bluuebunny/crossref_metadata_2025 huggingface dataset:
Shape identification in a magnetic separation system
Authors: Iatcheva Ilona , Stancheva Rumena , Kunov Georgi , Jordanian Irish
Published: October 2011

The present paper deals with a problem of shape identification in a magnetic separation system, used for separation of useful metal pieces from waste materials. The aim is to increase the productiveness of separation process. The effectiveness of the magnetic separator work is estimated on the basis of specific magnetic force, acting in the working zone of the device. This specific force depends on the magnetic field strength and its gradient. The forward problem of electromagnetic field determination has been solved using finite element method and Quickened 5.6 software package. The specific force determination and solution of the identification problem is realized in MATLOW.
An unified external network equivalent in steady-state security assessment
Authors: Dobrijevic Djordje , Popovic Dragan
Published: October 2011

The basic objective of this paper is to present the relevant methodological and practical aspects of forming the unified external network equivalent. This equivalent consistently respects the effects of primary voltage and frequency control of external power system, including the real possibilities and limitations, as well as the effects of possible action of under frequency load shedding or under frequency protection of generator. The first practical experience in the application of the equivalent has been gained on an example of the synchronous parallel operation of the 2nd UCTE Synchronous Zone. The results obtained show a very good accuracy of unified external network equivalent formed and also show the very high speed of steady-state security assessment in context of real interconnection.
Skin effect analysis in a free space conductor
Authors: Greconici Marian , Madescu Gheorghe , Mot Martian
Published: October 2011

The low-frequency skin effect in free space conductors is analyzed numerically. The electromagnetic field in conductors has been calculated numerically using a program based on finite elements method (FEM). The results, presented in a graphical form, are compared with the similar analytical results, assuming some approximations.
Efficient characterization of microwave applicator loaded with multilayer dielectric based on neural networks
Authors: Stankovic Zoran , Milovanovic Bratislav , Doncov Nebojsa , Marincic Aleksandar
Published: October 2011

In this paper, new neural network approach for characterization of cylindrical metallic cavity loaded with multilayer dielectric is suggested. Such cavity configuration has a great importance in realization of microwave resonant applicators, widely used for thermal processing of multilayer materials. Proposed neural model is based on representation of multilayer cavity load via several planparallel homogeneous dielectric slabs and superposition of separate influence of each dielectric slab parameters on the cavity resonant frequency. Model is incorporated into MLP neural network enabling its efficient implementation on modest hardware platform. Suggested approach is verified on the example of circular cylindrical metallic cavity loaded with two-layer dielectric.
A fuzzy set-based approach to range-free localization in wireless sensor networks
Authors: Velimirovic Andrija , Djordjevic Goran , Velimirovic Maja , Jovanovic Milica
Published: October 2011

Localization in Wireless Sensor Networks (WSNs) refers to the ability of determining the positions of sensor nodes, with an acceptable accuracy, based on known positions of several anchor nodes. Among the plethora of possible localization schemes, the Received Signal Strength (RSS) based range-free localization techniques have attracted significant research interest for their simplicity and low cost. However, these approaches suffer from significant estimation errors due to low accuracy of RSS measurements influenced by irregular radio propagation. In order to tackle the problem of RSS uncertainty, in this work we propose a fuzzy set-based localization method as an enhancement of the ring-overlapping scheme [1]. In the proposed method, first we use a fuzzy membership function based on RSS measurements to generate fuzzy sets of rings that constrain sensor node position with respect to each anchor. Then we generate fuzzy set of regions by intersecting rings from different ring sets. Finally, we employ weighted centroid method on the fuzzy set of regions to localize the node. The results obtained from simulations demonstrate that our solution improve localization accuracy in the presence of radio irregularity, but even for the case without radio irregularity.
Building 3D model of the mobile object using image pair
Authors: Micic Aca , Djordjevic Biljana
Published: October 2011

This paper deals with building 3D model of a mobile object based on one or more images obtaining from single CCD camera with fixed position. Some existing methods of analysis and measurements are applied and combined to obtain system for automatic generation of a 3D wired model suitable for application in adequate software packages.
Mid-term load forecasting using recursive time series prediction strategy with support vector machines
Authors: Stojanovic Milos , Bozic Milos , Stankovic Milena
Published: October 2011

Mediumterm load forecasting, using recursive time - series prediction strategy with Support Vector Machines (SVMs) is presented in this paper. The forecasting is performed for electrical maximum daily load for the period of one month. The data considered for forecasting consist of half hour daily loads and daily average temperatures for period of one year. An analysis of available data was performed and the most adequate set of features for our model are chosen. For evaluation of prediction accuracy we used data obtained from electricity load forecasting competition on the EUNITE network. Some drawn conclusions from the results are that the temperature significantly affects on load demand, but absence of future temperature information can be overcome with time - series concept. Also, it was shown that size and structure of the training set for SVM may significantly affect the accuracy of load forecasting.
The unified chaotic system describing the Lorenz and Chua systems
Authors: Elhadj Zeraoulia , Sprott Clinton
Published: October 2011

