bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of Composite Deck-girder Bridge by Solid Elements
Authors: Zhang Jiangtao , Koo Min-Se , Aminullah Akhmad , Jeong Young-Do
Published: October 2011

Among various types of highway bridges, the precast prestressed girder bridge has been one of the most popular and economical types adopted. General analyses of this kind of composite deck-girder bridge are made by beam element. Therefore the details of behaviours such as the stress in the strands along the length of girder, the stress and deformation of concrete, especially the mechanical behaviours at the interface between the girder and slab can’t be obtained exactly. Actually it is full of challenge to model prestress tendons in solid element. In this paper it is attempt to simulate this kind of composite bridge by 20-node solid element in ABAQUS. Six approaches of modelling the prestressing are introduced. Accompanying subroutine code for shrinkage and creep based on Kabir’s creep compliance curving fitted according to AASHTO LRFD Bridge Design Specification (2007) is used. Whole construction procedures are modelled by “remove” deck element firstly in non-composite section, resisting the self-weight of girder and sequent wet weight of deck, and thereafter “reactivate” them into composite section, resisting additional dead load and live load. Using a “perfectly elastic element” to model the cast-in-situ deck, the deck element can be reactivated at an appropriate stage based on the deformed girder. A prism is used for the verification of the subroutine and the primary results of a single span composite girder-deck bridge are obtained.
Modelling of Concrete-Filled Stainless Steel Columns in Fire
Authors: Uy Brian , Tao Zhong , Liao Fei-Yu , Han Lin-Hai
Published: October 2011

This paper investigates the finite element (FE) modelling of concrete-filled stainless steel tubular (CFSST) columns under ISO 834 standard fire, where heat properties, nonlinear material behaviour at elevated temperatures, enhanced strength corner properties of steel, and initial geometric imperfections were all included. Using the FE method, the behaviour of concrete-filled stainless steel tubular columns at elevated temperatures is compared with that of carbon steel composite columns.
Climate Change and Its Influences on Spatial Time-Dependent Reliability of Pretensioned Prestressed Concrete Bridge Girder Subject to Carbonation- induced Corrosion
Authors: Peng Jianxin , Zhang Jianren , Wang Lei
Published: October 2011

The paper will assess how increases in CO2 levels will affect carbonation-induced damage and safety loss to prestressed concrete structures. Probabilistic methods are used as there is significant spatial uncertainty and variability of deterioration mechanisms, material properties, dimensions, strength and load modelling and environments. The spatial time-dependent structural reliability analysis will predict the probability of corrosion initiation and the probability of failure (collapse) of a typical prestressed concrete AASHTO bridge girder over the next 100 years. Results are presented for a range of future CO2 emissions scenarios. For the worst case scenario the probability of corrosion initiation is 340% higher than the best mitigation scenario. There is thus a significant likelihood of corrosion damage that will need costly and disruptive repairs during the service life of many concrete structures. For the worst case scenario the probability of failure is 15% higher than that for the best mitigation scenario. For the worst case scenario the probability of failure corresponding to spatial effects is 18% higher than that for non-spatial analysis.
Experimental Testing of Stirrup Corroded RC Beam with Oblique Steel Reinforcement
Authors: Zhang Jianren , Hu Lili , Peng Jianxin
Published: October 2011

In this paper, 6 simply-supported RC beam with boliqur steel and stirrups reiforcements are corroded and an uncorroded RC beam as a comparative analysis were employed to test shear performance of inclined section, considering corrosion loss of cross section of stirrups and concrete, also taken the influence of bonding and dowel action between steel and concrete into accounts. This paper analyzes corrosion and establishes inclined section bearing capacity calculation model of corroded reinforced concrete for freely supported beam. This study will help understanding that under the state of corrosion of the stirrups, the shear capacity of reinforced concrete members equipped with corroded main bar. For different corrosion specimens, it is not true to form the judgement that the internal load-carrying capacity of the specimens reduce with the degree of corrosion deepen by direct observation from the appearance
Performance Based Seismic Retrofitting of Reinforced Concrete Buildings Using Steel Braces and a Link
Authors: Dicleli Murat , Durucan Cengizhan
Published: October 2011

This paper is focused on a proposed seismic retrofitting system (PRS) configured to upgrade the performance of seismically vulnerable reinforced concrete (RC) buildings. The PRS and a conventional retrofitting system using squat infill shear panels (SISPs) are used in an existing school and an office building. Nonlinear time history analyses of the buildings in the original and retrofitted conditions are conducted to assess the efficiency of the PRS. The analyses results revealed that the building retrofitted with the PRS has a more stable lateral force-deformation behavior with enhanced energy dissipation capability than that of the one retrofitted with SISPs. The building retrofitted with the PRS experiences significantly less damage due to more ductile behavior of the system.
Construction process simulation of moveable hybrid GFRP/ concrete bridge deck
Authors: He Jun , Liu Yuqing , Chen Airong , Dai Liang
Published: October 2011

