwater sediments. Isotopic ratios in background ambient air samples for the project were characteristic of leaded gasoline. Air sampling during paint removal showed a contribution of paint Pb ranging from about 20 to 40%. Isotopic ratios in the blood of 8 employees prior to the commencement of work showed that 6 of these had been previously exposed to the Broken Hill Pb possibly from earlier bridge paint removal projects. One subject appeared to have increased exposure to Pb probably from the paint renovations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. 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

  12. 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.

  13. A State-of-the-Art Review on Fatigue Life Assessment of Steel Bridges

    Directory of Open Access Journals (Sweden)

    X. W. Ye

    2014-01-01

    Full Text Available Fatigue is among the most critical forms of damage potentially occurring in steel bridges, while accurate assessment or prediction of the fatigue damage status as well as the remaining fatigue life of steel bridges is still a challenging and unsolved issue. There have been numerous investigations on the fatigue damage evaluation and life prediction of steel bridges by use of deterministic or probabilistic methods. The purpose of this review is devoted to presenting a summary on the development history and current status of fatigue condition assessment of steel bridges, containing basic aspects of fatigue, classical fatigue analysis methods, data-driven fatigue life assessment, and reliability-based fatigue condition assessment.

  14. Corrosion protection service life of epoxy-coated reinforcing steel in Virginia bridge decks.

    Science.gov (United States)

    2003-01-01

    The corrosion protection service life extension provided by epoxy-coated reinforcement (ECR) was determined by comparing ECR and bare steel bars from 10 Virginia bridge decks built between 1981 and 1995. The objective was to determine the corrosion p...

  15. Steel framing strategies for highly skewed bridges to reduce/eliminate distortion near skewed supports.

    Science.gov (United States)

    2014-05-01

    Different problems in straight skewed steel I-girder bridges are often associated with the methods used for detailing the cross-frames. Use of theoretical terms to describe these detailing methods and absence of complete and simplified design approac...

  16. Structural Optimization of Steel Cantilever Used in Concrete Box Girder Bridge Widening

    Directory of Open Access Journals (Sweden)

    Qian Wang

    2015-01-01

    Full Text Available The structural optimization method of steel cantilever used in concrete box girder bridge widening is illustrated in this paper. The structural optimization method of steel cantilever incorporates the conceptual layout design of steel cantilever beam based on the topological theory and the determination of the optimal location of the transverse external prestressed tendons which connect the steel cantilever and the box girder. The optimal design theory and the analysis process are illustrated. The mechanical model for the prestressed steel cantilever is built and the analytical expression of the optimal position of the transverse external tendon is deduced. At last the effectiveness of this method is demonstrated by the design of steel cantilevers which are used to widen an existing bridge.

  17. Laser welded steel sandwich panel bridge deck development : finite element analysis and stake weld strength tests.

    Science.gov (United States)

    2009-09-01

    This report summarizes the analysis of laser welded steel sandwich panels for use in bridge structures and : static testing of laser stake welded lap shear coupons. Steel sandwich panels consist of two face sheets : connected by a relatively low-dens...

  18. Stress-corrosion susceptibility of highway bridge construction steels. Phase I

    Science.gov (United States)

    1972-04-01

    A catalog of steels used in highway bridge construction has been developed. A state-of-the-art survey on the stress-corrosion susceptibility of these steels has been conducted. The types and concentrations of corrosives that can be experienced in the...

  19. 77 FR 54652 - Draft Program Comment for Common Post-1945 Concrete and Steel Bridges

    Science.gov (United States)

    2012-09-05

    ... Administration [FHWA Docket No. FHWA-2012-0075] Draft Program Comment for Common Post-1945 Concrete and Steel... Comment for Common Post-1945 Concrete and Steel Bridges; request for comments. SUMMARY: The Advisory... National Historic Preservation Act with regard to the effects of undertakings on common post-1945 concrete...

  20. Finite element model updating of multi-span steel-arch-steel-girder bridges based on ambient vibrations

    Science.gov (United States)

    Hou, Tsung-Chin; Gao, Wei-Yuan; Chang, Chia-Sheng; Zhu, Guan-Rong; Su, Yu-Min

    2017-04-01

    The three-span steel-arch-steel-girder Jiaxian Bridge was newly constructed in 2010 to replace the former one that has been destroyed by Typhoon Sinlaku (2008, Taiwan). It was designed and built to continue the domestic service requirement, as well as to improve the tourism business of the Kaohsiung city government, Taiwan. This study aimed at establishing the baseline model of Jiaxian Bridge for hazardous scenario simulation such as typhoons, floods and earthquakes. Necessities of these precaution works were attributed to the inherent vulnerability of the sites: near fault and river cross. The uncalibrated baseline bridge model was built with structural finite element in accordance with the blueprints. Ambient vibration measurements were performed repeatedly to acquire the elastic dynamic characteristics of the bridge structure. Two frequency domain system identification algorithms were employed to extract the measured operational modal parameters. Modal shapes, frequencies, and modal assurance criteria (MAC) were configured as the fitting targets so as to calibrate/update the structural parameters of the baseline model. It has been recognized that different types of structural parameters contribute distinguishably to the fitting targets, as this study has similarly explored. For steel-arch-steel-girder bridges in particular this case, joint rigidity of the steel components was found to be dominant while material properties and section geometries relatively minor. The updated model was capable of providing more rational elastic responses of the bridge superstructure under normal service conditions as well as hazardous scenarios, and can be used for manage the health conditions of the bridge structure.

  1. TOPICAL REVIEW: Corrosion resistance of Si–Al-bearing ultrafine-grained weathering steel

    Directory of Open Access Journals (Sweden)

    Toshiyasu Nishimura

    2008-01-01

    Full Text Available In the Ultra-steel project at the National Institute for Materials Science (NIMS, which run from 1996 to 2005, high-Si–Al-content ultrafine-grained (UFG weathering steel was developed by grain refinement and weathering guidance. It was found that this steel has excellent strength, toughness and corrosion resistance. Samples were prepared by multi pass warm rolling at temperatures between 773 and 873 K. The grain size of steel rolled at 873 K was about 1 μ m, and the tensile strength (TS and elongation (EL had excellent values of 800 MPa and 20%, respectively. In general, steels with high Si and Al contents exhibit inferior toughness to carbon steel (SM; however, the toughness of the developed sample was markedly improved by grain refinement. Cyclic corrosion tests in the presence of chloride ions confirmed that the developed steel exhibited excellent corrosion resistance, superior to that of SM. Electron probe microanalysis (EPMA and transmission electron microscopy (TEM analyses showed that Si and Al mainly exist in the inner rust layer. Si and Al were identified as existing in the Si2 + and Al3 + states in the nanoscale complex oxides constituting the inner rust layer. Electrochemical impedance spectroscopy(EIS measurement showed that the corrosion reaction resistance (Rt of the developed steel was much greater than that of SM. In the developed steel, the nanoscale complex oxides were formed in the inner rust layer, which increased Rt, and resulted in the excellent corrosion resistance.

  2. Shear Behavior of Corrugated Steel Webs in H Shape Bridge Girders

    Directory of Open Access Journals (Sweden)

    Qi Cao

    2015-01-01

    Full Text Available In bridge engineering, girders with corrugated steel webs have shown good mechanical properties. With the promotion of composite bridge with corrugated steel webs, in particular steel-concrete composite girder bridge with corrugated steel webs, it is necessary to study the shear performance and buckling of the corrugated webs. In this research, by conducting experiment incorporated with finite element analysis, the stability of H shape beam welded with corrugated webs was tested and three failure modes were observed. Structural data including load-deflection, load-strain, and shear capacity of tested beam specimens were collected and compared with FEM analytical results by ANSYS software. The effects of web thickness, corrugation, and stiffening on shear capacity of corrugated webs were further discussed.

  3. A system of steel-elastomer sandwich plates for strengthening orthotropic bridge decks

    Science.gov (United States)

    Feldmann, M.; Sedlacek, G.; Geßler, A.

    2007-03-01

    The use of a sandwich plate system (SPS) composed of two steel plates with a solid polymer (polyurethane) core has been introduced as a refurbishment procedure for steel decks of bridges, the so-called orthotropic decks consisting of a deckplate with longitudinal stiffeners and transverse crossbeams. Unfortunately, a great many of existing steel bridges still have structural members that do not comply with the recommendations given in design codes, and therefore damages have developed in them. For a satisfactory refurbishment of the bridges, the SPS technique fulfils all necessary requirements. To this end, both experimental and calculative investigations were carried out at RWTH Aachen to demonstrate the reinforcing and stiffening effect and to prove the suitability of the SPS-overlay technique for general use. The practical applicability of a SPS has been tested successfully in a pilot project for a German motorway bridge under severe traffic.

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

    Science.gov (United States)

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

    2017-11-01

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

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

    Science.gov (United States)

    2012-08-01

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

  6. Multidisciplinary health monitoring of a steel bridge deck structure

    NARCIS (Netherlands)

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

    2013-01-01

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

  7. Atmospheric Corrosion Behavior and Mechanism of a Ni-Advanced Weathering Steel in Simulated Tropical Marine Environment

    Science.gov (United States)

    Wu, Wei; Zeng, Zhongping; Cheng, Xuequn; Li, Xiaogang; Liu, Bo

    2017-11-01

    Corrosion behavior of Ni-advanced weathering steel, as well as carbon steel and conventional weathering steel, in a simulated tropical marine atmosphere was studied by field exposure and indoor simulation tests. Meanwhile, morphology and composition of corrosion products formed on the exposed steels were surveyed through scanning electron microscopy, energy-dispersive x-ray spectroscopy and x-ray diffraction. Results indicated that the additive Ni in weathering steel played an important role during the corrosion process, which took part in the formation of corrosion products, enriched in the inner rust layer and promoted the transformation from loose γ-FeOOH to dense α-FeOOH. As a result, the main aggressive ion, i.e., Cl-, was effectively separated in the outer rust layer which leads to the lowest corrosion rate among these tested steels. Thus, the resistance of Ni-advanced weathering steel to atmospheric corrosion was significantly improved in a simulated tropical marine environment.

  8. Stainless steel reinforcement as a replacement for epoxy coated steel in bridge decks : final report.

    Science.gov (United States)

    2013-08-01

    The corrosion resistance of 2304 stainless steel reinforcement and stainless steel clad reinforcement was compared to conventional and epoxy-coated reinforcement (ECR). 2304 stainless steel was tested in both the as-received condition (dark mottled f...

  9. STRENGTHENING OF A REINFORCED CONCRETE BRIDGE WITH PRESTRESSED STEEL WIRE ROPES

    Directory of Open Access Journals (Sweden)

    Kexin Zhang

    2017-10-01

    Full Text Available This paper describes prestressed steel wire ropes as a way to strengthen a 20-year-old RC T-beam bridge. High strength, low relaxation steel wire ropes with minor radius, high tensile strain and good corrosion resistance were used in this reinforcement. The construction process for strengthening with prestressed steel wire ropes—including wire rope measuring, extruding anchor heads making, anchorage installing, tensioning steel wire ropes and pouring mortar was described. Ultimate bearing capacity of the bridge after strengthening was discussed based on the concrete structure theory. The flexural strength of RC T-beam bridges strengthened with prestressed steel wire ropes was governed by the failure of concrete crushing. To investigate effectiveness of the strengthening method, fielding-load tests were carried out before and after strengthening. The results of concrete strain and deflection show that the flexural strength and stiffness of the strengthened beam are improved. The crack width measurement also indicates that this technique could increase the durability of the bridge. Thus, this strengthened way with prestressed steel wire rope is feasible and effective.

  10. Tropical Weather Resistant Galvanized Steel Coated and Uncoated

    Directory of Open Access Journals (Sweden)

    Suárez-Corrales Xenia Isbel

    2014-01-01

    Full Text Available The corrosion behavior of coated and uncoated galvanized steel products is determined by exposing them to accelerated and natural climatic test. Accelerated tests were carried out in climatic chambers and natural atmospheric test in a marine-coastal station (Cojimar. The influence of tropical humid climate on these products is determined. Adhesion is an important property for a good performance, from the decorative point of view or as an additional protection. The evaluation indicates that 95% of the galvanized steel products show a good corrosion resistance; although 71% of coated galvanized products and 100% of painted galvanized products do not cover the requirements with respect to the mechanical and corrosion protection aspects. For a good efficiency and economic performance of metal mechanical industry, a correct surface treatment and coating application is required. A key point is to increase the quality by improving a better corrosion protective performance respecting uncoated galvanized steel.

  11. Assessment on transient sound radiation of a vibrating steel bridge due to traffic loading

    Science.gov (United States)

    Zhang, He; Xie, Xu; Jiang, Jiqing; Yamashita, Mikio

    2015-02-01

    Structure-borne noise induced by vehicle-bridge coupling vibration is harmful to human health and living environment. Investigating the sound pressure level and the radiation mechanism of structure-borne noise is of great significance for the assessment of environmental noise pollution and noise control. In this paper, the transient noise induced by vehicle-bridge coupling vibration is investigated by employing the hybrid finite element method (FEM) and boundary element method (BEM). The effect of local vibration of the bridge deck is taken into account and the sound responses of the structure-borne noise in time domain is obtained. The precision of the proposed method is validated by comparing numerical results to the on-site measurements of a steel girder-plate bridge in service. It implies that the sound pressure level and its distribution in both time and frequency domains may be predicted by the hybrid approach of FEM-BEM with satisfactory accuracy. Numerical results indicate that the vibrating steel bridge radiates high-level noise because of its extreme flexibility and large surface area for sound radiation. The impact effects of the vehicle on the sound pressure when leaving the bridge are observed. The shape of the contour lines in the area around the bridge deck could be explained by the mode shapes of the bridge. The moving speed of the vehicle only affects the sound pressure components with frequencies lower than 10 Hz.

  12. Strain-Based Evaluation of a Steel Through-Girder Railroad Bridge

    OpenAIRE

    Daumueller, Andrew N.; Jáuregui, David V.

    2012-01-01

    In the state of New Mexico (USA), passenger rail began in 2008 between Belen and Santa Fe on the Rail Runner, following the acquisition of about 100 miles of existing rail and related infrastructure. Many of the bridges on this route are over 100 years old and contain fatigue prone details. This study focuses on a steel through-girder bridge along this corridor. To accurately evaluate these structures for load carrying capacity and fatigue, an accurate analytical model is required. Accordingl...

  13. Analysis of five-point bending test for multilayer surfacing system on orthotropic steel bridge

    NARCIS (Netherlands)

    Li, J.; Scarpas, A.; Tzimiris, G.; Kasbergen, C.; Hofman, R.; Voskuilen, J.

    2013-01-01

    The French five-point bending test (5PBT) provides a laboratory scale test that allows studying the fatigue resistance of surfacing systems on orthotropic steel deck bridges (OSDB). The surfacing structure for OSDB in the Netherlands consists mostly of multilayer system: top porous asphalt layer,

  14. Influence of asphalt on fatigue crack monitoring in steel bridge decks using guided waves

    NARCIS (Netherlands)

    Pahlavan, P.L.; De Soares Silva e Melo Mota, M.; Blacquière, G.

    2016-01-01

    Asphalt materials generally exhibit temperature-dependent properties, which can influence the performance of fatigue crack inspection and monitoring systems for bridge deck structures. For a non-intrusive fatigue crack sizing methodology applied to steel decks using ultrasonic guided waves, the

  15. Expert judgment in life-cycle degradation and maintenance modelling for steel bridges

    NARCIS (Netherlands)

    Kosgodagan, A; Morales Napoles, O.; Maljaars, J; Courage, W; Bakker, Jaap; Frangopol, Dan M.; van Breugel, Klaas

    2016-01-01

    Markov-based models for predicting deterioration for civil infrastructures are widely recognized as suitable tools addressing this mechanism. The objective of this paper is to provide insights regarding a network of orthotropic steel bridges in terms of degradation. Consequently, a model combining a

  16. Experimental Investigation of Membrane Materials used in Multilayer Surfacing Systems for Orthotropic Steel Deck Bridges

    NARCIS (Netherlands)

    Tzimiris, G.

    2017-01-01

    In the Netherlands asphaltic surfacings on orthotropic steel deck bridges (OSDB) mostly consist of two structural layers. The upper layer consists of what is known as very open porous asphalt (ZOAB) for noise reduction. For the lower layer Guss Asphalt (GA) is used. Earlier investigations have shown

  17. Section 3: Optimization of a 550/690-MPa high-performance bridge steel

    Energy Technology Data Exchange (ETDEWEB)

    Magee, A.B.; Gross, J.H.; Stout, R.D. [and others

    1997-04-01

    This project to develop a high-performance bridge steel was intended to avoid susceptibility of the steel to weld heat-affected-zone cracking and therefore minimize the requirement for preheat, and to increase its fracture toughness at service temperatures. Previous studies by the Lehigh University Center for Advanced Technology for Large Structural Systems have suggested that a Cu-Ni steels with the following composition was an excellent candidate for such a bridge steel: C/0.070; Mn/1.50; P/0.009; S/0.005; Si/0.25; Cu/1.00; Ni/0.75; Cr/0.50; Mo/0.50; V/0.06; Cb/0.010. To confirm that observation, 227-kg heats of the candidate steel were melted and processed to 25- and 50-mm-thick plate by various thermomechanical practices, and the weldability and mechanical properties determined. To evaluate the feasibility of reduced alloy content, two 227-kg heats of a lower hardenability steel were melted with C reduced to 0.06, Mn to 1.25, and Mo to 0.25 and similarly processed and tested. The results indicate that the steels were not susceptible to hydrogen-induced weld-heat-affected-zone cracking when welded without preheat. Jominy end-quench tests of the higher-hardenability steel indicate that a minimum yield-strength of 690 MPa should be readily attainable in thicknesses through 50 mm and marginally at 100 mm. The toughness of the steel readily met AASHTO specifications for Zone 3 in all conditions and thicknesses, and may be sufficiently tough so that the critical crack size will minimize fatigue-crack-extension problems.

  18. Brief research on arch hinge of the steel truss arch bridge by contact problem under local stress

    Science.gov (United States)

    He, Wei; Zhu, Yinqiao; Chen, Renlong

    2017-06-01

    Because of its wide deck, elegant design and reasonable stress, the steel truss arch bridge is suitable for urban bridges. In the steel truss arch bridge, the main arch hinge is an important structure, the local structure and the stress is complex, and it is necessary to analyze the local stress state of the arch hinge. Arch hinge problem belongs to the contact problem, this paper based on Chengdu Tianfu District Shenyang Lu Xi Duan Jin Jiang in bearing steel truss arch bridge design, take the finite element software ANSYS on the main arch hinge is locally analyzed, the arch at the junction of reliable performance test. Studies have shown that half through steel truss arch bridge should be adopted by reasonable cylindrical arch hinge, and Hertz theory is in the analysis of the arch hinge contact does not apply.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-08-20

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

  20. The application of strain field intensity method in the steel bridge fatigue life evaluation

    Science.gov (United States)

    Zhao, Xuefeng; Wang, Yanhong; Cui, Yanjun; Cao, Kaisheng

    2012-04-01

    Asce's survey shows that 80%--90% bridge damage were associated with fatigue and fracture problems. With the operation of vehicle weight and traffic volume increases constantly, the fatigue of welded steel bridge is becoming more and more serious in recent years. A large number of studies show that most prone to fatigue damage of steel bridge is part of the welding position. Thus, it's important to find a more precise method to assess the fatigue life of steel bridge. Three kinds of fatigue analysis method is commonly used in engineering practice, such as nominal stress method, the local stress strain method and field intensity method. The first two methods frequently used for fatigue life assessment of steel bridge, but field intensity method uses less ,and it widely used in fatigue life assessment of aerospace and mechanical. Nominal stress method and the local stress strain method in engineering has been widely applied, but not considering stress gradient and multiaxial stress effects, the accuracy of calculation stability is relatively poor, so it's difficult to fully explain the fatigue damage mechanism. Therefore, it used strain field intensity method to evaluate the fatigue life of steel bridge. The fatigue life research of the steel bridge based on the strain field method and the fatigue life of the I-section plate girder was analyzed. Using Ansys on the elastoplastic finite element analysis determined the dangerous part of the structure and got the stress-strain history of the dangerous point. At the same time, in order to divide the unit more elaborate introduced the sub-structure technology. Finally, it applies K.N. Smith damage equation to calculate the fatigue life of the dangerous point. In order to better simulating the actual welding defects, it dug a small hole in the welding parts. It dug different holds from different view in the welding parts and plused the same load to calculate its fatigue life. Comparing the results found that the welding

  1. Self-supporting method; an alternative method for steel truss bridge element replacement

    Science.gov (United States)

    Arsyad, Muhammad; Sangadji, Senot; As’ad, Sholihin

    2017-11-01

    Steel truss bridge often requires replacement of its element due to serious damage caused by traffic accidents. This replacement is carried out using temporary supporting structure. It would be difficult when the available space for the temporary structure is quite limited and or the position of work is at a high elevation. The self-supporting method is proposed instead of temporary supporting structure. This paper will discuss an innovative method of bridge rehabilitation by utilizing the existing bridge structure. It requires such temporary connecting structure that installed on the existing bridge element, therefore, the forces during replacement process could be transferred to the bridge foundation directly. By taking the case on a steel truss bridge Jetis Salatiga which requires element replacement due to its damages on two main diagonals, a modeling is carried out to get a proper repair method. Structural analysis is conducted for three temporary connecting structure models: “I,” “V,” and triangular model. Stresses and translations that occur in the structure are used as constraints. Bridge bearings are modeled in two different modes: fixed-fixed system and fixed-free one. Temperature load is given in each condition to obtain the appropriate time for execution. The triangular model is chosen as the best one. In the fixed-fixed mode, this method can be carried out in a temperature range 27-28.8° C, while in fixed-free one, the temperature it is allowed between 27-43.4 °C. The D4 is dismantled first by cutting the D4 leaving an area of 1140.2 mm2 or 127 mm web length to enable plastic condition until the D4 collapses. At the beginning of elongation occurs, immediately performed a slowly jacking on a temporary connecting structure so that the force on D4 is gradually transferred to the temporary connecting structure then the D4 and D5 are set in their place.

  2. Defining Appropriate Temperature for Perfect Erection Time of Steel Arch Bridge Closure to Minimize the Effect of the Thermal Stress. Case Study: The New Kutai Kartenagara Bridge, Indonesia

    Science.gov (United States)

    Sugihardjo, H.; Tavio; Prasetya, D.; Achmad, N. I.

    2017-11-01

    The impact of temperature change could govern the final stress of structural elements in the long-span steel bridges. The study was conducted to investigate the effect of temperature change during the construction of a new steel arch bridge, namely the Kutai Kartanegara Bridge. The main bridge has a total spanning length of 470 meters. The erection method of the bridge was the cantilever method with temporary towers, mast cranes, and stay cables. The deflections and internal forces of the steel elements were analyzed using the Midas Civil software. The study focuses on the effort to find the perfect erection time for the closure with regards to the temperature. By measuring the temperatures of the steel elements during the construction, it was found that they varied between 19 and 64 degrees Celsius. From the results of the analyses with various temperatures, it can be concluded that the recommended temperature for the closure erection was 44.6 degrees Celsius. This temperature is similar with the air temperature between either 6 AM and 12 noon or 12 noon and 6 PM. During this periods of time, the effect of thermal stress on the final internal forces in the bridge elements was found much lesser than those obtained during any other period of time.

  3. Experimental investigation of multilayer surfacing system on orthotropic steel bridge with the five-point bending test

    NARCIS (Netherlands)

    Tzimiris, G.; Liu, X.; Scarpas, A.; Li, J.; Hofman, R.; Voskuilen, J.

    Due to lightweight and flexibility, orthotropic steel deck bridges become popular the last decades but several problems were reported in relation to asphalt surfacing materials such as rutting, cracking, loss of bond between the surfacing system and steel deck. In the Netherlands a surfacing

  4. Remedial Modelling of Steel Bridges through Application of Analytical Hierarchy Process (AHP

    Directory of Open Access Journals (Sweden)

    Maria Rashidi

    2017-02-01

    Full Text Available The deterioration and failure of steel bridges around the world is of growing concern for asset managers and bridge engineers due to aging, increasing volume of traffic and introduction of heavier vehicles. Hence, a model that considers these heuristics can be employed to validate or challenge the practical engineering decisions. Moreover, in a time of increased litigation and economic unrest, engineers require a means of accountability to support their decisions. Maintenance, Repair and Rehabilitation (MR&R of deteriorating bridge structures are considered as expensive actions for transportation agencies and the cost of error in decision making may aggravate problems related to infrastructure funding system. The subjective nature of decision making in this field could be replaced by the application of a Decision Support System (DSS that supports asset managers through balanced consideration of multiple criteria. The main aim of this paper is to present the developed decision support system for asset management of steel bridges within acceptable limits of safety, functionality and sustainability. The Simplified Analytical Hierarchy Process S-AHP is applied as a multi criteria decision making technique. The model can serve as an integrated learning tool for novice engineers, or as an accountability tool for assurance to project stakeholders.

  5. Fatigue assessment of an existing steel bridge by finite element modelling and field measurements

    Science.gov (United States)

    Kwad, J.; Alencar, G.; Correia, J.; Jesus, A.; Calçada, R.; Kripakaran, P.

    2017-05-01

    The evaluation of fatigue life of structural details in metallic bridges is a major challenge for bridge engineers. A reliable and cost-effective approach is essential to ensure appropriate maintenance and management of these structures. Typically, local stresses predicted by a finite element model of the bridge are employed to assess the fatigue life of fatigue-prone details. This paper illustrates an approach for fatigue assessment based on measured data for a connection in an old bascule steel bridge located in Exeter (UK). A finite element model is first developed from the design information. The finite element model of the bridge is calibrated using measured responses from an ambient vibration test. The stress time histories are calculated through dynamic analysis of the updated finite element model. Stress cycles are computed through the rainflow counting algorithm, and the fatigue prone details are evaluated using the standard SN curves approach and the Miner’s rule. Results show that the proposed approach can estimate the fatigue damage of a fatigue prone detail in a structure using measured strain data.

  6. Monitoring of a steel incrementally launched bridge construction with strain and temperature FBGs sensors

    Science.gov (United States)

    Bueno, Antonio; Torres, Benjamín; Barrera, David; Calderón, Pedro; Sales, Salvador

    2010-04-01

    We present in this paper the results of monitoring the construction process of a steel incrementally launched bridge located at the Kadagua Valley in Bilbao (Spain) with FBG sensors. The installation of FBG strain and temperature sensors was done in order to obtain deformation and temperature variations during the launching operation. The deflection recovery process was also monitored. The setup carried out in the sensors installation process consists of five optical channels (one for each cross section monitored) and a multiplexed structure of nine strain sensor in each optical channel. Temperature sensors were also installed in order to measure temperature variation of the steel structure but also for thermal compensation for the FBG strain sensors. The installation of the optical sensors is explained in detail including cleaning, bonding and connection of the almost fifty sensors installed in this structure. We also are going to explain the behaviour of the steel structure by presenting several figures showing the strain values for each sensor taken in real time during the launching of the bridge.

  7. Fatigue assessment for selected connections of structural steel bridge components using the finite elements method

    Science.gov (United States)

    Śledziewski, Krzysztof

    2018-01-01

    Material fatigue it is one of the most frequent causes of steel bridge failures, particularly the bridges already existing. Thus, the procedure of fatigue life assessment is one of the most relevant procedures in a comprehensive assessment of load-carrying capacity and service life of the structure. A reliable assessment of the fatigue life is predominantly decisive for estimation of the remaining service life. Hitherto, calculation methods of welded joints took into account only stresses occurring in cross sections of whole elements and did not take into account stress concentration occurring in the vicinity of the weld, caused by geometrical aspects of the detail. At present, use of the Finite Element Analysis, makes possible looking for more accurate approach to the fatigue design of steel structures. The method of geometrical stresses is just such approach which is based on definition of stresses which take into account geometry of the detail. The study presents fatigue assessment of a representative type of welded joint in welded bridge structures. The testing covered longitudinal attachments. The main analyses were carried out on the basis of FEM and the method of local stresses, so-called "hot-spot" stresses. The obtained values of stresses were compared with the values obtained in accordance with the method of nominal stress.

  8. EXPERIMENTAL STUDY ABOUT THE APPLICATIONS OF REINFORCED CONCRETE BRIDGE PIERS WITH HIGH-STRENGTH-STEEL LONGITUDINAL AND HOOP REINFORCEMENT

    Science.gov (United States)

    Sogabe, Naoki; Kitsugi, Katsuhiko; Ibuki, Kazuyuki; Moriyama, Yoichi; Ishiyama, Kazuyuki; Yamanobe, Shinichi; Suda, Kumiko; Watanabe, Yoshimitsu

    The cross-sectional area of reinforced concrete bridge piers and the number of longitudinal reinforcing bars required for bridge piers can be reduced by usin g high-strength reinforcing steel with a yield strength of 685 N/mm2. Reduction in the quantity of materials for bridge pier structures is effective in enhancing constructibility and reducing construction cost because pier foundations can be made smaller. As an example of use of high-strength reinforcing steel in reinforced concrete bridge piers, high-strength blast furnace steel has been used to reinforce tall (about 60 to 120 m) bridge piers made with concrete with a design strength of 50 N/mm2. In this study, verification was made, through a series of structural experiments, with respect to the structural characteristics of concrete piers reinforced with high-strength electric furnace steel. This paper re ports the findings that may help promote the use of high-strength reinforcing steel in reinforced concrete piers.

  9. Structural Aspects of Railway Truss Bridges Affecting Transverse Shear Forces in Steel-Concrete Composite Decks

    Directory of Open Access Journals (Sweden)

    Siekierski Wojciech

    2015-03-01

    Full Text Available At the steel-concrete interface, the horizontal shear forces that are transverse to cross beams occur due to joint action of the steel-concrete composite deck and the truss girders. Numerical analysis showed that values of the forces are big in comparison to the longitudinal shear forces. In both cases extreme force values occur near side edges of a slab. The paper studies possibilities of reduction of these shear forces by structural alterations of the following: rigidity of a concrete slab, arrangement of a wind bracing, arrangement of concrete slab expansion joints. An existing railway truss bridge span has been analysed. Numerical analysis shows that it is possible to reduce the values of shear forces transverse to cross beams. It may reach 20% near the side edges of slabs and 23% in the centre of slab width.