This paper introduces the dynamical behaviors of a unified nonlinear chaotic system which describes a two-family chaotic system containing the original Lorenz and the original Chua systems as two extremes and some other systems as a transition in between via a new constructed joint function. This system can display two kinds of attractors, those with one scroll and those with two scrolls.
Wideband cyclic music algorithms: A frequency-domain approach
Authors: Pokrajac Ivan , Vucic Desimir
Published: October 2011

In this paper, we propose two spectral cyclic MUSIC DOA estimation algorithms for wideband cyclostationary signals: the wideband spectral cyclic conjugateMUSIC (WSCCM) algorithm and the extended wideband spectral cyclicMUSIC (EWSCM) algorithm. The proposed algorithms can be applied to estimate the spectral cyclic conjugate correlation matrix and the extended spectral cyclic correlation matrix of wideband cyclostationary signals. The presented algorithms do not require any knowledge of the optimal time lag parameter, which appears in the similar algorithms in time domain. In the proposed algorithms, the DOAs are estimated at each spectral component of the selected frequency band for a cyclic frequency of interest. This can be used to form the azimuth cyclic frequency diagram, similar to the azimuth frequency diagram in wideband direction-finding systems. Some simulation results are provided to confirm the theoretical findings.
Development directions of packaging made from polymer materials
Authors: Jovanovic Slobodan , Dzunuzovic Jasna
Published: October 2011

World packaging market achieves turnover of about $620 billion per year with
one third of this amount being associated to packaging made from polymer
materials. It is expected that this kind of packaging consumption will hold
at least 3% of world packaging market share in the next five years and that
it will surpass the consumption of all other materials used in the packaging
production. This can be contributed to product quality, low production costs
as well as significant investments made in the development of polymer
materials, packaging technology and packaging. This paper presents some
development directions for packaging made from polymer materials, such as:
packaging in the protective atmosphere, the use of active and intelligent
packaging, and the use of biopolymers and recycled polymers for packaging
production that come into direct contact with the packed product.
Changing Global Childhoods: The Impact on Children's Independent Mobility
Authors: Malone Karen
Published: October 2011

This special edition of Global Studies of Childhood reports on the global research currently under way to replicate the original seminal work by Mayer Hillman on children's independent mobility that was conducted in the United Kingdom in the early 1970s, and which was replicated in the United Kingdom and Germany in the 1990s (Hillman et al, 1990) and is now being revisited in 20 culturally diverse countries. The opportunity for children to move freely in the environment without an accompanying adult is defined in the literature as children's independent mobility or CIM (Hillman et al, 1990; Tranter & Whitelegg 1994). CIM is measured in terms of spatial range or roaming range, and this measure can be determined by parents or caregivers in terms of the boundaries they set or through a negotiation between children, parents or caregivers and even the community. Children's spatial range may change according to a child's maturation, health and cultural background, social and cultural influences in parenting styles and boundary making (often influenced by issues of safety and risk), physical attributes of the environment and differences in the role of the community as ‘loco parentis' and on the role children are purported to have in terms of being socially determinant. The research project that the four countries reported on in this special issue, namely Australia, Japan, South Africa and Tanzania, have participated in had two main aims. The first aim was to provide a national and international comparison of children's and parents' views of the independent mobility of children aged 7–15 years from a variety of social and cultural contexts by contributing to and building on the original seminal study (Hillman et al, 1990). It also provided the opportunity for general historical comparisons with original research that was collected using the same or similar questionnaires over the past 20 years. In the article written by Rudner & Malone on CIM in Australia, for example, a comparison is being made with the work of Tranter, from the early 1990s, with schools in similar localities (Tranter & Whitelegg 1994). Finally, the focus was to explore how CIM varies internationally, and to identify the factors affecting CIM and the implications this may have for children's lives. This final aim is particularly important as most of the research on CIM has been conducted in western industrialised nations (for instance, two recent publications by Freeman & Tranter [2011] and Fyhri et al [2011] report almost exclusively on studies in Europe, the United Kingdom, Australia and New Zealand) and therefore provides a very limited perspective of what is prioritised as the important debates, key trends and issues being purported globally around CIM.
Notes on the Variety and Uses of Satire, Sarcasm and Irony in Social Research, with Some Observations on Vices and Follies in the Academy
Authors: Watson Cate
Published: October 2011

