bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of a MV XLPE cable termination design with embedded electrodes
Authors: Dimitrijevic Radisa , Tasic Dragan , Raicevic Nebojsa , Aleksic Slavoljub , Pekaric-Nadj Neda
Published: October 2011

Insertion of embedded electrodes (EEs) inside a MV XLPE cable termination strongly affects electric field around the termination and accordingly must be carefully considered. In this paper, influence of embedded electrodes on voltage distribution in some constructions of the 20 kV cable terminations was analyzed. Different options were considered for a specific number of the EEs along the cable insulation surface, taking into account possible effects of floating or grounded EEs, their different position and separation. In every option, a basic method of stress relieving with resistive layer over the end of semi conducting screen and primary cable insulation was applied. Reference design was a cable termination without EE. Its voltage distribution, total electric field and tangential component were observed for comparison. The stress relief materials, in the shape of pads or tubes, were used. Their properties were kept the same in all constructions. Voltage distribution was monitored, starting from the end of the primary cable insulation in the vicinity of the phase conductor and ending at the cable insulation attached to the semiconducting screen end at ground potential. The different design options were experimentally verified. .
Antennas embedded in CMOS integrated circuits
Authors: Yordanov Hristomir , Russer Peter
Published: October 2011

In this work we propose novel integrated antennas for chip-to-chip wireless interconnects. In order to save chip area, the available CMOS circuit ground planes can be used as radiating elements. The interference between the integrated antennas and the on-chip circuit interconnects should be minimised. This can be obtained by introducing a transformer in the antenna feeding network.
Rotational speed measurement using induction coil sensor inserted in the magnetic field of the rotational permanent magnet
Authors: Todorovic Andreja , Jevtic Miroljub
Published: October 2011

In this paper the application of induction coil sensor, inserted into a mechanical rotational magnetic field of the rotational permanent magnet for the rotational speed measurements has been proposed and described. The sensor is simple, low-cost, and applicable for machine shafts speed measurements (spatially available and unavailable). On the shaft, whose rotational speed is measured, the rotational permanent magnet is fixed. From measured frequency value of induced voltage in the coil sensor the rotational speed value is given using PC with adequate software, interface for the analogue signal conditioning and AD converter. The rotational speed dependence on the induction coil sensor distance from the rotational permanent magnet has been given. The induced voltage dependence on the coil distance from the magnet has been obtained as well. The maximum distance for precise measurements of rotational speed has been determined from those relations.
Model of digital and signal channel in the network of Serbian electric power industry
Authors: Mitic Dragan , Lebl Aleksandar , Markov Zarko
Published: October 2011

In this paper we use data from extensive measurements, which are implemented in telecommunication networks of electric power industries in the six countries. The model of digital telecommunication channel and the model of hypothetical signaling CCS No7 channel under the influence of bursty errors are presented in the paper. These models can express very accurately data and signaling transmission in the digital telecommunication network (TN) of the Serbian Electric Power Industry (SEPI). We consider the model of digital and signaling channel first and after that analyze the availability of these channels under the influence of bursty errors.
Analysis and optimization of direct sequence spread spectrum scheme for an unmanned aerial vehicle PPM control signal
Authors: Todorovic Branislav , Orlic Vladimir
Published: October 2011

Binary pulse-position modulated (PPM) control signal is widely used in remotely controlled unmanned aerial vehicles. It consists of data frames, which contain a synchronizing pulse followed by a number of shorter pulses equal to the number of channels N. In this paper we present analysis and optimization of direct sequence spread spectrum (DS-SS) scheme for PPM control signal protection. That scheme uses (N+1) pseudonoise (PN) sequences: one of them (PN0) is assigned to the synchronizing pulse while the each of the remaining N sequences (PN1,PN2, . . . ,PNN) corresponds to the appropriate channel. At the receiving side, the set of (N+1) passive correlators is used to detect respective PN sequences and to reconstruct data. Onelevel and two-level detection are considered. Threshold settings optimization is based on the Neyman-Pearson procedure. As an additional performance measure we introduce probability of corruptive false alarms. Numerical results are presented.
Hmm … Hmmm … Excuse Me? A Case Study of Interruptive Caring in a Bilingual Classroom
Authors: Pimentel Charise
Published: October 2011

Drawing from ethnographic research data and couched in critical care research, the author introduces the concept of ‘interruptive caring’ – a critical approach to caring that both transforms deficit-oriented school practices and challenges the underlying ideologies that inform and rationalize the inequitable power imbalances that operate within a school system. The author examines the concept of ‘interruptive caring’ as it emerges in a stand-alone, two-way, dual-language bilingual elementary classroom. The article includes a discussion on the importance of contextualizing interruptive care practices within the larger sociopolitical contexts in which teachers work.
Alveolar echinococcosis in patient after cadaveric kidney transplantation
Authors: Dražilová S. , Kinčeková J. , Beňa Ľ. , Zachar M. , Švajdler M. , Zavacký P. , Jarčuška P.
Published: October 2011