  10. Strain-Based Evaluation of a Steel Through-Girder Railroad Bridge

    Directory of Open Access Journals (Sweden)

    Andrew N. Daumueller

    2012-01-01

    Full Text Available In the state of New Mexico (USA, passenger rail began in 2008 between Belen and Santa Fe on the Rail Runner, following the acquisition of about 100 miles of existing rail and related infrastructure. Many of the bridges on this route are over 100 years old and contain fatigue prone details. This study focuses on a steel through-girder bridge along this corridor. To accurately evaluate these structures for load carrying capacity and fatigue, an accurate analytical model is required. Accordingly, four models were developed to study the sensitivity of a bridge in New Mexico to floor-system connection fixity and the ballast. A diagnostic load test was also performed to evaluate the accuracy of the finite-element models at locations of maximum moments. Comparisons between the simulated and measured bridge response were made based on strain profiles, peak strains, and Palmgren-Miner’s sums. It was found that the models including the ballast were most accurate. In most cases, the pinned ended models were closer to the measured strains. The floor beams and girders were relatively insensitive to the ballast and end conditions of the floor-system members, whereas the stringers were sensitive to the modeling of the ballast.

  11. Numerical simulations and experimental measurements of steel and ice impacts on concrete for acoustic interrogation of delaminations in bridge decks

    Science.gov (United States)

    Mazzeo, Brian A.; Patil, Anjali N.; Klis, Jeffrey M.; Hurd, Randy C.; Truscott, Tadd T.; Guthrie, W. Spencer

    2014-02-01

    Delaminations in bridge decks typically result from corrosion of the top mat of reinforcing steel, which leads to a localized separation of the concrete cover from the underlying concrete. Because delaminations cannot be detected using visual inspection, rapid, large-area interrogation methods are desired to characterize bridge decks without disruption to traffic, without the subjectivity inherent in existing methods, and with increased inspector safety. To this end, disposable impactors such as water droplets or ice chips can be dropped using automatic dispensers onto concrete surfaces to excite mechanical vibrations while acoustic responses can be recorded using air-coupled microphones. In this work, numerical simulations are used to characterize the flexural response of a model concrete bridge deck subject to both steel and ice impactors, and the results are compared with similar experiments performed in the laboratory on a partially delaminated concrete bridge deck slab. The simulations offer greater understanding of the kinetics of impacts and the responses of materials.

  12. Long-term gage reliability for structural health monitoring of steel bridges

    Science.gov (United States)

    Samaras, Vasilis A.; Fasl, Jeremiah; Reichenbach, Matt; Helwig, Todd; Wood, Sharon; Frank, Karl

    2012-04-01

    Real-time monitoring of fracture critical steel bridges can potentially enhance inspection practices by tracking the behavior of the bridge. Significant advances have occurred in recent years on the development of robust hardware for field monitoring applications. These systems can monitor, process, and store data from a variety of sensors (e.g. strain gages, crack propagation gages etc.) to track changes in the behavior of the bridge. Thus, for a long-term monitoring system to be successful, the reliability of gages that are to be monitored for several years is very important. This paper focuses on the results of a research study focused on developing a wireless monitoring system with a useful life of more than 10 years. An important aspect of the study is to identify strain gages and installation procedures that result in long lives as well as characterizing the effect of temperature fluctuations and other environmental factors on the sensor drift and noise. In long-term monitoring applications, slight sensor drift and noise can build up over time to produce misleading results. Thus, a wide variety of gages that can be used to monitor bridges have been tested for over a year through environmental tests. The environmental tests were developed to determine the durability of the gages and their protective coatings (e.g. zinc-based spray, wax and silicon, etc.) against humidity, sun exposure and other environmental effects that are expected in long-term bridge monitoring applications. Moreover, fatigue tests were performed to determine the fatigue category of the weldable gages and to reveal any debonding issues of the bondable gages. This paper focuses on the results of laboratory tests on gage durability that were conducted as part of a research project sponsored by the National Institute of Standards and Technology (NIST).

  13. Nondestructive testing of defective ASTM A 514 steel on the I-275 Combs-Hehl twin bridges over the Ohio River in Campbell County, Kentucky.

    Science.gov (United States)

    2010-03-01

    Three defective ASTM A 514 steel splice plates were discovered on the I-275 Combs-Hehl twin bridges over the Ohio River. A follow-on in-depth field inspection of 1,356 A 514 steel plates on the bridges revealed 14 additional defective gusset and spli...

  14. Steel bridge in interaction with modern slab track fastening systems under various vertical load levels

    Science.gov (United States)

    Stančík, Vojtěch; Ryjáček, Pavel; Vokáč, Miroslav

    2017-09-01

    In modern slab tracks the continuously welded rail (CWR) is coupled through the fastening system with the substructure. The resulting restriction of expansion movement causes significant rail stress increments, which in the case of extreme loading may cause rail failures. These interaction phenomenon effects are naturally higher on a bridge due to different deformation capabilities of the bridge and the CWR. The presented contribution aims at investigating the state of the art European direct fastening system that is suitable for application on steel bridges. Analysis involves experimental determination of its nonlinear longitudinal interaction parameters under various vertical loads and numerical validation. During experimental procedures a two and a half meter long laboratory sample equipped with four nodes of the Vossloh DFF 300 was tested. There have been checked both DFF 300 modifications using the skl 15 tension clamps and the low resistance skl B15 tension clamps. The effects of clamping force lowering on the interaction parameters have also been investigated. Results are discussed in the paper.

  15. Wireless ultrasonic wavefield imaging via laser for hidden damage detection inside a steel box girder bridge

    Science.gov (United States)

    An, Yun-Kyu; Song, Homin; Sohn, Hoon

    2014-09-01

    This paper presents a wireless ultrasonic wavefield imaging (WUWI) technique for detecting hidden damage inside a steel box girder bridge. The proposed technique allows (1) complete wireless excitation of piezoelectric transducers and noncontact sensing of the corresponding responses using laser beams, (2) autonomous damage visualization without comparing against baseline data previously accumulated from the pristine condition of a target structure and (3) robust damage diagnosis even for real structures with complex structural geometries. First, a new WUWI hardware system was developed by integrating optoelectronic-based signal transmitting and receiving devices and a scanning laser Doppler vibrometer. Next, a damage visualization algorithm, self-referencing f-k filter (SRF), was introduced to isolate and visualize only crack-induced ultrasonic modes from measured ultrasonic wavefield images. Finally, the performance of the proposed technique was validated through hidden crack visualization at a decommissioned Ramp-G Bridge in South Korea. The experimental results reveal that the proposed technique instantaneously detects and successfully visualizes hidden cracks even in the complex structure of a real bridge.

  16. Structural behavior analysis of a continuous steel truss arch railway bridge integrating monitoring data

    Directory of Open Access Journals (Sweden)

    Yong-sheng Song

    2016-12-01

    Full Text Available Using theoretical modeling combined with monitoring data, the typical dynamic and static behaviors of a continuous steel truss arch railway bridge are evaluated. The dynamic behavior involves an impact factor induced by the action of running trains, and the static behavior refers to axial bending performance and the stress distribution among different planes of the truss. The transverse position, length, and speed of running trains are introduced to conduct an analysis of their influences on the dynamic and static behaviors of the bridge superstructure. A structural safety evaluation is also conducted by comparison with the provisions recommended by design codes and by analysis of absolute stress. It is concluded that three types of members present different dynamic behaviors and that the value of the impact factor for chords B exceeds the provision recommended by the design codes. Chords C present the greatest ratio of bending stress versus axial stress. An imbalance of stress distribution exists among the three planes of the truss, and the difference is the smallest when trains run along the middle railways. Because the train-induced stress is considerably lower, the dynamic and static performances of the bridge are within the scope of safety.

  17. Arch-Axis Coefficient Optimization of Long-Span Deck-Type Concrete-Filled Steel Tubular Arch Bridge

    Science.gov (United States)

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

    2017-11-01

    This paper is based on Nanpuxi super major bridge which is under construction and starts from Wencheng Zhejiang province to Taishun highway. A finite element model of the whole bridge is constructed using Midas Civil finite element software. The most adverse load combination in the specification is taken into consideration to determine the method of calculating the arch-axis coefficient of long-span deck-type concrete-filled steel tubular arch bridge. By doing this, this paper aims at providing references for similar engineering projects.

  18. 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....

  19. On the Rust Products Formed on Weathering and Carbon Steels Exposed to Chloride in Dry-Wet Cyclical Processes

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, K. E.; Morales, A. L.; Barrero, C. A., E-mail: cbarrero@fisica.udea.edu.co [Universidad de Antioquia, Grupo de Corrosion y Proteccion, Facultad de Ingenierias (Colombia); Greneche, J. M. [Universite du Maine, Laboratoire de Physique de l' Etat Condense - UMR CNRS 6087 (France)

    2005-02-15

    The rust products formed on weathering and carbon steels exposed to dry-wet cyclical processes in different chloride-rich solutions are carefully examined by means of different techniques. Special emphasis is given to the methodology of analysis of the data using 300 K and 77 K Moessbauer spectrometry and X-ray diffraction. The rust that is loosely bound to the metal surface and that it is lost during the corrosion process, for both types of steel, was found to be composed of lepidocrocite, superparamagnetic goethite, hematite, and traces of akaganeite. On the other hand, the adherent rust, which is differentiated as scraped and hit according to the way it is obtained, from both steels was found to be composed of akaganeite, spinel phase, goethite exhibiting broad distribution of particle sizes and lepidocrocite. The relative abundances of rust components for both steels were very similar, suggesting similar corrosion processes. Mass loss measurements show that the corrosion rates increases with increasing the chloride concentration. The presence of large quantities of spinel phase and akaganeite are a consequence of a corrosion process under the influence of very high chloride concentrations. Our results are useful for assessing the behavior of weathering steels where the levels of chlorides are high or in contact with sea water.

  20. INVESTIGATION OF LAUNCHING PROCESS FOR STEEL REINFORCED CONCRETE FRAMEWORK OF LARGE BRIDGES

    Directory of Open Access Journals (Sweden)

    V. A. Grechukhin

    2017-01-01

    Full Text Available Bridges are considered as the most complicated, labour-consuming and expensive components in roadway network of the Republic of Belarus. So their construction and operation are to be carried out at high technological level. One of the modern industrial methods is a cyclic longitudinal launching of large frameworks which provide the possibility to reject usage of expensive auxiliary facilities and reduce a construction period. There are several variants of longitudinal launching according to shipping conditions and span length: without launching girder, with launching girder, with top strut-framed beam in the form of cable-stayed system, with strut-framed beam located under span. While using method for the cyclic longitudinal launching manufacturing process of span is concentrated on the shore. The main task of the investigations is to select economic, quick and technologically simple type of the cyclic longitudinal launching with minimum resource- and labour inputs. Span launching has been comparatively analyzed with temporary supports being specially constructed within the span and according to capital supports with the help of launching girder. Conclusions made on the basis of calculations for constructive elements of span according to bearing ability of element sections during launching and also during the process of reinforced concrete plate grouting and at the stage of operation have shown that span assembly with application of temporary supports does not reduce steel spread in comparison with the variant excluding them. Results of the conducted investigations have been approbated in cooperation with state enterprise “Belgiprodor” while designing a bridge across river Sozh.

  1. Geodetic monitoring (TLS of a steel transport trestle bridge located in an active mining exploitation site

    Directory of Open Access Journals (Sweden)

    Skoczylas Arkadiusz

    2016-09-01

    Full Text Available Underground mining exploitation causes, in general, irregular vertical and horizontal shifts in the superficial layer of the rock mass. In the case of construction objects seated on this layer, a deformation of the object’s foundation can be observed. This leads to additional loads and deformations. Identification of surface geometry changes in construction objects located within the premises of underground mining exploitation areas is an important task as far as safety of mining sites is concerned. Surveys targeting shifts and deformations in engineering objects preformed with the use of classic methods are of a selective nature and do not provide the full image of the phenomenon being the subject of the observation. This paper presents possibilities of terrestrial laser scanning technology application in the monitoring of engineering objects that allows for a complete spatial documentation of an object subjected to the influence of an active mining exploitation. This paper describes an observation of a 100 m section of a steel transport trestle bridge located on the premises of hard coal mine Lubelski Węgiel “Bogdanka” S.A. carried out in 2015. Measurements were carried out using a Z+F Imager 5010C scanner at an interval of 3.5 months. Changes in the structure’s geometry were determined by comparing the point clouds recorded during the two measurement periods. The results of the analyses showed shifts in the trestle bridge towards the exploited coal wall accompanied by object deformation. The obtained results indicate the possibility of of terrestrial laser scanning application in studying the aftereffects of underground mining exploitation on surface engineering objects.

  2. A new method for detection of fatigue cracking in steel bridge girders using self-powered wireless sensors

    Science.gov (United States)

    Hasni, Hassene; Alavi, Amir H.; Jiao, Pengcheng; Lajnef, Nizar

    2017-04-01

    Development of fatigue cracking is affecting the structural performance of many of welded steel bridges in the United States. This paper presents a support vector machine (SVM) method for the detection of distortion-induced fatigue cracking in steel bridge girders based on the data provided by self-powered wireless sensors (SWS). The sensors have a series of memory gates that can cumulatively record the duration of the applied strain at a specific threshold level. Each sensor output has been characterized by a Gaussian cumulative density function. For the analysis, extensive finite element simulations were carried out to obtain the structural response of an existing highway steel bridge girder (I-96/M- 52) in Webberville, Michigan. The damage states were defined based on the length of the crack. Initial damage indicator features were extracted from the sensor output distribution at different data acquisition nodes. Subsequently, the SVM classifier was developed to identify multiple damage states. A data fusion model was proposed to increase the classification performance. The results indicate that the models have acceptable detection performance, specific ally for cracks larger than 10 mm. The best classification performance was obtained using the information from a group of sensors located near the damage zone.

  3. Iowa's bridge and highway climate change and extreme weather vulnerability assessment pilot.

    Science.gov (United States)

    2015-03-01

    The Iowa Department of Transportation (DOT) is responsible for approximately 4,100 bridges and structures that are a part of the : states primary highway system, which includes the Interstate, US, and Iowa highway routes. A pilot study was conduct...

  4. Remediation and Stabilization of Soils Contaminated by Lead Resulting from the Removal of Paint from Bridges

    OpenAIRE

    Banks, M.K.; Schwab, A. Paul

    2005-01-01

    Lead-based paints are commonly used for painting steel bridge structures. Soils in the immediate vicinity of older bridges have been contaminated with Pb as a result of normal weathering and peeling of the paint coupled with removal prior to repainting. The objectives of this project were to assess the extent of lead contamination near highway bridges and to evaluate phytoremediation and immobilization as means of remediation. We examined soils in the vicinity of approximately 20 bridges in I...

  5. Experimental and Analytical Investigation of Deformations and Stress Distribution in Steel Bands of a Two-Span Stress-Ribbon Pedestrian Bridge

    Directory of Open Access Journals (Sweden)

    G. Sandovic

    2017-01-01

    Full Text Available The article is dedicated to the analysis of problems related to design of pedestrian bridges with flexible ribbon bands made of steel. The study is based on test results of a bridge model that has two spans (each with a length of five meters. A simplified analytical technique has been proposed for predicting vertical deformations of the bridge structure subjected to symmetrical or asymmetrical loading patterns. The technique also allows assessing the tension forces in the ribbons, which are very important for design of such structures. The analysis reveals the importance of the flexural rigidity of the ribbons that might cause significant redistribution of stresses within the steel bands.

  6. Rust Layer Formed on Low Carbon Weathering Steels with Different Mn, Ni Contents in Environment Containing Chloride Ions

    Directory of Open Access Journals (Sweden)

    Gui-qin FU

    2016-11-01

    Full Text Available The rusting evolution of low carbon weathering steels with different Mn, Ni contents under a simulated environment containing chloride ions has been investigated to clarify the correlation between Mn, Ni and the rust formed on steels. The results show that Mn contents have little impact on corrosion kinetics of experimental steels. Content increase of Ni both enhances the anti-corrosion performance of steel substrate and the rust. Increasing Ni content is beneficial to forming compact rust. Semi-quantitative XRD phase analysis shows that the quantity ratio of α/γ*(α-FeOOH/(γ-FeOOH+Fe3O4 decreases as Mn content increases but it increases as Ni content increases. Ni enhances rust layer stability but Mn content exceeding 1.06 wt.% is disadvantageous for rust layer stability. The content increase of Mn does not significantly alter the parameters of the polarization curve. However, as Ni contents increases, Ecorr has shifted to the positive along with decreased icorr values indicating smaller corrosion rate especially as Ni content increases from 0.42 wt.% to 1.50 wt.%.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12844

  7. Immobilization of lead by application of soil amendment produced from vinegar residue, stainless steel slag, and weathered coal.

    Science.gov (United States)

    Pei, Guangpeng; Li, Yuxin; Zhu, Yuen; Shi, Weiyu; Li, Hua

    2017-10-01

    This paper presents a new soil amendment used for immobilization of soil Pb, produced from vinegar residue, stainless steel slag, and weathered coal. The pH value measuring, granulation and adsorption experiments were carried out to determine the optimal composition of soil amendment. Optimizing soil amendment B2 was composed of vinegar residue, weathered coal (humic acid 61.53 wt%), and stainless steel slag with the ratio of 80∶16∶4, and particle size was in the range of 2-4 mm. In the leaching column experiment, B2 addition reduced the Pb release from the soil as well as increasing leachate pH and decreasing the bioavailable Pb concentration. The leachate Pb concentration decreased with lengthened leaching time under lower pH, but such a phenomenon disappeared in the rebounding period. Compared to control, the DTPA extractable Pb content in soil decreased by 12.41, 13.20, and 8.78% with the B2 addition amount of 1.00, 2.00, and 2.00 wt%, respectively. In addition, the total Pb content of each soil layer generally rose as B2 addition increased. It was concluded that application of B2 led to lower transport and transformation of Pb in soil. Based on the single chemical extraction, the environmental risk of Pb was decreased after application of B2. Meanwhile, soil amendment was also a new way to recycle vinegar residue, stainless steel slag, and weathered coal.

  8. Evaluation of surface modification methods to mitigate rusting and pitting in weathering steel bridges : final report.

    Science.gov (United States)

    1986-09-01

    Accelerated laboratory atmospheric exposure simulation tests with an acceleration factor of 50 and extending for a maximum of 2200 wet-dry cycles (6-year exposure equivalent) gave corrosion loss data that agreed fairly well with the field data derive...

  9. Simulation of a long term atmospheric corrosion process on plain and weathering steels

    Directory of Open Access Journals (Sweden)

    Bolivar, F.

    2003-12-01

    Full Text Available Information on weathering steel behaviour and its rust products characteristics after decades of atmospheric exposure are scarce. On the other side, generally accepted laboratory tests for the assessment of its corrosion resistance have not been developed yet. Consequently, simulating corrosion in the laboratory during long periods of time is attractive for the interesting and complete information obtainable from them. In the present work, AISI-SAE 1008 and ASTM-588 B steel samples have been exposed for two years to a immersion-emersion CEBELCOR type test in the laboratory, simulating a moderate urban atmosphere. Two groups of six samples each were tested. After the first year, three samples of each batch were retired for analysis and the rest was kept until they reached two years of exposure. The half cell electrode potentials were measured daily. The rust was characterized by metallographic techniques, Mossbauer spectroscopy (MS, Fourier transform infrared spectroscopy (FTIR, and X-ray diffraction (XRD. Comparison was done with field exposure experiments reported in the literature, and conclusions on the behaviour of tested samples were drawn looking for differences and similarities with samples and structures under actual atmospheric conditions.

    La información sobre el comportamiento y las características de los productos de corrosión de los aceros auto protectores, después de varias décadas de exposición a la atmósfera, es escasa. Por otra parte, aún no se han desarrollado ensayos de laboratorio de aceptación general para evaluar su resistencia a la corrosión. En consecuencia, cada día toman más importancia los ensayos de laboratorio durante largos periodos de exposición. En el presente trabajo, se sometieron muestras de acero AISI-SAE 1008 y ASTM 588-B, durante dos años, a un ensayo de laboratorio de inmersión-emersión tipo CEBELCOR. Se ensayaron dos grupos de seis muestras de cada composición de acero, en una

  10. Bridges

    NARCIS (Netherlands)

    Zant, W.

    2017-01-01

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

  11. Steel framing strategies for highly skewed bridges to reduce/eliminate distortion near skewed supports : [summary].

    Science.gov (United States)

    2014-05-01

    In the past, bridges were aligned normal to crossing roads or obstacles in order to simplify bridge construction. However, the continuing expansion of the interstate system has challenged engineers to provide more horizontal clearance, reduce right-o...

  12. Modeling the response of fracture critical steel box-girder bridges.

    Science.gov (United States)

    2010-02-01

    Bridges that are classified as fracture critical by AASHTO require more frequent inspections than other types of : bridges, resulting in greater costs for their maintenance. Several historical events have shown, however, that : severe damage can occu...

  13. An Automated Sensing System for Steel Bridge Inspection Using GMR Sensor Array and Magnetic Wheels of Climbing Robot

    Directory of Open Access Journals (Sweden)

    Rui Wang

    2016-01-01

    Full Text Available Corrosion is one of the main causes of deterioration of steel bridges. It may cause metal loss and fatigue cracks in the steel components, which would lead to the collapse of steel bridges. This paper presents an automated sensing system to detect corrosion, crack, and other kinds of defects using a GMR (Giant Magnetoresistance sensor array. Defects will change the relative permeability and electrical conductivity of the material. As a result, magnetic field density generated by ferromagnetic material and the magnetic wheels will be changed. The defects are able to be detected by using GMR sensor array to measure the changes of magnetic flux density. In this study, magnetic wheels are used not only as the adhesion device of the robot, but also as an excitation source to provide the exciting magnetic field for the sensing system. Furthermore, compared to the eddy current method and the MFL (magnetic flux leakage method, this sensing system suppresses the noise from lift-off value fluctuation by measuring the vertical component of induced magnetic field that is perpendicular to the surface of the specimen in the corrosion inspection. Simulations and experimental results validated the feasibility of the system for the automated defect inspection.

  14. Study on Performance of Steel Fiber Concrete Bridge Pier Specimens under Horizontal Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Baiben Chen

    2017-01-01

    Full Text Available Because of that steel fiber can effectively prevent the extension and development of small cracks in the concrete, steel fiber reinforced concrete has good toughness and tensile strength. In the application of building materials, steel fiber reinforced concrete is an ideal elastic-plastic material. For the seismic performance, it has advantages. In order to analyze the seismic performance of steel fiber reinforced concrete, 4 piers of the scale model test under horizontal cyclic loading were done. The results showed that failure mode of steel fiber reinforced concrete is better than that of ordinary concrete, and has a large yield moment under the external loads.

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

    OpenAIRE

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2017-01-01

    The construction sector is a major source of greenhouse gases. Under the increasingconcern in climate change and growing construction activities, the whole sector is challengedto shift focus toward sustainable solutions. The traditional procurement oftenprioritizes the technical and economic viability, while their environmental performance is overlooked. Today’s designers are urged to seek new design options to reduce the environmental burdens. Sweden owns more than 24574 bridges and most of ...

  16. Cluster analysis of stress corrosion mechanisms for steel wires used in bridge cables through acoustic emission particle swarm optimization.

    Science.gov (United States)

    Li, Dongsheng; Yang, Wei; Zhang, Wenyao

    2017-05-01

    Stress corrosion is the major failure type of bridge cable damage. The acoustic emission (AE) technique was applied to monitor the stress corrosion process of steel wires used in bridge cable structures. The damage evolution of stress corrosion in bridge cables was obtained according to the AE characteristic parameter figure. A particle swarm optimization cluster method was developed to determine the relationship between the AE signal and stress corrosion mechanisms. Results indicate that the main AE sources of stress corrosion in bridge cables included four types: passive film breakdown and detachment of the corrosion product, crack initiation, crack extension, and cable fracture. By analyzing different types of clustering data, the mean value of each damage pattern's AE characteristic parameters was determined. Different corrosion damage source AE waveforms and the peak frequency were extracted. AE particle swarm optimization cluster analysis based on principal component analysis was also proposed. This method can completely distinguish the four types of damage sources and simplifies the determination of the evolution process of corrosion damage and broken wire signals. Copyright © 2017. Published by Elsevier B.V.

  17. Weathering steel as a potential source for metal contamination: Metal dissolution during 3-year of field exposure in a urban coastal site.

    Science.gov (United States)

    Raffo, Simona; Vassura, Ivano; Chiavari, Cristina; Martini, Carla; Bignozzi, Maria C; Passarini, Fabrizio; Bernardi, Elena

    2016-06-01

    Surface and building runoff can significantly contribute to the total metal loading in urban runoff waters, with potential adverse effects on the receiving ecosystems. The present paper analyses the corrosion-induced metal dissolution (Fe, Mn, Cr, Ni, Cu) from weathering steel (Cor-Ten A) with or without artificial patinas, exposed for 3 years in unsheltered conditions at a marine urban site (Rimini, Italy). The influence of environmental parameters, atmospheric pollutants and surface finish on the release of dissolved metals in rain was evaluated, also by means of multivariate analysis (two-way and three-way Principal Component Analysis). In addition, surface and cross-section investigations were performed so as to monitor the patina evolution. The contribution provided by weathering steel runoff to the dissolved Fe, Mn and Ni loading at local level is not negligible and pre-patination treatments seem to worsen the performance of weathering steel in term of metal release. Metal dissolution is strongly affected by extreme events and shows seasonal variations, with different influence of seasonal parameters on the behaviour of bare or artificially patinated steel, suggesting that climate changes could significantly influence metal release from this alloy. Therefore, it is essential to perform a long-term monitoring of the performance, the durability and the environmental impact of weathering steel. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Mössbauer and XRD analysis of corrosion products on weathering steel treated by wet-dry cycles using various solutions

    Energy Technology Data Exchange (ETDEWEB)

    Oyabu, Matashige; Nomura, Kiyoshi, E-mail: dqf10204@nifty.com [Kanazawa Institute of Technology (Japan); Koike, Yuya [Meiji University, Department of Applied Chemistry (Japan); Okazawa, Atsushi [The University of Tokyo, School of Arts and Sciences (Japan)

    2016-12-15

    Weathering steels (COR-TEN) were corroded by wet-dry cycles using a splay of various solutions in a laboratory. Corrosion products on weathering steel were characterized by X-ray diffractometry and Mössbauer spectrometry at room and low temperatures. Fine α-FeOOH, γ-FeOOH and γ-Fe {sub 2}O{sub 3} are fundamentally formed in various atmospheric conditions. β-FeOOH is additionally formed under the existence of chloride ions, but not formed when sulfate ions are coexisting. Spraying a NaF solution prevents the progress of corrosion.

  19. Simulation Study on Train-Induced Vibration Control of a Long-Span Steel Truss Girder Bridge by Tuned Mass Dampers

    Directory of Open Access Journals (Sweden)

    Hao Wang

    2014-01-01

    Full Text Available Train-induced vibration of steel truss bridges is one of the key issues in bridge engineering. This paper talks about the application of tuned mass damper (TMD on the vibration control of a steel truss bridge subjected to dynamic train loads. The Nanjing Yangtze River Bridge (NYRB is taken as the research object and a recorded typical train load is included in this study. With dynamic finite element (FE method, the real-time dynamic responses of NYRB are analyzed based on a simplified train-bridge time-varying system. Thereinto, two cases including single train moving at one side and two trains moving oppositely are specifically investigated. According to the dynamic characteristics and dynamic responses of NYRB, the fourth vertical bending mode is selected as the control target and the parameter sensitivity analysis on vibration control efficiency with TMD is conducted. Using the first-order optimization method, the optimal parameters of TMD are then acquired with the control efficiency of TMD, the static displacement of Midspan, expenditure of TMDs, and manufacture difficulty of the damper considered. Results obtained in this study can provide references for the vibration control of steel truss bridges.

  20. Impact on the environment from steel bridge paint deterioration using lead isotopic tracing, paint compositions and soil deconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Gulson, Brian, E-mail: brian.gulson@mq.edu.au [Department of Environmental Science, Macquarie University, Sydney, NSW 2109 (Australia); CSIRO Energy Flagship, North Ryde, NSW 2113 (Australia); Chiaradia, Massimo [Department of Mineralogy, University of Geneva, Geneva (Switzerland); Davis, Jeffrey [CSIRO Energy Flagship, North Ryde, NSW 2113 (Australia); O' Connor, Gary [Queensland Department of Environment & Heritage Protection, Brisbane, QLD 4000 (Australia)

    2016-04-15

    Deterioration and repair of lead paint on steel structures can result in contamination of the ambient environment but other sources of lead such as from past use of leaded paint and gasoline and industrial activities can also contribute to the contamination. Using a combination of high precision lead isotopic tracing, detailed paint examination, including with scanning electron microscopy, and soil deconstruction we have compared paint on a steel bridge and bulk soil and lead-rich particles separated from soil. The majority of Pb found in the paint derives from Australian sources but some also has a probable US origin. The isotopic data for the bulk soils and selected particles lie on a mixing line with end members the geologically ancient Broken Hill lead and possible European lead which is suggested to be derived from old lead paint and industrial activities. Data for gasoline-derived particulates lie on this array and probably contribute to soil Pb. Although paint from the bridge can be a source of lead in the soils, isotopic tracing, paint morphology and mineralogical identification indicate that other sources, including from paint, gasoline and industrial activities, are contributing factors to the lead burden. Even though physical characteristics and elemental composition are the same in some particles, the isotopic signatures demonstrate that the sources are different. Plots using {sup 206}Pb/{sup 208}Pb vs {sup 206}Pb/{sup 207}Pb ratios, the common representation these days, do not allow for source discrimination in this investigation. - Highlights: • Soil Pb values up to 1200 mg/kg below Pb painted bridge • Microscopy & SEM characterised up to 6 different paint layers. • Isotopes identified different sources of Pb including paint and gasoline. • Multiple methods provide definitive answers.

  1. On the mechanisms of the corrosion of weathering steel by SO2 in laboratory studies: influence of the environmental parameters

    Science.gov (United States)

    Marco, J. F.