In this article the author examines the uses of satire and its rhetorical devices, sarcasm and irony, in social research, analysing published research papers as well as drawing on her own autoethnographic data. In particular, she focuses on texts concerning discourses within the academy and the current predicament of the academic, each of which sets out to expose an aspect of the workings of power in institutions. While satire may be considered a narrative form, a means for and of representation, irony, as a rhetorical trope which exerts its effects through juxtaposition and the creation of incongruity, constitutes a potential analytical tool in social research, overturning expectations and operating within a ‘logic of discovery’. Satire therefore functions as a form of critical analysis while irony contributes to the development of theory and ‘paradigm innovation’.
Documenting the Discourse of a Hip Dixie, or, How Do We Speak of the South?
Authors: Chapman Daniel , McClain Jeremy
Published: October 2011

Negotiating representations in increasingly complex multicultural contexts is central to educational work. The authors use Rosenbaum & Douglas's 2003 documentary Searching for the Wrong-Eyed Jesus to explore paradoxical representations of White Southern men. Notions of white privilege, while applicable, are insufficient when one considers the White Southerners' lack of access to political power and the cultural coding that presumes reactionary, violent racists inhabit the region. As they begin thinking through the film, the authors utilize its interpretive framework, a hip gaze, to reimagine insider/outsider representations and their connections to the broader question of power and education. While not politically powerful in itself, the cultural force known as hip is both hegemonic and counter-hegemonic and inverts traditional notions of power. Hip is a response to and a justification for institutional desires to make student behavior conform and to crush dissent. However, the authors argue that it is these actions that train students to compartmentalize social selves from private selves which eventually render citizens willing to exchange political and economic power for cultural freedom. They conclude that there is an opportunity for a discourse on class oppression that can compel students to integrate their social selves and private selves.
Taking Responsibility for Race Inequality and the Limitless Acts Required: Beyond ‘Good/Bad Whites' to the Immeasurably Whitened Self
Authors: Kitching Karl
Published: October 2011

Certain radical race scholars argue that white people can and must act in anti-racist ways as part of a project that aims to end racial identities built on inequality, terror and domination. Yet revisioning the white subject as non-oppressive should not be the primary goal of anti-racism, as this re-centralises concern for those benefiting from whiteness. In this article, the author considers the ongoing erasure of white responsibility for race inequalities, and analyses the merits and tensions of ‘critical race’ and ‘race critical’ principles for exposing, politicising and countering them. He agrees with assertions that responsibilisation for race inequality is a radical process that cannot imply a finite state for individuals (‘good/bad whites’); it is a process that must involve constant turns away from the Self and towards the Other. Acts of white anti-racist transgression must not be reduced to ever having taken ‘full personal’ responsibility for race inequality. However, for different reasons, caution needs to be exercised about assuming a universal, fixed, knowable white self at the centre of such acts, one which always successfully inhabits being white. Contributing to ‘race-critical/post-race’ scholarship, the author uses Butler's (2005) separation of agency from responsibility to think about responsibility as the task of the immeasurably whitened self.
Inclusion: A Defining Definition?
Authors: Hodkinson Alan
Published: October 2011

Within this article the definition of inclusion is critically explored in relation to the previous New Labour government's educational policy of the late twentieth and early twenty-first centuries. This exploration demonstrates that inclusion rather than being located in terms of equality should actually be observed as a complex ideological construct which legitimised the process of the subordination and domination of vulnerable groups in our society. In the article it is argued that whilst supposing to ensure the presence of all children, on their terms, in mainstream schools, inclusion in this guise only insinuated itself in-the-place-of integration and thereby operated as a continuous and homogeneous reparation and modification of presence in the representation of children with special educational needs and/or disabilities. The article concludes therefore that inclusion became located as a ‘guise of truth’ which employed a cultural cloak of equality to create double binds where performativity was pitched against presence, standards against segregation and ablism against absence.
Empowerment in Education: Liberation, Governance or a Distraction? A Review
Authors: Lawson Tony
Published: October 2011

In a review of scholarly articles about the concept of empowerment, the author argues that the idea of empowerment has been deployed in three main ways. The first is where empowerment is conceived as a liberatory idea, in which power is transferred in education from the traditionally powerful to subsidiary groups within the educative process. The second conceptualises empowerment as a technique of governance, a way of disciplining modern citizens into a regime of self-surveillance. The third identifies empowerment, divorced amongst educationalists from wider social and political movements, as a distraction, which dissipates the potential for real educational change. The article concludes that a re-connection with the political is a necessary pre-condition for the achievement of the transformative potential of empowerment programmes.
Structural Health Monitoring System, Naini Bridge, India
Authors: Bhanushali Vikram , Andersen Jacob E. , Christensen Søren C.
Published: October 2011

The Structural Health Monitoring System (SHMS) for Naini Bridge was designed as a modern advanced monitoring system with the provisions for design verification, user safety support and optimization of maintenance planning. Also the system was designed to operate by a distributed data acquisition network based on standard data acquisition units and standard data acquisition software from US based National Instruments, in order to keep costs low.