52-years old man years following the kidney transplantation from deceased donor was admitted to the hospital with fever and progressive abdominal pain. The patient was diagnosed with chronic hepatitis C seven years before admission. Graft function in posttransplant period was stable and optimal, the patient was treated with standard maintenance immunosupresive protocol (cyclosporine A, mycophenolate mofetil and low-dose prednison), metylprednisolon bolus therapy (1 g/m2 body surface area), was administered two months prior to admission due to creeping creatinine (suspection of acute rejection was not confirmed by biopsy). Empiric antibiotic treatment due to febrile status was ineffective. Abdominal ultrasound and computer tomography (CT) scan revealed three tumorous lesions in the liver, radical surgical intervention was not executable. Histological examination of the tissue from the lesions demostrated alveolar echinococcosis, serology for Echinoccocus multilocularis was positive. Long-term treatment by mebendazol 200 mg twice daily led to disappearance of the clinical symptoms, but after the therapy cessasion patient was again hospitalized with fever and progression of cystic lesions in CT scan. Following the mebendazol therapy reinstalation the clinical course of echinococcosis was improved and remained stable, transplant kidney failure occurred due to progression of interstitial fibrosis/tubular atrophy and chronic haemodialysis was initiated one year later.
Competition for minerals (Zn, Mn, Fe, Cu) and Cd between sheep tapeworm (Moniezia expansa) and its definitive host sheep (Ovis aries)
Authors: Jankovská I. , Lukešová D. , Száková J. , Langrová I. , Vadlejch J. , Čadková Z. , Válek P. , Petrtýl M. , Kudrnáčová M.
Published: October 2011

Concentrations of various essential and toxic elements (Zn, Mn, Fe, Cu and Cd) were analysed by inductively coupled plasma optical emission spectrometry (ICP-OES) in the sheep tapeworm (Moniezia expansa) and in different tissues of its host Ovis aries. The element concentrations of the cestode parasites were compared to different organs (liver, kidney, and muscle) of sheep that were exposed to experimental amounts of Cd (0.2 g of CdCl2 added to 10 ml of distilled water and administered orally to the sheep every day for a period of 1 week). All sheep were randomly divided into four groups; the first group (Cd) contained uninfected, Cd exposed sheep, and its control (group C) were uninfected and unexposed to Cd; the second group (TCd) contained infected, Cd exposed sheep, and its control (group CT) contained infected, unexposed sheep. The experimental Cd exposure resulted in significantly higher Mn concentrations in sheep tapeworms (10.0 mg/kg) than in sheep muscle (0.6 mg/kg) and kidney (0.8 mg/kg). The experimental Cd exposure also significantly decreased the Cu concentrations in sheep liver and muscle. Moreover Cd exposure decreased the Fe concentrations in sheep kidney but caused it to increase in sheep liver and muscle. Zinc concentrations showed no differences between groups (Cd, TCd, C, T) in any monitored sheep tissues. The article also discuss the effect of tapeworm infection on a significant decrease of Fe in sheep muscle, liver and kidneys, as well as a decrease in Cu levels of the muscles and liver. This mineral imbalance may contribute to various health problems such as osteoporosis, metabolic processes disorder, antioxidant (SOD) dysfunction etc.
Influence of Echinococcus multilocularis infection on immune response of mice and their offspring
Authors: Reiterová K. , Antolová D.
Published: October 2011

Parasitic infection during pregnancy represents a serious stress factor and affects the course of pregnancy and the foeto-maternal relationship. The infection may not clinically manifest itself, however it can modulate the immune response of the offspring for a long-time. The influence of secondary Echinococcus multilocularis infection on the proportion of CD4+ and CD8+ T cells and the level of anti-Echinococcus antibodies were studied in Balb/c mice. The female mice were infected with homogenised metacestode material containing 2000 E. multilocularis protoscoleces (Group 1, 2). Group 1 was fertilised on day 60 post infection, while Group 2 remained unfertilised. Group 3 was uninfected and fertilised on the same day as Group 1. The numbers of both T cell subpopulations were higher in non-pregnant than in pregnant mice. In late pregnancy, the decline of CD4+, however, the increase of CD8+ T-cell subtypes were observed in both, infected and uninfected mothers, respectively. The strong humoral response with the high production of IgM and IgG2b antibodies in infected mice was detected. In infected mothers, IgG2b level was higher than in infected nonpregnant mice during almost whole monitored period. In Group 1, delivery caused suppression of Th2 immune response, represented by IgG1, under the level observed in uninfected mothers. The findings show the changes in helper regulatory and cytotoxic immunity mechanisms of infected mothers. In offspring of infected mothers all IgG subclasses were detected, however specific IgM were not transmitted neither transplacentary, nor transmammary.
The course of Echinococcus multilocularis infection and pregnancy in mice model
Authors: Antolová D. , Reiterová K.
Published: October 2011