    2017-11-01

    We report here on the mechanisms underlying the corrosion of weathering steel in accelerated laboratory tests using artificially polluted SO2-atmospheres. The role of corrosion parameters such as the SO2 concentration, the exposure time, the relative humidity and temperature of the environment are discussed in detail. Through the extensive use of Mössbauer spectroscopy in both its transmission and electron detection modes, as well as with the help of other analysis techniques, the characterization of the different corrosion products at the various stages of the corrosion process has been carried out. The results complement the data obtained in field studies and help to understand the mechanisms involved in this complex phenomenon.

  2. Digital image rectification tool for metrification of gusset plate connections in steel truss bridges.

    Science.gov (United States)

    2009-03-01

    A method was developed to obtain dimensional data from photographs for analyzing steel truss gusset plate : connections. The method relies on a software application to correct photographic distortion and to scale the : photographs for analysis. The a...

  3. Co-reduction of Copper Smelting Slag and Nickel Laterite to Prepare Fe-Ni-Cu Alloy for Weathering Steel

    Science.gov (United States)

    Guo, Zhengqi; Pan, Jian; Zhu, Deqing; Zhang, Feng

    2018-02-01

    In this study, a new technique was proposed for the economical and environmentally friendly recovery of valuable metals from copper smelting slag while simultaneously upgrading nickel laterite through a co-reduction followed by wet magnetic separation process. Copper slag with a high FeO content can decrease the liquidus temperature of the SiO2-Al2O3-CaO-MgO system and facilitate formation of liquid phase in a co-reduction process with nickel laterite, which is beneficial for metallic particle growth. As a result, the recovery of Ni, Cu, and Fe was notably increased. A crude Fe-Ni-Cu alloy with 2.5% Ni, 1.1% Cu, and 87.9% Fe was produced, which can replace part of scrap steel, electrolytic copper, and nickel as the burden in the production of weathering steel by an electric arc furnace. The study further found that an appropriate proportion of copper slag and nickel laterite in the mixture is essential to enhance the reduction, acquire appropriate amounts of the liquid phase, and improve the growth of the metallic alloy grains. As a result, the liberation of alloy particles in the grinding process was effectively promoted and the metal recovery was increased significantly in the subsequent magnetic separation process.

  4. Co-reduction of Copper Smelting Slag and Nickel Laterite to Prepare Fe-Ni-Cu Alloy for Weathering Steel

    Science.gov (United States)

    Guo, Zhengqi; Pan, Jian; Zhu, Deqing; Zhang, Feng

    2017-11-01

    In this study, a new technique was proposed for the economical and environmentally friendly recovery of valuable metals from copper smelting slag while simultaneously upgrading nickel laterite through a co-reduction followed by wet magnetic separation process. Copper slag with a high FeO content can decrease the liquidus temperature of the SiO2-Al2O3-CaO-MgO system and facilitate formation of liquid phase in a co-reduction process with nickel laterite, which is beneficial for metallic particle growth. As a result, the recovery of Ni, Cu, and Fe was notably increased. A crude Fe-Ni-Cu alloy with 2.5% Ni, 1.1% Cu, and 87.9% Fe was produced, which can replace part of scrap steel, electrolytic copper, and nickel as the burden in the production of weathering steel by an electric arc furnace. The study further found that an appropriate proportion of copper slag and nickel laterite in the mixture is essential to enhance the reduction, acquire appropriate amounts of the liquid phase, and improve the growth of the metallic alloy grains. As a result, the liberation of alloy particles in the grinding process was effectively promoted and the metal recovery was increased significantly in the subsequent magnetic separation process.

  5. History of Connecticut's short-term strain program for evaluation of steel bridges : July 2009.

    Science.gov (United States)

    2009-07-01

    Non-destructive strain monitoring has been used for two decades on Connecticuts bridges to : supplement visual field inspections. These studies have addressed a wide range of problems, : including fatigue cracking in diaphragm connections, cracked...

  6. Experimental use of Line-X coated steel pipe piles, Clay Hill Bridge (#2157) replacement project over the Mousam River, Route 9/Western Avenue, Kennebunk, Maine.

    Science.gov (United States)

    2013-02-01

    Steel pipe piles used by MaineDOT for bridge construction are typically coated with a fusion-bonded epoxy (FBE). FBE is a powder-based coating with properties similar to traditional : epoxies. Its name is derived from the process by which it adheres ...

  7. Field investigation of the corrosion protection performance of bridge decks and piles constructed with epoxy-coated reinforcing steel in Virginia.

    Science.gov (United States)

    1997-10-01

    The corrosion protection performance of epoxy-coated reinforcing steel (ECR) was assessed in three bridge decks and the piles : in three marine structures in Virginia in 1996. The decks were 17 years old, two of the marine structures were 8 years old...

  8. Hollow-core FRP-concrete-steel bridge columns under extreme loading.

    Science.gov (United States)

    2015-04-01

    This report presents the behavior of hollow-core fiber reinforced polymer concrete - steel columns (HC-FCS) under : combined axial-flexural as well as vehicle collision loads. The HC-FCS column consists of a concrete wall sandwiched between an ou...

  9. The behaviour of trough stiffener to crossbeam connections in orthotropic steel bridge decks

    NARCIS (Netherlands)

    Leendertz, J.S.; Kolstein, M.H.

    1995-01-01

    This article describes the behaviour and stress analysis of the crossbeams in orthotropic steel decks with continuous trapezoidal closed stiffeners. The trough stiffener to crossbeam connections, with or without cope holes, influence the behaviour of the crossbeam. The effects can be transferred to

  10. Modelling and Optimizing Imperfect Maintenance of Coatings on Steel Structures

    NARCIS (Netherlands)

    R.P. Nicolai (Robin); J.B.G. Frenk (Hans); R. Dekker (Rommert)

    2007-01-01

    textabstractSteel structures such as bridges, tanks and pylons are exposed to outdoor weathering conditions. In order to prevent them from corrosion they are protected by an organic coating system. Unfortunately, the coating system itself is also subject to deterioration. Imperfect maintenance

  11. Weathering resistance of thin plasma polymer films on pre-coated steel =

    Science.gov (United States)

    Serra, Ricardo Gil Henriques

    O trabalho apresentado teve origem no projecto de investigacao “Tailored Thin Plasma Polymers Films for Surface Engineering of Coil Coated Steel”, financiado pelo Programa Europeu ECSC Steel Research. Sistemas de aco galvanizado pre-pintado em banda a base de poliester e poliuretano foram submetidos a um processo de polimerizacao por plasma onde um filme fino foi depositado de modo a modificar as propriedades de superficie. Foram usados reactores de catodo oco, microondas e radio frequencia para a deposicao do polimero fino. Os sistemas preparados foram analisados de modo a verificar a influencia do processo de polimerizacao por plasma na alteracao das propriedades barreira dos sistemas pre-pintados em banda. Foi estudado o efeito dos diferentes passos do processo de polimerizacao por plasma, bem como o efeito de diferentes variaveis operatorias. A mistura precursora foi variada de modo a modificar as propriedades da superficie de modo a poder vir a obter maior hidrofobicidade, maior resistencia a marcas digitais, bem como maior facilidade de limpeza. Os testes foram conduzidos em solucao de NaCl 0,5 M. Para o trabalho foram usadas tecnicas de analise da morfologia da superficie como Microscopia de Forca Atomica e Microscopia Electronica de Varrimento. As propriedades electroquimicas dos sistemas foram estudadas por Espectroscopia de Impedancia Electroquimica. A estrutura dos filmes gerados no processo de polimerizacao por plasma foi caracterizada por Microscopia de Transmissao Electronica. A modificacao das propriedades opticas devido ao processo de polimerizacao por plasma foi tambem obtida.

  12. 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...

  13. Development and evaluation of a dual purpose bridge health monitoring and weigh-in-motion system for a steel girder bridge : phase two.

    Science.gov (United States)

    2016-06-30

    The primary objective of this second phase is the further development, demonstration : and field evaluation of a permanent dual purpose bridge weigh-in-motion and health monitoring : system over an extended period of time. Calibrated test truck resul...

  14. Students design composite bridges

    NARCIS (Netherlands)

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

    1999-01-01

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

  15. On the mechanisms of the corrosion of weathering steel by SO{sub 2} in laboratory studies: influence of the environmental parameters

    Energy Technology Data Exchange (ETDEWEB)

    Marco, J. F., E-mail: jfmarco@iqfr.csic.es [Instituto de Química Física “Rocasolano”, CSIC (Spain)

    2017-11-15

    We report here on the mechanisms underlying the corrosion of weathering steel in accelerated laboratory tests using artificially polluted SO{sub 2}-atmospheres. The role of corrosion parameters such as the SO{sub 2} concentration, the exposure time, the relative humidity and temperature of the environment are discussed in detail. Through the extensive use of Mössbauer spectroscopy in both its transmission and electron detection modes, as well as with the help of other analysis techniques, the characterization of the different corrosion products at the various stages of the corrosion process has been carried out. The results complement the data obtained in field studies and help to understand the mechanisms involved in this complex phenomenon.

  16. Seismic assessment of a multi-span steel railway bridge in Turkey based on nonlinear time history

    Science.gov (United States)

    Yılmaz, Mehmet F.; Çağlayan, Barlas Ö.

    2018-01-01

    Many research studies have shown that bridges are vulnerable to earthquakes, graphically confirmed by incidents such as the San Fernando (1971 USA), Northridge (1994 USA), Great Hanshin (1995 Japan), and Chi-Chi (1999 Taiwan) earthquakes, amongst many others. The studies show that fragility curves are useful tools for bridge seismic risk assessments, which can be generated empirically or analytically. Empirical fragility curves can be generated where damage reports from past earthquakes are available, but otherwise, analytical fragility curves can be generated from structural seismic response analysis. Earthquake damage data in Turkey are very limited, hence this study employed an analytical method to generate fragility curves for the Alasehir bridge. The Alasehir bridge is part of the Manisa-Uşak-Dumlupınar-Afyon railway line, which is very important for human and freight transportation, and since most of the country is seismically active, it is essential to assess the bridge's vulnerability. The bridge consists of six 30 m truss spans with a total span 189 m supported by 2 abutments and 5 truss piers, 12.5, 19, 26, 33, and 40 m. Sap2000 software was used to model the Alasehir bridge, which was refined using field measurements, and the effect of 60 selected real earthquake data analyzed using the refined model, considering material and geometry nonlinearity. Thus, the seismic behavior of Alasehir railway bridge was determined and truss pier reaction and displacements were used to determine its seismic performance. Different intensity measures were compared for efficiency, practicality, and sufficiency and their component and system fragility curves derived.

  17. Seismic assessment of a multi-span steel railway bridge in Turkey based on nonlinear time history

    Directory of Open Access Journals (Sweden)

    M. F. Yılmaz

    2018-01-01

    Full Text Available Many research studies have shown that bridges are vulnerable to earthquakes, graphically confirmed by incidents such as the San Fernando (1971 USA, Northridge (1994 USA, Great Hanshin (1995 Japan, and Chi-Chi (1999 Taiwan earthquakes, amongst many others. The studies show that fragility curves are useful tools for bridge seismic risk assessments, which can be generated empirically or analytically. Empirical fragility curves can be generated where damage reports from past earthquakes are available, but otherwise, analytical fragility curves can be generated from structural seismic response analysis. Earthquake damage data in Turkey are very limited, hence this study employed an analytical method to generate fragility curves for the Alasehir bridge. The Alasehir bridge is part of the Manisa–Uşak–Dumlupınar–Afyon railway line, which is very important for human and freight transportation, and since most of the country is seismically active, it is essential to assess the bridge's vulnerability. The bridge consists of six 30 m truss spans with a total span 189 m supported by 2 abutments and 5 truss piers, 12.5, 19, 26, 33, and 40 m. Sap2000 software was used to model the Alasehir bridge, which was refined using field measurements, and the effect of 60 selected real earthquake data analyzed using the refined model, considering material and geometry nonlinearity. Thus, the seismic behavior of Alasehir railway bridge was determined and truss pier reaction and displacements were used to determine its seismic performance. Different intensity measures were compared for efficiency, practicality, and sufficiency and their component and system fragility curves derived.

  18. Analysis on Adhesively-Bonded Joints of FRP-steel Composite Bridge under Combined Loading: Arcan Test Study and Numerical Modeling

    Directory of Open Access Journals (Sweden)

    Xu Jiang

    2016-01-01

    Full Text Available The research presented in this paper is an experimental study and numerical analysis on mechanical behavior of the adhesively-bonded joint between FRP sandwich bridge deck and steel girder. Generally, there are three typical stress states in the adhesively-bonded joint: shear stress, tensile stress, and combination of both. To realize these stress states in the adhesively-bonded joint during tests, a specific loading device is developed with the capacity of providing six different loading angles, which are 0°(pure tension, 18°, 36°, 54°, 72° and 90°(pure shear. Failure modes of adhesively-bonded joints are investigated. It indicates that, for the pure shear loading, the failure mode is the cohesive failure (near the interface between the adhesive layer and the steel support in the adhesive layer. For the pure tensile and combined loading conditions, the failure mode is the combination of fiber breaking, FRP delamination and interfacial adhesion failure between the FRP sandwich deck and the adhesive layer. The load-bearing capacities of adhesive joints under combined loading are much lower than those of the pure tensile and pure shear loading conditions. According to the test results of six angle loading conditions, a tensile/shear failure criterion of the adhesively-bonded joint is obtained. By using Finite Element (FE modeling method, linear elastic simulations are performed to characterize the stress distribution throughout the adhesively-bonded joint.

  19. Comprehensive evaluation of fracture critical bridges.

    Science.gov (United States)

    2014-02-01

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

  20. Dynamic and Static Behavior of Hollow-Core FRP-Concrete-Steel and Reinforced Concrete Bridge Columns under Vehicle Collision

    Directory of Open Access Journals (Sweden)

    Omar I. Abdelkarim

    2016-12-01

    Full Text Available This paper presents the difference in behavior between hollow-core fiber reinforced polymer-concrete-steel (HC-FCS columns and conventional reinforced concrete (RC columns under vehicle collision in terms of dynamic and static forces. The HC-FCS column consisted of an outer FRP tube, an inner steel tube, and a concrete shell sandwiched between the two tubes. The steel tube was hollow inside and embedded into the concrete footing with a length of 1.5 times the tube diameter while the FRP tube stopped at the top of footing. The RC column had a solid cross-section. The study was conducted through extensive finite element impact analyses using LS-DYNA software. Nine parameters were studied including the concrete material model, unconfined concrete compressive strength, material strain rate, column height-to-diameter ratio, column diameter, column top boundary condition, axial load level, vehicle velocity, and vehicle mass. Generally, the HC-FCS columns had lower dynamic forces and higher static forces than the RC columns when changing the values of the different parameters. During vehicle collision with either the RC or the HC-FCS columns, the imposed dynamic forces and their equivalent static forces were affected mainly by the vehicle velocity and vehicle mass.

  1. Covered Bridge Security Manual

    Science.gov (United States)

    Brett Phares; Terry Wipf; Ryan Sievers; Travis Hosteng

    2013-01-01

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

  2. Strain features and condition assessment of orthotropic steel deck cable-supported bridges subjected to vehicle loads by using dense FBG strain sensors

    Science.gov (United States)

    Wei, Shiyin; Zhang, Zhaohui; Li, Shunlong; Li, Hui

    2017-10-01

    Strain is a direct indicator of structural safety. Therefore, strain sensors have been used in most structural health monitoring systems for bridges. However, until now, the investigation of strain response has been insufficient. This paper conducts a comprehensive study of the strain features of the U ribs and transverse diaphragm on an orthotropic steel deck and proposes a statistical paradigm for crack detection based on the features of vehicle-induced strain response by using the densely distributed optic fibre Bragg grating (FBG) strain sensors. The local feature of strain under vehicle load is highlighted, which enables the use of measurement data to determine the vehicle loading event and to make a decision regarding the health status of a girder near the strain sensors via technical elimination of the load information. Time–frequency analysis shows that the strain contains three features: the long-term trend item, the short-term trend item, and the instantaneous vehicle-induced item (IVII). The IVII is the wheel-induced strain with a remarkable local feature, and the measured wheel-induced strain is only influenced by the vehicle near the FBG sensor, while other vehicles slightly farther away have no effect on the wheel-induced strain. This causes the local strain series, among the FBG strain sensors in the same transverse locations of different cross-sections, to present similarities in shape to some extent and presents a time delay in successive order along the driving direction. Therefore, the strain series induced by an identical vehicle can be easily tracked and compared by extracting the amplitude and calculating the mutual ratio to eliminate vehicle loading information, leaving the girder information alone. The statistical paradigm for crack detection is finally proposed, and the detection accuracy is then validated by using dense FBG strain sensors on a long-span suspension bridge in China.

  3. Study on the selection of steel or prestressed concrete cable stayed bridge by using diaggregate behavioral model; Hishukei rojitto model wo mochiita koshachokyo to PC shachokyo no kyoshiki sentaku ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Araki, Y.; Furuta, H.; Maeda, E.; Furukawa, K. [Yamaguchi University, Yamaguchi (Japan). Faculty of Engineering

    1994-09-15

    A discussion was given to make clear the selection factors in selecting bridge types (steel cable stayed bridge and prestressed concrete cable stayed bridge). The discussion is intended to consider the future development of both bridges. Quoting a cable stayed bridge with a span length of 250 m that can be selected from either bridge, an evaluation was made by using calculations that uses the disaggregate behavioral model theory based on questionnaire responses from engineers. The analysis uses the following procedure: utility function values of the two term behavioral model (having two choices) are specified and the characteristics variables are selected; the data are prepared according to the specifications, which are used to estimate parameters by a maximum likelihood estimation method; and estimation amount is estimated by using the covariance matrix, which is given a `t` value verification. The conclusions: what gives the large effect to the selection is the engineering capacity and sociality; the result contains vocational consciousness; the economy is measured by the large weight of construction cost for the upper part structures and cost required for large repairs; materials affect largely the reliability, and so does the technological level the constructibility; the comprehensive technical capability, freedom in design and the experience attained by Japan have great effects in terms of technological capability. 10 refs., 10 figs., 11 tabs.

  4. Seismic Performance of Self-Consolidating Concrete Bridge Columns

    Science.gov (United States)

    2017-09-01

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

  5. Alternatives to steel grid decks - phase II.

    Science.gov (United States)

    2012-09-01

    The primary objective of this research project was to investigate alternatives to open grid steel decks for movable bridges. Three alternative deck systems, including aluminum deck, ultra-high performance concrete (UHPC)-high-strength steel (HSS) dec...

  6. GFRP reinforced concrete bridge decks.

    Science.gov (United States)

    2000-07-01

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

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

    Science.gov (United States)

    2011-09-01

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

  8. The correlation between accelerated and field corrosion tests performed in carbon steel and weathering steel coupons, coated and non-coated; Correlacao entre ensaios acelerados e ensaios de campo em corpos-de-provas de aco carbono e aco patinavel, sem e com revestimento

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, Renato Altobelli

    2002-07-01

    The performance of four different organic coating systems applied to carbon and weathering steel coupons has been assessed in this investigation. applied on the surface of carbon steel and weathering steel coupons. The coupons have been evaluated using five different tests, three field tests and two accelerated tests. The field tests were carried out at three atmospheric stations, located at COSIPA in Cubatao-SP, at Alto da Serra in Cubatao-SP and at Paula Souza in Sao Paulo city. The accelerated tests consisted of (a) exposure to alternate cycles of ultraviolet radiation/condensation combined with salt spray cycles (UVCON combined with Salt Spray) and of (b) exposure to alternate cycles of ultraviolet radiation/condensation combined with the Prohesion test. The performance of the coatings was assessed by visual observation and photographs, using a method based on ASTM D-610, ASTM D-714 and ASTM-1654 standards to rank them. The oxide phases formed on the surfaces of the non-coated specimens of carbon and weathering steels, exposed to the same tests performed with the coated specimens, were identified using three different techniques: X-ray diffraction, Raman microscopy and Moessbauer spectroscopy. In the field tests, the specimens have been exposed for 1, 2, 3, 6 and 9 months. In the accelerated ones, the results were obtained after 1340 hours (4 cycles) test. The main component identified in all the specimens collected from the field tests and from the UVCON combined with the Prohesion test was lepidocrocite ({gamma}-FeOOH). Goethite ({alpha}-FeOOH ) and magnetite (Fe{sub 3}O{sub 4}) were identified as the other two main phases present in ali the specimens. In the UVCON combined with Salt Spray test, the dominant phase was magnetite, followed by goethite and lepidocrocite. The morphology of the rust formed on the specimens was examined by scanning electron microscopy (SEM). Structures corresponding to goethite and lepidocrocited were recognized on ali specimens

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

    Science.gov (United States)

    2010-10-01

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

  10. Bridge-in-a-backpack(TM) : task 3.2: investigating soil - structure interaction - modeling and experimental results of steel arches.

    Science.gov (United States)

    2015-07-01

    This report includes fulfillment of Task 3.2 of a multi-task contract to further enhance concrete filled FRP tubes, or : the Bridge in a Backpack. Task 3 is an investigation of soil-structure interaction for the FRP tubes. Task 3.2 is the : modeling ...

  11. 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

  12. 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...

  13. Myocardial Bridge

    Science.gov (United States)

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

  14. Steel plate girder diaphragm and cross-bracing loads : [summary].

    Science.gov (United States)

    2014-05-01

    Steel bridge designs are integrated so that every : component contributes to structural integrity, : including the concrete bridge deck, which : connects to the girders and makes the structure : rigid. Until the deck is completed and the : concrete i...

  15. Bridge deck resurfacing using Rosphalt 50.

    Science.gov (United States)

    2006-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Flaga Kazimierz

    2015-03-01

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

  17. Kings Covered Bridge rehabilitation, Somerset County, PA

    Science.gov (United States)

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

    2005-01-01

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

  18. Exodermic bridge deck performance evaluation.

    Science.gov (United States)

    2010-07-01

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

  19. Wacky Weather

    Science.gov (United States)

    Sabarre, Amy; Gulino, Jacqueline

    2013-01-01

    What do a leaf blower, water hose, fan, and ice cubes have in common? Ask the students who participated in an integrative science, technology, engineering, and mathematics (I-STEM) education unit, "Wacky Weather," and they will tell say "fun and severe weather"--words one might not have expected! The purpose of the unit…

  20. Experimental Program on Composite Steel and Concrete Beams

    Science.gov (United States)

    Dubecky, Daniel

    2015-11-01

    Plate bridges with encased beams are suitable for building bridges of short and medium range. The paper presented focuses on the research into progressive bridges with encased filler beams of modified steel sections designed to minimize steel consumption without affecting essentially the overall structure resistance. This type of construction is suitable for bridges over short and middle spans as it offers a number of advantages, such as little headroom, quite clear static action of forces and a short construction period with no falsework required. Among some disadvantages is the economic inefficiency of steel I-sections, which are employed in the majority of bridges of this type. Therefore, there is an urgent need for the development of more economical design approaches and more purposeful arrangement and employment of steel beams. The paper presented brings some results from experimental tests on elements with encased steel filler-beams acting compositely under both short-term static and dynamic loads, and long-term load.

  1. Assessing the service life of corrosion-deteriorated reinforced concrete member highway bridges in West Virginia.

    Science.gov (United States)

    2014-09-01

    Corrosion of steel-reinforced concrete bridges is a serious problem facing the WVDOT. This : paper provides an overview of techniques for evaluating the condition of reinforced concrete : bridge elements; methods for modeling the remaining service li...

  2. Long-term corrosion protection of bridge elements reinforcing materials in concrete : final report.

    Science.gov (United States)

    2017-09-01

    Preventing or mitigating the corrosion of reinforcing steel in bridge decks is a major challenge for state transportation agencies. With agency budgets stretched thinner every year, they must implement strategies to extend the service lives of bridge...

  3. Development and performance evaluation of fiber reinforced polymer bridge : [technical summary].

    Science.gov (United States)

    2014-03-01

    Conventionally, highway bridge decks in the US are predominantly made of steel-reinforced concrete. However, repair and : maintenance costs of these bridges incurred at the federal and state levels are overwhelming. As a result, for many years, there...

  4. Evaluating Louisiana new deck continuity detail for precast prestressed concrete girder bridges : research project capsule.

    Science.gov (United States)

    2014-08-01

    The goal of everyone in the transportation community is to build bridges : that are economic, easy to construct, and durable. Therefore, accelerating : bridge construction through the use of precast concrete or prefabricated : steel girders is a comm...

  5. Plastic collapse load of corroded steel plates

    Indian Academy of Sciences (India)

    ple, Bruneau & Zahrai (1997) and Zuraski & Johnson (1990) have studied fatigue strength of corroded steel specimens taken from aged bridges. Chen et al (2005) have studied mechani- cal properties of low alloy steels in chloride solution. Some research works were also done on structural integrity of aged structures.

  6. Strengthening Bridges with Prestressed CFRP Strips

    Science.gov (United States)

    Siwowski, Tomasz; Żółtowski, Piotr

    2012-06-01

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

  7. Experimental studies of Steel Corrugated Constructions

    Directory of Open Access Journals (Sweden)

    Lazarev Yuriy

    2016-01-01

    Full Text Available The purpose of this particular article is to assess existing calculations of steel corrugated constructions. Steel Corrugated Construction is a perspective type of constructions, which is exhibiting numerous advantages in comparison with one that currently applied in automobile and railroad networks (reinforced concrete water-throughput pipes, reinforced concrete frame bridges. The evaluation of experimental data on models of constructions of this particular type has been carried out in order to improve calculations of Steel Corrugated Constructions.

  8. Teaching Steel Connections Using an Interactive Virtual Steel Sculpture

    Science.gov (United States)

    Moaveni, Saeed; Chou, Karen C.

    2015-01-01

    Steel connections play important roles in the integrity of a structure, and many structural failures are attributed to connection failures. Connections are the glue that holds a structure together. The failures of the Hartford Coliseum in 1977, the Hyatt Regency Hotel in Kansas City in 1980, and the I-35W Bridge in Minneapolis in 2007 are all…

  9. 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.

  10. Weather forecast

    CERN Document Server

    Courtier, P

    1994-02-07

    Weather prediction is performed using the numerical model of the atmosphere evolution.The evolution equations are derived from the Navier Stokes equation for the adiabatic part but the are very much complicated by the change of phase of water, the radiation porocess and the boundary layer.The technique used operationally is described. Weather prediction is an initial value problem and accurate initial conditions need to be specified. Due to the small number of observations available (105 ) as compared to the dimension of the model state variable (107),the problem is largely underdetermined. Techniques of optimal control and inverse problems are used and have been adapted to the large dimension of our problem. our problem.The at mosphere is a chaotic system; the implication for weather prediction is discussed. Ensemble prediction is used operationally and the technique for generating initial conditions which lead to a numerical divergence of the subsequent forecasts is described.

  11. Putting Weather into Weather Derivatives

    Science.gov (United States)

    Smith, L. A.; Smith, L. A.

    2001-12-01

    Just as weather forecasting has a colorful and often farsighted history within geophysics, financial mathematics has a long and turbulent history within mathematics. Thus it is no surprise that the intersection of real physics and real financial mathematics provides a rich source of problems and insight in both fields. This presentation targets open questions in one such intersection: quantifying ``weather risk.'' There is no accepted (operational) method for including deterministic information from simulation models (numerical weather forecasts, either best guess or by ensemble forecasting methods), into the stochastic framework most common within financial mathematics. Nor is there a stochastic method for constructing weather surrogates which has been proven successful in application. Inasmuch as the duration of employable observations is short, methods of melding short term, medium-range and long term forecasts are needed. On these time scales, model error is a substantial problem, while many methods of traditional statistical practice are simply inappropriate given our physical understanding of the system. A number of specific open questions, along with a smaller number of potential solutions, will be presented. >http://www.maths.ox.ac.uk/~lenny/WeatherRisk

  12. Ældre betonbroers bæreevne (Load bearing capacity of old concrete bridges)

    DEFF Research Database (Denmark)

    Nielsen, Anders

    1999-01-01

    was carried. - The other is a motor way bridge from 1939, which were reinforced 1991 with external steel plates on the areas of shear on the beams. Four beams were carried to our laboratory and load tested. The steel plates have doubled the load bearing capacity of the beams.......Two old bridges have been analysed in connection with their demolition. The first one is a pedestrian bridge, the Gefion bridge, from 1894. This is the first bridge of reinforced concrete in Denmark. Here the creep in the concrete severely have changed the way in which the load on the bridge...

  13. Kawasaki Steel Giho, Vol. 27, No. 4, 1995. Special issue on steel structure

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    ;Contents (Partial): Vertical Gust Prediction of Cable-Stayed Bridges in Yawed Wind; Design and Construction of a Super Platform Structure Made of Steel; Prefabricated Steel Deck of Battledeck Floor Type for Redecking; Aesthetic Design of Structures; and Lift-up Construction Method for Multi-layer Building.

  14. Strengthening of RC bridge slabs using CFRP sheets

    Directory of Open Access Journals (Sweden)

    Fahmy A. Fathelbab

    2014-12-01

    Full Text Available Many old structures became structurally insufficient to carry the new loading conditions requirements. Moreover, they suffer from structural degradation, reinforcement steel bars corrosion, bad weather conditions…etc. Many official authorities in several countries had recognized many old bridges and buildings as structurally deficient by today’s standards. Due to these reasons, structural strengthening became an essential requirement and different strengthening techniques appeared in market. Fiber Reinforced Polymer (FRP strengthening techniques established a good position among all other techniques, giving excellent structural results, low time required and moderate cost compared with the other techniques. The main purpose of this research is to study analytically the strengthening of a reinforced concrete bridge slabs due to excessive loads, using externally bonded FRP sheets technique. A commercial finite element program ANSYS was used to perform a structural linear and non-linear analysis for strengthened slab models using several schemes of FRP sheets. A parametric study was performed to evaluate analytically the effect of changing both FRP stiffness and FRP schemes in strengthening RC slabs. Comparing the results with control slab (reinforced concrete slab without strengthening it is obvious that attaching FRP sheets to the RC slab increases its capacity and enhances the ductility/toughness.