Glass/carbon FRP composites have been gaining popularity and acceptance in the bridge construction industry because of their high strength-to-weight, corrosion resistance, higher energy absorption, and competitive cost. A novel cost-effective moveable hybrid GFRP/Concrete deck system was proposed, and the concrete cast on the GFRP plate was simulated by sand irrigation test. The load-displacement relationship, stiffness and stress distribution were investigated to verify the feasibility of GFRP plate serve as the framework. Base on the test results, 3-D FEM is established to analyze the mechanical properties of the GFRP plate under construction process. The FEA results showed fairly good agreement with the experimental ones in terms of strength, deformation, and stiffness. Results confirmed that the stiffness and strength of GFRP plate under construction loading meet the requirements of relative code, and the FEM can be used to provide some guidance in the design of GFRP plate.
Comparison of a Single and Double Main Span Suspension Bridge for the Western Scheldt Crossing
Authors: Daniel Ryszard A. , Van Dooren Frank J. , De Meijer Rob H.
Published: October 2011

The option of a double main span suspension bridge has thoroughly been studied in the Netherlands as an alternative to a bridge with a very long single main span. This paper presents the conclusions of that study, along with comparative conceptual designs of both bridge options. The study and the designs allowed pronouncing the double main span bridge feasible despite the large horizontal loads on its middle pylon. The results can be indicative for prospective multi-span suspension bridges.
Tied Arch Bridges with Optimized Arrangement of a Limited Number of Hangers
Authors: Van Bogaert Philippe
Published: October 2011

Slender steel tied arch bridges are highly valued for their aesthetic appearance. However, the hangers are often experienced as a disturbing factor, as they decrease the transparency and lightness of the bridge. As demonstrated by the design of a new railway bridge, adjacent to historic Vierendeel-bridges, there may be interest in building tied arches with few hangers. A limited number of hangers, causes the arches to be subjected to patch loading, a far less favourable condition than is generally used. However, an optimum arrangement of sloping hangers can be found. This is obtained by distributing the hanger nodes in an even manner and concentrating the nodes on the lower chord near to the centre. The bending moments in the arch springs and at the nodes are becoming balanced. In addition, the buckling loads become more favourable in this type of arrangement. This optimisation is applied to the steel arch bridge at Mechelen, designed to comply with the existing Vierendeel-bridges, thus respecting part of the bridge heritage at this location.
Aerodynamic Stability of Large Suspension Bridge using Cable Frames
Authors: Yoshimura Toshihiro , Kawahara Mutsuto
Published: October 2011

A new method for improving the structural rigidity of a suspension bridge without dramatically increasing the weight of the structure is presented. The design introduces cable frames that are arranged in way to keep the distances of the cables. The frame provides an increase in the torsional stiffness. The aim of the frame is to maintain the position of the cables in such a way that they act together to provide the diaphragm effect. The new method is called a “2x4 Cables System”. It was first theoretically proven here that such a system improves the stiffness against torsional flutter. Then, vibration analysis for the torsional stiffness of the frame with four cables are shown and discussed. Vibration analyses were performed using SAP90 to check the structure’s aerodynamic rigidity and stability. Numerical results for the 2x4 models and basic model (model without the frame) were analyzed here. The natural frequencies of the different models were also discussed. Using the index created by Selberg that shows the stability of suspension bridges, the limiting wind velocity of flutter is shown to be controlled by both the bending and torsional vibration frequencies of the structure.

In conclusion, the 2x4 system is able to ensure about twice the torsional rigidity of suspended girder by the numbers of cable frames. And thus it will respond to the challenges in structural engineering to ensure more aerodynamic stability of the system and further examinations are being designed with the wind-tunnel test in mind. With the new method, it will become possible to control the stability and the weight of large suspension bridges and thus make these aesthetically pleasing structures feasible and economically viable.
A slender pedestrian bridge made of textile reinforced concrete
Authors: Hegger Josef , Goralski Claus , Kulas Christian
Published: October 2011

The pedestrian bridge over a state road in Albstadt, Germany, had to be torn down due to immense corrosion damages of the steel reinforcement. The design of the new bridge allows a slender construction, thus, the new composite material textile reinforced concrete (TRC) is used. By using textiles made of non-corrosive materials like alkali-resistant glass rovings, concrete covers can be reduced to a minimum of only some millimetres to minimize the cross-sections.