Parasitic infection during pregnancy can affect the course of pregnancy, complicate the foeto-maternal relationship and increase abortion rate. The work was aimed to study the course of E. multilocularis secondary infection and reproductive parameters in infected mice. The Balb/c mice were bred in the exponential phase of the metacestode growth, after infection with two different doses (0.5 ml or 1.25 ml) of metacestode material. In comparison to uninfected control group, the effect of infection on reproductive parameters (natality, size of litters) and the course of disease during pregnancy and after the delivery were monitored. The weight of E. multilocularis larval stages was higher in both fertilised groups in comparison to unfertilised control. The number of deliveries and litter counts were similar in both, infected and uninfected mice. Present study confirmed only minor impact of alveolar echinococcosis on the reproduction of rodents, intermediate hosts of parasite.
A new species of Parastrigea (Digenea, Strigeidae) endoparasite of Buteogallus urubitinga (Aves, Accipitridae) from Argentina
Authors: Drago F. , Lunaschi L.
Published: October 2011

A new strigeid digenean, Parastrigea macrobursa n. sp., is described from specimens recovered from the small intestine of the great black-hawk, Buteogallus urubitinga (Aves: Accipitridae), from Formosa Province, Argentina. The new species is characterized by having a tulip-shaped forebody, a hindbody without neck region, a large, well delimited copulatory bursa, and a very deep genital atrium. Three species of Parastrigea share the shape of the copulatory bursa namely P. faini, P. astridae and P. tulipoides. Parastrigea faini and P. astridae differ mainly from the new species by having the forebody strongly divided in two regions and very developed lateral expansions, and Parastrigea tulipoides by having a long neck region and a longer body size. This new species represents the first record of a member of the genus Parastrigea Szidat, 1928 parasitizing birds from Argentina. A key is presented for the species currently recognized as valid in the genus.
Raphidascaris (Ichthyascaris) arii sp. n. (Nematoda: Anisakidae), a new ascaridoid nematode from marine catfishes in the Gulf of Thailand
Authors: Yooyen T. , Moravec F. , Wongsawad C.
Published: October 2011

A new nematode species, Raphidascaris (Ichthyascaris) arii sp. n. (Anisakidae), is described from male and female specimens found in the intestine of two species of marine siluriform fishes, the spotted catfish Arius maculatus (Thunberg) (Ariidae) (type host) and the striped eel catfish Plotosus lineatus (Thunberg) (Plotosidae) from the coastal region of the Gulf of Thailand, Thailand. Based on light and scanning electron microscopy examinations, the new species differs from other nine representatives of the subgenus Ichthyascaris Wu, 1949 mainly in the length of spicules (210–333 μm), body length of gravid females (10–17 mm), and in the presence of small cuticular spines or protuberances on the tail tip of both sexes and 21–30 pairs of preanal and 8 pairs of postanal papillae in the male. This is the first species of this subgenus reported from fishes of the order Siluriformes and the first species of the subgenus Ichthyascaris Wu, 1949 recorded from the Gulf of Thailand.
Resurrection of Pomphorhynchus tereticollis (Rudolphi, 1809) (Acanthocephala: Pomphorhynchidae) based on new morphological and molecular data
Authors: Špakulová M. , Perrot-Minnot M. , Neuhaus B.
Published: October 2011

Pomphorhynchus tereticollis (Rudolphi, 1809) is here redescribed on the basis of Rudolphi’s material, deposited in the Museum für Naturkunde Berlin, and on acanthocephalans recently collected from the type host Platichthys flessus (L.) and the region embodying the type locality. Out of the paratypes of P. tereticollis, the lectotype and paralectotypes have been designated. Their morphology fits well with that of newly collected material of P. tereticollis dissected from the type fish host from the Baltic coast near Stralsund. The resurrection of P. tereticollis, previously considered a synonym of Pomphorhynchus laevis (Zoega in Müller, 1779), is supported by several morphological features distinguishing the two Pomphorhynchus species: 1. The basal parts of the proboscis hooks located on the posterior proboscis half possess proximal projections in P. tereticollis but not in P. laevis. This shape of the hook bases is clearly visible only in unfixed fresh worms; 2. The last hooks are situated at the anterior part of the bulbus or rarely at the posterior-most end of the proboscis in P. tereticollis, while they lie anterior to the end of the proboscis in P. laevis; 3. The proboscis hooks No. 5 or 6 are markedly stout (robust) and clearly distinct in comparison with the surrounding hooks in P. tereticollis, while less robust and more similar to the hooks in P. laevis. In addition, genetic divergence between P. tereticollis and P. laevis based on ITS1, ITS2 and COI sequencing supports the existence of two distinct species and reveals that some isolates previously identified as P. laevis were actually P. tereticollis. Previous and present morphological and genetic data show that both Pomphorhynchus species occur in freshwaters throughout Europe and may infect the same fish hosts, such as chub and barbel, and also several species of isopods (Gammaridae). This study also provides morphological evidence that Pomphorhynchus intermedius Engelbrecht, 1957 is a synonym of P. tereticollis, because the only discrimination character of the former species, the “existing but small proximal projections of basal parts of the proboscis hooks located on the posterior proboscis half” are present also in P. tereticollis.
Suppression of root-knot nematodes in potting mixes amended with different composted biowastes
Authors: D’Addabbo T. , Papajová I. , Sasanelli N. , Radicci V. , Renčo M.
Published: October 2011

