bluuebunny/crossref_metadata_2025_split huggingface dataset:
16.10: Challenges with water ingress in bridge cable systems
Authors: Jensen Jakob Laigaard , Lambertsen Jens , Zinck Morten , Stefansson Einar 
Published: September 2017

ABSTRACTExperiences over the last 20 years with operation and maintenance of cable borne bridges of various ages shows that water ingress in steel cable systems often occurs and causes a large risk of serious corrosion with may lead to restriction in traffic, extra ordinary inspection and maintenance costs and in worst case bridge closure. Examples of such experiences cover suspension bridges as well as cable stay bridges in USA, UK, Germany, France, Argentina, Sweden, Norway, Denmark and many other countries. The problem with water ingress is particularly critical as inspections for corrosion in cable systems are difficult to carry out and early warnings difficult to obtain.Water ingress into a cable system means that there is a significant risk of steel corrosion even with precautions by use of galvanization and HDPE coating of cable wires. Although, cable system designs generally comprise multiple barriers against corrosion, there is often a weak link in the design. This combined with an unintended outcome in the construction phase or inadequate maintenance, may allow water to start accumulating and lead to corrosion.This paper will explain and discuss cases from main cable and cable stay systems and point out the water ingress modes and their causes for main cable systems and different cable stays systems. Based hereupon, the paper discusses the weaknesses of the different steel cable concepts and different mitigations. The discussion also includes the mitigation of the water ingress problem by use of dehumidification. For main cables of suspension bridges, the concept has been in operation for more than 15 years with success. Considering the number of known problems with water in cable stays, the paper also contemplates on the possibility of using dehumidification for cable stay bridges as a way of handling the large amount of existing cable stay bridges.
16.11: Experimental tests on the fatigue behaviour of thick‐plate trough railway bridges
Authors: Breunig Stephanie , Kuhlmann Ulrike 
Published: September 2017

ABSTRACTOne of the basic aspect of sustainability assessment for bridges is the durability namely the fatigue resistance, because bridges are planned for very long lives of more than 100 years and suffer from high cyclic loading which may restrict lifetime of the bridge by fatigue failure. Nowadays final decisions on tenders are usually based on production costs and not on lifetime costs where a high performance in view of durability may pay off.Within a German FOSTA‐AiF‐research project an evaluation method for a life‐cycle assessment on railway bridges was developed and then applied on three different bridge types, exemplified by real reference bridges. For short spans, as an innovative bridge type, thick‐plate trough bridges were investigated because benefits in terms of sustainability were assumed due to the reduced construction time, simplified fabrication as well as prolonged durability through post‐weld treatment. Especially for the thick‐plate trough bridge, which was compared to different variants and an innovative composite bridge solution the sustainability assessment revealed high potential.This paper gives an overview on the fatigue investigations on thick‐plate trough bridges in the frame of this research project also in view of the weld improvement through Pneumatic Impact Treatment (PIT). Aims of these investigations were the improvement of single construction details and the characterization of the load‐bearing behaviour in order to identify the most critical fatigue detail for the fatigue assessment of these small span bridges with the help of experimental investigations and analytical methods.
16.17: N‐M‐Q interaction of cross sections in steel‐concrete double composite girder bridges
Authors: Nishioka Bungo , Imagawa Yusuke , Ohyama Osamu 
Published: September 2017

ABSTRACTRecently, a double composite structure is watched in Japan. This is a structure of composite I girder bridges with lower concrete slab which is one of the major characteristics of double composite structures. That can be considered as an effective cross section, that is, moments of inertia drastically increases in comparison with usual one. Additionally, by adopting the composite action between steel girder and lower concrete slab in the region of the intermediate supports, it is not necessary to take into account of the local buckling. Moreover, the hybrid rigid frame bridge between steel girder and reinforced concrete(RC) pier has some advantages for the seismic design and also maintenance. However, this type of structures hasn't yet been researched so well in Japan. Before applying the limit state design method, for designing this structure, under the action of normal force(N), shear force(Q), bending moment(M) and each combination should be confirmed at which all cross section is in full plastic. So, in this paper, the interaction relationships among bending moment and shear force, normal force and bending moment and normal force, shear force and bending moment are discussed are reported. One of numerical results in case of applying N‐M‐Q is shown that the safety area regarding a verification of the ratio of Q/Qpℓ= 0.7 and Q/Qpℓ= 0.9 decrease about 11% and 24% compared with that of Q/Qpℓ= 0.0, respectively.
16.27: Fabrication activities and quality aspects of the Third Bosphorus Bridge orthotropic steel deck
Authors: Molinaro Carmine , Sorge Roberto , Fiscina Gennaro 
Published: September 2017