  15. Repair systems for deteriorated bridge piles : final report.

    Science.gov (United States)

    2017-04-01

    The objective of this research project is to develop a durable repair system for deteriorated steel bridge piles that : can be implemented without the need for dewatering. A rigorous survey of the relevant practice nationwide was : conducted to infor...

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

    Science.gov (United States)

    2015-03-01

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

  17. Synthesis of concrete bridge piles prestressed with CFRP systems.

    Science.gov (United States)

    2017-06-01

    The Texas Department of Transportation frequently constructs prestressed concrete piles for use in bridge : foundations. Such prestressed concrete piles are typically built with steel strands that are highly susceptible to : environmental degradation...

  18. Formability of new high performance A710 grade 50 structural steel.

    Science.gov (United States)

    2014-01-01

    This project compared the formability of modified ASTM A710 Grade B50 ksi yield strength steel, jointly developed by : Northwestern University and the Illinois Department of Transportation, with ASTM A606 Type 4 weathering steel used in Illinois : an...

  19. Steel making

    CERN Document Server

    Chakrabarti, A K

    2014-01-01

    "Steel Making" is designed to give students a strong grounding in the theory and state-of-the-art practice of production of steels. This book is primarily focused to meet the needs of undergraduate metallurgical students and candidates for associate membership examinations of professional bodies (AMIIM, AMIE). Besides, for all engineering professionals working in steel plants who need to understand the basic principles of steel making, the text provides a sound introduction to the subject.Beginning with a brief introduction to the historical perspective and current status of steel making together with the reasons for obsolescence of Bessemer converter and open hearth processes, the book moves on to: elaborate the physiochemical principles involved in steel making; explain the operational principles and practices of the modern processes of primary steel making (LD converter, Q-BOP process, and electric furnace process); provide a summary of the developments in secondary refining of steels; discuss principles a...

  20. Weather track optimization through graphics theory

    OpenAIRE

    Martínez de Osés, Francesc Xavier

    2005-01-01

    Safe seafaring is closely related to the weather observation. The improvement of the system that covers the integration on board of weather information available on the ship’s bridge, should keep in mind the ship’s type and track but also the human factor or the task to be carried out by the officer on watch. This paper tries to provide a set of criteria to be used for designing an ergonomic concept of a weather receiving information station within a Ship Control Centre, to optimise the ship...

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

    Science.gov (United States)

    2017-06-01

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

  2. 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,...

  3. 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.

  4. Foul weather

    Science.gov (United States)

    Carlowicz, Michael

    In an effort to cut costs and meet its operations budget for fiscal year 1997 and into the future, the National Weather Service (NWS) will be cutting staff and services throughout the rest of the budget year, which ends in October. After reviewing current programs and identifying ways to reduce operating costs, NWS management announced on March 21 that the Service will accelerate planned cuts in staff and operations at headquarters, regional offices, and central operations and field offices, while “re-engineering certain programs.”

  5. Fatigue analysis and life prediction of composite highway bridge decks under traffic loading

    OpenAIRE

    Leitão,Fernando N.; Silva,José Guilherme S. da; Andrade,Sebastião A. L. de

    2013-01-01

    Steel and composite (steel-concrete) highway bridges are currently subjected to dynamic actions of variable magnitude due to convoy of vehicles crossing on the deck pavement. These dynamic actions can generate the nucleation of fractures or even their propagation on the bridge deck structure. Proper consideration of all of the aspects mentioned pointed our team to develop an analysis methodology with emphasis to evaluate the stresses through a dynamic analysis of highway bridge decks includin...

  6. 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...

  7. High strength reinforcing steel bars : low-cycle fatigue behavior : final report - part B.

    Science.gov (United States)

    2017-03-01

    High-strength steel (HSS) reinforcing steel, specifically ASTM A706 Grade 80 (550), is now permitted by the AASHTO LRFD Bridge Design Specifications for use in reinforced concrete bridge components in non-seismic regions. Using Grade 80 (550) reinfor...

  8. High strength reinforcing steel bars : low cycle fatigue behavior : final report - part B.

    Science.gov (United States)

    2017-03-01

    High-strength steel (HSS) reinforcing steel, specifically ASTM A706 Grade 80 (550), is now permitted by the AASHTO LRFD Bridge Design Specifications for use in reinforced concrete bridge components in non-seismic regions. Using Grade 80 (550) reinfor...

  9. High strength reinforcing steel bars : concrete shear friction interface : final report : Part A.

    Science.gov (United States)

    2017-03-01

    High-strength steel (HSS) reinforcement, specifically ASTM A706 Grade 80 (550), is now permitted by the AASHTO LRFD Bridge Design Specifications for use in reinforced concrete bridge components in non-seismic regions. Using Grade 80 (550) steel reinf...

  10. Field testing of the Wolf Creek curved girder bridge : part I : vibration tests.

    Science.gov (United States)

    2009-01-01

    The Wolf Creek Bridge is a curved, multi-girder three span steel composite bridge located south of Narrows, Virginia, that was completed in 2006. A finite element model of the bridge revealed that pier flexibility may be important in modeling the bri...

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

    Science.gov (United States)

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

    2012-04-01

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

  12. 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.

  13. Strategic sensor locations of FPR bridge decks

    Science.gov (United States)

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

    2003-07-01

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

  14. Assessment of Steel Bearing Structures - Estimation of the Remaining Fatigue Life

    Science.gov (United States)

    Omishore, Abayomi

    2017-10-01

    A significant number of steel bridges exist in operation worldwide. The budget for new infrastructure projects is tight, so the importance of inspection, maintenance and assessment of the existing bridges increases. A new fatigue assessment guideline for the estimation of the remaining fatigue life of steel bridges should be developed soon. This paper presents (i) a discussion based on the state-of-the-art review and (ii) new possibilities of applications of probabilistic methods for the time dependent reliability assessment of the lifetime of steel bridges. The probabilistic fatigue assessment procedure can be applied to existing steel bridges under cyclic loading. The guideline concentrates on the existing traffic infrastructure made from old steel due to its public importance. The essential general methods for these calculations are provided using structural and fracture mechanics and the reliability theory used in a probabilistic framework.

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

    Directory of Open Access Journals (Sweden)

    Mei Kuihua

    2017-01-01

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

  16. Performance assessment of deteriorated and retrofitted steel HP piles.

    Science.gov (United States)

    2016-06-01

    Steel piles are known to deteriorate at high rates in Nebraska, partially as a result of exposure to weathering, and partially due to corrosive soils. The Nebraska Department of Roads (NDOR) employs a reinforced concrete jacket to slow the progressio...

  17. An Alternative to Steel: Bamboo-A review (New Advances).

    OpenAIRE

    Bhardwaj, Sandeep; Sharma, Rupali; Kumar, Rajender

    2014-01-01

    Bamboo can be replaced steel in low to medium structures. It is environmental friendly, sustainable and low cost. Here we discussed advances in bamboo material use in bridge components, as reinforcement in concrete known as bambcrete, as a replacement of structural steel in industrial structure. Also discussed new advances in bamboo and bamboo material property.

  18. Monthly Weather Review

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Supplements to the Monthly Weather Review publication. The Weather Bureau published the Monthly weather review Supplement irregularly from 1914 to 1949. The...

  19. UTM Weather Presentation

    Science.gov (United States)

    Chan, William N.; Kopardekar, Parimal H.; Carmichael, Bruce; Cornman, Larry

    2017-01-01

    Presentation highlighting how weather affected UAS operations during the UTM field tests. Research to develop UAS weather translation models with a description of current and future work for UTM weather.

  20. Seismic vulnerability assessment of a continuous steel box girder ...

    Indian Academy of Sciences (India)

    Tae-Hyung Lee

    2018-02-07

    Feb 7, 2018 ... indicate that the bridge structures equipped with seismic isolation devices (e.g. LRBs) significantly mitigated the damages due to earthquakes. Keywords. Continuous steel box girder bridge; fragility curves; seismic vulnerability assessment; damage state; nonlinear dynamic analysis; lead rubber bearing. 1.

  1. 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...

  2. Modal analysis of cable-stayed UHPC bridge

    Directory of Open Access Journals (Sweden)

    Tej Petr

    2017-01-01

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

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

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2016-01-01

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

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

    DEFF Research Database (Denmark)

    Du, Guangli; Pettersson, Lars; Karoumi, Raid

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-05-30

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

  6. Effects of CFRP Strengthening on Dynamic and Fatigue Responses of Composite Bridge

    Directory of Open Access Journals (Sweden)

    Kittisak Kuntiyawichai

    2014-01-01

    Full Text Available This paper investigates the effect of CFRP strengthening on dynamic and fatigue responses of composite bridge using finite element program ABAQUS. Dynamic and fatigue responses of composite bridge due to truck load based on AASHTO standard are investigated. Two types of CFRP strengthening techniques, CFRP sheets and CFRP deck, are applied to both the damaged and undamaged bridges. For the case of damaged bridge, two through-thickness crack sizes, 3 mm and 6 mm in depth, are assumed at midspan of the steel girders. Furthermore, effects of the number of steel girders on the dynamic and fatigue responses are also considered. The results show that the maximum responses of composite bridges occur for dual lane cases. By using CFRP as a strengthening material, the maximum stress and deflection of the steel girders reduce and consequently increase the fatigue life of the girders. After introducing initial crack into the steel girders of the composite bridges, the fatigue life of the bridges is dramatically reduced. However, the overall performance of the damaged composite bridge can be improved by using CFRP, albeit with less effectiveness. Therefore, if cracks are found, steel welding must be performed before strengthening the composite bridge by CFRP.

  7. Tool steels

    DEFF Research Database (Denmark)

    Højerslev, C.

    2001-01-01

    On designing a tool steel, its composition and heat treatment parameters are chosen to provide a hardened and tempered martensitic matrix in which carbides are evenly distributed. In this condition the matrix has an optimum combination of hardness andtoughness, the primary carbides provide...... resistance against abrasive wear and secondary carbides (if any) increase the resistance against plastic deformation. Tool steels are alloyed with carbide forming elements (Typically: vanadium, tungsten, molybdenumand chromium) furthermore some steel types contains cobalt. Addition of alloying elements...... serves primarily two purpose (i) to improve the hardenabillity and (ii) to provide harder and thermally more stable carbides than cementite. Assuming proper heattreatment, the properties of a tool steel depends on the which alloying elements are added and their respective concentrations....

  8. Material Structural Deficiencies of Road Bridges in the U.S.

    Directory of Open Access Journals (Sweden)

    Daniel N. Farhey

    2018-01-01

    Full Text Available This study analyzes the National Bridge Inventory in the U.S. to determine the relative structural deficiencies of bridge materials, comparing between the overall national values and each state, geographically. The analysis considers the most common bridge construction materials—concrete, steel, and prestressed/post-tensioned concrete. The results suggest need to reassess the efficacy of best performance practices for steel bridges and for states with structural deficiencies above the national average. Geographic consistency of structurally deficient bridge density with population density shows need to improve intervention strategies for regions with higher levels of service usage. The study also compares the relative operational lifespan of bridge materials in each state. The average structurally deficient bridge ages are lower than the 75-year life-cycle expectancy. Prestressed/post-tensioned concrete bridges reveal relatively lower lifespan. Over time, concrete and steel bridges show some gradual improvement with decreasing percentage of structural deficiency and increasing lifespan. Prestressed/post-tensioned concrete bridges reveal shifting earlier accumulation of structural deficiency for a particular age group. The study also reveals relative climate effects. Climate conditions correlate differently with the structural deficiency and life cycle of bridge materials in each state. Structurally deficient bridge densities show correlation with climate maps, especially under colder and moist conditions.

  9. Structural steel coatings for corrosion mitigation.

    Science.gov (United States)

    2010-10-01

    Task 1 of this project was to survey the performance of coating systems for steel bridges in Missouri and to evaluate coating and : recoating practices. Task 1 was led under the direction of Dr. Glenn Washer from the University of Missouri located in...

  10. 50 ksi steel h-pile capacity.

    Science.gov (United States)

    2015-06-01

    The objective of this study is to re-evaluate the adoption, with the objective of potentially extending the utilization of Fy = 50 ksi for : the structural capacity of steel H-piles (AISC HP sections) for bridge foundations. Specific consideration is...

  11. Weather in Your Life.

    Science.gov (United States)

    Kannegieter, Sandy; Wirkler, Linda

    Facts and activities related to weather and meteorology are presented in this unit. Separate sections cover the following topics: (1) the water cycle; (2) clouds; (3) the Beaufort Scale for rating the speed and force of wind; (4) the barometer; (5) weather prediction; (6) fall weather in Iowa (sleet, frost, and fog); (7) winter weather in Iowa…

  12. Stålplader gav dobbelt bæreevne (Steel plates doubled the load bearing capacity)

    DEFF Research Database (Denmark)

    Nielsen, Jan Broch

    1999-01-01

    Abstract from an examination of motor road bridge beams reinforced with steel plates on the sides and bottom. The plates doubled the load bearing capacity of the beams.......Abstract from an examination of motor road bridge beams reinforced with steel plates on the sides and bottom. The plates doubled the load bearing capacity of the beams....

  13. Bridge resource program.

    Science.gov (United States)

    2013-09-01

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

  14. Vulnerabilidad sísmica y capacidad de carga de un puente en acero basado en confiabilidad estructural Seismic vulnerability and load carrying capacity studies of a steel bridge based on structural relia

    Directory of Open Access Journals (Sweden)

    Edgar Muñoz

    2008-01-01

    Full Text Available Por medio de la confiabilidad estructural, para un Puente en Colombia después de su monitoreo. Los resultados de este trabajo son parte de una nueva metodología para evaluar puentes existentes mediante una colaboración entre Universidad-Empresas-Gobierno Nacional. Este estudio ayuda en la toma de decisiones y en la priorización de tareas de rehabilitación. Este estudio incluyó: caracterización dinámica de las vibraciones naturales del puente; adquisición de datos de fuerzas internas debidas al tráfico por medio de tecnología de LVDT's y Strain Gages; evaluación de las fuerzas actuales comparadas contra los esfuerzos máximos permitidos; modelación estática, dinámica y estructural. Adicionalmente se hizo un estudio de amenaza sísmica y respuesta dinámica del área del puente y nueve (9 diferentes espectros de respuesta fueron obtenidos, cada uno con un periodo de retorno diferente. Se encontró que las torres del puente tienen una probabilidad de falla mayor que la permitida por los códigos. Lo anterior condujo a un reforzamiento inmediato del puente.In this document, seismic vulnerability and load carrying capacity analyses are presented for a bridge in Colombia after monitoring by means of reliability of structures. Results of this work are part of a new methodology to evaluate existing bridges carried out though a partnership among University - Private Companies - and Goverment. This study helps in decision making on the priority of rehabilitation tasks. This study included: dynamic characterization of natural vibrations of the bridge; data logging of inner forces due to traffic by using LVDT's and strain gages technology; evaluation of actual forces to be compared to allowed stresses, dynamic and static structural modelling. Also, a seismic hazard and dynamic response of the local area of the bridge was developed and nine (9 different response spectra were obtained, each one varying its return period. It was found that the

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

    Science.gov (United States)

    2011-08-01

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

  16. Field evaluations of waterproof membrane systems for bridge decks, 1972-1974.

    Science.gov (United States)

    1975-01-01

    Waterproof membrane systems are being studied by many agencies from the standpoint of their effectiveness in protecting the reinforcing steel in concrete bridge decks against corrosion. Trial applications and evaluations of six such systems, includin...

  17. The protection effectiveness of waterproof membrane systems on bridge decks in Louisiana : final report.

    Science.gov (United States)

    1978-12-01

    The effects of de-icing salts on concrete and reinforcing steel is well documented, and efficient methods of protection from the penetrating chloride ions have long been sought. Concrete bridge decks need the protection, and waterproofing the concret...

  18. Bridge deck resurfacing using Rosphalt 50 : interim report - first year, December 2004.

    Science.gov (United States)

    2004-12-01

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

  19. Application of titanium alloy bars for strengthening reinforced concrete bridge girders (part a: shear) : final report.

    Science.gov (United States)

    2017-07-04

    Large numbers of conventionally reinforced concrete bridges (RC) were constructed during the interstate highway expansion of the 1950s and remain in the national inventory. Coincidently, deformed steel reinforcing bars were standardized. The stand...

  20. Probabilistic Model for Fatigue Crack Growth in Welded Bridge Details

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard; Yalamas, Thierry

    2013-01-01

    In the present paper a probabilistic model for fatigue crack growth in welded steel details in road bridges is presented. The probabilistic model takes the influence of bending stresses in the joints into account. The bending stresses can either be introduced by e.g. misalignment or redistribution...... of stresses in the structure. The fatigue stress ranges are estimated from traffic measurements and a generic bridge model. Based on the probabilistic models for the resistance and load the reliability is estimated for a typical welded steel detail. The results show that large misalignments in the joints can...

  1. RECONSTRUCTION AND REINFORCEMENT OF BRIDGE ACROSS THE RIVER. SYLVA IN KUNGUR, RUSSIA

    Directory of Open Access Journals (Sweden)

    R. Ye. Heizn

    2010-04-01

    Full Text Available Sylva Bridge at Kungur city is one of the oldest road bridges in Perm region, the West Urals, Russia. Its erection was begun in 1912 and was interrupted with the First World War and the further events in Russia. The bridge was opened only in 1931. For 75 years of bridge operation the most part of bridge constructions has been acquired plural damages, both mechanical and corrosion. After the bridge inspection in 2003 and according to the calculations of its capacity, the decision on reconstruction of the bridge was accepted. The purpose of rehabilitation was to replace the timber deck by steel orthotropic deck with asphalt pavement. A new deck was to be engaged in combined action with the existing metal structures with the help of socles with high-strength bolts. Due to this, the bridge carrying capacity was increased as required by the present standards. In 2006, after tests, the bridge was opened for traffic.

  2. WEATHER INDEX- THE BASIS OF WEATHER DERIVATIVES

    Directory of Open Access Journals (Sweden)

    Botos Horia Mircea

    2011-07-01

    Full Text Available This paper approaches the subject of Weather Derivatives, more exactly their basic element the weather index. The weather index has two forms, the Heating Degree Day (HDD and the Cooling Degree Day (CDD. We will try to explain their origin, use and the relationship between the two forms of the index. In our research we started from the analysis of the weather derivatives and what they are based on. After finding out about weather index, we were interested in understanding exactly how they work and how they influence the value of the contract. On the national level the research in the field is scares, but foreign materials available. The study for this paper was based firstly on reading about Weather Derivative, and then going in the meteorogical field and determining the way by which the indices were determined. After this, we went to the field with interest in the indices, such as the energy and gas industries, and figured out how they determined the weather index. For the examples we obtained data from the weather index database, and calculated the value for the period. The study is made on a period of five years, in 8 cities of the European Union. The result of this research is that we can now understand better the importance of the way the indices work and how they influence the value of the Weather Derivatives. This research has an implication on the field of insurance, because of the fact that weather derivative are at the convergence point of the stock markets and the insurance market. The originality of the paper comes from the personal touch given to the theoretical aspect and through the analysis of the HDD and CDD index in order to show their general behaviour and relationship.

  3. 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...

  4. A Load-Deflection Study of Fiber-Reinforced Plastics as Reinforcement in Concrete Bridge Decks

    OpenAIRE

    Boyd, Curtis Barton

    1997-01-01

    Approximately fifty percent of the bridges in the United States are considered deficient. The deterioration of the concrete components is a leading cause of the problem. The deterioration of concrete bridge decks is due primarily to corrosion of the reinforcing steel in the concrete. A promising solution to the problem is the use of fiber reinforced plastics (FRP) as a replacement for reinforcing steel. The use of FRP as reinforcement has the following advantages of lightweight, high tensile ...

  5. Daily Weather Records

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These daily weather records were compiled from a subset of stations in the Global Historical Climatological Network (GHCN)-Daily dataset. A weather record is...

  6. Mariners Weather Log

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Mariners Weather Log (MWL) is a publication containing articles, news and information about marine weather events and phenomena, worldwide environmental impact...

  7. Land Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — METAR is the international standard code format for hourly surface weather observations. The acronym roughly translates from French as Aviation Routine Weather...

  8. Weather Radar Stations

    Data.gov (United States)

    Department of Homeland Security — These data represent Next-Generation Radar (NEXRAD) and Terminal Doppler Weather Radar (TDWR) weather radar stations within the US. The NEXRAD radar stations are...

  9. National Convective Weather Diagnostic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current convective hazards identified by the National Convective Weather Detection algorithm. The National Convective Weather Diagnostic (NCWD) is an automatically...

  10. Natural Weathering Exposure Station

    Data.gov (United States)

    Federal Laboratory Consortium — The Corps of Engineers' Treat Island Natural Weathering Exposure Station is a long-term natural weathering facility used to study concrete durability. Located on the...

  11. Surface Weather Observations Hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard hourly observations taken at Weather Bureau/National Weather Service offices and airports throughout the United States. Hourly observations began during the...

  12. Pilot Weather Reports

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Aviation weather reports relayed from pilots to FAA air traffic controllers or National Weather Service personnel. Elements include sky cover, turbulence, wind...

  13. Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Surface Weather Observation Collection consists primarily of hourly, synoptic, daily, and monthly forms submitted to the archive by the National Weather Service...

  14. Internet Weather Source

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Weather Service (NWS) National Telecommunications Gateway provides weather, hydrologic, and climate forecasts and warnings for the United States, its...

  15. Hegelian Steel

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    2015-01-01

    . Developing a Hegelian inspired historical-sociological approach this paper however argues that national and transnational societies emerged simultaneously and in a co-evolutionary and mutually supportive fashion. In most European settings national societies did not become the central horizon of individuals...... of the European steel industry....

  16. American Weather Stories.

    Science.gov (United States)

    Hughes, Patrick

    Weather has shaped United States' culture, national character and folklore; at times it has changed the course of history. The seven accounts compiled in this publication highlight some of the nation's weather experiences from the hurricanes that threatened Christopher Columbus to the peculiar run of bad weather that has plagued American…

  17. Prevention of chloride-induced corrosion damage to bridges

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, Stephen D.; Covino, Bernard S., Jr.; Bullard, Sophie J.; Holcomb, Gordon R.; Russell, James H.; Ziomek-Moroz, Margaret; Virmani, Y.P. (FHWA, USDOT) | Butler, J.T. (Joseph T. Butler, Inc.); Nelson, F.J. (Oregon Dept. of Transportation) | Thompson, N.G. (CC Technologies)

    2002-01-01

    The annual direct cost of bridge infrastructure corrosion to the U.S. economy is estimated at $8.3 billion, with indirect costs approximately 10 times higher. Of the approximately 600000 bridges in the U.S., between 15% and 20% are listed as ?structurally deficient,? frequently due to corrosion damage. Five technologies are presented for reducing the cost of chloride-induced corrosion damage: (1) conductive coating anodes for cathodic protection of existing reinforce concrete bridges, (2) epoxy-coated rebar (ECR), (3) stainless steel rebar, and (4) high-performance concrete for extending the service life of new structures, and (5) metalizing to provide economical, long-term corrosion protection of steel bridges. Conductive coating anodes and stainless steel rebar represent ongoing work by the Oregon Department of Transportation with final verdicts not expected for years. The ECR and metalizing technology have longer track records and are better established in the bridge construction and protection industry. Application of these technologies is guided by a thorough understanding of their performance, of characteristics of the bridge and its environment, and of the results that are sought.

  18. Convective Weather Avoidance with Uncertain Weather Forecasts

    Science.gov (United States)

    Karahan, Sinan; Windhorst, Robert D.

    2009-01-01

    Convective weather events have a disruptive impact on air traffic both in terminal area and in en-route airspaces. In order to make sure that the national air transportation system is safe and efficient, it is essential to respond to convective weather events effectively. Traffic flow control initiatives in response to convective weather include ground delay, airborne delay, miles-in-trail restrictions as well as tactical and strategic rerouting. The rerouting initiatives can potentially increase traffic density and complexity in regions neighboring the convective weather activity. There is a need to perform rerouting in an intelligent and efficient way such that the disruptive effects of rerouting are minimized. An important area of research is to study the interaction of in-flight rerouting with traffic congestion or complexity and developing methods that quantitatively measure this interaction. Furthermore, it is necessary to find rerouting solutions that account for uncertainties in weather forecasts. These are important steps toward managing complexity during rerouting operations, and the paper is motivated by these research questions. An automated system is developed for rerouting air traffic in order to avoid convective weather regions during the 20- minute - 2-hour time horizon. Such a system is envisioned to work in concert with separation assurance (0 - 20-minute time horizon), and longer term air traffic management (2-hours and beyond) to provide a more comprehensive solution to complexity and safety management. In this study, weather is dynamic and uncertain; it is represented as regions of airspace that pilots are likely to avoid. Algorithms are implemented in an air traffic simulation environment to support the research study. The algorithms used are deterministic but periodically revise reroutes to account for weather forecast updates. In contrast to previous studies, in this study convective weather is represented as regions of airspace that pilots

  19. Weather Conditions, Weather Information and Car Crashes

    Directory of Open Access Journals (Sweden)

    Adriaan Perrels

    2015-11-01

    Full Text Available Road traffic safety is the result of a complex interaction of factors, and causes behind road vehicle crashes require different measures to reduce their impacts. This study assesses how strongly the variation in daily winter crash rates associates with weather conditions in Finland. This is done by illustrating trends and spatiotemporal variation in the crash rates, by showing how a GIS application can evidence the association between temporary rises in regional crash rates and the occurrence of bad weather, and with a regression model on crash rate sensitivity to adverse weather conditions. The analysis indicates that a base rate of crashes depending on non-weather factors exists, and some combinations of extreme weather conditions are able to substantially push up crash rates on days with bad weather. Some spatial causation factors, such as variation of geophysical characteristics causing systematic differences in the distributions of weather variables, exist. Yet, even in winter, non-spatial factors are normally more significant. GIS data can support optimal deployment of rescue services and enhance in-depth quantitative analysis by helping to identify the most appropriate spatial and temporal resolutions. However, the supportive role of GIS should not be inferred as existence of highly significant spatial causation.

  20. Wind tunnel test of musi VI bridge

    Science.gov (United States)

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

    2017-11-01

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

  1. Fatigue analysis and life prediction of composite highway bridge decks under traffic loading

    Directory of Open Access Journals (Sweden)

    Fernando N. Leitão

    Full Text Available Steel and composite (steel-concrete highway bridges are currently subjected to dynamic actions of variable magnitude due to convoy of vehicles crossing on the deck pavement. These dynamic actions can generate the nucleation of fractures or even their propagation on the bridge deck structure. Proper consideration of all of the aspects mentioned pointed our team to develop an analysis methodology with emphasis to evaluate the stresses through a dynamic analysis of highway bridge decks including the action of vehicles. The design codes recommend the application of the curves S-N associated to the Miner's damage rule to evaluate the fatigue and service life of steel and composite (steel-concrete bridges. In this work, the developed computational model adopted the usual mesh refinement techniques present in finite element method simulations implemented in the ANSYS program. The investigated highway bridge is constituted by four longitudinal composite girders and a concrete deck, spanning 40.0m by 13.5m. The analysis methodology and procedures presented in the design codes were applied to evaluate the fatigue of the bridge determining the service life of the structure. The main conclusions of this investigation focused on alerting structural engineers to the possible distortions, associated to the steel and composite bridge's service life when subjected to vehicle's dynamic actions.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-06-15

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

  3. 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...

  4. Weatherization and Intergovernmental Program - Weatherization Assistance Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-06-01

    The U.S. Department of Energy’s (DOE) Weatherization Assistance Program reduces energy costs for low-income households by increasing the energy efficiency of their homes, while ensuring their health and safety.

  5. Application of Economic Indicators to Asses the Bridges of Rehablitation

    Directory of Open Access Journals (Sweden)

    Pitoňák Martin

    2015-05-01

    Full Text Available The aim of this paper is to point out the advantage of Cost Benefit Analysis (CBA and its economic indicators to assess a rehabilitation of bridges. The paper includes short example of assessment of the project economic efficiency in which economic indicators are applied in order to evaluate of two technology project variants of bridge object rehabilitation. It quantifies and compares the economic results of alternative 1 with the monolithic prestress construction and alternative 2, with the composite steel - concrete bridge. The contribution reflects the current practice of economic analysis recommended by the Ministry of Transport, Construction and Regional Development.

  6. Application of Economic Indicators to Asses the Bridges of Rehablitation

    Science.gov (United States)

    Pitoňák, Martin; Valuch, Milan

    2015-05-01

    The aim of this paper is to point out the advantage of Cost Benefit Analysis (CBA) and its economic indicators to assess a rehabilitation of bridges. The paper includes short example of assessment of the project economic efficiency in which economic indicators are applied in order to evaluate of two technology project variants of bridge object rehabilitation. It quantifies and compares the economic results of alternative 1 with the monolithic prestress construction and alternative 2, with the composite steel - concrete bridge. The contribution reflects the current practice of economic analysis recommended by the Ministry of Transport, Construction and Regional Development.

  7. review of elastic analys ew of elastic analysis of box girder bridges ...

    African Journals Online (AJOL)

    eobe

    Tel: +234-803-746-2228. REVIEW OF ELASTIC ANALYS. DEPARTMENT OF CIVIL ENGINEERING. E-mail ...... concrete box girder bridge, the Lavic Road bridge in. California, monitored over a 2-year period from ..... analysis of curved steel box beams, Masters Thesis,. University of Maryland. 52. Oleinik, J. C., and Heins, ...

  8. Stochastic finite element analysis of long-span bridges with CFRP ...

    Indian Academy of Sciences (India)

    are represented by 139 beam elements, the cable stays are modelled with 30 truss elements. The stiffening girder and the towers of the Jindo Bridge were made of steel (Tappin & Clark. 1985). For the purpose of discussion, a same span length of cable-stayed bridge with CFRP stay cables is schemed. Except for the ...