Suppressiveness of soil amendments with different rates of composted biowaste materials, olive pomace, municipal green wastes, sewage sludge and spent mushroom substrate, was evaluated against the root-knot nematode Meloidogyne incognita on tomato in potting mixtures. Soil amendments were applied at 0, 10, 25, 50 and 100 g kg−1 soil, according to a randomized block design with five replications for each treatment. Sixty days after tomato transplanting, nematode population density on plant roots and in soil and root gall infestation were assessed on each root system, and plant top and root weight were also recorded. Soil pH, dry and organic matter content, total and ammoniacal nitrogen were analyzed at the same time. Olive pomace-based composts resulted in the highest nematode suppression (73–97 %, according to the rate) and significantly reduced gall formation on tomato roots. Olive-waste compost affected positively tomato growth only in combination with sheep wool wastes, but it caused phytotoxicity when mixed with chicken manure and urea. Soil amendments with composted mushroom substrate also provided a consistent nematode suppression and a significant increase of plant growth, whereas composted municipal green wastes were more suppressive and positively affected tomato growth when combined with sewage sludge. Soil chemical parameters were scarcely affected by compost amendments, as organic matter was significantly increased only by the olive pomace-derived composts and nitrogen content only at the highest rate of the five composts. Data from the experiment confirmed the potential of compost amendments for sustainable management of root-knot nematodes both in field and greenhouse container media, though their technical effectiveness and economic convenience are strictly dependent on a correct proportion and local availability of raw materials used in the composting process.
Cutaneous trematode Collyriclum faba in wild birds in Costa Rica
Authors: Literák I. , Sitko J. , Sychra O. , Čapek M.
Published: October 2011

An adult Collyriclum faba was found in a cutaneous cyst at the base of the lower mandible in a blue-gray tanager (Thraupis episcopus, Thraupidae) examined in the Zona Protectora Las Tablas, Costa Rica on 18 August 2010. A total of 1878 birds belonging to 217 species were examined in the country during 2004, 2009, and 2010. C. faba was found for the first time in blue-gray tanager and for the first time in Costa Rica as well.
Design for movements in bridges
Authors: Sørensen Ove , Bloomstine Matthew L. , Bitsch Niels , Linneberg Poul
Published: October 2011

Many years of experience of design and maintenance of bridges shows that movement structures are among the more expensive as far as maintenance costs are concerned. These structures are the so-called mechanical ones and require regular maintenance from time to time, or part or full replacement.

The design philosophy should therefore be based on:

as few as possible movement structures

long durability

easy to maintain and replace

This paper describes:

Typical movement structures like expansion joints, bearings, hydraulic and mechanical dampers and cable support arrangements that allow movements.

General arrangements of the articulation systems of some major bridges relating to the above mentioned design philosophies.

Installation, operation and maintenance experiences.

Special features in connection with replacement of the Teflon sliding disks in spherical bearings after 22 years of use.

Experience from replacement of a 35-year-old roller shutter expansion joint with a new water tight modular type on a suspension bridge.

Challenges in the future.
Great demand and great challenge
Authors: Ge Yao Jun , Xiang Hai Fan
Published: October 2011

Under the background of high annual growth rates of GDP, China has experienced with the evergrowing demand in improving traffic infrastructure nationwide for about three decades, which results in intensive investment in traffic infrastructure development, in particular highway transportation construction. Two ground plans, the National Trunk Highway System and the National Expressway Network, have been launched successively, and thousands of highway bridges have been built for each year. In order to meet with the great demand in highway bridge development, Chinese bridge community is facing several challenges in the design and analysis of major bridges, especially of super long-span bridges. Aerodynamic challenge of suspension bridges was introduced by three typical examples including a single-box-girder with a central stabilizer, a twin-box-girder and a trial design with the combination of stabilizers and central slotted decks. Bridging capacity challenge was explained by three cable-stayed bridges with about 1000 m main span and a record-breaking span-length arch bridge. The other technical challenge was focused on the rational design and analysis of a double main span suspension bridge and a twin parallel deck cable-stayed bridge.
Retrofit Engineering for Steel Bridge Structures in Japan
Authors: Miki Chitoshi , Konishi Takuyo
Published: October 2011

The cases of fatigue damage, repair and retrofit applied are presented. The causes of fatigue damage are categorized as follows. (a) welding defects were remained during fabrication, (b) inappropriate structural details of low fatigue strength were adopted, (c) stresses and deformations unforeseen in design occurred at joints of members (d) structures behavior in a manner not expected, such as vibration due to wind. Case studies include girder bridges, orthotropic steel bridge decks, steel bridge pier structures and others.
Two Steel Bridges for the High Speed Railway line Madrid-Barcelona-French Border
Authors: Sobrino Juan A.
Published: October 2011

Two steel bridges have been recently completed on the high speed railway (HSR) line connecting Madrid, Barcelona and the French Border (Perpignan). Both structures cross over existing infrastructures with a limited vertical clearance in order to reduce environmental impact. The conceptual design is similar for the two structures: a composite steel-concrete deck suspended on steel tied curved members. An innovative solution, at least for the Spanish HSR lines, that has been used in the past in concrete road bridges. These bridges are two of the three first steel structures built for the HSR in Spain. This paper synthesises the design, structural behaviour and construction of these bridges near the city of Barcelona, Spain:

Llinars Bridge crosses, at a very high skew angle, one of the busiest highways (AP-7) in Spain. This viaduct has an overall length of 574 with a maximum span of 75 m.