ABSTRACTThe Third Bosphorus Bridge is the link of two continents, Asia and Europe, joining the two sides of Istanbul, Turkey. With its “hybrid” cable‐stayed/suspended configuration, its 322m A‐shaped towers and its Orthotropic Steel Deck, the widest (59m, 8 lanes of motorway and 2 lanes of railway) and heaviest in the world (each of the 59 segments weighting about 850 Ton, over 50000 Tons total), this is not a common bridge. And, as a consequence, not common are the technical requirements, the reference Norms and Standards and the problems and challenges encountered and tackled during its construction. This statement has proved to be particularly true with regard to the Orthotropic Steel Deck for two reasons: a) the complexity of the fabrication operations, given the difficulty of the Design and the unusual dimensions and weights involved; b) the exceptionally high quality levels to be met in terms of dimension control, surface preparation and welded joints in particular, arising from the adoption of the UNI EN 1090–2 Execution Class EXC4, requiring the EN ISO 5817 level B and the additional quality requirements specified for quality level B+.This paper aims to describe the whole process of the Steel Deck fabrication. Raw material procurement and preparation activities are discussed. Prefabrication activities, showing how each 850 Tons segment is broken up into components to satisfy handling and assembling needs are analysed. The automated and manual welding procedures developed to meet quality and productivity requirements are described. Final segment assembly and coating activities are shown. Last but not least, the QA/QC System put in place is described, showing, where relevant, how the implications arising from UNI EN 1090–2 EXC4 come into play and how they are dealt with.
16.30: Safety evaluation of a large‐span double‐deck cable‐stayed steel bridge under fire
Authors: Liu Yushu , Lou Guobiao , Ju Xiaochen , Liu Xiaoguang 
Published: September 2017

ABSTRACTThis paper presents a detailed safety evaluation of a large‐span cable‐stayed steel bridge under fire, which is also the first large‐span double‐deck highway cable‐stayed steel bridge in China. This steel bridge is a crucial part of urban lifeline engineering and is close to an industrial park which might raise the probability of being damaged by oil tank trucks or hazardous chemical vehicles, especially when a truck traveling on the lower deck of the bridge catches fire, it will endanger the safety of major steel bridge components supporting the upper deck and steel trusses on two sides. So, it is very important to conduct the performance evaluation and design of this steel bridge under fire. In this paper, the dangerous fire scenarios are selected and fluid dynamic simulations are conducted and the temperatures of the air and steel components are obtained, based on the component temperatures, structural analysis and capacity checks are made to offer reasonable preventive measures and solutions to protect the bridge subjected to the fire loading. The methodology presented in this paper is an effective approach for fire performance evaluation of bridge structures and has the potential for applications to other types of bridge structures.
18.01: Effective Vibration Dampers: Mast, towers and chimneys
Authors: Christensen Rasmus Magdal , Nielsen Mogens Gunhard , Støttrup‐Andersen Ulrik 
Published: September 2017

ABSTRACTSlender steel structures such as mast and towers consisting of or supporting cylindrical elements or chimneys can be susceptible vortex shedding. Vortex Introduced Vibrations (VIV) can be induced for slender structures because a fluctuating across wind force is generated from vortices shed alternately from opposite side of the structure. Significant VIV occurs when the frequency of the vortex shedding is the same as the natural frequency of the structure. If the critical wind speed for VIV is often occurring for the structure and the vibration amplitudes caused by the VIV are critical with respect to fatigue it can result in failure of the structure. Here an effective method of damping the vibrations can be the installation of a Tuned Liquid Sloshing Damper (TLSD). This paper focuses on design of a TLSD and compares this to the tuned mass damper (TMD) solution.Compared to the fabrication and installation of a TMD it is much simpler to make a container and fill it with liquid. The container is often made as a square box or a cylinder that is easily mounted at the top of a mast, tower or chimney providing the most efficient damping of the critical vibration mode. Also with respect to maintenance the TLSD is preferred as it only requires that the liquid level is controlled whereas a TMD needs maintenance and possibly repair or even replacement of damper parts.The TLSD is designed by calculating the dimensions that will result in a mode shape of the sloshing liquid with a frequency close to the natural frequency of the structure that wish to be dampened. As the liquid moves in the container the sloshing energy of the water reduces the dynamic response of the structure subjected to VIV. Experiments have shown that the TLSD is rather broad‐banded in its efficiency and also that it is effective with sloshing liquid mass down to values below 1% of the effective mass of the mode that it is designed to dampen.Ramboll has experience with design of both types of dampers TMD and TLSD for broadcast masts and towers and for chimneys. Especially for a broadcast tower in Norway where a TMD has been replaced by a TLSD Ramboll has tested the efficiency of the TLSD for comparison with the replaced TMD. This paper will present these results and give an introduction to TSLD design.
18.05: Second‐order effects of cantilever concrete filled double skin tube (CFDST) transmission towers
Authors: Alhalaby Mahmoud , Wang Yong 
Published: September 2017