So far the SHMS has through advanced GPS and Weigh in Motion monitoring proven able to detect the frequency of overloaded vehicles passing the bridge and to verify some design parameters concerning temperature movements.
The Øresund and the Great Belt links – Experience and Developments
Authors: Vincentsen Leif J. , Lundhus P.
Published: October 2011

The Øresund Link opened to traffic in 2000 and as a cross-border infrastructure it connects Copenhagen in Denmark and Malmø in Sweden, two urban areas. The Great Belt Link opened to traffic in 1997/1998. This link connects two non-urban areas in the central part of Denmark and has become the most important connection between East and West Denmark. The paper presents some of the experience gathered and the development in traffic at both links. Also topics such as environmental impact, traffic safety and financing are dealt with in the paper.
Cable-stayed Bridges across the Panama Canal and the Orinoco
Authors: Humpf Karl , Saul Reiner
Published: October 2011

This paper presents two major bridges in South America which have been designed and built in record periods in geotechnical and seismically critical areas combining effectively local workforce and international experience.
Stonecutters Bridge – Latest Construction Challenges
Authors: Kite Steve , Hubert Iain , Venetz Christian
Published: October 2011

Stonecutters Bridge will span 1018m across the Rambler Channel in Hong Kong providing 73.5m high clearance above the busy shipping channel. Construction commenced in early 2004. Upper tower construction from level +175m to +293m combines circular duplex stainless steel skin segments with carbon steel anchor boxes at the core and a concrete infill wall to form the composite structure. The 88m lengths of steel twin-box decks around the towers are over land. Individual deck segments were delivered to site by barge and offloaded using a frame cantilevering from the tower. After segment welding, a Heavy Lift operation is used to raise the 4000T decks by 75m, using strand jacks on temporary works supported from the towers and the concrete back spans. Transverse and longitudinal sliding operations are required for final positioning. Trial assembly of the steelwork components during fabrication in China ensures accurate fit up and geometry control during erection so that site operations are not hindered. Main span cantilevering and installation of the prefabricated parallel wire stay cables will follow.
La Vicaria Arch over La Fuentesanta Reservoir
Authors: Pérez-Fadón Martínez Santiago , Herrero José Emilio , Martin-Tereso L. , Sanchez M.
Published: October 2011

La Vicaria Arch is a through arch bridge placed over La Fuensanta Reservoir on the River Segura, Albacete (Spain). The total length of the viaduct is 260 m, with 2 arches that spans 168 m. Each arch is inclined 10º inwards at both sides of the deck. The arch sections are quasi-rectangular formed by folded steel plates filled with self-compacting concrete. The deck section comprises two longitudinal steel beams connected with a concrete slab. The construction system involves assembling a 120 m tied arch on the ground and after that, lifting it 40 m with hydraulic jacks to connect it to the rest of the structure, built as a cantilever erection. This article describes the most relevant facts of the bridge and peculiarities related to the construction process.
Design of an innovative composite bridge combining reinforced concrete with Ultra-High Performance Fibre Reinforced Concrete
Authors: Brühwiler Eugen , Fehling Ekkehard , Bunje Kai , Pelke Eberhard
Published: October 2011

A novel concept is applied for the design and construction of an innovative 46m long overpass road bridge. The principle of this design concept is to use Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) to “harden” only those zones where the structure is exposed to severe environmental and high mechanical actions, i.e. top surface of the deck slab, kerb elements and the zone above the middle support including a unique UHPFRC hinge. All other parts of the bridge structure remain in conventional reinforced and prestressed concrete as these parts are subjected to moderate exposure. This conceptual idea (originally developed for the rehabilitation of existing concrete structures) combines efficiently protection and resistance functions. The resulting bridge has significantly improved structural resistance and durability. By the time of writing this paper, the bridge was in the tendering phase.
Lifetime Performance of GFRP Pultruded Profiles for Structural Applications
Authors: Correia João R. , Branco Fernando A. , Ferreira João G. , Fonseca Susana C. , Rodrigues João P. C.
Published: October 2011