Sant Boi Bridge crosses several existing infrastructures (highway, road and railway). The overall length of the bridge is 870 m with a maximum span of 63 m.
Application of sleeve joints between steel beams and CFT columns to railway structures
Authors: Yoda Teruhiko , Yamada Masato , Hayashi Atsushi , Nozawa Shin-ichiro
Published: October 2011

A design equation for estimating the ultimate strength of sleeve joints was presented on the basis of the experimental study. The static loading tests by using the T-shaped sleeve joint specimens were carried out in order to investigate the effects of the diaphragm and the applicability of the sleeve joints to railway structures. The test results indicate that the diaphragm affects the ultimate strength, and that the application of the proposed design method to the T-shaped sleeve joints is promising.
Tunnels Supported on Bearing Blocks
Authors: Pompeu Santos S.
Published: October 2011

The paper presents an innovative and cost-effective solution for the construction of tunnels of the roadway and railway types, executed with tunnel boring machines (TBMs), when the referred tunnels are executed in soft soils (e.g., alluviums), in seismic areas. This solution can also be used for the strengthening of existing tunnels, using the existing tunnel as a formwork for the execution of the interior strengthening. In this paper a description of the solution is presented, as well as its application to a specific case.
Ship Collision Impact Analysis of Pile-Supported Structure for Protection System
Authors: Lee Seong-Lo , Bae Yong-Gwi , Kim Ho-Kyung
Published: October 2011

Ship collision analyses for the hard impact on rigid wall and the soft impact on protective structure were carried out to evaluate the ship collision force on substructure and the energy dissipation of pile-supported structure during ship collision. The ship with bulbous bow and the pile-supported structure were modeled in a finite element analysis package. As results, the deformations, displacements and stresses of protection system were obtained and the kinetic energy of colliding ship were analyzed into the absorbed parts such as plastic deformations of protective structure and vessel, friction between structure and vessel, rebounding of vessel, etc. The collision energy of vessel was almost translated to the plastic deformation energy of the pile-supported structure and the considerable energy was also translated to that of vessel.
Simulation of Low-cycle Fatigue in Integral Abutment Piles
Authors: Hällmark Robert , Collin Peter , Petursson Hans , Johansson Bernt
Published: October 2011

Integral abutment bridges are bridges without any expansion joints, and their largest benefits are the lower construction- and maintenance costs. In order to build longer integral bridges it might be necessary to allow plastic hinges to be developed in the piles. Lateral thermal movements are the major reason to plastic deformations, and since temperature variations are cyclic it has to be proved that low-cycle fatigue will not occur. A simulation of the pile strain spectra should be able to take into account the strains caused by temperature variations and traffic loads. Such a model has been created from real temperature data and traffic loads measured by Bridge-Weigh-In-Motion technology. Monte Carlo simulations have been performed in order to simulate daily and annual temperature changes as well as the varying traffic loads. Piles strains have been calculated, and their fatigue effect has been evaluated.
Structural behaviour of GFRP beams under high temperature condition
Authors: Vieira Janine , Batista Eduardo
Published: October 2011

Glass fiber reinforced polymers, GFRP, are extensively applied in industrial plants as those of oil and gas exploitation. Its high corrosion resistance combined with appropriate structural behavior brings many advantages to this material, especially when environmental conditions demand for corrosion resistant materials. In this context the pultrusion technology permits large production of standardized shapes for structural applications, which appears as a good solution where metal sections can be replaced by GFRP members.

The present research is aimed to study the structural behavior of pultruded members under high temperature conditions, as those that could develop in accident scenarios in industrial installations. For this, an experimental program is under development and the present paper shows the results of pultruded beams tested under high temperature conditions, revealing its stiffness and strength degradation, as well as creep. The temperature range up to 100º C, with both steady state and transient temperature conditions. The composite material is based on E-glass fiber plus polyester isopthalic or vinyl ester matrix.
Traffic Structures in Eastern Germany – A historical Review
Authors: Weller Bernhard , Tasche Martin
Published: October 2011