The paper describes the design, structural analysis and load-bearing behavior of a 100 m long pedestrian bridge subdivided into six prefabricated TRC parts, each offering a maximum length of

17.20 m and a maximum span of 15.05 m. The 3.21 m wide cross-section, which is a T-beam, has a height of only 43.5 cm resulting in a slender bridge construction with a slenderness ratio of only H:L = 1:35.
Extremely Slender Steel and Composite Deck Slab for Railway Bridges
Authors: Fink Josef , Herrmann Paul , Juen Lukas
Published: October 2011

This paper presents the investigations of the static strength behaviour of an innovative composite sandwich system. It consists of a concrete core sandwiched in between of two steel plates and interconnected by continuous shear connectors. In the course of the research full-scale tests were made to derive simple models for analysis. After explanation of the functionality and characteristics of the composite plate, the evaluated test-results as well as the analytical models will be presented and compared. The main focus is thereby on the determination of stresses and strains in the composite cross section.
Adaptable High-Rise Buildings
Authors: Von Borstel Thomas , Sigrist Viktor
Published: October 2011

This paper presents an innovative concept that allows a flexible use of high-rise buildings by
incorporating adaptable structural components, thus contributing to a sustainable development by
extending the building's service life. The focus lies on vertical adaptability which implies a
structural conception for different floor heights and for adding and removing temporary floor slabs,
respectively. Contrary to conventional buildings, dead loads originating from floor slabs might be
variable in an adaptable high-rise. Attention is drawn to this characteristic and its impact on the
structural design. Typically, adaptable structures resist lateral loads by using a reinforced concrete
core located in the centre of the floor plan and a diagrid placed along the perimeter surface. It is
shown that this type of lateral-load-resisting system is not only attractive from an architectural point
of view but also economical if used to enable vertical adaptations.
Dimensioning of Structures made of UHPFRC
Authors: Rauch Marion , Sigrist Viktor
Published: October 2011

Ultra high performance fibre reinforced concrete (UHPFRC) is a new construction material that enables the construction of slender and aesthetically appealing structures. First applications in structural engineering demonstrate the potential of this new building material. Most promising in that respect is the use of UHPFRC in combination with steel reinforcement. For this reason, the behaviour of UHPFRC tension chords reinforced with different types of steel has been experimentally investigated. In this paper an analytical model is presented which allows the calculation of the behaviour of reinforced UHPFRC tension chords. Based on a parametrical study failure modes and minimum reinforcement requirements are studied. Considering applications, significant benefits can be achieved with regard to the aesthetics by using filigree trusses. The possibilities are outlined with help of an example girder made of UHPFRC.
The load bearing capacity of fillet welded connections of high strength steels
Authors: Rasche Christina , Kuhlmann Ulrike
Published: October 2011

This paper presents results of a research project analysing the strength of fillet welded connections of high strength steels. Particularly, the influence of the strength of filler metals on the behaviour of welded connections is discussed. Tests on longitudinal fillet welded lap joints and cruciform joints have been conducted together with numerical simulations to investigate the load bearing behaviour. The aim is to determine the load bearing capacity of these connections in dependence on both, the strength of the filler metal as well as the base material and the influence of the load direction. The results show that the load bearing capacity of the connections is not only dependent on the base metal but also on the strength of the filler metal.
Study on Small and Medium Continuous Beams in Beijing-Shanghai High-speed Railway
Authors: Liu Wenshuo , Dai Gonglian
Published: October 2011

Continuous beam is the most frequently used bridge type in Beijing-Shanghai (Jing-Hu) high-speed railway (HSR), because it has been regarded as an effective way across the existed lines or different obstacles. In this paper, based on the study of a series of prestressed concrete (PC) continuous bridges with main span of 40m, 48m, 56m, 64m, 72m and 80m, major features of different spans has been described, such as structure parameters, mechanical characters and material amount. Then, the difference of bearing capacity and post-construction creep of bridges between cantilever casting method and cast-scaffold method has been compared.

By thorough analysis on stress variation and changing of creep after the construction in the whole life cycle, it is pointed out that the design of bridges should be able to meet the specifications in the whole life cycle, especially the stress of the short period after the operation and the deformation of the latter of the operation period should be controlled. Improvements and innovation are also proposed for future continuous beams.
Seismic Retrofit of Tokyo Tower
Authors: Kunitsu Hiroaki , Kashimoto Nobutaka , Nishino Keisuke
Published: October 2011

The Tokyo Tower, a popular tourist spot, is a television tower with a broadcast radius of 100 km in the Kanto region of Japan. In 2003, the tower had begun ground-wave digital broadcasting. This new service required the installation of a new antenna and transmitter room, which had increased the dead weight of the tower by approximately 10%. The increased dead weight will amplify the seismic responses of the tower, which was designed under the former aseismic design code. To control these seismic responses and ensure the safety in the current code, it was decided to reinforce the tower using vibration control dampers.

Due to the effect of the dampers, the story shear force responses, particularly at the location where the damper is installed, are reduced by 20-30%, and the stresses in the columns (induced by bending moments) and the diagonal members (induced by story shear forces) at the middle levels of the tower become lower than the elastic limit, which means that this method effectively reduces seismic responses using only a fraction of the dampers.