  9. Advanced analysis and design for fire safety of steel structures

    CERN Document Server

    Li, Guoqiang

    2013-01-01

    Advanced Analysis and Design for Fire Safety of Steel Structures systematically presents the latest findings on behaviours of steel structural components in a fire, such as the catenary actions of restrained steel beams, the design methods for restrained steel columns, and the membrane actions of concrete floor slabs with steel decks. Using a systematic description of structural fire safety engineering principles, the authors illustrate the important difference between behaviours of an isolated structural element and the restrained component in a complete structure under fire conditions. The book will be an essential resource for structural engineers who wish to improve their understanding of steel buildings exposed to fires. It is also an ideal textbook for introductory courses in fire safety for master’s degree programs in structural engineering, and is excellent reading material for final-year undergraduate students in civil engineering and fire safety engineering. Furthermore, it successfully bridges th...

  10. Environmental life cycle assessment of railway bridge materials using UHPFRC

    Directory of Open Access Journals (Sweden)

    Bizjak Karmen Fifer

    2016-10-01

    Full Text Available The railway infrastructure is a very important component of the world’s total transportation network. Investment in its construction and maintenance is significant on a global scale. Previously published life cycle assessment (LCA studies performed on road and rail systems very seldom included infrastructures in detail, mainly choosing to focus on vehicle manufacturing and fuel consumption. This article presents results from an environmental study for railway steel bridge materials for the demonstration case of the Buna Bridge in Croatia. The goal of these analyses was to compare two different types of remediation works for railway bridges with different materials and construction types. In the first part, the environmental impact of the classical concrete bridge construction was calculated, whereas in the second one, an alternative new solution, namely, the strengthening of the old steel bridge with ultra-high-performance fibre-reinforced concrete (UHPFRC deck, was studied. The results of the LCA show that the new solution with UHPFRC deck gives much better environmental performance. Up to now, results of LCA of railway open lines, railway bridges and tunnels have been published, but detailed analyses of the new solution with UHPFRC deck above the old bridge have not previously been performed.

  11. Monitoring Bridge Dynamic Responses Using Fiber Bragg Grating Tiltmeters.

    Science.gov (United States)

    Xiao, Feng; Chen, Gang S; Hulsey, J Leroy

    2017-10-20

    In bridge health monitoring, tiltmeters have been used for measuring rotation and curvature; however, their application in dynamic parameter identification has been lacking. This study installed fiber Bragg grating (FBG) tiltmeters on the bearings of a bridge and monitored the dynamic rotational angle. The dynamic features, including natural frequencies and mode shapes, have been identified successfully. The innovation presented in this paper is the first-time use of FBG tiltmeter readings to identify the natural frequencies of a long-span steel girder bridge. The identified results have been verified using a bridge finite element model. This paper introduces a new method for the dynamic monitoring of a bridge using FBG tiltmeters. Limitations and future research directions are also discussed in the conclusion.

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

    Directory of Open Access Journals (Sweden)

    Knoppers Bartha

    2011-10-01

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

  13. Probabilistic Model for Fatigue Crack Growth in Welded Bridge Details

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard; Yalamas, Thierry

    2013-01-01

    In the present paper a probabilistic model for fatigue crack growth in welded steel details in road bridges is presented. The probabilistic model takes the influence of bending stresses in the joints into account. The bending stresses can either be introduced by e.g. misalignment or redistributio...

  14. Design of the New Arch Bridge at Mioveni

    Directory of Open Access Journals (Sweden)

    Alexandru Dima

    2014-07-01

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

  15. Cathodic protection of RC structures - Far more than bridge decks

    NARCIS (Netherlands)

    Nerland, O.C.; Polder, R.B.

    2002-01-01

    When the first trials with Cathodic Protection (CP) on reinforced concrete (RC) structures were carried out nearly 30 years ago the main aim was treating steel in bridge decks, suffering from chloride induced corrosion. Various types of anode systems (conductive asphalt, conductive mortars, carbon

  16. Repair of earthquake damaged bridge columns with fractured bars.

    Science.gov (United States)

    2013-07-01

    The objective of this study is to repair three, half-scale RC bridge columns that will be tested to failure under slow cyclic loading. : These columns will have fractured longitudinal and transverse steel. The ultimate goal is to develop repair metho...

  17. Fatigue Assessment of Full-Scale Retrofitted Orthotropic Bridge Decks

    NARCIS (Netherlands)

    Teixeira De Freitas, S.; Kolstein, M.H.; Bijlaard, F.S.K.

    2017-01-01

    Full-scale fatigue tests were performed on two retrofitted orthotropic bridge decks (OBDs). The retrofitting systems consist of adding a second steel plate on the top of the existing deck. The aim is to reduce the stresses at the fatigue-sensitive details and therefore extend the fatigue life of

  18. PCP cracking and bridge deck reinforcement : an interim report.

    Science.gov (United States)

    2010-10-28

    TxDOT Project 0-6348 Controlling Cracking in Prestressed Concrete Panels and Optimizing Bridge Deck : Reinforcing Steel started on September 1, 2008 and is scheduled to end on August 31, 2012. The project is : proceeding on schedule. This repor...

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

    Science.gov (United States)

    Sekiya, Hidehiko; Kinomoto, Takeshi; Miki, Chitoshi

    2016-11-09

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-31

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

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

    Directory of Open Access Journals (Sweden)

    Shunquan Qin

    2017-12-01

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

  2. Weather and road capacity

    OpenAIRE

    Jensen, Thomas Christian

    2014-01-01

    The paper presents estimations of the effect of bad weather on the observed speed on a Danish highway section; Køge Bugt Motorvejen. The paper concludes that weather, primarily precipitation and snow, has a clear negative effect on speed when the road is not in hypercongestion mode. Furthermore, the capacity of the highway seems to be reduced in bad weather and there are indications that travel time variability is also increased, at least in free-flow conditions. Heavy precipitation reduces s...

  3. Space Weather Analysis

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Space Weather Analysis archives are model output of ionospheric, thermospheric and magnetospheric particle populations, energies and electrodynamics

  4. Space Weather Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Space Weather Computational Laboratory is a Unix and PC based modeling and simulation facility devoted to research analysis of naturally occurring electrically...

  5. NASA Weather Support 2017

    Science.gov (United States)

    Carroll, Matt

    2017-01-01

    In the mid to late 1980's, as NASA was studying ways to improve weather forecasting capabilities to reduce excessive weather launch delays and to reduce excessive weather Launch Commit Criteria (LCC) waivers, the Challenger Accident occurred and the AC-67 Mishap occurred.[1] NASA and USAF weather personnel had advance knowledge of extremely high levels of weather hazards that ultimately caused or contributed to both of these accidents. In both cases, key knowledge of the risks posed by violations of weather LCC was not in the possession of final decision makers on the launch teams. In addition to convening the mishap boards for these two lost missions, NASA convened expert meteorological boards focusing on weather support. These meteorological boards recommended the development of a dedicated organization with the highest levels of weather expertise and influence to support all of American spaceflight. NASA immediately established the Weather Support Office (WSO) in the Office of Space Flight (OSF), and in coordination with the United Stated Air Force (USAF), initiated an overhaul of the organization and an improvement in technology used for weather support as recommended. Soon after, the USAF established a senior civilian Launch Weather Officer (LWO) position to provide meteorological support and continuity of weather expertise and knowledge over time. The Applied Meteorology Unit (AMU) was established by NASA, USAF, and the National Weather Service to support initiatives to place new tools and methods into an operational status. At the end of the Shuttle Program, after several weather office reorganizations, the WSO function had been assigned to a weather branch at Kennedy Space Center (KSC). This branch was dismantled in steps due to further reorganization, loss of key personnel, and loss of budget line authority. NASA is facing the loss of sufficient expertise and leadership required to provide current levels of weather support. The recommendation proposed

  6. Nonlinear seismic analysis of continuous RC bridge

    Directory of Open Access Journals (Sweden)

    Čokić Miloš M.

    2017-01-01

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

  7. Bridge vehicle impact assessment.

    Science.gov (United States)

    2011-12-01

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

  8. Movable bridge maintenance monitoring.

    Science.gov (United States)

    2013-10-01

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

  9. Cable Supported Bridges

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

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

  10. Bridge Crossing Simulator

    Science.gov (United States)

    2014-10-07

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

  11. Principles of Bridge Reliability

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, Andrzej S.

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

  12. Weather and emotional state

    Science.gov (United States)

    Spasova, Z.

    2010-09-01

    Introduction Given the proven effects of weather on the human organism, an attempt to examine its effects on a psychic and emotional level has been made. Emotions affect the bio-tonus, working ability and concentration, hence their significance in various domains of economic life, such as health care, education, transportation, tourism, etc. Data and methods The research has been made in Sofia City within a period of 8 months, using 5 psychological methods (Eysenck Personality Questionnaire (EPQ), State-Trait Anxiety Inventory (STAI), Test for Self-assessment of the emotional state (developed by Wessman and Ricks), Test for evaluation of moods and Test "Self-confidence - Activity - Mood" (developed by the specialists from the Military Academy in Saint Petersburg). The Fiodorov-Chubukov's complex-climatic method was used to characterize meteorological conditions because of the purpose to include in the analysis a maximal number of meteorological elements. 16 weather types are defined in dependence of the meteorological elements values according to this method. Abrupt weather changes from one day to another, defined by the same method, were considered as well. Results and discussions The results obtained by t-test show that the different categories of weather lead to changes in the emotional status, which indicates a character either positive or negative for the organism. The abrupt weather changes, according to expectations, have negative effect on human emotions but only when a transition to the cloudy weather or weather type, classified as "unfavourable" has been realized. The relationship between weather and human emotions is rather complicated since it depends on individual characteristics of people. One of these individual psychological characteristics, marked by the dimension "neuroticism", has a strong effect on emotional reactions in different weather conditions. Emotionally stable individuals are more "protected" to the weather influence on their emotions

  13. Strength and fatigue of three glass fiber reinforced composite bridge decks with mechanical deck to stringer connections.

    Science.gov (United States)

    2012-02-01

    Replacement of the steel grating deck on the lift span of the Morrison Bridge in Portland, OR, will utilize glass : fiber reinforced polymer (FRP) panels to address ongoing maintenance issues of the deteriorated existing deck, improve driver : safety...

  14. Performance of a bridge deck with glass fiber reinforced polymer bars as the top mat of reinforcement.

    Science.gov (United States)

    2005-01-01

    The purpose of this research was to investigate the performance of glass fiber reinforced polymer (GFRP) bars as reinforcement for concrete decks. Today's rapid bridge deck deterioration is calling for a replacement for steel reinforcement. The advan...

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

    Science.gov (United States)

    2008-10-01

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

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

    Science.gov (United States)

    2008-08-01

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

  17. Experimental investigation on FRP to steel adhesively-bonded joint under tensile loading

    NARCIS (Netherlands)

    Jiang, X.; Kolstein, M.H.; Bijlaard, F.S.K.

    2012-01-01

    Due to various advantages of Fibre-Reinforced Polymer (FRP) decks, the FRP to steel composite girder system is being increasingly used in the construction of new bridges as well as the rehabilitation projects of old bridges. This paper focus on the mechanical behaviors and failure modes of the

  18. Weather and road capacity

    DEFF Research Database (Denmark)

    Jensen, Thomas Christian

    2014-01-01

    The paper presents estimations of the effect of bad weather on the observed speed on a Danish highway section; Køge Bugt Motorvejen. The paper concludes that weather, primarily precipitation and snow, has a clear negative effect on speed when the road is not in hypercongestion mode. Furthermore...

  19. Weathering drought in Africa

    OpenAIRE

    Cornforth, Rosalind

    2013-01-01

    Close to 19 million people in sub-Saharan Africa are threatened by severe food \\ud shortages, partly due to variations in the weather. Our understanding of \\ud meteorology is improving all the time, but can science really help the people at \\ud the sharp end of Africa’s weather?

  20. KSC Weather and Research

    Science.gov (United States)

    Maier, Launa; Huddleston, Lisa; Smith, Kristin

    2016-01-01

    This briefing outlines the history of Kennedy Space Center (KSC) Weather organization, past research sponsored or performed, current organization, responsibilities, and activities, the evolution of weather support, future technologies, and an update on the status of the buoys located offshore of Cape Canaveral Air Force Station and KSC.

  1. Tales of future weather

    NARCIS (Netherlands)

    Hazeleger, W.; Hurk, Van Den B.J.J.M.; Min, E.; Oldenborgh, Van G.J.; Petersen, A.C.; Stainforth, D.A.; Vasileiadou, E.; Smith, L.A.

    2015-01-01

    Society is vulnerable to extreme weather events and, by extension, to human impacts on future events. As climate changes weather patterns will change. The search is on for more effective methodologies to aid decision-makers both in mitigation to avoid climate change and in adaptation to changes.

  2. Tales of future weather

    NARCIS (Netherlands)

    Hazeleger, W.; van den Hurk, B.J.J.M.; Min, E.; van Oldenborgh, G.J.; Wang, X.; Petersen, A.C.; Stainforth, D.A.; Vasileiadou, E.; Smith, L.A.

    2015-01-01

    Society is vulnerable to extreme weather events and, by extension, to human impacts on future events. As climate changes weather patterns will change. The search is on for more effective methodologies to aid decision-makers both in mitigation to avoid climate change and in adaptation to changes. The

  3. Weather Fundamentals: Clouds. [Videotape].

    Science.gov (United States)

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) discusses how clouds form, the different types of clouds, and the important role they play in…

  4. Designing a Weather Station

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

    The collection and analysis of weather data is crucial to the location of alternate energy systems like solar and wind. This article presents a design challenge that gives students a chance to design a weather station to collect data in advance of a large wind turbine installation. Data analysis is a crucial part of any science or engineering…

  5. Weather in Mountainous Terrain (Overcoming Scientific Barriers to Weather Support)

    Science.gov (United States)

    2011-02-15

    Weather in Mountainous Terrain (Overcoming Scientific Barriers to Weather Support) Fiesta Resort & Conference Center Tempe, AZ February 1...Meteorology Overcoming Scientific Barriers to Weather Support Fiesta Resort & Conference Center Tempe, AZ February 1 & 2, 2010 Hosted by University

  6. The Vibration Based Fatigue Damage Assessment of Steel and Steel Fiber Reinforced Concrete (SFRC Composite Girder

    Directory of Open Access Journals (Sweden)

    Xu Chen

    2015-01-01

    Full Text Available The steel-concrete composite girder has been usually applied in the bridge and building structures, mostly consisting of concrete slab, steel girder, and shear connector. The current fatigue damage assessment for the composite girder is largely based on the strain values and concrete crack features, which is time consuming and not stable. Hence the vibration-based fatigue damage assessment has been considered in this study. In detail, a steel-steel fiber reinforced concrete (SFRC composite girder was tested. The steel fiber reinforced concrete is usually considered for dealing with the concrete cracks in engineering practice. The composite girder was 3.3m long and 0.45m high. The fatigue load and impact excitation were applied on the specimen sequentially. According to the test results, the concrete crack development and global stiffness degradation during the fatigue test were relatively slow due to the favourable performance of SFRC in tension. But on the other hand, the vibration features varied significantly during the fatigue damage development. Generally, it confirmed the feasibility of executing fatigue damage assessment of composite bridge based on vibration method.

  7. 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.

  8. Proposal and study of a long-span composite cable-stayed bridge with new hybrid girder; Atarashii gosei kozo shuketa wo mochiita chodai fukugo shachokyo no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, K.; Hishiki, Y.; Furuichi, K. [Kajima Corp., Tokyo (Japan)

    1999-09-30

    A hybrid or mixed structure (composite structures) are a matter of increasing concern which takes in each advantage of steel and concrete. A field of bridges is no exception, with the plan and construction carried out for the new type of composite bridge, such as a composite cable-stayed bridge and a composite extra dose bridge as a long span bridge, and a composite truss bridge and a corrugated steel plate web bridge as a medium-span bridge, with technological development becoming active in this field. In such a technological trend, a hybrid two-girder structure was devised, a structure consisting of a concrete filled steel pipe for a girder and a precast (PC) floor plate for a floor board, as the girder structure of a long-span cable-stayed bridge in the subject research; also, applicability was examined using, as an example, the composite cable-stayed bridge with hybrid girders employed for the span. This paper reports the result of the analysis of the entire system, the analysis made for the purpose of examining the characteristic and the feasibility of this hybrid girder. The analysis revealed the structural feasibility of the long-span composite cable-stayed bridge using two hybrid girders of concrete-filled steel pipes thus devised. (NEDO)

  9. Static and Dynamic Characteristics of a Long-Span Cable-Stayed Bridge with CFRP Cables

    Directory of Open Access Journals (Sweden)

    Xu Xie

    2014-06-01

    Full Text Available In this study, the scope of CFRP cables in cable-stayed bridges is studied by establishing a numerical model of a 1400-m span of the same. The mechanical properties and characteristics of CFRP stay cables and of a cable-stayed bridge with CFRP cables are here subjected to comprehensive analysis. The anomalies in the damping properties of free vibration, nonlinear parametric vibration and wind fluctuating vibration between steel cables and CFRP cables are determined. The structural stiffness, wind resistance and traffic vibration of the cable-stayed bridge with CFRP cables are also analyzed. It was found that the static performances of a cable-stayed bridge with CFRP cables and steel cables are basically the same. The natural frequencies of CFRP cables do not coincide with the major natural frequencies of the cable-stayed bridge, so the likelihood of CFRP cable-bridge coupling vibration is minuscule. For CFRP cables, the response amplitudes of both parametric vibration and wind fluctuating vibration are smaller than those of steel cables. It can be concluded from the research that the use of CFRP cables does not change the dynamic characteristics of the vehicle-bridge coupling vibration. Therefore, they can be used in long-span cable-stayed bridges with an excellent mechanical performance.

  10. Plasma nitriding of steels

    CERN Document Server

    Aghajani, Hossein

    2017-01-01

    This book focuses on the effect of plasma nitriding on the properties of steels. Parameters of different grades of steels are considered, such as structural and constructional steels, stainless steels and tools steels. The reader will find within the text an introduction to nitriding treatment, the basis of plasma and its roll in nitriding. The authors also address the advantages and disadvantages of plasma nitriding in comparison with other nitriding methods. .

  11. Preliminary investigation of steel girder end panel shear resistance.

    Science.gov (United States)

    2010-01-01

    Prior to 1973, steel bridges in California were designed based on Allowable Stress : Design and the shear design of web and transverse stiffeners was based on the : average shear stress in the web. The tension field action equation similar to the : c...

  12. Epoxy coated reinforcement in bridge decks

    Science.gov (United States)

    Wills, J.

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

  13. 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. 

  14. Daily Weather Maps

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Several different government offices have published the Daily weather maps over its history. The publication has also gone by different names over time. The U.S....

  15. Surface Weather Observations Monthly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface Weather Observation 1001 Forms is a set of historical manuscript records for the period 1893-1948. The collection includes two very similar form types: Form...

  16. Uruguay - Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface weather observation forms for 26 stations in Uruguay. Period of record 1896-2005, with two to eight observations per day. Files created through a...

  17. Space Weather Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of space weather datasets from the National Oceanic and Atmospheric Administration and from the World Data Service for Geophysics,...

  18. Oil Rig Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weather observations taken at offshore platforms along the United States coastlines. The majority are located in oil-rich areas of the Gulf of Mexico, Gulf of...

  19. Cape Kennedy Weather Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digitized data taken from original weather observations taken at Cape Kennedy Air Force Station, Florida. Elements recorded are wind speed and direction,...

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

    Science.gov (United States)

    Flaga, Kazimierz; Furtak, Kazimierz

    2015-03-01

    Steel-concrete composite structures have been used in bridge engineering from decades. This is due to rational utilisation of the strength properties of the two materials. At the same time, the reinforced concrete (or prestressed) deck slab is more favourable than the orthotropic steel plate used in steel bridges (higher mass, better vibration damping, longer life). The most commonly found in practice are composite girder bridges, particularly in highway bridges of small and medium spans, but the spans may reach over 200 m. In larger spans steel truss girders are applied. Bridge composite structures are also employed in cable-stayed bridge decks of the main girder spans of the order of 600, 800 m. The aim of the article is to present the cionstruction process and strength analysis problems concerning of this type of structures. Much attention is paid to the design and calculation of the shear connectors characteristic for the discussed objects. The authors focused mainly on the issues of single composite structures. The effect of assembly states on the stresses and strains in composite members are highlighted. A separate part of problems is devoted to the influence of rheological factors, i.e. concrete shrinkage and creep, as well as thermal factors on the stresses and strains and redistribution of internal forces.

  1. [Composite (etched) bridge].

    Science.gov (United States)

    de Kloet, H J; van Pelt, A W

    1996-11-01

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

  2. 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....

  3. Ultrahigh carbon steels, Damascus steels, and superplasticity

    Energy Technology Data Exchange (ETDEWEB)

    Sherby, O.D. [Stanford Univ., CA (United States). Dept. of Materials Science and Engineering; Wadsworth, J. [Lawrence Livermore National Lab., CA (United States)

    1997-04-01

    The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.

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

    Science.gov (United States)

    2009-10-01

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

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

    Directory of Open Access Journals (Sweden)

    V. O. Samosvat

    2017-10-01

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

  6. 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.

  7. Bridges Expansion Joints

    OpenAIRE

    Sergey W. Kozlachkow

    2012-01-01

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

  8. Bridge the Gap

    DEFF Research Database (Denmark)

    Marselis, Randi Lorenz

    2017-01-01

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

  9. Virtual Bridge Design Challenge

    Science.gov (United States)

    Mitts, Charles R.

    2013-01-01

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

  10. Linguistic Barriers and Bridges

    DEFF Research Database (Denmark)

    Thuesen, Frederik

    2016-01-01

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

  11. Comparative testing of radiographic testing, ultrasonic testing and phased array advanced ultrasonic testing non destructive testing techniques in accordance with the AWS D1.5 bridge welding code : [summary].

    Science.gov (United States)

    2014-02-01

    To ensure that Florida bridges remain safe and structurally secure for their 50-year-plus service life, they are inspected regularly. For steel bridges, welds critical to the bridges integrity do not even leave the workshop unless they meet rigoro...

  12. Progress in thermomechanical control of steel plates and their commercialization

    Directory of Open Access Journals (Sweden)

    Kiyoshi Nishioka and Kazutoshi Ichikawa

    2012-01-01

    Full Text Available The water-cooled thermomechanical control process (TMCP is a technology for improving the strength and toughness of water-cooled steel plates, while allowing control of the microstructure, phase transformation and rolling. This review describes metallurgical aspects of the microalloying of steel, such as niobium addition, and discusses advantages of TMCP, for example, in terms of weldability, which is reduced upon alloying. Other covered topics include the development of equipment, distortions in steel plates, peripheral technologies such as steel making and casting, and theoretical modeling, as well as the history of property control in steel plate production and some early TMCP technologies. We provide some of the latest examples of applications of TMCP steel in various industries such as shipbuilding, offshore structures, building construction, bridges, pipelines, penstocks and cryogenic tanks. This review also introduces high heat-affected-zone toughness technologies, wherein the microstructure of steel is improved by the addition of fine particles of magnesium-containing sulfides and magnesium- or calcium-containing oxides. We demonstrate that thanks to ongoing developments TMCP has the potential to meet the ever-increasing demands of steel plates.

  13. Progress in thermomechanical control of steel plates and their commercialization

    Science.gov (United States)

    Nishioka, Kiyoshi; Ichikawa, Kazutoshi

    2012-04-01

    The water-cooled thermomechanical control process (TMCP) is a technology for improving the strength and toughness of water-cooled steel plates, while allowing control of the microstructure, phase transformation and rolling. This review describes metallurgical aspects of the microalloying of steel, such as niobium addition, and discusses advantages of TMCP, for example, in terms of weldability, which is reduced upon alloying. Other covered topics include the development of equipment, distortions in steel plates, peripheral technologies such as steel making and casting, and theoretical modeling, as well as the history of property control in steel plate production and some early TMCP technologies. We provide some of the latest examples of applications of TMCP steel in various industries such as shipbuilding, offshore structures, building construction, bridges, pipelines, penstocks and cryogenic tanks. This review also introduces high heat-affected-zone toughness technologies, wherein the microstructure of steel is improved by the addition of fine particles of magnesium-containing sulfides and magnesium- or calcium-containing oxides. We demonstrate that thanks to ongoing developments TMCP has the potential to meet the ever-increasing demands of steel plates.

  14. Long Span Bridges in Scandinavia

    DEFF Research Database (Denmark)

    Gimsing, Niels Jørgen

    1998-01-01

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

  15. Sustainable Bridge Infrastructure Procurement

    DEFF Research Database (Denmark)

    Safi, Mohammed; Du, Guangli; Simonsson, Peter

    2016-01-01

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

  16. Stiffness of Railway Soil-Steel Structures

    Directory of Open Access Journals (Sweden)

    Machelski Czesław

    2015-12-01

    Full Text Available The considerable influence of the soil backfill properties and that of the method of compacting it on the stiffness of soil-steel structures is characteristic of the latter. The above factors (exhibiting randomness become apparent in shell deformation measurements conducted during construction and proof test loading. A definition of soil-shell structure stiffness, calculated on the basis of shell deflection under the service load, is proposed in the paper. It is demonstrated that the stiffness is the inverse of the deflection influence function used in structural mechanics. The moving load methodology is shown to be useful for testing, since it makes it possible to map the shell deflection influence line also in the case of group loads (concentrated forces, as in bridges. The analyzed cases show that the shell’s span, geometry (static scheme and the height of earth fill influence the stiffness of the structure. The soil-steel structure’s characteristic parameter in the form of stiffness k is more suitable for assessing the quality of construction works than the proposed in code geometric index ω applied to beam structures. As shown in the given examples, parameter k is more effective than stiffness parameter λ used to estimate the deformation of soil-steel structures under construction. Although the examples concern railway structures, the methodology proposed in the paper is suitable also for road bridges.

  17. The anchors of steel wire ropes, testing methods and their results

    Directory of Open Access Journals (Sweden)

    J. Krešák

    2012-10-01

    Full Text Available The present paper introduces an application of the acoustic and thermographic method in the defectoscopic testing of immobile steel wire ropes at the most critical point, the anchor. First measurements and their results by these new defectoscopic methods are shown. In defectoscopic tests at the anchor, the widely used magnetic method gives unreliable results, and therefore presents a problem for steel wire defectoscopy. Application of the two new methods in the steel wire defectoscopy at the anchor point will enable increased safety measures at the anchor of steel wire ropes in bridge, roof, tower and aerial cable lift constructions.

  18. Space Weather: Terrestrial Perspective

    Directory of Open Access Journals (Sweden)

    Pulkkinen Tuija

    2007-05-01

    Full Text Available Space weather effects arise from the dynamic conditions in the Earth’s space environment driven by processes on the Sun. While some effects are influenced neither by the properties of nor the processes within the Earth’s magnetosphere, others are critically dependent on the interaction of the impinging solar wind with the terrestrial magnetic field and plasma environment. As the utilization of space has become part of our everyday lives, and as our lives have become increasingly dependent on technological systems vulnerable to space weather influences, understanding and predicting hazards posed by the active solar events has grown in importance. This review introduces key dynamic processes within the magnetosphere and discusses their relationship to space weather hazards.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-09-15

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

  20. Carbon fiber-reinforced polymer strengthening and monitoring of the grondals bridge in Sweden

    DEFF Research Database (Denmark)

    Täljsten, Björn; Hejll, Arvid; James, Gerard

    2007-01-01

    The Grondal Bridge is a large freivorbau bridge (prestressed concrete box bridge), approximately 400 min length with a free span of 120 m. It was opened to tram traffic in the year 2000. Just after opening cracks were noticed in the webs, these cracks have then increased, the size of the largest...... cracks exceeded 0.5 mm, and at the end of 2001 the bridge was temporarily strengthened. This was carried out with externally placed prestressed steel stays. The reason for the cracking is still debated and will be further discussed in this paper. Nevertheless, it was clear that the bridge needed...... to be strengthened. The strengthening methods used were CFRP plates at the serviceability limit state and prestressed dywidag stays at the ultimate limit state. The strengthening was carried out during 2002. At the same time monitoring of the bridge commenced, using LVDT crack gauges as well as optical fiber sensors....

  1. Olympian weather forecasting

    Science.gov (United States)

    Showstack, Randy

    A unique public-private partnership will provide detailed weather information at the 2002 Winter Olympics in Utah, 8-24 February About 50 meteorologists with the National Weather Service (NWS) and several private groups will work in the background to provide accurate forecasts.This is the first time that U.S. government and private meteorologists will share forecasting responsibilities for the Olympics, according to the Salt Lake Organizing Committee for the Olympic Games. The partnership includes meteorologists with the University of Utah and KSL-TV in Salt Lake City.

  2. Structural Assessment of Externally Strengthened Bridge Deck Panels

    Science.gov (United States)

    Sim, Jongsung; Oh, Hongseob; Meyer, Christian

    2006-03-01

    Deteriorated concrete bridge decks are strengthened with external bonding technique using either steel plate or various FRPs to enhance the decreased load carrying capacity and serviceability. But the failure characteristics of bridge decks strengthened with various materials can be changed according to mechanical properties of strengthening materials or strengthening scheme as well as the strengthening amount. In this paper, strengthening effect of deck strengthened with carbon fiber sheets, glass fiber sheets or steel plates is compared. And the theoretical load carrying capacity are evaluated using yield line theory and punching shear model properly modified for the strengthened RC member. The panels strengthened with sheet type FRP materials failed more often in a ductile mode, indicating that the failure developed after the rebar yielded.

  3. 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

  4. Sustainable Bridge Infrastructure Procurement

    DEFF Research Database (Denmark)

    Safi, Mohammed; Du, Guangli; Simonsson, Peter

    2016-01-01

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

  5. 'Is it the weather?'

    NARCIS (Netherlands)

    B. Jacobsen (Ben); W.A. Marquering (Wessel)

    2004-01-01

    textabstractWe show that results in the recent strand of the literature that tries to explain stock returns by weather induced mood shifts of investors might be data-driven inference. More specifically, we consider two recent studies (Kamstra, Kramer and Levi, 2003a and Cao and Wei, 2004) that claim

  6. Weather, Climate, and You.

    Science.gov (United States)

    Blai, Boris, Jr.

    Information from the American Institute of Medical Climatologists on human responses to weather and climatic conditions, including clouds, winds, humidity, barometric pressure, heat, cold, and other variables that may exert a pervasive impact on health, behavior, disposition, and the level of efficiency with which individuals function is reviewed.…

  7. Weathering the storm

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, B.