This paper sheds light on the milestones of the development of design and construction of bridges and station halls in Eastern Germany. A link will be made from the oldest stone bridge in Creuzburg/Werra built in 1223 to the long span archbridges in Göhren and Plauen (span 90 m) built in 1905. The same will be done for concrete and steel bridges on the basis of regional examples. There are various characteristic types of structures which could not establish themselves over time, but still exist though. The bridges designed by M. Möller and F. Visintini or the timber arches of P. de l´Orme or Emy are such situations. The characteristic design principles are presented with a special emphasis on the particular “state of the art” in technology and structural knowledge at the time. This can be shown particularly well for the development of long-span station halls. The span of the main station hall in Leipzig grew from approximately 20 m in 1839 to 294 m in 1915.
Fatigue sensibility of R/C secondary elements of bridges
Authors: Zanuy Carlos , De La Fuente Pablo , Pacheco J. , Albajar Luis
Published: October 2011

The influence of fatigue may be an important but not usually contemplated aspect on the behaviour of some components of concrete structures. Here a study on the bridge approach slabs is presented. It is shown how the cyclic load causes a progressive deterioration of the compression zone of concrete and its contribution in the tensile chord between cracks. The increase of deflections and crack widths along the fatigue life is observed experimentally, under maximum and minimum loads. The growth of the remnant values of these variables evidences the important irreversibility of the fatigue degradation.
New Steel-Concrete Adherence Connections for Composite Bridges
Authors: Lebet Jean-Paul , Thomann M.
Published: October 2011

Steel-concrete composite bridges with precast slabs are ideal when building new bridge structures or replacing existing bridges, due to the short duration of on-site work. However, the steel-concrete connections generally used in this construction method - groups of stud shear connectors - tend to slow down the erection procedure. New connections by adherence, whose resistance is due to friction between various interfaces, constitute a very promising and innovative solution to this question. The paper presents experimental and analytical research conducted on these connections. Results show that these connections exhibit a high resistance to shear forces and are very rigid, but have a limited ductility. A calculation model is developed which takes into account the kinematics of the connection deformation and the behaviour laws for the various interfaces. A simplified method for determining the resistance of these connections is also proposed.
Lateral torsional buckling of steel-concrete composite bridge I-girders
Authors: Davaine Laurence , Lebet Jean-Paul
Published: October 2011

I-girders of steel concrete composite bridges should be verified against Lateral Torsional Buckling (LTB) under traffic loads next to the intermediate supports. This paper introduces to the different methods of Eurocode 3 part 2 (steel bridges) to verify LTB and applies them to an example of typical twin-girder bridge. It shows that Eurocode 3 is very severe in comparison to the previous European National Standards and in comparison to a second order linear elastic analysis. The main reason of this conservative aspect is the use of the European buckling curve d.
The Durability of Repaired Concrete Structures
Authors: Tilly Graham
Published: October 2011

This paper addresses the performances of concrete repairs in practice as opposed to accelerated laboratory testing. The performances were assessed through case-histories obtained from European countries ranging from Finland in the north to Greece in the south. Some 230 case-histories were obtained for structures up to 150 years old. Corrosion was the most common mode of deterioration occurring in 55 per cent of the cases, other modes included frost damage, cracking and AAR. Types of repair included patching, sprayed concrete, crack injection and restoration of strength. Performances of the repairs were generally disappointing; 20 per cent failed in 5 years, 55 per cent failed in 10 years and 90 per cent failed in 25 years. The longest repair life was 52 years. The types and causes of the failures are discussed.
Methodology for Inspection of Reinforced Concrete Subway Tunnel
Authors: Yanez Fernando , Delfin Federico , Aguila Victor , Torrens Vladimir , Lopez Ignacio
Published: October 2011

A complete evaluation of 30 years old underground railway tunnel was made. The reinforced concrete tunnel, 12 km long, 6 m high and 10 m wide, was built in a open cut of about 10 m depth on the gravel soil of Santiago of Chile.

To asses the actual condition of the tunnel, an especial methodology was developed which is the object of this paper. It includes a complete mapping of defects like cracks, efflorescence, corrosion and others. Two kind of index were designed: general indexes related to total amount of defects per unit of length, and particular indexes related to magnitude or intensity of the defect per unit of length.

The methodology was very effective and its results indicated that cracks and filtrations correlated well with structural typology; efflorescence correlated with gardens on top of the tunnel; and corrosion correlated with ventilations ducts, where water may flow down directly.
Indigenous and Signature Cable-Stayed Bridges – Attitudes Towards Improvement of Infrastructure
Authors: Schlaich Mike
Published: October 2011

Designing a bridge so that the local context is taken into consideration allows for indigenous construction, i.e. employing local methods, materials and labour. Several cable-stayed bridges are described to exemplify that design based on local context may lead to a large variety of structural solutions. Following such principles the present trend towards signature bridges frequently requested by clients can be used to improve our infrastructure with elegant and economic bridges.

(This paper is an extended version of article presented at the cenem conference at the Bengal University of Science and Technology in Kolkata, India in January 2007.)
A new concept for a large vertical lift bridge over the river Seine in Rouen
Authors: Moussard Michel
Published: October 2011

A large new lift bridge is being completed over the River Seine, half way between the City of Rouen and its harbour located downstream.

To fit with this environment engineers and architects have designed an innovative structure, which combines efficiency, reliability and elegance.