This document also describes the reinforcement of the tower body as part

Fig. 1. (1958 and Present)

of the digitization work, and the painting of the tower body as part of the maintenance work.
Metropol Parasol: A new Plaza and a unique Timber Mega Structure right in the heart of Seville
Authors: Schmid Volker
Published: October 2011

This paper describes the conceptual and structural design of Metropol Parasol, a unique hybrid structure right in the centre of the old town of Seville. The structure of the Parasols, the most visible part of the redevelopment of the Plaza de la Encarnación, is made from timber, steel and concrete. It comprises a museum, shops and a new designed plaza level, 5 m above ground. The focus point of the new structure is the 28 m high and 150 m long timber mega structure. The six merging Parasols are manufactured from up to 3 m high laminated veneer lumber plates (LVL). The timber structure is protected against weathering, by a 3 mm thick elastic polyurethane coating, sprayed onto the LVL planks. Due to the hot climate the epoxy-adhesive for the bonded-in steel rods is post cured in order to increase its heat resistance to up to 80° Celsius.
The bridge of peace
Authors: De Lucchi Michele
Published: October 2011

The Bridge of Peace is a monument to shared values and solidarity. Built in Tbilisi, it links the Bericoni district to Rikhe Park, in the area in which the new Presidential Palace stands. The bridge is a footbridge. 160 metres long, it is suspended from a grid frame, supported solely by the four pillars on its two embankments. Access to it is also by four stairways orientated to the points of the compass and reaching the centre of the bridge. As spacious and welcoming as a large piazza, suspended above the tumultuous river M’tkvari, the bridge is visible from all points of the city. It restores vitality to the historic centre by uniting it with the green area on the other side of the river. The “fluid” form, chosen by the client from the proposals initially submitted, is precisely what the built version expresses. This has been achieved thanks to engineering that creates a seemingly uninterrupted and formally harmonious roof shell, with a ground anchorage on forked pillars that give the structure its impetus.
Blast Resistance Behaviour of Steel Frame Structures
Authors: Varas Jesus Mediavilla , Soetens Frans
Published: October 2011

The effect of a blast explosion on a typical steel frame building is investigated by means of computer simulations. The simulations help to identify possible hot spots that may lead to local or global failure. The blast energy is transferred to the structure by means of the façade. In particular, attention is paid to the modelling of the façade using adequate failure criteria.
Risk Management of Environmentally Constrained Infrastructures
Authors: Bianchi Ennio
Published: October 2011

Ennio Bianchi, born in 1961, is a Civil Engineer, graduating from the University of Melbourne, Australia. Ennio has worked for a number of consulting engineering and risk management companies, and is now Group Manager, Risk, in Noel Arnold & Associates. Ennio has since received a Graduate Diploma in Risk Management and his main area of expertise is in the area of Property Risk Management.

Risk profiling of major infrastructures is critical in an increasingly challenging world influenced by social, environmental, legal and political factors. This risk management model and approach provides both a conceptual and systematic framework to the identification of hazards, vulnerability assessment and risk control methodology to the design and building of infrastructure and structures in environmentally constrained environments. Key areas of focus will include a pro-active look at physical building constraints, location, fire and essential services, and the impact of neighbouring facilities and utilities.
Bayesian probabilistic assessment of in-situ concrete strength
Authors: Jacinto Luciano , Santos Luís Oliveira , Neves Luís C.
Published: October 2011

Core testing is considered the most accurate technique for the assessment of in-situ concrete strength. EN 13791:2007 gives guidance for estimating in-situ compressive strength in existing structures and states that core testing is the reference method. However, the number of cores that can be taken from a structure is usually limited, so it may be advantageous to supplement the core tests with some type of indirect test. The standard mentioned above establishes two alternatives for the calibration of indirect tests, both based on core tests results taken from the structure being assessed. One of them requires at least 18 core tests. But if it is available 18 core tests, it is only natural to ask if it is really necessary to supplement those core tests with an indirect test. This question motivates the study here presented. Specifically, this study deals with the determination of the number of cores above which the use of an indirect test, as a supplement to core tests, is no longer attractive.
Measuring Sustainability: Tools for Transitioning to an Ecological Age
Authors: Anderson John
Published: October 2011

The paradigm of development in the twenty-first century needs to adhere to the principles and objectives of sustainable development. In particular, the built environment must shift to address environmental limitations and social aspects. Achieving sustainable development goals requires support and consensus among stakeholders and decision-makers. While this prerequisite has advanced rapidly in the past decade, it is the second phase, implementation and realization of sustainability goals, which is proving more challenging.