    2007-06-15

    Although growth of 50% over 10 years is forecast for the coal industry in Canada, operators face a skills shortage and have to overcome harsh weather conditions to move their coal. The papers reviews the industry and reports on recent developments. 6 figs.

  8. Rainy Weather Science.

    Science.gov (United States)

    Reynolds, Karen

    1996-01-01

    Presents ideas on the use of rainy weather for activities in the earth, life, and physical sciences. Topics include formation and collision of raindrops, amount and distribution of rain, shedding of water by plants, mapping puddles and potholes, rainbow formation, stalking storms online, lightning, and comparing particles in the air before and…

  9. The steel scrap age.

    Science.gov (United States)

    Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M

    2013-04-02

    Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age.

  10. Bridge management system for the Western Cape provincial government, South Africa: implementation and utilization

    CSIR Research Space (South Africa)

    Nell, AJ

    2008-10-01

    Full Text Available Examples of structural repairs a) repairs to culvert wing walls, abutment walls as well as deck slab, b) replacement of existing steel bridge handrails with precast concrete rails, c) repairs to bridge abutment by means of externally reinforced concrete... general problem of reinforcement corrosion. New precast reinforced concrete railings were proposed in instances were vandalism had occurred; • Bearings were generally in a good condition; • Selected road safety elements were also identified for repair...

  11. Deterministic and Probabilistic Analysis of NPP Communication Bridge Resistance Due to Extreme Loads

    Directory of Open Access Journals (Sweden)

    Králik Juraj

    2014-12-01

    Full Text Available This paper presents the experiences from the deterministic and probability analysis of the reliability of communication bridge structure resistance due to extreme loads - wind and earthquake. On the example of the steel bridge between two NPP buildings is considered the efficiency of the bracing systems. The advantages and disadvantages of the deterministic and probabilistic analysis of the structure resistance are discussed. The advantages of the utilization the LHS method to analyze the safety and reliability of the structures is presented

  12. A Novel Concrete-Based Sensor for Detection of Ice and Water on Roads and Bridges

    OpenAIRE

    Tabatabai, Habib; Aljuboori, Mohammed

    2017-01-01

    Hundreds of people are killed or injured annually in the United States in accidents related to ice formation on roadways and bridge decks. In this paper, a novel embedded sensor system is proposed for the detection of black ice as well as wet, dry, and frozen pavement conditions on roads, runways, and bridges. The proposed sensor works by detecting changes in electrical resistance between two sets of stainless steel poles embedded in the concrete sensor to assess surface and near-surface cond...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-01-30

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

  14. Weatherization Works: An interim report of the National Weatherization Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M.A.; Berry, L.G. [Oak Ridge National Lab., TN (United States); Kinney, L.F. [Synertech Systems Corp., Syracuse, NY (United States)

    1993-11-01

    The National Weatherization Evaluation is the first comprehensive evaluation of the Weatherization Assistance Program since 1984. The evaluation was designed to accomplish the following goals: Estimate energy savings and cost effectiveness; Assess nonenergy impacts; Describe the weatherization network; Characterize the eligible population and resources; and Identify factors influencing outcomes and opportunities for the future. As a national program, weatherization incorporates considerable diversity due to regional differences. Therefore, evaluation results are presented both in aggregate and for three climate regions: cold, moderate and hot.

  15. Behaviour of several fatigue prone bridge details

    Science.gov (United States)

    Kubiš, Petr; Ryjáček, Pavel

    2017-09-01

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

  16. Magnetic Nondestructive Testing Techniques of Constructional Steel

    Directory of Open Access Journals (Sweden)

    Xiong Er-gang

    2016-01-01

    Full Text Available Steel is a kind of ferromagnetic material, which is extensively applied in such fields as buildings, bridges, railways, machines and lifeline engineering etc. Those engineering structures built of constructional steel will unavoidably experience some damages during their service lifetime, thus which will influence the distribution regularity of internal forces in structures, result in over-stresses, cause the local failure of structures, and even lead to collapse of the whole structure. Therefore, it is a pressing topic to study how to directly evaluate the real-time stressed states of structural members, damages and steel characteristics in present structural health monitoring and diagnosing fields. And the achievements of this research will be of theoretical significance and of application value of engineering. This paper summarizes varieties of new magnetic nondestructive testing techniques used in constructional steel, respectively investigates the testing principles, characteristics and application for the magnetic Barkhausen noise technique, magnetic acoustic emission technique, magnetic flux leakage technique, magnetic memory technique and magnetic absorption technique, and points out the problems present in the application of these new techniques to actual testing and the further research objective.

  17. The Cultural Bridge Model.

    Science.gov (United States)

    West, Edith A.

    1993-01-01

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

  18. 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...

  19. State's First Bridge

    Data.gov (United States)

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

  20. EMPIRICAL ANALYSIS OFEXTREME WEATHER CONDITIONS ...

    African Journals Online (AJOL)

    USER

    2016-10-31

    Oct 31, 2016 ... Ethiopian Journal of Environmental Studies & Management 9(6): 680 ... The frequency of delay, diversion and outright cancellation occasioned by poor weather ... weather condition has significant influence on aviation safety.

  1. Severe Weather Data Inventory (SWDI)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Severe Weather Data Inventory (SWDI) is an integrated database of severe weather records for the United States. SWDI enables a user to search through a variety...

  2. North America Synoptic Weather Maps

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Series of Synoptic Weather Maps. Maps contains a surface analysis comprised of plotted weather station observations, isobars indicating low and high-pressure...

  3. Reserves in load capacity assessment of existing bridges

    Science.gov (United States)

    Žitný, Jan; Ryjáček, Pavel

    2017-09-01

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

  4. Forward Affect Bridge.

    Science.gov (United States)

    Bonshtein, Udi; Torem, Moshe

    2017-01-01

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

  5. Bridges Expansion Joints

    Directory of Open Access Journals (Sweden)

    Sergey W. Kozlachkow

    2012-05-01

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

  6. Performance evaluation of one coat systems for new steel bridges.

    Science.gov (United States)

    2011-06-01

    In an effort to address cost issues associated with shop application of conventional three-coat systems, the Federal : Highway Administration completed a study to investigate the performance of eight one-coat systems and two control : coatings for co...

  7. Marine atmospheric corrosion of carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Morcillo, M.; Alcantara, J.; Diaz, I.; Chico, B.; Simancas, J.; Fuente, D. de la

    2015-07-01

    Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a) environmental conditions necessary for akaganeite formation; (b) characterisation of akaganeite in the corrosion products formed; (c) corrosion mechanisms of carbon steel in marine atmospheres; (d) exfoliation of rust layers formed in highly aggressive marine atmospheres; (e) long-term corrosion rate prediction; and (f) behaviour of weathering steels. Field research has been carried out at Cabo Vilano wind farm (Camarinas, Galicia) in a wide range of atmospheric salinities and laboratory work involving the use of conventional atmospheric corrosion techniques and near-surface and bulk sensitive analytical techniques: scanning electron microscopy (SEM)/energy dispersive spectrometry (EDS), X-ray diffraction (XRD), Mossbauer spectroscopy and SEM/μRaman spectroscopy. (Author)

  8. Whether weather affects music

    Science.gov (United States)

    Aplin, Karen L.; Williams, Paul D.

    2012-09-01

    The creative output of composers, writers, and artists is often influenced by their surroundings. To give a literary example, it has been claimed recently that some of the characters in Oliver Twist and A Christmas Carol were based on real-life people who lived near Charles Dickens in London [Richardson, 2012]. Of course, an important part of what we see and hear is not only the people with whom we interact but also our geophysical surroundings. Of all the geophysical phenomena to influence us, the weather is arguably the most significant because we are exposed to it directly and daily. The weather was a great source of inspiration for artists Claude Monet, John Constable, and William Turner, who are known for their scientifically accurate paintings of the skies [e.g., Baker and Thornes, 2006].

  9. Stability of rectangular concrete-filled steel tubes

    Directory of Open Access Journals (Sweden)

    Kanishchev Ruslan

    2017-01-01

    Full Text Available The paper deals with the theoretical analysis of the influence of imperfections on the stability and carrying capacity of axially compressed cold-formed rectangular steel tubes filled with concrete, which use as bearing structures in the structural engineering, bridges, underground subway systems and tunnels. The behavior of the mentioned above composite structures under load were presented by numerical modelling in software ABAQUS. The support conditions of loaded edges of the steel section were considered as clamped in the models. The results of the analysis were shown the influence of imperfections on the stability and carrying capacity of the composite columns.

  10. Prestressed concrete. Composite material perfectly utilizing the merits of steel and concrete; Puresutoresu concrete. Ko to concreteto no tokucho wo kanzen ni ikashita fukugo sozai

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, M. [Kyokuto Kogen Concrete Shinko Co. Ltd., Tokyo (Japan)

    1996-10-15

    Since the early stage of the development of the prestressed concrete (PC) manufacturing techniques, it has been said that forming a single PC structure by uniting precast segments with PC steel material into one is a construction method making the most of the feature of PC. This paper roughly describes the history of the development of PC and concrete examples of PC, centering on the construction techniques effectively utilizing the principle of PC and its materials. Especially, a PC bridge is superior to a steel bridge with respect to noise and vibration, so that the construction works of replacing railway steel bridges and railway elevated bridges by PC bridges have come to be seen in many places recently. In order to increase the span of a PC bridge, the reduction of the weight is a major factor. Therefore, an outer cable system has come to be used so as to reduce the thickness is cross section of the web of a PC beam as much as possible. The changes of the maximum span of cable stayed bridge are listed in a table in comparison of PC bridges with steel bridges. 29 refs., 9 figs., 1 tab.

  11. Tool steels. 5. edition

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, G.; Krauss, G.; Kennedy, R.

    1998-12-31

    The revision of this authoritative work contains a significant amount of new information from the past nearly two decades presented in an entirely new outline, making this a must have reference for engineers involved in tool-steel production, as well as in the selection and use of tool steels in metalworking and other materials manufacturing industries. The chapter on tool-steel manufacturing includes new production processes, such as electroslag refining, vacuum arc remelting, spray deposition processes (Osprey and centrifugal spray), and powder metal processing. The seven chapters covering tool-steel types in the 4th Edition have been expanded to 11 chapters covering nine main groups of tool steels as well as other types of ultrahigh strength steels sometimes used for tooling. Each chapter discusses in detail processing, composition, and applications specific to the particular group. In addition, two chapters have been added covering surface modification and trouble shooting production and performance problems.

  12. BORONIZING OF STEEL

    OpenAIRE

    ULUKÖY, Arzum; CAN, Ahmet Çetin

    2006-01-01

    Boride layer has many advantages in comparison with traditional hardening methods. The boride layer has high hardening value and keeps it's hardeness at high temperatures, and it also shows favorible properties, such as the resistance to wear, oxidation and corrosion. The process can be applied at variety of materials, for instance steel, cast iron, cast steel, nickel and cobalt alloys and cermets. In this rewiew, boronizing process properties, boride layer on steel surfaces and specification...

  13. Alteration of coal by weathering. Final report; Alteracion del carbon a la intemperie. Informe final

    Energy Technology Data Exchange (ETDEWEB)

    Ramon Alvarez, W. [Instituto Nacional del Carbon, Oveido (Spain)

    1997-11-01

    Weathering studies were carried out on coal piles: firstly using a typical sophisticated blend used by the Spanish Steel Company ENSIDESA (13 different coals). A pile of 100 t of this blend was stored at INCAR`s stockyard and laboratory analysis and tests, pilot and semi-industrial scale carbonization tests were carried out at different intervals of time during about one year.

  14. Municipalities' Preparedness for Weather Hazards and Response to Weather Warnings.

    Directory of Open Access Journals (Sweden)

    Kaddour Mehiriz

    Full Text Available The study of the management of weather-related disaster risks by municipalities has attracted little attention even though these organizations play a key role in protecting the population from extreme meteorological conditions. This article contributes to filling this gap with new evidence on the level and determinants of Quebec municipalities' preparedness for weather hazards and response to related weather warnings. Using survey data from municipal emergency management coordinators and secondary data on the financial and demographic characteristics of municipalities, the study shows that most Quebec municipalities are sufficiently prepared for weather hazards and undertake measures to protect the population when informed of imminent extreme weather events. Significant differences between municipalities were noted though. Specifically, the level of preparedness was positively correlated with the municipalities' capacity and population support for weather-related disaster management policies. In addition, the risk of weather-related disasters increases the preparedness level through its effect on population support. We also found that the response to weather warnings depended on the risk of weather-related disasters, the preparedness level and the quality of weather warnings. These results highlight areas for improvement in the context of increasing frequency and/or severity of such events with current climate change.

  15. Experimental assessment of an RFID-based crack sensor for steel structures

    Science.gov (United States)

    E Martínez-Castro, R.; Jang, S.; Nicholas, J.; Bansal, R.

    2017-08-01

    The use of welded steel cover plates had been a common design practice to increase beam section capacity in regions of high moment for decades. Many steel girder bridges with cover plates are still in service. Steel girder bridges are subject to cyclic loading, which can initiate crack formation at the toe of the weld and reduce beam capacity. Thus, timely detection of fatigue cracks is of utmost importance in steel girder bridge monitoring. To date, crack monitoring methods using in-house radio frequency identification (RFID)-based sensors have been developed to complement visual inspection and provide quantitative information of damage level. Offering similar properties at a reduced cost, commercial ultra-high frequency (UHF) passive RFID tags have been identified as a more financially viable option for pervasive crack monitoring using a dense array of sensors. This paper presents a study on damage sensitivity of low-cost commercial UHF RFID tags for crack detection and monitoring on metallic structures. Using backscatter power as a parameter for damage identification, a crack sensing system has been developed for single and multiple tag configurations for increased sensing pervasiveness. The effect on backscatter power of the existence and stage of crack propagation has been successfully characterized. For further automation of crack detection, a damage index based on the variation of backscatter power has also been established. The tested commercial RFID-based crack sensor contributes to the usage of this technology on steel girder bridges.

  16. Analysis of causes of crack for a rectangular slab bridge based on ANSYS

    Science.gov (United States)

    He, Zhi-yong; Xv, Peng-fei

    2010-03-01

    With the increment of the duration of service, traffic volume as well as the overloaded and overweighed vehicles cause serious damage to some early constructed expressways, and make the road condition getting worse. Thus, the expressways have been transforming from massive construction to upgrading and regenerational time. Based on the inspection data of all bridges on some expressway, a rectangular slab bridge was modeled and beam's crack causes were analyzed by ANSYS. As a result, the deficiency in transverse reinforcement was the main cause of the longitudinal cracks in the reinforced concrete bridge beam. It is shown that the strength has been increased significantly by the application of bonding steel plate on the bottom of the bridge beam. The present study provides a valuable example for further reference on the design, monitoring, as well as strengthening the bridges of similar type.

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

    Science.gov (United States)

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

    2017-12-01

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

  18. Active Control of Suspension Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

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

  19. 47 CFR 80.1007 - Bridge-to-bridge radiotelephone installation.

    Science.gov (United States)

    2010-10-01

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

  20. 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.

  1. Bridging the Gap

    DEFF Research Database (Denmark)

    Dahlberg, Rasmus

    2016-01-01

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

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

    Science.gov (United States)

    2014-06-01

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

  3. The Influence of the Track Axis Curvature at Railway Filler-Beam Deck Bridges

    Directory of Open Access Journals (Sweden)

    Răzvan Marian Stănescu

    2016-06-01

    Full Text Available The article presents a comparative study between the simplified method calculation proposed by the prescriptions of design codes and the analysis with the FEM program LUSAS [1], regarding the influence of the curvature of the track axis at railway bridges with steel beams embedded in concrete.

  4. Mitigation strategies for early-age shrinkage cracking in bridge decks.

    Science.gov (United States)

    2010-04-01

    Early-age shrinkage cracking has been observed in many concrete bridge decks in Washington State and elsewhere around the U.S. The cracking increases the effects of freeze-thaw damage, spalling, and corrosion of steel reinforcement, thus resulting in...

  5. Severe Weather Forecast Decision Aid

    Science.gov (United States)

    Bauman, William H., III; Wheeler, Mark M.; Short, David A.

    2005-01-01

    This report presents a 15-year climatological study of severe weather events and related severe weather atmospheric parameters. Data sources included local forecast rules, archived sounding data, Cloud-to-Ground Lightning Surveillance System (CGLSS) data, surface and upper air maps, and two severe weather event databases covering east-central Florida. The local forecast rules were used to set threat assessment thresholds for stability parameters that were derived from the sounding data. The severe weather events databases were used to identify days with reported severe weather and the CGLSS data was used to differentiate between lightning and non-lightning days. These data sets provided the foundation for analyzing the stability parameters and synoptic patterns that were used to develop an objective tool to aid in forecasting severe weather events. The period of record for the analysis was May - September, 1989 - 2003. The results indicate that there are certain synoptic patterns more prevalent on days with severe weather and some of the stability parameters are better predictors of severe weather days based on locally tuned threat values. The results also revealed the stability parameters that did not display any skill related to severe weather days. An interactive web-based Severe Weather Decision Aid was developed to assist the duty forecaster by providing a level of objective guidance based on the analysis of the stability parameters, CGLSS data, and synoptic-scale dynamics. The tool will be tested and evaluated during the 2005 warm season.

  6. Combating bad weather

    CERN Document Server

    Mukhopadhyay, Sudipta

    2015-01-01

    Every year lives and properties are lost in road accidents. About one-fourth of these accidents are due to low vision in foggy weather. At present, there is no algorithm that is specifically designed for the removal of fog from videos. Application of a single-image fog removal algorithm over each video frame is a time-consuming and costly affair. It is demonstrated that with the intelligent use of temporal redundancy, fog removal algorithms designed for a single image can be extended to the real-time video application. Results confirm that the presented framework used for the extension of the

  7. Brazilian Space Weather Program

    Science.gov (United States)

    Padilha, Antonio; Takahashi, Hisao; de Paula, Eurico; Sawant, Hanumant; de Campos Velho, Haroldo; Vitorello, Icaro; Costa, Joaquim; Souza, Jonas; Cecatto, José; Mendes, Odim; Gonzalez Alarcon, Walter Demétrio

    A space weather program is being initiated at the Brazilian National Institute for Space Research (INPE) to study events from their initiation on the sun to their impacts on the earth, including their effects on space-based and ground-based technological systems. The program is built on existing capabilities at INPE, which include scientists with a long tradition and excellence in the observation, analysis and modeling of solar and solar-terrestrial phenomena and an array of geophysical instruments that spans all over the Brazilian territory from the north to south of the magnetic dip equator. Available sensors include solar radio frequency receivers and telescopes, optical instruments and solar imagers, GNSS receivers, ionosondes, radars, allsky imagers, magnetometers and cosmic ray detectors. In the equatorial region, ionosphere and thermosphere constitute a coupled system with electrodynamical and plasma physical processes being responsible for a variety of peculiar phenomena. The most important of them are the equatorial electrojet current system and its instabilities, the equatorial ionization anomaly, and the plasma instabilities/irregularities of the night-time ionosphere (associated with the plasma bubble events). In addition, space weather events modify the equatorial ionosphere in a complex and up to now unpredictable manner. Consequently, a main focus of the program will be on monitoring the low, middle and upper atmosphere phenomena and developing a predictive model of the equatorial ionosphere through data assimilation, that could help to mitigate against the deleterious effects on radio communications and navigation systems. The technological, economic and social importance of such activities was recognized by the Brazilian government and a proposal for funding was approved for the period 2008-2011. New ground instruments will be installed during this period allowing us to extend our current capability to provide space weather observations, accurate

  8. Weather Radar Studies.

    Science.gov (United States)

    1986-03-31

    Cartesian grid . Specifi software odles ane shown in, Table 151-3 ail ’ecIbe briefly in this section below. TAi S- _ _ _ UT LUWL ps mw Lqw Tomn am DWq..G. Se 2...beman the weather radar project software devalopmet personnel and the Limoa Control Syms Egiesering Oroup personnel who rde’-d and implementd the moun...We a~ad hove smard our dom collecton wish the FL-2 ainanmd whh the musmmot umm. Data amum ope ea lymA Mmnhb mod carnatly a sshdukd so coomm -kbro

  9. The Weather in Richmond

    OpenAIRE

    Harless, William Edwin

    2014-01-01

    ABSTRACT: The Weather in Richmond is a short documentary about the Oilers, the football team at Richmond High School in downtown Richmond, California, as they struggle in 2012 with the legacy of winning no games, with the exception of a forfeit, in two years. The video documents the city of Richmond’s poverty and violence, but it also is an account of the city’s cultural diversity, of the city’s industrial history and of the hopes of some of the people who grow up there. The...

  10. The effect of span length and girder type on bridge costs

    Directory of Open Access Journals (Sweden)

    Batikha Mustafa

    2017-01-01

    Full Text Available Bridges have an important role in impacting the civilization, growth and economy of cities from ancient time until these days due to their function in reducing transportation cost and time. Therefore, development of bridges has been a knowledge domain in civil engineering studies in terms of their types and construction materials to confirm a reliable, safe, economic design and construction. Girder-bridge of concrete deck and I-beam girder has been used widely for short and medium span bridges because of ease and low-cost of fabrication. However, many theoretical and practical investigations are still undertaken regarding the type of beam girder; i.e steel composite or prestressed concrete. This paper evaluates the effect of bridge span and the type of girder on the capital cost and life cycle costs of bridges. Three types of girders were investigated in this research: steel composite, pre-tensioned pre-stressed concrete and post-tensioned pre-stressed concrete. The structural design was analyzed for 5 span lengths: 20, 25, 30, 35 and 40m. Then, the capital construction cost was accounted for 15 bridges according to each span and construction materials. Moreover, the maintenance required for 50 years of bridge life was evaluated and built up as whole life costs for each bridge. As a result of this study, the influence of both span length and type of girder on initial construction cost and maintenance whole life costs were assessed to support the decision makers and designers in the selection process for the optimum solution of girder bridges.

  11. Experimental Study on Ultrahigh Strength Concrete Filled Steel Tube Short Columns under Axial Load

    Directory of Open Access Journals (Sweden)

    Xiaojun Zhou

    2017-01-01

    Full Text Available Based on the project of Modaoxi Bridge, an experimental study on the compressive behavior of ultrahigh strength concrete filled steel tube (UHSCFST short column was conducted. A total of 9 UHSCFST specimens were tested, and the cube strength (fcu of the core concrete reached 115.4 MPa. Main parameters were the confining factor (ξ=0.608, 0.919, and 1.015, steel ratio (α=14.67%, 20.02%, and 21.98%, and steel strength (fy = 349 MPa, 352 MPa, and 427 MPa. The axially loading test results showed that the visible damage of steel tube occurred under the ultimate load. The higher the confining effect, the less the damage features. And all specimens basically presented a drum-type failure mode. The confining effect of steel tube effectively changed the brittle failure mode of ultrahigh strength concrete (UHSC and tremendously improved the load bearing capacity and ductility of specimens. Moreover, the higher the steel ratio and steel strength of the specimens, the stronger the confining effect. Meanwhile the excellent mechanical properties will be obtained. Also it is recommended that the UHSCFST prefers Q345 or above strength steel tube to ensure sufficient ductility, and the steel ratio should be more than 20%. Furthermore, the confining effect of steel tubes can improve the ultimate bearing capacity of the ultrahigh strength CFST short columns.

  12. Modern Steel Framed Schools.

    Science.gov (United States)

    American Inst. of Steel Construction, Inc., New York, NY.

    In view of the cost of structural framing for school buildings, ten steel-framed schools are examined to review the economical advantages of steel for school construction. These schools do not resemble each other in size, shape, arrangement or unit cost; some are original in concept and architecture, and others are conservative. Cost and…

  13. Statistical determination of significant curved I-girder bridge seismic response parameters

    Science.gov (United States)

    Seo, Junwon

    2013-06-01

    Curved steel bridges are commonly used at interchanges in transportation networks and more of these structures continue to be designed and built in the United States. Though the use of these bridges continues to increase in locations that experience high seismicity, the effects of curvature and other parameters on their seismic behaviors have been neglected in current risk assessment tools. These tools can evaluate the seismic vulnerability of a transportation network using fragility curves. One critical component of fragility curve development for curved steel bridges is the completion of sensitivity analyses that help identify influential parameters related to their seismic response. In this study, an accessible inventory of existing curved steel girder bridges located primarily in the Mid-Atlantic United States (MAUS) was used to establish statistical characteristics used as inputs for a seismic sensitivity study. Critical seismic response quantities were captured using 3D nonlinear finite element models. Influential parameters from these quantities were identified using statistical tools that incorporate experimental Plackett-Burman Design (PBD), which included Pareto optimal plots and prediction profiler techniques. The findings revealed that the potential variation in the influential parameters included number of spans, radius of curvature, maximum span length, girder spacing, and cross-frame spacing. These parameters showed varying levels of influence on the critical bridge response.

  14. Construction of the Chamagawa bridge; Chamagawabashi no seko

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-09-30

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

  15. Technique for Determining Bridge Displacement Response Using MEMS Accelerometers

    Directory of Open Access Journals (Sweden)

    Hidehiko Sekiya

    2016-02-01

    Full Text Available In bridge maintenance, particularly with regard to fatigue damage in steel bridges, it is important to determine the displacement response of the entire bridge under a live load as well as that of each member. Knowing the displacement response enables the identification of dynamic deformations that can cause stresses and ultimately lead to damage and thus also allows the undertaking of appropriate countermeasures. In theory, the displacement response can be calculated from the double integration of the measured acceleration. However, data measured by an accelerometer include measurement errors caused by the limitations of the analog-to-digital conversion process and sensor noise. These errors distort the double integration results. Furthermore, as bridges in service are constantly vibrating because of passing vehicles, estimating the boundary conditions for the numerical integration is difficult. To address these problems, this paper proposes a method for determining the displacement of a bridge in service from its acceleration based on its free vibration. To verify the effectiveness of the proposed method, field measurements were conducted using nine different accelerometers. Based on the results of these measurements, the proposed method was found to be highly accurate in comparison with the reference displacement obtained using a contact displacement gauge.

  16. Bridge-Vehicle Impact Assessment

    Science.gov (United States)

    2011-08-01

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

  17. Colorado statewide historic bridge inventory.

    Science.gov (United States)

    2011-05-01

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

  18. Strengthening bridges using composite materials.

    Science.gov (United States)

    1998-03-01

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

  19. Virginia Bridge Information Systems Laboratory.

    Science.gov (United States)

    2014-06-01

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

  20. Uncontrolled concrete bridge parapet cracking.

    Science.gov (United States)

    2013-06-01

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

  1. Weatherization Apprenticeship Program

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Eric J

    2012-12-18

    Weatherization improvement services will be provided to Native people by Native people. The proposed project will recruit, train and hire two full-time weatherization technicians who will improve the energy efficiency of homes of Alaska Natives/American Indians residing in the Indian areas, within the Cook Inlet Region of Alaska. The Region includes Anchorage as well as 8 small tribal villages: The Native Villages of Eklutna, Knik, Chickaloon, Seldovia, Ninilchik, Kenaitze, Salamatof, and Tyonek. This project will be a partnership between three entities, with Cook Inlet Tribal Council (CITC) as the lead agency: CITCA's Employment and Training Services Department, Cook Inlet Housing Authority and Alaska Works Partnership. Additionally, six of the eight tribal villages within the Cook Inlet Region of Alaska have agreed to work with the project in order to improve the energy efficiency of their tribally owned buildings and homes. The remaining three villages will be invited to participate in the establishment of an intertribal consortium through this project. Tribal homes and buildings within Anchorage fall under Cook Inlet Region, Inc. (CIRI) tribal authority.

  2. Solar weather monitoring

    Directory of Open Access Journals (Sweden)

    J.-F. Hochedez

    2005-11-01

    Full Text Available Space Weather nowcasting and forecasting require solar observations because geoeffective disturbances can arise from three types of solar phenomena: coronal mass ejections (CMEs, flares and coronal holes. For each, we discuss their definition and review their precursors in terms of remote sensing and in-situ observations. The objectives of Space Weather require some specific instrumental features, which we list using the experience gained from the daily operations of the Solar Influences Data analysis Centre (SIDC at the Royal Observatory of Belgium. Nowcasting requires real-time monitoring to assess quickly and reliably the severity of any potentially geoeffective solar event. Both research and forecasting could incorporate more observations in order to feed case studies and data assimilation respectively. Numerical models will result in better predictions of geomagnetic storms and solar energetic particle (SEP events. We review the data types available to monitor solar activity and interplanetary conditions. They come from space missions and ground observatories and range from sequences of dopplergrams, magnetograms, white-light, chromospheric, coronal, coronagraphic and radio images, to irradiance and in-situ time-series. Their role is summarized together with indications about current and future solar monitoring instruments.

  3. Space Weather- Physics and Effects

    CERN Document Server

    Bothmer, Volker

    2007-01-01

    This book is a state-of-the-art review on the physics of space weather and on space weather impacts on human technology, including manned spaceflight. With contributions from a team of international experts, this comprehensive work covers all aspects of space weather physical processes, and all known aspects of space hazards from humans, both in space and on Earth. Space Weather - Physics and Effects provides the first comprehensive, scientific background of space storms caused by the sun and its impact on geospace focuses on weather issues that have become vital for the development of nationwide technological infrastructures explains magnetic storms on Earth, including the effects of EUV radiation on the atmosphere is an invaluable aid in establishing real-time weather forecasts details the threat that solar effects might have on modern telecommunication systems, including national power grid systems, aircraft and manned spaceflight.

  4. 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,…

  5. Bridge the Gap.

    Science.gov (United States)

    Klein, Mel; Cufaude, Jeffrey B.

    1989-01-01

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

  6. Bridging the gap

    Science.gov (United States)

    2012-08-01

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

  7. Quantum Bidding in Bridge

    Directory of Open Access Journals (Sweden)

    Sadiq Muhammad

    2014-06-01

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

  8. 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...