This paper presents results of an ongoing experimental research performed at IST on two critical topics, regarding the use of glass fibre reinforced polymer (GFRP) pultruded profiles in structural applications: the long-term durability and the fire behaviour. The first part of this paper presents test results on the changes suffered by GFRP pultruded profiles under accelerated exposure to moisture, temperature and UV radiation. Although some reduction was observed in the mechanical properties, the durability tests proved the generally good long-term behaviour of this material. The second part of this paper presents results of experiments on the fire behaviour of GFRP profiles. Large-scale fire resistance tests on both unprotected and protected GFRP profiles (with different active and passive protection systems) were conducted to investigate the thermal and mechanical response of the material under fire and to determine the fire resistance and applicability of the investigated systems.
Trau Kod Dam Near Siem Reap, Cambodia: Sustainable Infrastructure in a
Developing Community
Authors: Woodward Ryan
Published: October 2011

The New York City Professional Chapter of Engineers Without Borders has taken on a fast-paced project in Cambodia at the Balang Commune near Siem Reap, to be completed in January 2008. Working closely with a Cambodian engineer and a non-governmental organization, the team is constructing a privately funded concrete dam to replace an earthen structure that washed away during the rainy season of 2000.

As with much of Cambodia, this region depends heavily on the dam and adjacent reservoir for irrigation during the dry season. Since the dam’s failure six years ago, thousands of residents in the area have been relying on one growing season instead of two, and the economic effects have devastated the already impoverished region. This simple project will restore and improve upon the region's irrigation system, leading to increased cropping intensity and higher total production, creating more demand for labour, and contributing to a reduction in poverty.

In addition to helping restore a sustainable local economy, the dam construction is part of a greater effort to empower developing communities to create tangible, positive change. Engineers have an opportunity to contribute their unique skill set to such projects, yet little guidance exists on how to proceed in an unfamiliar environment. This paper will provide guidance on issues unique to designing and coordinating a sustainable non-profit project in a developing nation, including the use of local materials and labour. The implementation of a maintenance and inspection program will be discussed, with the aim of training local staff to perform this work.

The paper will illuminate technical issues of designing and constructing a retrofit concrete dam adjoining to an existing earthen embankment, including issues of global structural stability, soil seepage, and relevant structural details. The construction phasing will be discussed with an emphasis on community involvement and transfer of technology. The larger irrigation system affected by the dam and reservoir restoration will be described, and the anticipated impacts on agriculture, commerce, and health of the community will be discussed.

Engineers Without Borders–USA (EWB–USA) is a non-profit humanitarian organization, partnering with developing communities to improve their quality of life by implementing sustainable engineering projects. By bringing together disparate volunteers, organizations like EWB can intensify the benefits and ensure the sustainability of projects like this one.
Hypothesis of Railway Connection (Only Goods) Europe-Africa Placed Among Sicily and Tunisia
Authors: La Mendola Pietro , Minischetti Mario , Tatì Angelo
Published: October 2011

In this article it is analyzed, in the scenario of the present time engineering knowledge and of next future time transport opportunities, the possibility, more times assumed in past, to realize a railway link between Europe and Africa through the Channel of Sicily. The performances of this infrastructure are examined by a technical and economic point of view. Socio-political transformations deriving from the presence of one similar infrastructure in the context of the European and Mediterranean transports are examined.
An Experimental Study on the Concrete Durability
Authors: Bob Corneliu , Abri Ovidiu
Published: October 2011

The paper provides a tentative for a practical model of assessing the corrosion of reinforcing steel in concrete structures. A theoretical model as well as a formula for both the carbonation depth and chloride ion penetration is presented. Experimental programme presents the influence of carbon dioxide on depth of carbonation.
Tubular Trusses for Steel-Concrete Composite Bridges
Authors: Hirt Manfred A. , Nussbaumer Alain
Published: October 2011

The main subject area of this contribution is the recent development of composite bridges in Europe using welded steel truss girders made of circular hollow sections. The governing criterion for the design of such tubular structures with welded nodes often is fatigue. Comparison between cast steel nodes and welded nodes is made. Also, the beneficial effect of weld peening on the fatigue strength is mentioned. Finally, a brief summary on the development of a new shear connection for prefabricated concrete deck elements is made.
A new European Standard on products and systems for Protection and Repair of concrete structures – EN 1504
Authors: Gusia Peter J.
Published: October 2011

CEN developed the EN 1504 series of standards covering all aspects of protection, maintenance and reinforcement of concrete structures. These new standard series governs products and systems for protection and repair of concrete structures on a European scale. The national body of rules on maintenance of bridges and other civil engineering structures is to be largely replaced in a gradual process by these group of European standards. Any inadequate specifications in EN standards on the use of building products need to be supplemented by application standards permitting a harmonized use of such products.
Punching Shear Retrofit of Reinforced Concrete Flat Slabs Subjected to Static and reversed Cyclic Loads
Authors: Bu Wensheng , Polak Maria Anna
Published: October 2011