As such, the structural engineer working in concert with other building professionals is increasingly required to address issues of sustainable building. However, the actions required for a sustainable built environment are simultaneously neither readily apparent nor easily analyzed. Consequently, the research presents an analysis for measuring sustainability within the built environment with a specific focus on the role of the structural engineer. The work explores the tools currently available to measure sustainability impacts such as Life Cycle Analysis. Further, the challenges with competing sustainability goals are presented and possible solutions provided. The results suggest that sustainable development requires a more radical departure from the current means and methods of modern building practice and habit than initial thought necessary.
Forensic Engineering Ethics and Failures of Infrastructure Facilities
Authors: Kardon Joshua B.
Published: October 2011

When engineered infrastructure facilities fail, questions regarding the failure, including questions related to responsibility for damages, can be answered in a court of law. Testimony from experts is often presented to aid the court in answering those questions. Rules and laws controlling litigation, and the use of experts, differ from country to country. This paper describes the function of technical expert witnesses in the United States, and examines ethical implications of an expert’s participation in the legal system.

Testimony provided by experts retained on behalf of individual sides in a dispute is contrasted with testimony of an expert retained directly by the court or by the presiding judge, as may be the practice in some situations in US courts, and in the legal systems of countries other than the US.

Expert testimony relating to a real infrastructure failure is examined to illustrate these two points of the paper: 1) it is ethically acceptable for an expert to provide testimony in support of one side of a dispute, and 2) experts retained directly by the court may not be in the best interest of justice where there is not a guaranteed absence of bias.
The Real Price – Holistic Cost-Efficiency Considerations in Design and Construction of Infrastructure Projects
Authors: Fischer Oliver , Katz Casimir , Putz Alexander , Schneider Friedrich , Streit Walter , Willberg Uwe
Published: October 2011

The present paper focuses on holistic sustainability evaluations for infrastructure measures and the related engineering structures. Following a brief overview on the current state of development of rating concepts both in the building and infrastructure sector, general options for assessing the over- all sustainability are discussed and some major infrastructure-specific characteristics regarding the holistic performance are explained. Since indirect (external) effects often play an important role in the assessment of infrastructure measures, the respective influence on the overall performance and the interrelation between direct and indirect costs are exemplarily discussed by means of three examples (road infrastructure). Hereby, it is shown that the indirect costs easily may reach a level being in the range of the construction costs of the entire project and that an initial additional investment during construction in high-quality structural members and components is being typically paid off by a reduced maintenance effort, even if the external effects are not included.
Consideration of Scale Effect in Concrete Members
Authors: Terai Masakazu , Minami Koichi
Published: October 2011

This paper investigates the scale effect in concrete members subjected to shear loading. Some concrete structural type (RC and SRC) of different sized test specimens were prepared and tested. Moreover, a shear loading test on some geometrically similar specimens, having diameters from d=300 to 1100 mm, was conducted in the present study to investigate the scale effect in large-scaled concrete structural members. The results clearly indicate that the size effect for large scale members is clearly observed. The validity of theku value in Hirosawa’s equation ,which is the most popular shear design equation in Japan, is verified through the comparison with the test results on 37 RC and SRC specimens failing in shear, 14 specimens were collected from this paper and 23 specimens from the works published recently. From the inverse analysis ofku, it is important of the review ofku for the seismic design of large scale structures.
Modelling of a major Composite Cable-stayed Bridge
Authors: Xu Dong , Xu Fangyuan , Zhao Yu
Published: October 2011

The second Jiaojiang Bridge is a composite cable-stayed bridge with the span arrangement of 70m+140m+480m+140m+70m. During the analysis, spatial grid model is adopted by the authors to undertake a research program focusing on the modelling and reinforcement design of the concrete upper plate of the composite box girder. The advantage of this model is that the stress results cover all the spatial effects including shear lag, statically indeterminate shear flow inside the side boxes and in the concrete upper plate.
New Approach for Bridges with Very High Durability
Authors: Berger Johannes , Kollegger Johann
Published: October 2011

Tests have demonstrated that the demands on the ultimate limit state and serviceability limit state for structures can be also achieved without reinforcing bars. The durability of a bridge without reinforcing bars depends in this case only on the durability of the concrete since corrosion is no longer a determining factor regarding the lifetime of the structure. The requirements of the serviceability limit state and the ultimate limit state are fulfilled by providing post-tensioning tendons fitted with strands fully encapsulated in plastic ducts and water-tight anchorages. Since the proposed bridge does not contain any steel, which would be endangered by material-dependent corrosion, there is no need for an insulation of the deck consequently there is also no need for the use of a pavement and edge beams.
Research on the Structural System of Super 1000m Cable-Stayed Bridges
Authors: Xiao Ru-Cheng , Sun Bin , Jia Li-Jun , Zhuang Dong-Li
Published: October 2011