Its masterpiece is the lifting system, located in between the two independent lifting spans. It features two reinforced concrete hollow shafts supporting an innovative and ingenious butterfly–shaped, crossleverage system, which optimizes both structural and mechanical designs.
Strength and Ductility of Welded High Strength Steel (HSS) Connections in Bridges
Authors: Günther Hans-Peter , Rasche Christina , Kuhlmann Ulrike
Published: October 2011

High strength steels are more and more used in structural applications such as bridges or high-rise buildings. By increasing the strength of the steel the loads which have to be transferred in the welded connections increase in the same way. As high strength steels in general have a lower deformation capacity it is especially of importance for the connections to ensure beside the strength also sufficient ductility. This paper presents first results of a research project analysing the strength and ductility of welded high strength steel connections. Existing design rules according to Eurocode 3 are introduced and discussed showing that these rules are in many ways inadequate for high strength steel connections as they give e.g. very thick welds. First results of static strength tests on fillet welded connections together with numerical simulations are presented.
Steel-concrete composite bridges subjected to fatigue loading
Authors: Porsch Markus , Üstündag Cenk , Hanswille Gerhard
Published: October 2011

In current national and international standards of composite structures of steel and concrete the determination of the ultimate load capacity and the fatigue life of headed shear studs takes place with separate and independent verifications at the ultimate limit state, serviceability limit state and fatigue limit state. The effect of pre-damage due to fatigue loading is not considered. This paper deals with the results of a comprehensive program of experimental work with more than 90 standard EC4-push-out test specimens and two full scale-beam tests which consider the crack propagation through the stud foot and the local damage of concrete surrounding the studs as relevant consequences of high cycle loading. Based on the results of the push-out tests, new design methods were developed to predict the fatigue life and the residual strength of headed shear studs after high cycle loading. Considering the interaction between the local damage and the behaviour of the global structure, these research results were taken as the basis to simulate the cyclic behaviour of composite beams.
Development of a structural system for short span bridges
Authors: Sternberg Anja , Sigrist Viktor
Published: October 2011

In the present contribution the development of an innovative structural system for short span roadbridges is presented. In particular, the use of prestressed concrete tension ties is shown to offer new possibilities for the conception and design of bridge structures. Aesthetics as well as structural efficiency are discussed. Transparency and structural simplicity are characteristics that contribute to a clear appearance. The reduction of dead load while maintaining sufficient stiffness is a general optimization task in structural engineering; it is shown that by choosing suitable dimensions and materials and an appropriate level of prestress convincing solutions can be achieved.
Rehabilitation and Simulation of Movable Bridge
Authors: Liu Xue , Chen Weizhen , Yang Guang
Published: October 2011

Jiefang Bridge, the only rolling lift bascule bridge existing in China, was built in 1927. This paper presents the research of the rehabilitation design as well as the rolling operation restoration of this movable bridge. After structure inspection and evaluation, it is determined to begin with that numbers of severely corroded members must be replaced, the deck system retrofitted, and the rolling function restored in order to remain the original appearance of the bridge. Then, in order to accurately assess the mechanical performance of movable bridge, the kinematical simulation of the bascule span, during operation under multiple loading conditions and combinations including vehicle load, wind load, and inertial force is carefully studied based on a 3-D FE model. As the result of the research, the rehabilitation design is optimized, counterweight improved, and operation velocity and acceleration proposed. Presently, the rehabilitation of Jiefang Bridge has been finished and rolling operation successfully restored. Subsequent field testing and monitoring have proved that the theoretical analysis of the bridge is valid.
Structural steel maintenance and rehabilitation methods of current Canadian infrastructure
Authors: Stiemer Siegfried F.
Published: October 2011

Engineers choose steel based on its durability, ease of maintenance, proven lifecycle performance and versatility in highways and infrastructure applications. This paper will report on various types and sizes of public infrastructure in Canada with an emphasis on bridges. The focus will be on the maintenance and rehabilitation of steel bridges. Public infrastructure in Canada that has undergone maintenance and rehabilitation will be identified. Projects include the Lion’s Gate Bridge in Vancouver, BC, and the MacKay and MacDonald Bridges in Halifax, Nova Scotia. Canadian Public Works departments and others in charge of handling maintenance have been the major source of information in this investigation. Also included in the scope of this paper is how infrastructure is assessed in terms of the extent to which maintenance is needed.

Maintenance can take either the form of preventive or reactive maintenance. Preventive maintenance practices are proactive actions, such as inspections and servicing. Reactive maintenance takes place after damage has occurred to repair or replace deteriorated components. Regular maintenance includes yearly activities such as cleaning out expansion joints in bridges, patching holes in the asphalt and clearing curbs of sand and salt accumulated from winter ice and snow control. The paper will give a comprehensive overview of the state-of-the-art methods and practice of maintenance and rehabilitation for bridges in Canada.
Using SPS technology to strengthen an orthotropic bridge deck
Authors: Marzahn Gero A. , Hamme Markus
Published: October 2011

Despite their magnificent load-carrying properties, some orthotropic steel plates in steel bridge decks are showing signs of reduced fatigue resistance. This has led to much costly repair and maintenance work that in turn restricts traffic flow, an issue of particular concern within the heavily occupied German highway system.