ABSTRACTConcrete Filled Double Skin Tubes (CFSDT) are an alternative to steel lattice transmission towers for supporting overhead transmission lines due to their many advantages including small footprint, fast construction, easy maintenance and elimination of large number of connections. CFDST transmission towers are tapered cantilever structure consisting of a CFDST pole and steel cross‐arms. Due to high slenderness, one key issue for static design of CFDST poles is the effect of second‐order bending (P‐Delta effect). A parametric study was conducted to investigate the second‐order effects exhibited by the CFDST transmission towers. The main parameters investigated include Horizontal to Vertical Load Ratio (HVLR) which reflects the range of environmental loads such as wind and ice, taper ratio (ratio of the bottom to the top outer diameter of the tower), and Hollow Section Ratio (HSR, ratio of the outer diameter of the inner steel tube to the inner diameter of the outer steel tube). The results of the numerical simulations indicate that the second‐order bending moments at failure of CFDST transmission towers are significant, magnifying the total bending moment by 20% or more of the first‐order bending moments. Based on the results of a parametric numerical investigation of second‐order effects of CFDST transmission tower under different conditions, this paper proposes a simplified analytical equation to estimate the second‐order bending moment.
21.10: Upgrading of a riveted railway bridge: Retrofitting of corroded plate girder steelwork
Authors: Hołowaty Janusz 
Published: September 2017

ABSTRACTThe long service of railway bridges results in natural ageing and degradation which weakens the structures if they are not maintained regularly. Poor funding and prolonged service without regular repair may result in severe corrosion damage and lower structural capacity. Older structures also feature some structural solutions which have made them prone to corrosion. However, prolonged service combined with no regular painting and a harsh environment are the major reasons for corrosion resulting in the loss of a section which should be repaired accordingly.Plate girder spans on a railway bridge were retrofitted when severe corrosion to the steelwork was discovered. The corrosion was more evident in the four oldest spans with the longest lifespan. The top flanges of the spans as well as bracing members and many rivet heads showed damage with different corrosion rates. The corrosion was uniform with local deep pitting. There was also crevice corrosion between the flange plates near the vertical stiffeners. The damaged flange plates were replaced with new thicker plates, along with the corroded bracing elements. Pretension bolts were used for the new connections. The spans were also upgraded and new cantilevers and centring shims were welded on the steelwork. Despite the corrosion losses, the plate girders were retrofitted, giving the bridge further decades of operation.
21.11: Asymmetrical cross sections in historic riveted bridges
Authors: Van Bogaert Philippe 
Published: September 2017

ABSTRACTThe assessment of the load‐carrying capacity of two steel bridges dating from 1907 and 1912, showed that most of the heavily loaded cross‐sections were asymmetrical. The bridges are of the two‐hinged portal frame type. Compared to simple beam bridges, portal frames with clamped or hinged supports allow redistribution of bending moments from the span centre towards the frame nodes. Consequently, the beam height at the span centre can be reduced, which is exactly what is needed for obtaining maximum vertical clearance of the subjacent waterway. Both bridges show heavy corrosion, some parts of the flanges and angle profiles of the end portals being seriously weakened. Full inventory has been made of the corrosion damage, as it appeared mostly in the edge frames of both structures. Reduction or suppressing of flanges has been introduced in the FE‐models of both bridges to assess the remaining load‐carrying capacity for real traffic loading.A particular characteristic are the asymmetrical cross‐sections of the main portal frames. Because of this, the compression and tensile stresses in both flanges are of unequal magnitude, favouring the latter. The reason for this became evident rather quickly. In tensile parts of the riveted structure, weakening of cross‐sections by holes has been taken into account, whereas it is not considered in compressed areas. Older standards and literature confirm the fact that this was allowed at the time riveted structures were still being built.As today little is known about riveting, it was felt that this needed further underpinning. Apart from the longitudinal effects, lateral shrinkage of rivets during placing and plastic deformation also exist within the holes. The plastic deformation in the hole introduces a high compression between the rivet and the hole edge. As the heated rivet is cooling down and before further shrinking of the rivet diameter, this pressure must be reversed. Hence, cooling does not reduce the rivet diameter entirely, a portion being used to decompress the connection. Approximations of the process have been worked out and showed that the final reduction of the rivet section is less than the tolerance for fitting bolts. Hence, the assumptions made in the past may be underpinned to a certain extent.This surely was resourceful during assessment of historic structures, requiring considerably more detailed numerical modelling than new structures, thus having better chances to preserve these valuable bridges for continuing use.
21.13: Experimental study on retrofitting method against fatigue cracking at the upper end of vertical stiffeners
Authors: Sakamoto Chihiro , Sakano Masahiro , Konishi Hideyuki , Koyama Masahiro 
Published: September 2017