Trial designs of three different cable-stayed bridges, namely traditional fully self-anchored cable- stayed bridge (CSB), partially earth-anchored cable-stayed bridge (PEACSB) and cable-stayed- suspension bridge (CSSB), are carried out based on the same design criterion with the mid-span of 1400m. Results show that all three structures are feasible. Based on numerical calculation, effects of several structural parameters on static performance are presented. The three structures are compared regarding mechanical performance and cost. Results show that PEACSB and CSSB are favourable. As an application, in the design competition of the Second Humen Bridge, PEACSB and CSSB are applied to two navigation channels, respectively. Main ideas and outlines of the two schemes are presented. Finally, the prospect of the research on structural system of super 1000m cable-stayed bridges is discussed.
Practical Design of Continuous Two Main-span Suspension Bridge in Korea
Authors: Jung Jaeho , Kim Jaehong , Baek Jonggyun , Choi Hyunsok
Published: October 2011

Recent years, multi-span cable supported bridges can be considered as viable alternatives instead of bridges with very long span in certain bridge environments. However, only a few multi-span suspension bridges have yet been constructed. This paper presents the practical design of continuous two main-spans suspension bridge in Korea. The total length of the bridge is 1,750m with three pylons and two main-spans. The length of each main span is 650m and the side span is 225m in length. The pentagonal shape of stiffening girder is applied to secure the safety of aerodynamic stability. There are special design precautions to be considered in the design of multi- span continuous suspension bridge, such as the deflection of bridge spans and the cable slip at the middle pylon’s cable saddle. To solve those problems, parametric studies were performed and the optimized section of pylon was determined. In addition, the state-of-the-art technologies such as a high strength cable with 1960MPa in strength are adopted. In this paper, the economic efficiency of designed bridge is also briefly discussed by comparing with the mechanical behavior of other types of bridge with similar environmental conditions.
Structural response of spatial arches with imposed curvature
Authors: Sarmiento Marta , Ruiz-Teran Ana M. , Aparicio Ángel C.
Published: October 2011

Spatial arch bridges have an important out of plane behaviour, or are not even contained in a plane in some cases. The structural behaviour and the geometrical configurations of inferior-deck arch bridges with imposed curvature (those in which the curved plan projections of both, arch and deck, coincide) are being studied in detail by the authors. The present study focuses on the influence of multiple variables on the structural behaviour of this bridge typology with the aim of proposing the most appropriate solutions for controlling the out-of-plane response.
A Parametric Study on the Ultimate Behaviors of Multi-Span Suspension Bridges
Authors: Choi Dong-Ho , Na Ho-Sung , Gwon Sun Gil , Yoo Dong Ho , Moon Chang
Published: October 2011

Multi-span suspension bridges show greater vertical deflection of the girders and greater longitudinal displacement of the towers, as compared to typical three-span suspension bridges with the same center span length. These characteristics are affected by the sag ratio of the main cable, live load conditions, the strength of the main cable and the boundary conditions between the tower and girder. Therefore, to demonstrate the structural characteristics of the entire system, we analyzed the ultimate behavior of multi-span suspension bridges by considering these parameters.
Design Procedure for Plane Elements with Skew Reinforcement
Authors: Schulz Mauro , Silva de Seixas Oliveira Eduardo
Published: October 2011

The paper presents a design procedure for plane elements with skew reinforcement. Such concrete structures occur frequently in practice, and include shells and bridges of skew geometry. The formulation is based on plasticity and concrete is assumed to have no tensile strength. The methodology is similar to Nielsen’s equations for membranes with orthotropic reinforcement, and applies Baumann’s two-plate approximation for shells. The skew flexural reinforcement is determined considering the complete set of internal forces and the actual angle formed by the reinforcing bars. When compared to the classical solution recommended by the CEB, the proposed formulation presents some important advantages. The problem is defined in the local system, avoiding transformations to the principal axes. Therefore, the procedure simplifies manual and numerical calculations. The third direction reinforcement proves to be dispensable in many conditions. Although the proposed two-way reinforcement increases the total amount of steel, it also improves reinforced concrete detailing. The proposed formulation can be applied to bridge decks with skew reinforcement. The theory is discussed through examples.
Long-term monitoring of temperatures in steel box girders
Authors: De Backer Hans , Outtier Amelie , De Pauw Bart , Van Bogaert Philippe
Published: October 2011

During a period of several years, temperature variations have been monitored at several points of a cross section of the Vilvoorde Viaduct, which is one of the most important steel box girders of the Belgian highway network. Analysis of the monitoring data indicates that substantial temperature variations exist, during a 24-hour cycle of heating and cooling. Values of more than 30 degrees or more are found to be quite common. In addition temperature gradients have been measured of more than 20 degrees between both sides of the steel box girder, which could result in additional displacements and warping of the cross section.

Although thermal loads are not often considered during the first design steps of steel box girders, their influence can be quite substantial. When the thermal loads and more specifically the thermal gradients within the steel box girders reach considerable values, a number of other effects are influenced. High thermal gradients will reduce the cohesion of waterproofing layers and wearing courses, thus reducing the composite behaviour of these layers with the deck plate.