  9. Bridging the Gap?

    Science.gov (United States)

    Salter, Colin

    2009-01-01

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

  10. Standard guide for mutual inductance bridge applications for wall thickness determinations in boiler tubing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This guide describes a procedure for obtaining relative wall thickness indications in ferromagnetic and non-ferromagnetic steels using the mutual inductance bridge method. The procedure is intended for use with instruments capable of inducing two substantially identical magnetic fields and noting the change in inductance resulting from differing amounts of steel. It is used to distinguish acceptable wall thickness conditions from those which could place tubular vessels or piping at risk of bursting under high temperature and pressure conditions. 1.2 This guide is intended to satisfy two general needs for users of industrial Mutual Inductance Bridge (MIB) equipment: (1) the need for a tutorial guide addressing the general principles of Mutual Inductance Bridges as they apply to industrial piping; and (2) the need for a consistent set of MIB performance parameter definitions, including how these performance parameters relate to MIB system specifications. Potential users and buyers, as well as experienced M...

  11. 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....

  12. Transport infrastructure monitoring: A ground based optical displacement monitoring system, field tests on a bridge, the Musmeci's bridge in Potenza, Italy.

    Science.gov (United States)

    Hagene, J. K.

    2012-04-01

    being a decision support system. Field trials as part of the ISTIMES project took place in Potenza, Italy, for a week in July 2011. The test target was Musmeci's bridge, a bridge with a design where aesthetic values have been just as important as traditional civil engineering aspects. Several technologies and techniques were tested at the same part of the bridge to allow for data correlation between different sensors. The camera and processing parts of the optical displacement monitoring system were mounted on a concrete wall at the one end of the bridge while the LED reference points were mounted on the bridge approximately 40 metres away. The tests at the Musmeci's bridge are successful and verifying some of the findings from the tests in Switzerland. However, we learned a lesson with regards to temporary mounting of the reference points using glossy stainless steel parts. A short period early in the morning, when illuminated by the sun, these stainless steel parts were just as bright as the LED reference point leading to potential noise in the measurements. Due to availability of the raw data this could be fixed later doing post processing on the stored data. One of the findings was that we have relatively large time of day variation that appear to be periodic with a cycle time of about 24 hours, at least with similar weather conditions. These displacements appear to be in the order of 10 mm and is probably due to thermal effects. Several shorter displacements have also been registered with amplitudes of a couple of mm and duration around 10 seconds. These shorter displacement peaks appear to be caused by heavy vehicles passing by on the bridge. The introduction of the processing using sub-pixel resolution looks very promising and appears to give a significant improvement of the actual resolution of the system. Even thought the measurements in the field are successfully completed we have noted larger slowly moving displacements than originally expected. This combined

  13. Analytical Evaluation of Reinforced Concrete Pier and Cast-in-Steel-Shell Pile Connection Behavior considering Steel-Concrete Interface

    Directory of Open Access Journals (Sweden)

    Jiho Moon

    2016-01-01

    Full Text Available The seismic design of bridges may require a large-diameter deep pile foundation such as a cast-in-steel-shell (CISS pile where a reinforced concrete (RC member is cast in a steel casing. In practice, the steel casing is not considered in the structural design and the pile is assumed to be an RC member. It is partially attributed to the difficulties in evaluation of composite action of a CISS pile. However, by considering benefits provided by composite action of the infilled concrete and the steel casing, both the cost and size of CISS pile can be reduced. In this study, the structural behavior of the RC pier and the CISS pile connection is simulated by using an advanced 3D finite element (FE method, where the interface between the steel and concrete is also modeled. Firstly, the FE model is verified. Then, the parametric study is conducted. The analysis results suggest that the embedment length and the friction coefficient between the steel casing and the infilled concrete affect the structural behavior of the RC pier. Finally, the minimum embedment length with reference to the AASHTO design guideline is suggested considering the composite action of the CISS pile.

  14. Chemical weathering of flat continents

    Science.gov (United States)

    Maffre, Pierre; Goddéris, Yves; Ladant, Jean-Baptiste; Carretier, Sébastien; Moquet, Jean-Sébastien; Donnadieu, Yannick; Labat, David; Vigier, Nathalie

    2017-04-01

    Mountain uplift is often cited as the main trigger of the end Cenozoic glacial state. Conversely, the absence of major uplift is invoked to explain the early Eocene warmth. This hypothesis relies on the fact that mountain uplift increases the supply of "fresh" silicate rocks through enhanced physical erosion, and boosts CO2 consumption by chemical weathering. Atmospheric CO2 —and therefore climate— then adjust to compensate for the changes in weatherability and keep the geological carbon cycle balanced (Walker's feedback). Yet, orography also strongly influences the global atmospheric and oceanic circulation. Consequently, building mountains does not only change the weathering regime in the restricted area of the orogen, but also modifies the worldwide distribution of the weathering flux. We conduct a numerical experiment in which we simulate the climate of the present day world, with all mountain ranges being removed. Up-to-date weathering and erosion laws (West, 2012; Carretier et al., 2014) are then used to quantify the global weathering for a "flat world". Specifically, the parameters of the weathering law are first carefully calculated such that the present day distribution of the weathering fluxes matches the riverine geochemical data. When removing mountains, we predict a warmer and wetter climate, especially in geographic spots located in the equatorial band. The calculated response of the global weathering flux ranges from an increase by 50% to a decrease by 70% (relative to the present day with mountains). These contrasted responses are pending on the parameterisation of the weathering model, that makes it more sensitive to reaction rate (kinetically-limited mode) or to rock supply by erosion (supply-limited mode). The most likely parameterisation —based on data-model comparison— predicts a decrease of CO2 consumption by weathering by 40% when mountains are removed. These results show that (1) the behaviour of the weathering engine depends on the

  15. The Fatigue Behavior of Steel Structures under Random Loading

    DEFF Research Database (Denmark)

    Agerskov, Henning

    2008-01-01

    Fatigue damage accumulation in steel structures under random loading has been studied in a number of investigations at the Technical University of Denmark. 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 with a total of 540 fatigue tests have been carried through on various types of welded plate test specimens and full-scale offshore tubular joints. The materials that have been used are either conventional structural steel or high-strength steel. The fatigue tests...... and the fracture mechanics analyses have been carried out using load histories, which are realistic in relation to the types of structures studied, i.e. primarily bridges, offshore structures and chimneys. In general, the test series carried through show a significant difference between constant amplitude...

  16. Effect of cracking and randomness of inputs on corrosion initiation of reinforced concrete bridge decks exposed to chlorides

    Directory of Open Access Journals (Sweden)

    P. Konecny

    2017-01-01

    Full Text Available The paper is aimed at the indicative evaluation of the effect of random scatter of input parameters in case of durability of reinforced concrete bridge deck. The time to onset of corrosion of steel reinforcement of concrete bridge deck exposed to chloride is evaluated. The effect of cracking in concrete onto chloride ingress is considered. The selected steel reinforcement protection strategies are: unprotected steel reinforcement, epoxy-coated steel reinforcement and water-proof barrier bellow asphalt overlay. The preliminary model for damage effect on chloride ion ingress through water proof membrane under penetrable asphalt overlay is used. 2-D finite element chloride ingress model is combined with Monte Carlo simulation technique. The innovative crack effect modeling via highly penetrable elements is applied. Deterministic and probabilistic calculations are compared.

  17. Synthesis of bridged β-cyclodextrin–polyethylene glycol and evaluation of its inhibition performance in oilfield wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Changjun, E-mail: changjunzou@126.com; Liu, Yuan; Yan, Xueling; Qin, Yibie; Wang, Meng; Zhou, Lu

    2014-10-15

    The bridged β-cyclodextrin–polyethylene glycol (β-CD–PEG) is synthesized through reaction of β-CD with PEG, which has been characterized by Fourier transform infrared spectroscope. The inhibition efficiency of bridged β-CD–PEG on corrosion of Q235 carbon steel in 0.5 M HCl solution has been investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss measurements. The results show that β-CD–PEG acted as a mixed-type inhibitor and performed excellent inhibiting effect for the corrosion of the Q235 carbon steel. The steel surface morphologies are analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) and then an adsorption mechanism model is proposed. The high inhibitory efficiency of β-CD–PEG is related with the adsorption of polymer molecules at the steel surface and a protective film formation. Finally, these results present a novel corrosion inhibitor works in oil-gas field. - Highlights: • The bridged β-CD–PEG is synthesized by polyethylene glycol and cyclodextrin. • The bridged β-CD–PEG acts as an inhibitor for carbon steel in oilfield wastewater. • The high inhibitory efficiency is related with a protective film formation. • The adsorption of β-CD–PEG is well described by the Langmuir adsorption isotherm.

  18. BORONIZING OF STEEL

    Directory of Open Access Journals (Sweden)

    Arzum ULUKÖY

    2006-02-01

    Full Text Available Boride layer has many advantages in comparison with traditional hardening methods. The boride layer has high hardening value and keeps it's hardeness at high temperatures, and it also shows favorible properties, such as the resistance to wear, oxidation and corrosion. The process can be applied at variety of materials, for instance steel, cast iron, cast steel, nickel and cobalt alloys and cermets. In this rewiew, boronizing process properties, boride layer on steel surfaces and specifications and the factors that effect boride layer are examined

  19. Now, Here's the Weather Forecast...

    Science.gov (United States)

    Richardson, Mathew

    2013-01-01

    The Met Office has a long history of weather forecasting, creating tailored weather forecasts for customers across the world. Based in Exeter, the Met Office is also home to the Met Office Hadley Centre, a world-leading centre for the study of climate change and its potential impacts. Climate information from the Met Office Hadley Centre is used…

  20. The Challenge of Weather Prediction

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 1. The Challenge of Weather Prediction Difficulties in Predicting the Weather. B N Goswami. Series Article Volume 2 Issue 1 January 1997 pp 8-15. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. The Challenge of Weather Prediction

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 3. The Challenge of Weather Prediction Old and Modern Ways of Weather Forecasting. B N Goswami. Series Article Volume 2 Issue 3 March 1997 pp 8-15. Fulltext. Click here to view fulltext PDF. Permanent link:

  2. Weather Fundamentals: Hurricanes & Tornadoes. [Videotape].

    Science.gov (United States)

    1998

    The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) features information on the deadliest and most destructive storms on Earth. Through satellite…

  3. Japanese space weather research activities

    Science.gov (United States)

    Ishii, M.

    2017-01-01

    In this paper, we present existing and planned Japanese space weather research activities. The program consists of several core elements, including a space weather prediction system using numerical forecasts, a large-scale ground-based observation network, and the cooperative framework "Project for Solar-Terrestrial Environment Prediction (PSTEP)" based on a Grant-in Aid for Scientific Research on Innovative Areas.

  4. Regional-seasonal weather forecasting

    Energy Technology Data Exchange (ETDEWEB)

    Abarbanel, H.; Foley, H.; MacDonald, G.; Rothaus, O.; Rudermann, M.; Vesecky, J.

    1980-08-01

    In the interest of allocating heating fuels optimally, the state-of-the-art for seasonal weather forecasting is reviewed. A model using an enormous data base of past weather data is contemplated to improve seasonal forecasts, but present skills do not make that practicable. 90 references. (PSB)

  5. Detection of Weather Radar Clutter

    DEFF Research Database (Denmark)

    Bøvith, Thomas

    2008-01-01

    . Especially in the application of weather radar data in quantitative precipitation estimation and forecasting a high data quality is important. Clutter detection is one of the key components in achieving this goal. This thesis presents three methods for detection of clutter. The methods use supervised......Weather radars provide valuable information on precipitation in the atmosphere but due to the way radars work, not only precipitation is observed by the weather radar. Weather radar clutter, echoes from non-precipitating targets, occur frequently in the data, resulting in lowered data quality...... and precipitating and non-precipitating clouds. Another method uses the difference in the motion field of clutter and precipitation measured between two radar images. Furthermore, the direction of the wind field extracted from a weather model is used. The third method uses information about the refractive index...

  6. Bridge the Gap

    DEFF Research Database (Denmark)

    Marselis, Randi Lorenz

    2017-01-01

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

  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. Glass Stronger than Steel

    Science.gov (United States)

    Yarris, Lynn

    2011-03-28

    A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

  9. Metallurgy: Printing steels

    Science.gov (United States)

    Todd, Iain

    2018-01-01

    Additive manufacturing has been used to fabricate a common stainless steel, which imparts a unique microstructure to this material, making it stronger and more ductile than that produced with conventional methods.

  10. Consideration on extradosed prestressed concrete road bridge; Dorokyo ni okeru daihenshin PC keburu kyo

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, A.; Honma, A. [Japan Highway Public Corp., Tokyo (Japan)

    1997-03-31

    The details of the investigation on the Odawara Blue Way Bridge for which extradosed type is employed are provided, and a report is made about the situation of the study on the future construction of the 2nd Tomei-Meishin Expressway. The extradosed PC bridge is considered to have intermediate structural characteristics of those of the conventional beam bridge and PC cable stayed bridge, and is expected to be applied to bridges having approximately from 100 to 200m span. The features of the extradosed PC bridge is outlined. Approximately 1/35 beam height on the intermediate support and 1/10 main tower height against the center span are considered to be proper. PC steel products can be used efficiently because stress fluctuation of diagonals and the load sharing rate of the diagonal member are less than those of the PC cable stayed bridge and safety factor similar to that of general internal cable can be adopted. Construction works for the main tower and the diagonal member are easy due to low height of the main tower, and the bridge is advantageous also in the maintenance control because no beam is required. 5 refs., 8 figs., 2 tabs.

  11. Research on Collapse Process of Cable-Stayed Bridges under Strong Seismic Excitations

    Directory of Open Access Journals (Sweden)

    Xuewei Wang

    2017-01-01

    Full Text Available In order to present the collapse process and failure mechanism of long-span cable-stayed bridges under strong seismic excitations, a rail-cum-road steel truss cable-stayed bridge was selected as engineering background, the collapse failure numerical model of the cable-stayed bridge was established based on the explicit dynamic finite element method (FEM, and the whole collapse process of the cable-stayed bridge was analyzed and studied with three different seismic waves acted in the horizontal longitudinal direction, respectively. It can be found from the numerical simulation analysis that the whole collapse failure process and failure modes of the cable-stayed bridge under three different seismic waves are similar. Furthermore, the piers and the main pylons are critical components contributing to the collapse of the cable-stayed bridge structure. However, the cables and the main girder are damaged owing to the failure of piers and main pylons during the whole structure collapse process, so the failure of cable and main girder components is not the main reason for the collapse of cable-stayed bridge. The analysis results can provide theoretical basis for collapse resistance design and the determination of critical damage components of long-span highway and railway cable-stayed bridges in the research of seismic vulnerability analysis.

  12. 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.

  13. Mechanical Behaviour and Durability of FRP-to-steel Adhesively-bonded Joints

    NARCIS (Netherlands)

    Jiang, X.

    2013-01-01

    During the last two decades, fiber-reinforced polymer (FRP) bridge decks have been increasingly used as a competitive alternative for wood, concrete and orthotropic steel decks, due to their various advantages: light-weight, good corrosion resistance, low maintenance cost and rapid installation for

  14. Life after Steel

    Science.gov (United States)

    Mangan, Katherine

    2013-01-01

    Bobby Curran grew up in a working-class neighborhood in Baltimore, finished high school, and followed his grandfather's steel-toed bootprints straight to Sparrows Point, a 3,000-acre sprawl of industry on the Chesapeake Bay. College was not part of the plan. A gritty but well-paying job at the RG Steel plant was Mr. Curran's ticket to a secure…

  15. Heterogeneous distribution of nanophase aluminosilicate weathering products: Interpreting Martian weathering

    Science.gov (United States)

    Kraft, M. D.; Sharp, T. G.; Rampe, E. B.

    2011-12-01

    Nanocrystalline alteration products form in a range of soil and regolith weathering environments on Earth. In some weathering systems, poorly crystalline aluminosilicates such as allophane are distributed heterogeneously, as a function of depth in a vertical weathering profile or as a function of micro-environmental factors. Both of these factors can be important for understanding weathering processes on Earth and are particularly important to consider when interpreting allophane on Mars. Chemical and mineralogical measurements of Mars could be confounded by a vertical heterogeneity common to many weathering systems, because what is observed at the surface by spacecraft may not be representative of the complete weathering system. Appropriate caution should be taken to compare surface measurements of Mars to terrestrial weathering environments that examine soil columns. Also, nanocrystalline aluminosilicates are known to form coatings on regolith particles and rock fragments and can be compositionally distinct from weathering products formed in the greater regolith matrix. These types of coatings are particularly important to consider for interpreting remotely sensed spectral measurements because fragmented rocks, from sand to boulders, comprise much of the relatively dust-free surfaces of Mars. Due to their strong influence on spectral observations, coatings could be strongly detectable by thermal infrared spectroscopy relative to coexisting, weakly aggregated fine-grained weathering products, resulting in the oversampling of coatings. Consequently, detected nanocrystalline aluminosilicates phases may not represent the overall weathering system. As an example of these influences, we will consider the high-silica material(s) detected in Mars northern plains. Although there are several models for how this material formed, if it formed by in situ regolith weathering then the high-silica material was precipitated from dissolved regolith materials. Evidence for

  16. Can the Weather Affect My Child's Asthma?

    Science.gov (United States)

    ... Giving Teens a Voice in Health Care Decisions Can the Weather Affect My Child's Asthma? KidsHealth > For ... Affect My Child's Asthma? Print A A A Can the Weather Affect My Child's Asthma? Yes. Weather ...

  17. 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

  18. Reliability-based Assessment of Fatigue Life for Bridges

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard

    2012-01-01

    The reliability level for bridges is discussed based on a comparison of the reliability levels proposed and used by e.g. JCSS, ISO, NKB and Eurocodes. The influence of reserve capacity by which failure of a specific detail does not lead to structural collapse is investigated. The results show...... that the reliability level can be significantly reduced if the probability of collapse given local failure is small. A method for reliability analysis of welded steel details is described using both an SN-approach and a Fracture Mechanics approach. By using a fracture mechanics it is possible to take the influence...

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

    Directory of Open Access Journals (Sweden)

    Ali Akbar Ramezanianpour

    2016-10-01

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

  20. Efficient construction of the motorway and highway bridge superstructure (experimental studies

    Directory of Open Access Journals (Sweden)

    Babayev Vladimir

    2017-01-01

    Full Text Available The design of the span structure of the bridge was presented. Its structure was formed by the creation of a composite steel and concrete element consisting spatial steel perforated boxlike-section blocks, a system of shear links of a special type and a monolithic reinforced concrete slab containing inside emptiness-formers The novelty of the design and methods of its creation predetermined the need for experimental testing. It was implemented in full-scale conditions and had, in addition to research, acceptance nature. In this connection, the article presents the results of tests of the composite steel and concrete structure of the superstructure of the bridge over Sukhoy Torets in Barvenkovo. The nature of its deformation under the static and dynamic loads is shown. During the tests, the components of the stress-strain state were determined at the distinguished points of the structure, fixed under static load. The amplitude and frequency response of the bridge unit were established for various dynamic impact options. Based on the obtained data, the structural resistance features under load impacts was analyzed, the design model of the bridge was verified, and the compliance of the accepted design parameters with the limitations of the applicable reference documents was confirmed.

  1. Study on Repaired Earthquake-Damaged Bridge Piers under Seismic Load

    Directory of Open Access Journals (Sweden)

    Jun Deng

    2015-01-01

    Full Text Available The concrete bridge pier damaged during earthquakes need be repaired to meet the design standards. Steel tube as a traditional material or FRP as a novel material has become popular to repair the damaged reinforced concrete (RC bridge piers. In this paper, experimental and finite element (FE studies are employed to analyze the confinement effectiveness of the different repair materials. The FE method was used to calculate the hysteretic behavior of three predamaged circle RC bridge piers repaired with steel tube, basalt fiber reinforced polymer (BFRP, and carbon fiber reinforced polymer (CFRP, respectively. Meanwhile, the repaired predamaged circle concrete bridge piers were tested by pseudo-static cyclic loading to study the seismic behavior and evaluate the confinement effectiveness of the different repair materials and techniques. The FE analysis and experimental results showed that the repaired piers had similar hysteretic curves with the original specimens and all the three repair techniques can restore the seismic performance of the earthquake-damaged piers. Steel tube jacketing can significantly improve the lateral stiffness and peak load of the damaged pier, while the BFRP and CFRP sheets cannot improve these properties due to their thin thickness.

  2. Space Weather Forecasting: An Enigma

    Science.gov (United States)

    Sojka, J. J.

    2012-12-01

    The space age began in earnest on October 4, 1957 with the launch of Sputnik 1 and was fuelled for over a decade by very strong national societal concerns. Prior to this single event the adverse effects of space weather had been registered on telegraph lines as well as interference on early WWII radar systems, while for countless eons the beauty of space weather as mid-latitude auroral displays were much appreciated. These prior space weather impacts were in themselves only a low-level science puzzle pursued by a few dedicated researchers. The technology boost and innovation that the post Sputnik era generated has almost single handedly defined our present day societal technology infrastructure. During the decade following Neil's walk on the moon on July 21, 1969 an international thrust to understand the science of space, and its weather, was in progress. However, the search for scientific understand was parsed into independent "stove pipe" categories: The ionosphere-aeronomy, the magnetosphere, the heliosphere-sun. The present day scientific infrastructure of funding agencies, learned societies, and international organizations are still hampered by these 1960's logical divisions which today are outdated in the pursuit of understanding space weather. As this era of intensive and well funded scientific research progressed so did societies innovative uses for space technologies and space "spin-offs". Well over a decade ago leaders in technology, science, and the military realized that there was indeed an adverse side to space weather that with each passing year became more severe. In 1994 several U.S. agencies established the National Space Weather Program (NSWP) to focus scientific attention on the system wide issue of the adverse effects of space weather on society and its technologies. Indeed for the past two decades a significant fraction of the scientific community has actively engaged in understanding space weather and hence crossing the "stove

  3. Simulation of multivariate diffusion bridges

    DEFF Research Database (Denmark)

    Bladt, Mogens; Finch, Samuel; Sørensen, Michael

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

  4. Morphological aspects of myocardial bridges

    Directory of Open Access Journals (Sweden)

    Almira Lujinović

    2013-11-01

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

  5. MODERN ASPECTS OF BRIDGES MONITORING

    Directory of Open Access Journals (Sweden)

    M. I. Kazakevych

    2007-12-01

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

  6. A study on ship impacting a flexible crashworthy device for protecting bridge pier

    Directory of Open Access Journals (Sweden)

    Yang Liming

    2015-01-01

    Full Text Available As the accident of a vessel impacting a bridge pier will cause serious disaster, such as destroyed bridge, sinking ship and polluting environment, the technology and method to protect bridge pier from ship collision have been widely investigated recently. Due to the huge kinetic energy of large-tonnage ship and the short time duration in the collision, the studies involve impact mechanics. A developed flexible crashworthy device has been developed to protect bridges, which consists of an outer steel-periphery, an inner steel-periphery and the rubber coating SWRCs(soft elements installed between them. When the SWRC crashworthy device is installed, the collision duration under low impact force is prolonged due to its high compliance, which results in the ship having enough time to turn its navigation direction and most of the remainder kinetic energy being carried off by the turned away ship. Consequently, both impact forces on the ship and on the bridge pier decrease markedly. This is the key reason as to why the SWRC crashworthy device can avoid the destruction of both the bridge and the ship. Based on our results of theoretical studies and numerical simulations, the present paper will propose an experiment-adopted a real ship to impact a flexible crashworthy device. The collision test has been performed 12 times with different speed, carrying capacity, and impact angle of the ship. After the experiments, the ship, flexible crashworthy device and the pier are not damaged. The experiments show that the flexible crashworthy device can turn away the impact ship, so that the ship moves along the outer part of the device, which reduces the ship impact force on the bridge pier obviously. It not only protects bridges but also avoids the damage to ships.

  7. Space weather and power grids: findings and outlook

    Science.gov (United States)

    Krausmann, Elisabeth; Andersson, Emmelie; Murtagh, William; Mitchison, Neil

    2014-05-01

    in industry against moderate space weather, the vulnerability of the power grid with respect to Carrington-type events is less conclusive and needs to be assessed. • The assessment of space-weather impact on society needs to consider possible interdependencies between critical infrastructures. These interdependencies are not routinely assessed. • Effective risk communication is required to bridge the gap between science and policy and to convey the significance of scientific results to decision makers. • Emergency-response planning for a severe space-weather event needs to consider the full range of potential impacts on critical infrastructure. • For a severe geomagnetic storm inter-institutional and probably international emergency planning efforts are required as response capabilities of individual countries might be overloaded. • In the USA work is in progress to augment the existing regulatory requirements for power-grid operations by introducing new standards to better meet the challenges posed by space-weather risk.

  8. Bridging the Gap.

    Science.gov (United States)

    Webb, Michele

    2016-01-01

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

  9. Bridging the Emissions Gap

    OpenAIRE

    Blok, K.

    2012-01-01

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

  10. Bridging biometrics and forensics

    Science.gov (United States)

    Yan, Yanjun; Osadciw, Lisa Ann

    2008-02-01

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

  11. 33 CFR 115.40 - Bridge repairs.

    Science.gov (United States)

    2010-07-01

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

  12. Fish Springs weather CY 2010

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Weather data for calendar year 2010 at Fish Springs National Wildlife Refuge. Data is provided for each month and includes maximum temperature, minimum temperature,...

  13. KZTL Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  14. Northern Hemisphere Synoptic Weather Maps

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Daily Series of Synoptic Weather Maps. Part I consists of plotted and analyzed daily maps of sea-level and 500-mb maps for 0300, 0400, 1200, 1230, 1300, and 1500...

  15. Space weather and risk management

    Directory of Open Access Journals (Sweden)

    H. Lappalainen

    2005-01-01

    Full Text Available The term space weather is used for the solar driven variability in particle and electromagnetic conditions of the near-Earth space that may harm the performance of ground-based and space-borne technology. The European Union (EU and the European Space Agency (ESA have started a common programme called the Global Monitoring for Environment and Security (GMES. Many of the GMES operational services will rely on technology prone to space weather phenomena. For long-term environmental monitoring this is not a problem, but for applications of risk management in emergency situations the impact of space weather should be considered and evaluated. In this paper, we discuss how ESA's previous activity together with European national initiatives in the space weather area can be used to support GMES and how EU could participate in this work in its Framework Programmes and within the European Research Area (ERA.

  16. Road weather management performance metrics.

    Science.gov (United States)

    2008-04-29

    This report presents the results of a study to identify appropriate measures of performance that can be attributed to the Federal Highway Administrations (FHWA) Road Weather Management Program (RWMP) products and activities. Specifically, the stud...

  17. KZAU Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  18. KZHU Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  19. KZFW Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  20. KZMA Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  1. KZSE Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  2. KZLC Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  3. KZME Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  4. KZBW Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  5. KZMP Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  6. KZID Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  7. paza Center Weather Advisory (CWA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CWA is an aviation weather warning for conditions meeting or approaching national in-flight advisory (AIRMET, SIGMET or SIGMET for convection) criteria. CWAs are...

  8. Weather change and Mood Disorder

    National Research Council Canada - National Science Library

    Jun Sato; Hiroyuki Mizoguchi; Kanoko Fukaya

    2011-01-01

      Mood disorder such as depression is serious problem in today's society. Weather change has been known to influence the condition of patients with mood disorder, and the seasonality in the evolvement of depressive symptoms...

  9. US Weather Bureau Storm Reports

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weather Bureau and US Army Corps and other reports of storms from 1886-1955. Hourly precipitation from recording rain gauges captured during heavy rain, snow,...

  10. Student Workshops for Severe Weather Warning Decision Making using AWIPS-2 at the University of Oklahoma

    Science.gov (United States)

    Zwink, A. B.; Morris, D.; Ware, P. J.; Ernst, S.; Holcomb, B.; Riley, S.; Hardy, J.; Mullens, S.; Bowlan, M.; Payne, C.; Bates, A.; Williams, B.

    2016-12-01

    For several years, employees at the Cooperative Institute of Mesoscale Meteorological Studies at the University of Oklahoma (OU) that are affiliated with Warning Decision Training Division (WDTD) of the National Weather Service (NWS) provided training simulations to students from OU's School of Meteorology (SoM). These simulations focused on warning decision making using Dual-Pol radar data products in an AWIPS-1 environment. Building on these previous experiences, CIMMS/WDTD recently continued the collaboration with the SoM Oklahoma Weather Lab (OWL) by holding a warning decision workshop simulating a NWS Weather Forecast Office (WFO) experience. The workshop took place in the WDTD AWIPS-2 computer laboratory with 25 AWIPS-2 workstations and the WES-2 Bridge (Weather Event Simulator) software which replayed AWIPS-2 data. Using the WES-2 Bridge and the WESSL-2 (WES Scripting Language) event display, this computer lab has the state-of-the-art ability to simulate severe weather events and recreate WFO warning operations. OWL Student forecasters attending the workshop worked in teams in a multi-player simulation of the Hastings, Nebraska WFO on May 6th, 2015, where thunderstorms across the service area produced large hail, damaging winds, and multiple tornadoes. This paper will discuss the design and goals of the WDTD/OWL workshop, as well as plans for holding similar workshops in the future.

  11. Thermochemical surface engineering of steels

    DEFF Research Database (Denmark)

    Thermochemical Surface Engineering of Steels provides a comprehensive scientific overview of the principles and different techniques involved in thermochemical surface engineering, including thermodynamics, kinetics principles, process technologies and techniques for enhanced performance of steels...

  12. Continuous steel production and apparatus

    Science.gov (United States)

    Peaslee, Kent D [Rolla, MO; Peter, Jorg J [McMinnville, OR; Robertson, David G. C. [Rolla, MO; Thomas, Brian G [Champaign, IL; Zhang, Lifeng [Trondheim, NO

    2009-11-17

    A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

  13. Brazing titanium to stainless steel

    Science.gov (United States)

    Batista, R. I.

    1980-01-01

    Titanium and stainless-steel members are usually joined mechanically for lack of any other effective method. New approach using different brazing alloy and plating steel member with nickel resolves problem. Process must be carried out in inert atmosphere.

  14. A tale of Wootz steel

    National Research Council Canada - National Science Library

    Ranganathan, S; Srinivasan, Sharada

    2006-01-01

    The extraordinary romance and thrilling adventure associated with the tale of wootz steel shows how Indian metallurgists were the world leaders in antiquity in the manufacture of this legendary high-grade steel...

  15. 47 CFR 80.163 - Operator requirements of the Bridge-to-Bridge Act.