ABSTRACTLots of fatigue crackings were reported at the upper end of vertical stiffeners connected to sway bracings in steel highway girder bridges. In this study, we propose two types of retrofitting methods against fatigue cracking at the upper end of vertical stiffeners under RC slab. They are steel plate reinforcement using a jack‐up jig, and angle steel reinforcement using thread rolling screw (TRS). The effectiveness of those two types of retrofitting methods are experimentally investigated through fatigue tests using a large specimen with three main girders under alternative loading using two actuators. As a result, both retrofitting methods can reduce the local stress concentration at the crack initiation point to about half of that before reinforcement, and can prevent fatigue cracking. Post cracking measure, i.e. angle steel reinforcement using TRS after grinding away crack tips can extend fatigue crack propagation life more than 10 times of that without the reinforcement.
21.14: Life cycle analysis of steel structures: Why the recycling potential must be considered
Authors: Hauke Bernhard , Kuhnhenne Markus , Kreissig Johannes 
Published: September 2017

ABSTRACTA clearly structured argumentation is presented why considering the recycling potential in life cycle analysis of steel structures is the correct choice. The both prevailing production routes of structural steel, electric arc furnace and blast furnace are looked at as well as end‐of‐life collection scenarios including re‐use or recycling rates. The value of structural steel is differentiated between material value and product value when a product, e.g. a steel beam is rolled out of the steel material. With this the fair evaluation is made based on cradle to gate versus considering additionally the end‐of life scenarios of recycling and reuse. Shortcomings and merits of the methods are pointed out.
22.01: Fire and seismic assessment of an existing steel‐concrete composite structure
Authors: de Silva Donatella , Nuzzo Iolanda , Bilotta Antonio , Losanno Daniele , Nigro Emidio , Serino Giorgio 
Published: September 2017

ABSTRACTAn existing steel‐concrete composite structure is analyzed in order to assess its level of protection against both fire and earthquakes. The building has been designed and built more than thirty years ago, implying that both these hazards may not be adequately verified with respect to the current codes. As concerns the fire protection, intumescent coating (IC) was applied on steel members, while an original passive energy dissipation system was employed against seismic actions. In particular, special devices were introduced to sustain the floors, which are suspended at reticular beams on the top of concrete pillars. A Fire Safety Engineering approach has been adopted to assess the structural resistance to fire. To define the thermal properties of the protective, experimental tests were carried out on the existing IC and a new IC. Moreover, thermomechanical analyses of the existing steel structure were carried out, under different fire scenarios, selected according to the fire risk of the different occupancy class of the structure. Non‐linearities and large displacements effects were taken into account. The seismic structural response has been investigated by implementing a dynamic nonlinear analysis according to the current Italian Code. In particular the seismic passive protection system, consisting in dissipative hysteretic devices combined with isolators, has been modelled as a parallel elastic and elasto‐plastic springs' system. Mechanical parameters adopted for the analyses are the result of a wide bibliography study.
22.02: The music square canopy: An outdoor stage for Amager Kulturpunkt
Authors: Aanhaanen Jaap 
Published: September 2017

ABSTRACTMusiktorvet, or “The Music Square” is the connecting element for a number of local cultural institutions, like music venues, a scenographic art institution, a children's theater and children's day care institutions. The music square is their collective outdoor stage, marked by a recently completed canopy.The canopy provides shelter and functional space, setting the stage for concerts, circus, markets, theatre, etc. Provisions are made to allow both spontaneous and planned events, for example by a number of fixed light setups for various stage positions, whilst fixing points are provided in the roof for the attachment of audio and lighting racks.The 500m2 canopy is formed by a grillage of welded steel box beams, supported by five slender columns, placed around the perimeter of the roof. The 70 tons roof was produced in 8 pieces which were assembled at the production facility, using the final bolted connections, before welding. This was done to ensure that all parts would fit perfectly together for the on‐site assembly. After the roof was assembled on the ground, the whole roof was lifted into place in one lifting operation.The top of the roof is covered with triangular ETFE foil cushions, whilst a ceiling of reflective, perforated aluminum panels allows a large amount of sunlight to penetrate the roof structure. A special feature of the canopy is the steel mesh curtains that can be drawn around the perimeter of the canopy to create a more sheltered space, to match the type of event taking place. The installation of the mesh curtains required a consideration of the various wind loading conditions for open, closed and semi‐closed conditions.This paper describes the design process and the chosen solutions with their argumentation, as well as the production and erection process.