Hence, the quantification of the thermal loads working on steel box girders becomes quite important. While this was previously done using detailed finite element models, including solar radiation, cooling, convective airflow, etc. this research paper will give tangible design values for thermal gradients in steel box girders, based on actual measurements, which are in some cases higher than those values given by the current design codes, especially when looking at the temperature difference between two points of the same cross-section.
Aerodynamic Behaviour of Very Long Cable-Stayed Bridges during Construction
Authors: Morgenthal Guido
Published: October 2011

Two new cable-stayed bridges have pushed the world record for the span length of cable-stayed bridges to over 1000m. The design of these bridges, both located in typhoon prone regions, is strongly influenced by wind effects during their erection. Rigorous wind tunnel test programmes have been devised and executed to determine the aerodynamic behaviour of the structures in the most critical erection conditions. Testing was augmented by analytical and numerical analyses to verify the safety of the structures throughout construction and to ensure that no serviceability problems will affect the erection process. This paper outlines the structural and aerodynamic properties of the structures and discusses similarities as well as interesting differences.
The Behavior of Rion - Antirion Bridge Seismic Protection System During the Earthquake of "Achaia-Ilia" on June 8, 2008
Authors: Infanti Samuele , Papanikolas Panayotis , Stathopoulos-Vlamis Aris
Published: October 2011

On June 08, 2008 at 15:25 a strong earthquake with moment magnitude Mw=6,5, named “Achaia- Ilia” occurred in Greece. The focal depth was estimated to be around 30km and the epicentre was located at a distance 36 km SW from the Rion-Antirion Bridge.

The Rion-Antirion Bridge, a five-span cable-stay bridge (286m + 560m + 560m + 560m + 286m), has been designed to withstand earthquakes with P.G.A. of 0,48g and tectonic movements up to 2m between consecutive pylons. In order to satisfy the above requirements the deck superstructure was made continuous for the full length of 2252m and fully suspended from the four pylons.

An innovative energy dissipation system, designed by Vinci and developed by FIP Industriale, connects the deck to the pylons and limits the lateral movement of the deck during an earthquake, while dissipating the seismic energy with huge – never built before - viscous dampers. The bridge is also equipped with a complete monitoring system capable of collecting high frequency data at critical parts of the structure during a seismic or wind dynamic event.

The paper presents evidences of the good performance of the dissipation system during the above mentioned earthquake. From the analysis of the monitoring data collected during the event and the thorough inspections performed after, it was confirmed that the behaviour of the bridge was in accordance with the analytical predictions and well within the serviceability limit states.
Safety against Tunnel Fire for Post-Installed Reinforcement
Authors: Kunz Jakob
Published: October 2011

As traffic space is becoming scarce in urbanized areas and flyovers are often not wanted for reasons of aesthetics and noise, urban tunnels become more and more important to accommodate the increasing traffic.

A common way to connect carriageways or ceiling slabs to circular tunnel linings is to apply post- installed reinforcement. If an appropriate adhesive is used, connecting reinforcement can be considered as cast-in-place reinforcement for design purposes as confirmed by corresponding European Technical Approvals.

However, under fire conditions, the bond of the adhesive is not comparable to that of cast-in-place reinforcement. In order to get reliable design data for post-installed reinforcement under fire, specific tests were performed. Combination of the experimentally derived critical temperatures for the rebar adhesives with the temperature evolution in the concrete results in fire design data for post-installed reinforcement.

Sometimes the concern for tunnel fires is so primordial, that general design data are not sufficient. This paper also shows the example of the Shanghai-Chongming tunnel in China, where specific fire tests were performed in order to confirm the safe behaviour under fire of the post-installed reinforcement.
Network-level seismic risk management of regional road infrastructure
Authors: Zandonini Riccardo , Yue Yanchao , Bortot Francesca , Zonta Daniele
Published: October 2011

This paper presents the results of seismic evaluation carried out on the road network of the Autonomous Province of Trento (APT). The APT Bridge Management System (BMS) incorporates seismic vulnerability analysis capability based on the definition of fragility curves for all the bridges inventoried. Currently in the APT-BMS, fragility curves are developed by capacity- spectrum approach according to HAZUS guidelines. We show that, in the case of the APT stock, the direct seismic risk involving collapse or loss of life is moderate. In contrast, we expect a critical problem in network operation in a post-earthquake situation, when it will be necessary to identify the safest path between any two places in APT region. This problem is addressed using Dijkstra’s graph search algorithm. The results can be used by decision makers to prepare a pre-earthquake plan, and for the post-earthquake emergency response. Google Earth and GIS tools are used to present the results.
Influence of detailing on shear in existing concrete viaducts
Authors: Vergoossen Rob , Sliedrecht Henk
Published: October 2011