The paper presents research program on retrofitting reinforced concrete slab-column connections to increase their punching shear strength and ductility in seismic regions. The current testing program includes five specimens, with and without shear reinforcement. The goal is to experimentally study the efficiency of shear bolt retrofitting technique in preventing collapse of flat concrete slabs in seismic regions. The proposed technique using shear bolt reinforcement allows repair and strengthening of existing, previously built flat reinforced concrete slabs supported on columns, which do not have adequate punching shear strength at the column area. A shear bolt consists of a headed vertical rod threaded at the other end for anchoring using a washer and nut system. The bolts are installed in holes drilled in a slab in concentric perimeters around the column. The presented results of the experimental work include large-scale interior reinforced concrete slab-column connections tested under vertical and reversed cycling horizontal loads. The hysteretic response behaviour is presented which shows how transverse reinforcements increase punching shear capacity, ductility and energy dissipation capability of slab-column connections. Discussion related to crack formation and propagation, deformations and strains in the reinforcements is included. The computed capacities of the specimens are compared to the experimental values.
Pushing the limits of U shaped viaducts
Authors: Gauthier Yves , Montens Serge , Kataria Rajan , Touat Arezki
Published: October 2011

The Pragati-Maidan viaduct is an extradosed railway bridge with a main span of 93 m. The deck cross-section has a U shape, which permits a perfect integration of the metro system in the superstructure.

The extradosed cables are covered by a concrete beam that allows to considerm them as internal prestressing. This beam also increases the stiffness of the main span.

This bridge is a the first of ist kind to be erected using the cantilever construction method, and it is the first extradosed bridge ever built in India.
Zhoushan Island-Mainland Connection Project Built for a Long and Efficient Life
Authors: Wang Chang-Jiang , Song Hui , Ge Yao-Jun , Yang Yong-xin , Wang Wu-Gang , Chen Xiang-Yang
Published: October 2011

The Zhoushan Island-Mainland Connection Project in China is a grand project with the total length of 64.6 km including 27.3 km-long five major bridges spanning five channels in succession, among which Xihoumen Bridge is a suspension bridge with its main span of 1650m, and Jintang Bridge has a main navigational channel section, a 620m long steel cable-stayed bridge. After aerodynamic investigation and vibration control related to flutter and vortex-shading having been thoroughly carried out for a efficient life of the project, severe sea environment brings about another kind of life-time problem, durability, and some new technologies are employed against chloride corrosion from the sea for a long life of the project.
The "Ziegelgrabenbrücke": Main Structure of the second „Strelasundquerung”
Authors: Kleinhanß Karl
Published: October 2011

After a construction time of three years, the 2830 m long Rügen Bridge in the course of the second Strelasundquerung is approaching its completion in autumn 2007.

The cable-stayed bridge crossing the Ziegelgraben forms the outstanding part of the link due to a number of innovative technical developments as the strand cables system Dyna Grip.

The superstructure with a length of 600 m and an overall steel weight of 6500 tons was successfully erected within only five months.

The main goal of the design – to create a modern and elegant civil engineering structure which is, in spite of its enormous dimensions compatible with the medieval townscape – has been achieved: the new cable-stayed bridge is already today considered a new landmark of the World Heritage Stralsund.
Fatigue assessment of composite bridges in high speed railway lines including resonance phenomena
Authors: Figueiredo Helder , Calçada Rui , Delgado Raimundo
Published: October 2011

This work presents a fatigue assessment method, applicable in normal and in resonance conditions, based on the dynamic analysis of the bridge and on the linear damage accumulation method. The determined damage levels include the single train passages and the train crossings, the later determined by a new method based on a random simulation of the crossing point.
Segmental hollow box girder bridges with bow shaped segments
Authors: Rombach Günter , Abendeh R.
Published: October 2011

Segmental bridges made of small precast elements have become a standard construction method for many bridges and elevated expressways in the world. Nevertheless some important aspects need still further investigation. One is the unavoidable gap between two adjacent elements caused by the heat of hydration during segment production (‘bowing effect'). This imperfection may significantly influence the bearing capacity of the structure and it's serviceability.