Drawing upon the experience of the ship-building industry, which has encountered the same problem of fatigue-induced damage with roll-on/roll-off ferries, the viability of transferring Sandwich-Plate-System (SPS) technology to steel road bridges was considered. On behalf of the German Federal Ministry of Transportation, the Northrhine-Westfalia Department of Transportation and the state-owned company Strassen.NRW decided, therefore, to undergo a pilot project aimed at a permanent reconstruction and rehabilitation of orthotropic steel deck plates in a road bridge for the first time [1]. This paper reports on the reasons for such rehabilitation measures and the fundamental design issues of the project, and illustrates the repair work that has been done.
External Post-Tensioning Retrofit and High- and Low-Cycle Fatigue Study of
Connections and Joints in Steel-Concrete Box-Girder Bridges
Authors: Bursi Oreste S. , Mammino Armando , Forte Manuel , Tondini Nicola , Tonon Enrico
Published: October 2011

This paper reports the study of a viaduct retrofit by means of external post-tensioning. The structure is a steel-concrete box-girder bridge and the retrofit has been necessary mainly owing to an advanced corrosion state which has affected the structural steel of the boxes. During the design two solutions have been conceived: i) cables with a parabolic development; ii) cables with a rectilinear development. The advantages and the drawbacks of these solutions designed by S.I.GE.S s.a.s. are here presented. In parallel with this problem, an on going study is being carried out on the: i) dynamic regime in order to identify the sensitive details; ii) validation of the Finite Element (FE) model by means of output-only ambient vibration tests; iii) optimization and physical testing of the critical details. This study is devoted to improve both the high- and low-cycle fatigue strength in steel-concrete box-girder bridges and the results achieved so far are here reported.
Replacing US railroad bridges within hours, a.k.a Change Outs "Railroad Bridge Change-outs"
Authors: Moreu Fernando
Published: October 2011

This paper describes the replacement and upgrading of railroad bridges in the US, through specific “change-outs” case examples, identifying the different factors which make them the keystone of railroad bridge maintenance, repair and replacement nowadays. It also covers advancements in the railroad industry related to railroad bridge upgrades which minimize railroad traffic interruptions. Finally, it identifies potential areas of development and expansion from these lessons learned on railroad engineering which might be useful for other structural engineers involved with infrastructure design, construction and maintenance.
Canal bridge Magdeburg – Studies, draft, construction and enterprise
Authors: Mündecke Michael , Ruszczynski C. , Stratmann H.
Published: October 2011

The transfer of the canalMittellandkanalacross the river Elbe was the core of project 17 in the course of the transport project Deutsche Einheit (Reunification).

The structure consists of two parts: the foreshore bridge with two eight-field continuous beams and the main bridge with one three-field continuous beam. The total length is 918 m with a maximum span of 106 m and a total weight of 24 900 t of steel. The shipping trough is 34 m wide and the overall height of the superstructure is 8.15 m.

The solution of a waterway junction had to compete with the idea of a barrage in the river Elbe but was selected because of economical reasons and a minor intervention in the area of unspoiled nature.
Design and Construction Innovations for the Puente Centenario, Panamá
Authors: Manzanarez Rafael , Sanjines Alex , Donikian Roupen , Humpf Karl
Published: October 2011

The Puente Centenario over the Panama Canal, named to commemorate 100 years of Panamanian independence, includes the longest mainspan for a concrete cable-stayed bridge in the Western Hemisphere. With the completion of the approach routes, the 420m mainspan bridge was opened to traffic in September 2005. The entire crossing measures 1050m between abutments and traverses the canal east-west and forms part of a new bypass highway connecting the northwestern part of Panama City with the Panamerican Highway. The alignment crosses the canal at its narrowest point, north of the Pedro Miguel Locks, near the town of Paraíso. The project required design and construction innovations to satisfy the strict project criteria within the context of the existing geology, seismic hazard, limited material availability, canal security, complex logistics and optimized construction methods.
Large composite bridges with strutted frame systems - the Lockwitztal Bridge and the Haseltal Bridge
Authors: Reintjes Karl-Heinz
Published: October 2011

The two bridges discussed have similar longitudinal structure systems and were built by similar construction methods. With respect to cross section and also in certain other respects, different solutions were adopted. The Lockwitztal Bridge and the Haseltal Bridge are both steel-concrete composite bridges. The superstructure is supported in the large central spans by struts that, together with the superstructure and the piers, form a frame system. The steel construction of the superstructure has a constant depth and was built by launching with the use of auxiliary piers. The piers and the struts were built and connected with the superstructure before the casting of the deck slab. This construction method economically combines the launching of steel girders, the support of the superstructure by inclined struts in the main spans, the easy erection of the struts by using the launched superstructure and, furthermore, favorably exploits the fact that most of the load results from the concrete deck slab.The characteristics of the two structures are discussed. The similarities and the differences of the structural elements and the construction methods are shown, and the structure efficiency is evaluated.