For a lot of existing concrete bridges and viaducts a sufficient safety against shear failure can be proved with an in depth structural assessment based on the present design regulations and taking into account hidden capacities, such as an increase in strength in time in the actual structure in regard to the design strength. However some structures still have a lower reliability value. As an example of this, in this paper a few bridges and viaducts, on which the road-capacity had to be increased, are presented. It is illustrated that, with the knowledge of today, the detailing of prestressing or reinforcement and changes of cross-sections in these structures causes lower reliability values as designed.
The Refurbishing of the Nibelungen Bridge Worms, Germany
Authors: Pelke Eberhard
Published: October 2011

If the Nibelungen Bridge (Fig.1), opened on traffic in 1953, is forced into the corset of present-day technical regulations, then it loses its adequate load-bearing capacity. However, if one follows

Finsterwalder’s ingenious design idea of 1930 and enriches it with the ideal of fully prestressing, a careful strengthening will result with just a few external tendons laid carefully inside the two hollow boxes and an allowance for shear approach that will enable the structure to cope with today’s live loads. Apart from the replacement of the tiebacks in one land pier, the further defects are due to the greatly changed, aggressive environmental conditions and the effect of de-icing salt that could not be foreseen in 1953.

Knowledge of construction history also helped to preserve

Fig. 1: Nibelungen Bridge Worms, 1953

this masterpiece of civil engineering without having to make any concessions with regards to its use.
Seismic Retrofit Design for a Network Arch Bridge with Energy Absorbing Devices
Authors: Sugioka Koichi , Kobayashi Hiroshi , Mashima Nobuhiro , Matsushita Hiroaki
Published: October 2011

This article describes performance-based seismic retrofit design for a network arch bridge.

Three-dimensional non-linear dynamic time history analyses were carried out considering

site-specific earthquake ground motions. The damage control design concept was employed to achieve a rational seismic retrofit with seismic response-control. Optimal design using hysteretic shear panel dampers with low yield strength steel, effective for absorbing the seismic energy, is discussed from dynamic analyses.
Introduction of Non-Destructive Highway Inspection Methods using High Definition Video and Infrared Imaging Technology
Authors: Matsumoto Masato , Ahlstrom Lee , Sugimoto Masanobu , Hashimoto Kazuaki , Nagao Yuji
Published: October 2011

The current budget shortfalls being experienced by nearly all highway and bridge owners around the world serve to jeopardize the efficient management and maintenance of highway structures. The resulting consequences of this dilemma include premature structure deterioration, higher rehabilitation and repair costs and, in some instances, a higher probability of premature structural failure. Informed and proper bridge maintenance requires constant monitoring of structural conditions, yet most of the highway bridge inspections performed in Japan involve visual inspections, which are costly in both time and labour. More efficient, objective and safer bridge inspections can be realized only through technological improvements.

NEXCO-West, one of Japan’s major toll road operators, has introduced a combination of new high definition video (HDV) and infrared (IR) thermographic technology that together serve to reduce inspection costs and increase inspection result accuracy and reliability. The high definition video camera (HDV) records the surface condition of the concrete structures, while application of IR supported thermographic assessments support analysis of structural integrity through analyzing temperature variations within the structure at different times of the day; operating on the principle that damaged and/or deteriorating concrete demonstrates more temperature variation throughout the day than do sound structural elements.

This paper describes the mechanisms of these inspection methods and introduces some examples of practical on-site application to highway bridge superstructures. The technologies offer a powerful tool for decision-making engineers responsible for developing highway maintenance strategies and contribute to efficient and smart infrastructure management.
Dynamic response of bridge system with knocking-off members
Authors: Matsumura Masahide , Yoshida Masahiko , Ochi Nobuhito
Published: October 2011

Displacement restrainer, restraints transverse movement of the superstructure of the isolated bridges, is adopted to protect expansion joints from damage during earthquake. Here to mitigate damage of bridge pier and/or its foundation and to enhance redundancy of the isolated viaducts in a strong earthquake, it can be considered that the displacement of the superstructure against a small and moderate earthquake is restraint and the displacement against a strong earthquake is freed to shift to isolated condition. Knock-off members will provide these responses of the vibration system.

This study presents the outline of some of displacement restrainers having the knock-off function and reveals the effectiveness of the knock-off in the isolated bridge system through dynamic loading test using small-size shaking table. It is also analytically verified the influences of the breaking characteristics on seismic response of the system.
The Design of Post-tensioned Concrete Box Girders to Eurocodes
Authors: Low Angus
Published: October 2011

The effect of the new Eurocodes on the design of prestressed concrete box-girder bridges is investigated. The Moment/Stress plot is introduced to display the combined effect of many different clauses. Its use together with economic data from current projects leads to a surprising result. Even for quite long span structures it will be more economic to use reinforced concrete instead of prestressed concrete as currently used. The subject is discussed.