A thermo-mechanical finite element model has been developed and verified by full-scale test data to study systematically the match casting process for different boundary conditions. A simple model for practical purposes is presented to estimate the bowing. Next 2 typical real segmental bridges with perfect and imperfect segments had been modeled to analyze the behavior of bridges with imperfect segments. The various analysis showed that compressive stresses in the deck slab and thus the load bearing capacity of the structure as well as the durability are highly reduced by the bowing effect.
Analysis and behaviour of CFRP-strips at deviation saddle for CFRP prestressed bridges
Authors: Knippers Jan , Saad Fathy , Hwash Mohamed
Published: October 2011

This research work presents the application of CFRP-Strips as prestressing elements for bridges, e.g. extradosed bridges and externally prestressed box girder concrete bridges. The application of CFRP-Strips as external pre-tensioned elements is not only governed by the general structural and dynamic behaviour of the hybrid system but also by having the right concept for the construction joints, i.e. the anchorage of the CFRP-Strips at the deviation saddle and at the deck structure. The load bearing capacity and the deformational behaviour of deviated CFRP-Strips is influenced mainly by contact surface, the deviation angle and the diameter of the deviation saddle. This paper introduces the results of an Experimental program of deviated CFRP-Strips at deviation saddle. The effect of the different parameters on the load bearing capacity, strain responses up to failure and the mode of failure of the CFRP-Strip at the deviation saddle will be investigated. Additionally, analytical study for the application of externally prestressed concrete bridges , i.e. Extradosed bridges is presented to highlight the efficiency of this application.
Dynamic characteristics of Seohae cable-stayed bridge based on results from long-term structural health monitoring
Authors: Park Jongchil , Park Chanmin , Kang Hyeongtaek , Jo Byungwan
Published: October 2011

This paper presents the long-term dynamic characteristics of a cable-stayed bridge where installed the SHM (Structural Health Monitoring) system. Modal parameters such as natural frequencies and mode shapes were identified from the modal analysis using the three-dimensional finite element model. The modal parameters of the developed baseline model have a good correlation with those identified from field ambient vibrations. By the analysis of correlations between the measured natural frequencies and temperatures, it was found the natural frequency was in linearly inverse proportion to the temperature. Mode shapes were extracted from the TDD (Time Domain Decomposition) technique for ambient vibration measurements. Finally, these results demonstrate that the TDD technique can apply to identify modal parameters of large-scaled bridges.
Laser scanning for bridge inspection and management
Authors: Tang Pingbo , Akinci Burcu , Garrett James H.
Published: October 2011

The current process for acquiring bridge geometric data for the National Bridge Inventory (NBI) is based on manual surveying, manual data processing and interpretation. Hence, it is time-consuming and error-prone. This paper presents a laser-scanning-based approach to acquire geometric data for bridge inspection, describes a case study and discusses the advantages of this approach over current practice from the perspectives of both bridge inspection and management. Both current approach and laser-scanning based approach are composed of three major steps of data collection, data processing and data interpretation. Yet, a comparison of these approaches highlights major differences in the accuracy and comprehensiveness of the data collected. Based on the comparison, we suggest a need for a formalized way to decompose higher level bridge inspection goals to enable successful application of laser scanning technology for bridge inspection.
Structural health monitoring with wireless sensors to enhance sustainability in structural engineering
Authors: Krueger Markus , Grosse Christian U. , Reinhardt Hans-Wolf
Published: October 2011

Acoustic emission techniques (AET) are an alternative monitoring method to investigate the status of a bridge or some of its components. It has the potential to detect defects in terms of cracks occurring during the routine use of bridges. A monitoring system for large structures is developed based on a new kind of MEMS sensors as well as conventional sensors requiring just very low power. Besides the sensors the recording and analysis technique needs powerful algorithms to handle and to reduce the immense amount of data. Systems developed for structural health monitoring use embedded network techniques along with wireless communication and MEMS. Algorithms to reduce the amount of data and to enable the localization of damage areas by array techniques have to be developed. The paper is giving an overview about data processing and analysis techniques needed for wireless sensor networks with respect to structural health monitoring. The focus is especially in the field of acoustic emission techniques where often a large amount of data must be processed.
Structural health monitoring of existing bridges by vibration measurement
Authors: Miyashita Takeshi , Nagai Masatsugu , Iwasaki Eiji
Published: October 2011

This paper describes some studies relating to structural health monitoring techniques based on vibration measurement using laser Doppler vibrometer (LDV) and MEMS based sensor. 1) Compact and portable LDV measurement system was developed and applied to tensile force measurement of cables in a cable-stayed bridge. 2) The system combining LDV with Total Station was developed for the purpose of automated remote measurement for whole large bridge. 3) A new wireless LAN accelerometer based on MEMS technology was evaluated and applied to field measurement of bridges.
Efficient reconstruction of bridges with small and medium spans
Authors: Hechler Oliver , Girkes Andreas
Published: October 2011

The traffic density is growing during the last decades. As a consequence numerous new roads and railway lines were built or are planned to be realized in the near future. On the other hand existing bridges must carry the increased traffic. Most of these bridges were not originally designed for the high service loads and the amount of traffic of today. Many of the structures are aged and, depending on the maintenance and repair carried out, do not longer suit the purpose. Further the demand for increased capacity requires often a deck widening for the carried traffic, or a longer span for traffic underneath. Most situations mentioned finally need the reconstruction of the bridge or replacement of the deck. According to statistics short span bridges are the most frequent category.