    Science.gov (United States)

    2010-10-01

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

  16. 47 CFR 80.331 - Bridge-to-bridge communication procedure.

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

    L. E. Hislop; M. A. Ritter

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

  18. Crack propagation modelling for high strength steel welded structural details

    Science.gov (United States)

    Mecséri, B. J.; Kövesdi, B.

    2017-05-01

    Nowadays the barrier of applying HSS (High Strength Steel) material in bridge structures is their low fatigue strength related to yield strength. This paper focuses on the fatigue behaviour of a structural details (a gusset plate connection) made from NSS and HSS material, which is frequently used in bridges in Hungary. An experimental research program is carried out at the Budapest University of Technology and Economics to investigate the fatigue lifetime of this structural detail type through the same test specimens made from S235 and S420 steel grades. The main aim of the experimental research program is to study the differences in the crack propagation and the fatigue lifetime between normal and high strength steel structures. Based on the observed fatigue crack pattern the main direction and velocity of the crack propagation is determined. In parallel to the tests finite element model (FEM) are also developed, which model can handle the crack propagation. Using the measured strain data in the tests and the calculated values from the FE model, the approximation of the material parameters of the Paris law are calculated step-by-step, and their calculated values are evaluated. The same material properties are determined for NSS and also for HSS specimens as well, and the differences are discussed. In the current paper, the results of the experiments, the calculation method of the material parameters and the calculated values are introduced.

  19. Fatigue Life Assessment of Orthotropic Steel Deck with UHPC Pavement

    Directory of Open Access Journals (Sweden)

    Xu Jiang

    2017-01-01

    Full Text Available In recent years, a number of large-span bridges with orthotropic steel decks were constructed in China. With increasing traffic volumes and higher wheel loads, many fatigue cracks developed at the welds and the edge of cut-out holes. This paper aims at presenting the numerical analysis on the fatigue performance of the orthotropic steel deck using ultrahigh performance concrete (UHPC overlay as the deck pavement instead of the conventional asphalt concrete pavement. By using finite element method (FEM model, stress distribution at fatigue sensitive locations under the action of wheel loads is characterized and the obtained stress ranges indicate that the UHPC pavement significantly reduces the magnitude of the stress peak valued. A suggested truck stream model based on the weigh-in-motion (WIM data of four bridges in China is employed to calculate the stress variation at specific fatigue details. Furthermore, the fatigue damage accumulation at fatigue details under the UHPC and conventional asphalt concrete pavement is studied based on Miner’s linear cumulative damage rule and the rain-flow method. The results indicate that the UHPC pavement on the orthotropic steel deck can extend the service lives of the concerned regions over 100 years, but the fatigue lives will reduce significantly when the elastic modulus of UHPC decreases to 50% of the original value.

  20. Fatigue damage of steel components

    DEFF Research Database (Denmark)

    Fæster, Søren; Zhang, Xiaodan; Huang, Xiaoxu

    2014-01-01

    Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials......Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials...

  1. Long-Term Structural Health Monitoring System for a High-Speed Railway Bridge Structure.

    Science.gov (United States)

    Ding, You-Liang; Wang, Gao-Xin; Sun, Peng; Wu, Lai-Yi; Yue, Qing

    2015-01-01

    Nanjing Dashengguan Bridge, which serves as the shared corridor crossing Yangtze River for both Beijing-Shanghai high-speed railway and Shanghai-Wuhan-Chengdu railway, is the first 6-track high-speed railway bridge with the longest span throughout the world. In order to ensure safety and detect the performance deterioration during the long-time service of the bridge, a Structural Health Monitoring (SHM) system has been implemented on this bridge by the application of modern techniques in sensing, testing, computing, and network communication. The SHM system includes various sensors as well as corresponding data acquisition and transmission equipment for automatic data collection. Furthermore, an evaluation system of structural safety has been developed for the real-time condition assessment of this bridge. The mathematical correlation models describing the overall structural behavior of the bridge can be obtained with the support of the health monitoring system, which includes cross-correlation models for accelerations, correlation models between temperature and static strains of steel truss arch, and correlation models between temperature and longitudinal displacements of piers. Some evaluation results using the mean value control chart based on mathematical correlation models are presented in this paper to show the effectiveness of this SHM system in detecting the bridge's abnormal behaviors under the varying environmental conditions such as high-speed trains and environmental temperature.

  2. Long-Term Structural Health Monitoring System for a High-Speed Railway Bridge Structure

    Science.gov (United States)

    Wu, Lai-Yi

    2015-01-01

    Nanjing Dashengguan Bridge, which serves as the shared corridor crossing Yangtze River for both Beijing-Shanghai high-speed railway and Shanghai-Wuhan-Chengdu railway, is the first 6-track high-speed railway bridge with the longest span throughout the world. In order to ensure safety and detect the performance deterioration during the long-time service of the bridge, a Structural Health Monitoring (SHM) system has been implemented on this bridge by the application of modern techniques in sensing, testing, computing, and network communication. The SHM system includes various sensors as well as corresponding data acquisition and transmission equipment for automatic data collection. Furthermore, an evaluation system of structural safety has been developed for the real-time condition assessment of this bridge. The mathematical correlation models describing the overall structural behavior of the bridge can be obtained with the support of the health monitoring system, which includes cross-correlation models for accelerations, correlation models between temperature and static strains of steel truss arch, and correlation models between temperature and longitudinal displacements of piers. Some evaluation results using the mean value control chart based on mathematical correlation models are presented in this paper to show the effectiveness of this SHM system in detecting the bridge's abnormal behaviors under the varying environmental conditions such as high-speed trains and environmental temperature. PMID:26451387

  3. Thermally Stable Nanocrystalline Steel

    Science.gov (United States)

    Hulme-Smith, Christopher Neil; Ooi, Shgh Woei; Bhadeshia, Harshad K. D. H.

    2017-10-01

    Two novel nanocrystalline steels were designed to withstand elevated temperatures without catastrophic microstructural changes. In the most successful alloy, a large quantity of nickel was added to stabilize austenite and allow a reduction in the carbon content. A 50 kg cast of the novel alloy was produced and used to verify the formation of nanocrystalline bainite. Synchrotron X-ray diffractometry using in situ heating showed that austenite was able to survive more than 1 hour at 773 K (500 °C) and subsequent cooling to ambient temperature. This is the first reported nanocrystalline steel with high-temperature capability.

  4. Vibration based structural assessment of the rehabilitation intervention in r.c. segmental bridge

    OpenAIRE

    Franchetti Paolo; Frizzarin Michele; Leonardi Andrea; Zeni Fabio

    2015-01-01

    A vibration based structural assessment campaign was carried out on a r.c. segmental bridge in North East Italy. The bridge has a cantilever static scheme, fixed at the top of the piers and with a hinge at the centre of the span. The particular configuration of the hinge consists in a couple of steel elements, each one composed by a tongue and groove joint. Since the year 1960, the hinge was subjected to consumption and degradation, that caused a malfunctioning of the device. An intervention ...

  5. Design of piles for integral abutment bridges.

    Science.gov (United States)

    1984-08-01

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

  6. Developing deterioration models for Nebraska bridges.

    Science.gov (United States)

    2011-07-01

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

  7. Monitoring bridge scour using fiber optic sensors.

    Science.gov (United States)

    2015-04-01

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

  8. Faster bridge construction using precast substructures : brief.

    Science.gov (United States)

    2011-07-01

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

  9. A-3 steel work completed

    Science.gov (United States)

    2009-01-01

    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  10. Life-Cycle Monitoring of Long-Span PSC Box Girder Bridges through Distributed Sensor Network: Strategies, Methods, and Applications

    Directory of Open Access Journals (Sweden)

    Zheheng Chen

    2015-01-01

    Full Text Available Structural health monitoring (SHM has attracted much attention in recent years, which enables early warnings of structural failure, condition assessments, and rational maintenance/repair strategies. In the context of bridges, many long-span steel bridges in China have been installed with the SHM systems; however, the applications of the SHM in prestressed concrete (PSC bridges are still rather limited. On the other hand, the PSC box girder bridges are extensively used in highway and railway systems and premature damage of these bridges is often reported, resulting in considerable maintenance and/or replacement costs. First, this paper presents a state-of-art review on the SHM of long-span PSC bridges. Monitoring strategies, methods, and previous applications for these bridges are summarized and discussed. In order to well capture the behavior of the bridge during its whole life and to maximize the use of sensors, a life-cycle monitoring strategy is proposed, in which the sensor layout is determined according to requirements for construction monitoring, completion test, and in-service monitoring. A case study is made on a three-span PSC box girder bridge in China. The system configuration, sensor layout, and data communications, and so forth, are presented. The up-to-date monitored structural responses are analyzed and compared with the design values.

  11. The violin bridge as filter.

    Science.gov (United States)

    Bissinger, George

    2006-07-01

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

  12. Crashworthy railing for timber bridges

    Science.gov (United States)

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

    1999-01-01

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

  13. Fatigue tests on aluminium bridges

    NARCIS (Netherlands)

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

    2004-01-01

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

  14. Vulnerability of bridges to fire

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  15. Crossing borders via mental bridges

    DEFF Research Database (Denmark)

    Keil, Dirk

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

  16. Finite Element Analysis for Fatigue Damage Reduction in Metallic Riveted Bridges Using Pre-Stressed CFRP Plates

    Directory of Open Access Journals (Sweden)

    Elyas Ghafoori

    2014-04-01

    Full Text Available Many old riveted steel bridges remain operational and require retrofit to accommodate ever increasing demands. Complicating retrofit efforts, riveted steel bridges are often considered historical structures where structural modifications that affect the original construction are to be avoided. The presence of rivets along with preservation requirements often prevent the use of traditional retrofit methods, such as bonding of fiber reinforced composites, or the addition of supplementary steel elements. In this paper, an un-bonded post-tensioning retrofit method is numerically investigated using existing railway riveted bridge geometry in Switzerland. The finite element (FE model consists of a global dynamic model for the whole bridge and a more refined sub-model for a riveted joint. The FE model results include dynamic effects from axle loads and are compared with field measurements. Pre-stressed un-bonded carbon fiber reinforced plastic (CFRP plates will be considered for the strengthening elements. Fatigue critical regions of the bridge are identified, and the effects of the un-bonded post-tensioning method with different pre-stress levels on fatigue susceptibility are explored. With an applied 40% CFRP pre-stress, fatigue damage reductions of more than 87% and 85% are achieved at the longitudinal-to-cross beam connections and cross-beam bottom flanges, respectively.

  17. FLEXURAL TOUGHNESS OF STEEL FIBER REINFORCED CONCRETE

    Directory of Open Access Journals (Sweden)

    Fehmi ÇİVİCİ

    2006-02-01

    Full Text Available Fiber concrete is a composite material which has mechanical and physical characteristics unlike plain concrete. One of the important mechanical characteristics of fiber concrete is its energy absorbing capability. This characteristics which is also called toughness, is defined as the total area under the load-deflection curve. A number of composite characteristics such as crack resistance, ductility and impact resistance are related to the energy absorbtion capacity. According to ASTM C 1018 and JSCE SF-4 the calculation of toughness is determined by uniaxial flexural testing. Fiber concrete is often used in plates such as bridge decks, airport pavements, parking areas, subjected to cavitation and erosion. In this paper, toughness has been determined according to ASTM C 1018 and JSCE SF-4 methods by testing beam specimens. Energy absorbing capacities of plain and steel fiber reinforced concrete has been compared by evaluating the results of two methods. Also plain and steel fiber reinforced plate specimens behaviors subjected to biaxial flexure are compared by the loaddeflection curves of each specimen.

  18. Impacts of Severe Weather, Climate Zone, and Energy Factors on Base Realignment and Closure (BRAC)

    Science.gov (United States)

    2015-03-26

    automobile -sized missiles fly through the air in excess of 300 ft; steel reinforced concrete structures badly damaged; high-rise buildings have...States Automobile Association USAF United States Air Force VSP Voluntary Separation Pay WS Weather Squadron 148 Appendix C – Links to Base...roofmg maierial (>20%) Broken a lass in windows, entryways or atritun~ Uplift of lightweight roof structure Significant damage to exterior walls and

  19. Microbial-Influenced Corrosion of Corten Steel Compared with Carbon Steel and Stainless Steel in Oily Wastewater by Pseudomonas aeruginosa

    Science.gov (United States)

    Mansouri, Hamidreza; Alavi, Seyed Abolhasan; Fotovat, Meysam

    2015-07-01

    The microbial corrosion behavior of three important steels (carbon steel, stainless steel, and Corten steel) was investigated in semi petroleum medium. This work was done in modified nutrient broth (2 g nutrient broth in 1 L oily wastewater) in the presence of Pseudomonas aeruginosa and mixed culture (as a biotic media) and an abiotic medium for 2 weeks. The behavior of corrosion was analyzed by spectrophotometric and electrochemical methods and at the end was confirmed by scanning electron microscopy. The results show that the degree of corrosion of Corten steel in mixed culture, unlike carbon steel and stainless steel, is less than P. aeruginosa inoculated medium because some bacteria affect Corten steel less than other steels. According to the experiments, carbon steel had less resistance than Corten steel and stainless steel. Furthermore, biofilm inhibits separated particles of those steels to spread to the medium; in other words, particles get trapped between biofilm and steel.

  20. RC beams with steel fibers under impact loads - doi: 10.4025/actascitechnol.v36i1.17561

    Directory of Open Access Journals (Sweden)

    Iana Ingrid Rocha Damasceno

    2014-01-01

    Full Text Available The use of steel fibers as addition improves several mechanical properties of concrete, whose tensile strength and resilience are of great interest for designs of structures subjected to impact loads, such as military facilities, nuclear power plants, bridges and overpasses. However, there are few studies that assessed the effects of adding steel fiber on reinforcements of reinforced concrete. To assess these effects, four concrete beams under impact loads were tested, with reinforcements and different amounts of steel fibers being monitored. The results showed a better performance of beams with fibers, presenting lower strains on reinforcements and cracking.

  1. Internal force analysis of steel sheet pile cofferdam by considering the construction "path" effect

    Directory of Open Access Journals (Sweden)

    Dong LIANG

    2016-04-01

    Full Text Available In the process of installing inner support, the force loaded on the steel sheet pile is continuous, that is, the installation of inner support always happens after the accumulative deformation caused by inside and outside pressure difference of the steel sheet pile cofferdam. Taking the steel sheet pile cofferdam construction of a specially long span bridge as example, the paper puts forwards a spatial model of steel sheet pile cofferdam considering the construction “path” based on ANSYS. The model calculation result and the actual measurement result are compared. The results show that the model based on considering the “path” effects has a more similar calculating result with the measured value.

  2. A delayed hypersensitivity reaction to a stainless steel crown: a case report.

    Science.gov (United States)

    Yilmaz, A; Ozdemir, C E; Yilmaz, Y

    2012-01-01

    Stainless steel crowns are commonly used to restore primary or permanent teeth in pediatric restorative dentistry. Here, we describe a case of a delayed hypersensitivity reaction, which manifested itself as perioral skin eruptions, after restoring the decayed first permanent molar tooth of a 13-year-old Caucasian girl with a preformed stainless steel crown. The eruptions completely healed within one week after removal of the stainless steel crown. The decayed tooth was then restored with a bis-acryl crown and bridge. Since no perioral skin eruptions occurred during the six-month follow-up, we presume that the cause of the perioral skin eruptions was a delayed hypersensitivity reaction, which was triggered by the nickel in the stainless steel crown.

  3. Electrothermally Tunable Bridge Resonator

    KAUST Repository

    Hajjaj, Amal Z.

    2016-12-05

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

  4. Bridging the Evaluation Gap

    Directory of Open Access Journals (Sweden)

    Paul Wouters

    2017-02-01

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

  5. Design without thermal bridges

    Directory of Open Access Journals (Sweden)

    Maltseva Irina

    2018-01-01

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

  6. Looking Beyond the Bridge

    DEFF Research Database (Denmark)

    Jahn, Elke; Rosholm, Michael

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

  7. Peculiarities and problems of determination of the predicted durability term of steel constructions coatings

    Directory of Open Access Journals (Sweden)

    Андрій Іванович Ковальов

    2017-07-01

    Full Text Available The subject of predicted durability term of steel constructions coatings using accelerated tests and experimental determination of steel constructions coatings fire-resistance after weather testings is raised in the article. The benefits and drawbacks of steel constructions in present-day building industry and construction design are introduced. The factors influencing steel constructions fire resistance increase are presented. The article shows that the most advanced and ideal for the protection of steel constructions is using the agents that expand and blow up under the temperature influence, forming thus a porous structure on the surface to be protected. The stages to receive the necessary indexes of predicted durability term of steel constructions coatings as well as methods to carry out climate tests both in the heated and unheated premises are described. For experimental determination of steel constructions coatings fire resistance it is suggested to use the method based on the experimental determination of the temperature of a steel plate with fire-resistant coating in the conditions of high temperatures typical of a fire, and on the solution of inverse and direct tasks of heat conduction for determination of thermal and physical characteristics of fire-resistant coatings and dependence of minimum coating thickness on the thickness of the steel plate, durability of fire impact and the steel critical temperature value. It is concluded that there is the necessity to develop the methodological support that makes it possible to estimate the coatings fire-resistance after or in the process of carrying out the accelerated climate tests as compared to the control examples. The list of problems that come into being while determining the steel constructions coatings fire-resistance after the climate tests is distinguished as well as the purpose of the future researches and tasks that should be solved

  8. Weather Risk Management in Agriculture

    Directory of Open Access Journals (Sweden)

    Martina Bobriková

    2016-01-01

    Full Text Available The paper focuses on valuation of a weather derivative with payoffs depending on temperature. We use historical data from the weather station in the Slovak town Košice to obtain unique prices of option contracts in an incomplete market. Numerical examples of prices of some contracts are presented, using the Burn analysis. We provide an example of how a weather contract can be designed to hedge the financial risk of a suboptimal temperature condition. The comparative comparison of the selected option hedging strategies has shown the best results for the producers in agricultural industries who hedges against an unfavourable weather conditions. The results of analysis proved that by buying put option or call option, the farmer establishes the highest payoff in the case of temperature decrease or increase. The Long Straddle Strategy is the most expensive but is available to the farmer who hedges against a high volatility in temperature movement. We conclude with the findings that weather derivatives could be useful tools to diminish the financial losses for agricultural industries highly dependent for temperature.

  9. Two-Class Weather Classification.

    Science.gov (United States)

    Lu, Cewu; Lin, Di; Jia, Jiaya; Tang, Chi-Keung

    2017-12-01

    Given a single outdoor image, we propose a collaborative learning approach using novel weather features to label the image as either sunny or cloudy. Though limited, this two-class classification problem is by no means trivial given the great variety of outdoor images captured by different cameras where the images may have been edited after capture. Our overall weather feature combines the data-driven convolutional neural network (CNN) feature and well-chosen weather-specific features. They work collaboratively within a unified optimization framework that is aware of the presence (or absence) of a given weather cue during learning and classification. In this paper we propose a new data augmentation scheme to substantially enrich the training data, which is used to train a latent SVM framework to make our solution insensitive to global intensity transfer. Extensive experiments are performed to verify our method. Compared with our previous work and the sole use of a CNN classifier, this paper improves the accuracy up to 7-8 percent. Our weather image dataset is available together with the executable of our classifier.

  10. Guns, Germs and Steel

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 1. Guns, Germs and Steel - A Short History of Everybody for the Last 13,000 years. Suri Venkatachalam. Book Review Volume 6 Issue 1 January 2001 pp 84-88. Fulltext. Click here to view fulltext PDF. Permanent link:

  11. Japan steel mill perspective

    Energy Technology Data Exchange (ETDEWEB)

    Murase, K. [Kobe Steel Ltd., Tokyo (Japan)

    2004-07-01

    The international and Japan's steel industry, the coking coal market, and Japan's expectations from Canada's coal industry are discussed. Japan's steel mills are operating at full capacity. Crude steel production for the first half of 2004 was 55.8 million tons. The steel mills are profitable, but costs are high, and there are difficulties with procuring raw materials. Japan is trying to enhance the quality of coke, in order to achieve higher productivity in the production of pig iron. Economic growth is rising disproportionately in the BRICs (Brazil, Russia, India, and China), with a large increase in coking coal demand from China. On the supply side, there are several projects underway in Australia and Canada to increase production. These include new developments by Elk Valley Coal Corporation, Grande Cache Coal, Western Canadian Coal, and Northern Energy and Mining in Canada. The Elga Mine in the far eastern part of Russia is under development. But the market is expected to remain tight for some time. Japan envisions Canadian coal producers will provide a stable coal supply, expansion of production and infrastructure capabilities, and stabilization of price. 16 slides/overheads are included.

  12. Braze alloy spreading on steel

    Science.gov (United States)

    Siewert, T. A.; Heine, R. W.; Lagally, M. G.

    1978-01-01

    Scanning electron microscopy (SEM) and Auger electron microscopy (AEM) were employed to observe elemental surface decomposition resulting from the brazing of a copper-treated steel. Two types of steel were used for the study, stainless steel (treated with a eutectic silver-copper alloy), and low-carbon steel (treated with pure copper). Attention is given to oxygen partial pressure during the processes; a low enough pressure (8 x 10 to the -5th torr) was found to totally inhibit the spreading of the filler material at a fixed heating cycle. With both types of steel, copper treatment enhanced even spreading at a decreased temperature.

  13. Non-destructive inspection protocol for reinforced concrete barriers and bridge railings

    Science.gov (United States)

    Chintakunta, Satish R.; Boone, Shane D.

    2014-02-01

    Reinforced concrete highway barriers and bridge railings serve to prevent errant vehicles from departing the travel way at grade separations. Despite the important role that they play in maintaining safety and their ubiquitous nature, barrier inspection rarely moves beyond visual inspection. In August 2008, a tractor-trailer fatally departed William Preston Lane, Jr. Memorial Bridge after it dislodged a section of the bridge barrier. Investigations following the accident identified significant corrosion of the anchor bolts attaching the bridge railing to the bridge deck. As a result of the information gathered during its investigation of the accident, the National Transportation Safety Board (NTSB) made recommendations to the Federal Highway Administration concerning Non-Destructive Evaluation (NDE) of concrete bridge railings. The Center for nondestructive evaluation (NDE) at Turner Fairbank Highway Research Center in McLean, VA is currently evaluating feasibility of using four technologies - ground penetrating radar (GPR), ultrasonic pulse-echo, digital radiography and infrared thermal imaging methods to develop bridge inspection methods that augment visual inspections, offer reliable measurement techniques, and are practical, both in terms of time and cost, for field inspection work. Controlled samples containing predefined corrosion levels in reinforcing steel were embedded at barrier connection points for laboratory testing. All four NDE techniques were used in the initial phase I testing. An inspection protocol for detecting and measuring the corrosion of reinforced steel embedded in the anchorage system will be developed as part of phase II research. The identified technologies shall be further developed for field testing utilizing a structure with a barrier in good condition and a structure with a barrier in poor condition.

  14. Non-destructive inspection protocol for reinforced concrete barriers and bridge railings

    Energy Technology Data Exchange (ETDEWEB)

    Chintakunta, Satish R. [Engineering and Software Consultants, Inc., 14123 Robert Paris Ct., Chantilly, VA 20151 (United States); Boone, Shane D. [Federal Highway Administration, Turner Fairbank Highway Research Center, 6300 Georgetown Pike, McLean, VA 22101 (United States)

    2014-02-18

    Reinforced concrete highway barriers and bridge railings serve to prevent errant vehicles from departing the travel way at grade separations. Despite the important role that they play in maintaining safety and their ubiquitous nature, barrier inspection rarely moves beyond visual inspection. In August 2008, a tractor-trailer fatally departed William Preston Lane, Jr. Memorial Bridge after it dislodged a section of the bridge barrier. Investigations following the accident identified significant corrosion of the anchor bolts attaching the bridge railing to the bridge deck. As a result of the information gathered during its investigation of the accident, the National Transportation Safety Board (NTSB) made recommendations to the Federal Highway Administration concerning Non-Destructive Evaluation (NDE) of concrete bridge railings. The Center for nondestructive evaluation (NDE) at Turner Fairbank Highway Research Center in McLean, VA is currently evaluating feasibility of using four technologies - ground penetrating radar (GPR), ultrasonic pulse-echo, digital radiography and infrared thermal imaging methods to develop bridge inspection methods that augment visual inspections, offer reliable measurement techniques, and are practical, both in terms of time and cost, for field inspection work. Controlled samples containing predefined corrosion levels in reinforcing steel were embedded at barrier connection points for laboratory testing. All four NDE techniques were used in the initial phase I testing. An inspection protocol for detecting and measuring the corrosion of reinforced steel embedded in the anchorage system will be developed as part of phase II research. The identified technologies shall be further developed for field testing utilizing a structure with a barrier in good condition and a structure with a barrier in poor condition.

  15. Packaged stainless steel flowsensor

    NARCIS (Netherlands)

    Leussink, P.J.; Jansen, Henricus V.; Elwenspoek, M.; Elwenspoek, Michael Curt

    2001-01-01

    There are many thermal flowsensors that are realised with MEMS/MST-techniques. All these sensors consisted of one or more heating elements and one or more sensing elements. Thermocouples [2],[3] or resistors [1] were used as sensing elements, and membranes [2] or bridges [1] as sensing structures.

  16. Abiotic Versus Biotic Weathering Of Olivine As Possible Biosignatures

    Science.gov (United States)

    Longazo, Teresa G.; Wentworth, Susan J.; Clemett, Simon J.; Southam, Gordon; McKay, David S.

    2001-01-01

    We are investigating the weathering of silicate minerals by both purely inorganic, and biologically mediated processes using field-emission scanning electron microscopy (FESEM) and energy dispersive x-ray spectroscopy (EDS). By resolving surface textures and chemical compositions of weathered surfaces at the sub-micron scale we hope to be able to distinguish abiotic from biotic weathering processes and so establish a new biosignature applicable to the study of astromaterials including but not limited to the Martian meteorites. Sterilized olivine grains (San Carlos, Arizona) no more than 1-2 mm in their longest dimension were optically assayed to be uniform in color and free of inclusions were selected as weathering subjects. Prior to all experiments surface morphologies and Fe/Mg ratios were determined for each grain using FE-SEM and EDS. Experiments were divided into two categories abiotic and biotic and were compared with "naturally" weathered samples. For the preliminary experiments, two trials (open and closed to the ambient laboratory environment) were performed under abiotic conditions, and three trials under biotic conditions (control, day 1 and day 2). The open system abiotic trials used sterile grains heated at 98 C and 200 C for both 24 and 48 hours in 1L double distilled de-ionized water. The closed system abiotic trials were conducted under the same conditions but in a sealed two layer steel/Teflon "bomb" apparatus. The biotic trials used sterile grains mounted in a flow-through device attached to a wellhead on the Columbia River aquifer. Several discolored, altered, grains were selected to document "natural" weathering surface textures for comparison with the experimental samples. Preliminary results indicate there are qualitative differences in weathered surface textures among all the designed experiments. The olivine grains in abiotic trials displayed etching, pitting, denticulate margins, dissolution and clay formation. The scale of the features

  17. Space Weather, Environment and Societies

    CERN Document Server

    Lilensten, Jean

    2006-01-01

    Our planet exists within a space environment affected by constantly changing solar atmosphere producing cosmic particles and electromagnetic waves. This "space weather" profoundly influences the performance of our technology because we primarily use two means for transmitting information and energy; namely, electromagnetic waves and electricity. On an everyday basis, we have developed methods to cope with the normal conditions. However, the sun remains a fiery star whose 'angry' outbursts can potentially destroy spacecrafts, kill astronauts, melt electricity transformers, stop trains, and generally wreak havoc with human activities. Space Weather is the developing field within astronomy that aims at predicting the sun’s violent activity and minimizing the impacts on our daily lives. Space Weather, Environment, and Societies explains why our technological societies are so dependent on solar activity and how the Sun disturbs the transmission of information and energy. Footnotes expand specific points and the ...

  18. Weather data gap problem resolved

    Science.gov (United States)

    Bush, Susan

    It looks as though the United States will avoid the crisis situation of a gap in weather data resulting from the aging GOES-7 satellite and technical problems with the next generation of weather satellites (GOESNEXT). Officials at the National Oceanic and Atmospheric Administration, which oversees the National Weather Service, recently announced their decision to borrow at least one and possibly several European satellites until the GOES-NEXT program gets off the ground.The GOES (Geostationary Operational Environmental Satellites) series is currently 3 years behind schedule and $500 million over budget. Problems with its complex design, program management by both NOAA and the National Aeronautics and Space Administration and poor performance by the contractor led Department of Commerce Secretary Robert Mosbacher to slow down the GOES-NEXT series to ensure that it is built right.

  19. Identification of aeroelastic forces on bridge cables from full-scale measurements

    DEFF Research Database (Denmark)

    Acampora, Antonio; Macdonald, J.H.G.; Georgakis, Christos

    2011-01-01

    Despite much research in recent years, large amplitude vibrations of inclined cables continue to be of concern for cable-stayed bridges. Various mechanisms have been suggested for their excitation, including rain-wind excitation, dry inclined cable galloping, high reduced velocity vortex shedding...... Bridge. The system records wind conditions and weather conditions, as well as accelerations of certain cables and a few locations on the deck and tower. Using state-of-the-art methods of output-only system identification, the vibration modes of the cables have been identified. From these modes...

  20. Steel fiber reinforced concrete behavior, modelling and design

    CERN Document Server

    Singh, Harvinder

    2017-01-01

    This book discusses design aspects of steel fiber-reinforced concrete (SFRC) members, including the behavior of the SFRC and its modeling. It also examines the effect of various parameters governing the response of SFRC members in detail. Unlike other publications available in the form of guidelines, which mainly describe design methods based on experimental results, it describes the basic concepts and principles of designing structural members using SFRC as a structural material, predominantly subjected to flexure and shear. Although applications to special structures, such as bridges, retaining walls, tanks and silos are not specifically covered, the fundamental design concepts remain the same and can easily be extended to these elements. It introduces the principles and related theories for predicting the role of steel fibers in reinforcing concrete members concisely and logically, and presents various material models to predict the response of SFRC members in detail. These are then gradually extended to d...