This paper discusses the potential for composite bridges with short and medium spans for the reconstruction of old bridges, considering the specific requirements resulting from the existing environment and by severe constraints for site work. Via case studies structural systems with hotrolled beams and appropriate construction methods matching special site restrictions are analysed. In this regard the variety of structural systems and dimensional flexibility is shown, particularly if available construction depth is restricted. The paper is also focused on decreasing the traffic disturbances by using prefabrication and an appropriate erection method.
Soft-WIM: vehicle identification from bridge measurement
Authors: Schnellenbach-Held Martina , Lubasch Peer , Buschmeyer Wilhelm
Published: October 2011

This paper presents an approach for the identification of operational loads given measured static responses of a bridge structure and its corresponding analytical model. In an optimization process single vehicles and corresponding attributes are identified from data recorded during the presence of one or multiple vehicles on the bridge. The vehicle attributes gross weight, velocity, axle loads and axle spacings are determined. The problem is solved by means of two encapsulated evolutionary optimization routines. The objective function is represented by the calculation of the difference between measured and computed strains. For measurement, only two sensors which are installed in one cross section without any installations on top of the bridge are required.

The application to real measurements as well as obtained results will be shown. The results demonstrate that structural health monitoring in conjunction with adequate mechanisms can successfully support the acquisition of additional, valuable information.
Development of advanced robot system for bridge inspection and monitoring
Authors: Lee Jong Seh , Hwang Inho , Lee Hu Seok
Published: October 2011

Conventional bridge inspection involves the physical positioning of an inspector by the hydraulic telescoping boom of a “snooper truck” thereby providing visual access to bridge components. The process is time consuming, hazardous, and may be affected by lighting conditions. Therefore, it is of great interest that an automated and/or teleoperated inspection robot be developed to replace the manual inspection procedure. This paper describes the advanced bridge inspection robot system under development and other related activities currently undergoing at the Bridge Inspection Robot Development Interface. Its primary goal is to develop advanced robot systems for bridge inspection and monitoring for immediate field application and commercialization. This research project will contribute to advancement of infrastructure maintenance technology, enhancement of construction industry competitiveness, and promotion of national capacity for technology innovation.
A concrete code for Africa
Authors: Wium Jan A. , Ngab Ali S.
Published: October 2011

Many countries in Africa use either foreign developed concrete codes or no codes at all. This paper presents the process for the development of a concrete code for Africa. The code will use existing international codes as reference documents, but will reflect the materials, construction practice and local environment of the African regions. The basis of design and durability aspects will receive special attention in the development of the code. A working group structure has been created, consisting of African participants and international specialists. The task is now to compile information about the African continent which will include climatic and environmental regions, materials information, level of technology and training, and construction practices. Decisions are also needed on the scope of the code, both as it relates to structures and loading. The process started towards the end of 2005 and a date of 2010 has been set for the preparation of a first draft.
Aesthetic issues of railway stations in Japan and in Europe
Authors: Kido Ewa Maria
Published: October 2011

Aesthetics has been described as an important factor of railway infrastructure. The paper characterizes policies of railway companies in Japan and Europe during recent period of “station renaissance” when aesthetics became important issue. It compares Japanese and European railway stations and introduces strategies to improve design process and stations in Japan, such as strengthening of the relationship between city planning, station planning and management; reinforcing the advanced community-based planning; introducing the measures to increase public awareness of aesthetics; promoting of a comprehensive station design; enforcing of landscape and aesthetic control; conducting design competitions for railway stations and maintaining stricter control of advertising in public places.
Blast resistance of structural members
Authors: Rutner Marcus P.
Published: October 2011

This paper gives a brief overview of the current status of specific resistance design strategies of structural systems against car bomb blast and focuses further on load-carrying behavior and failure modes of loadbearing structural key elements. The axially-loaded column is chosen for structural response and resistance capacity analysis. The ideal outcome should be invention of a strengthening technology, which is effective and “invisible” for terrorists. This study aims at implementing measures on how to prevent local failure of load-bearing structural members by the specific local resistance design approach. The alternate path design approach is not content of this paper. Making steel sections to composite sections is presented as a strengthening measure, which can be applied to new as well as to existing structures. The arising protection concepts are currently elaborated and tested in regard to its effectiveness in comparative analyses. The studies have been performed at the interface of advanced computational simulation software application, material science, experimental testing and continuum mechanics. The analysis is conducted by MSC.DYTRAN and LS DYNA and the applied models backed up by experimental testing.