Abstract: This paper focuses on the drag characteristics of optimally span-loaded planar, wingletted, and C wings. The span load is optimized resulting in minimum induced or total drag. The wing-root bending moment is kept constant for all analyzed wings to ascertain that different wings have comparable weight. The optimum span loadings for the different types of wing are calculated using a fast and simple numerical method. The wings are analyzed in the Trefftz plane, infinitely far behind the wing. Lagrange multipliers are used to calculate the optimum span loading resulting in minimum induced or total drag, with the wing-root bending moment and/or the lift coefficient as constraint. The induced drag can be calculated using the optimum span loading. The profile drag is assumed to be a function of the local lift coefficient. The results indicate that the C wing does not have real aerodynamic performance advantages compared to a wingletted wing. For wings with span and/or aspect ratio constraints, a winglet offers a drag reduction relative to a planar wing.

Abstract: Ground level electric and magnetic fields from overhead power transmission lines are of increasingly important considerations in several research areas. Common methods for the calculation of the magnetic fields created by power transmission lines assume straight horizontal lines parallel to a flat ground and parallel with each other. The influence of the sag due to the line weight is neglected or modeled by introducing an effective height for the horizontal line in between the maximum and minimum heights of the line. Also, the influences of the different heights of the towers, the different distances of the power transmission lines' spans, and the different angles between the power transmission lines' spans are neglected. These assumptions result in a model where magnetic fields are distorted from those produced in reality. This paper presents a complete technique, with the effect of the conductor sag is taken in the account, to calculate the magnetic-field intensity at any field point above or near the earth's surface, from any numbers of spans of various configurations; namely, unequal heights of the towers, unequal spans between towers, and the power transmission lines' spans are not parallel to each other. This complete technique is applied on the Egyptian 500-kV single-circuit overhead transmission line, and the investigations of the number of spans, the angle between spans, the span length, and the heights of the towers are discussed and compared with the results obtained from the common two-dimensions straight-line technique.

Abstract: A large and highly twisted turbine blade for an IGT having a lower span serpentine flow cooling circuit and an upper span serpentine flow cooling circuit connected in series to provide low flow cooling for the blade. The lower span serpentine is a forward flowing 5-pass serpentine, while the upper span is an aft flowing 3-pass serpentine circuit. The last leg of the lower span serpentine and the first leg of the upper span serpentine are both aligned along the leading edge region to provide cooling there. The trailing edge includes lower span exit cooling holes and upper span exit cooling holes in which the lower span exit holes are connected to the first leg of the lower span serpentine and the upper span exit holes are connected to the last leg of the upper span serpentine. All of the cooling air from the lower span serpentine circuit that does not flow out the lower span exit holes flows into the upper span serpentine circuit to provide low flow cooling with the lower span cooled before the upper span.

Abstract: Long span soil-steel composite bridges, which are generally assembled from corrugated flexible plates and surrounded by compacted granular soil material started to become more frequent in highway and railway networks. They provide quick and more economical solutions compared to traditional bridges. The performance of soil-steel strucutures is governed by soil-structure interaction. The flexible steel part of the structure acquires part of its rigidity from the confining backfill soil. In the past, the design calculations were kept empirical because of the limited usage of soil-steel structures. Today there is a need for deeper understanding the soil-structure interactive behaviour and review of the available design procedures. This thesis presents the evaluation of several soil-steel composite bridges made of deep corrugated steel plates by in-situ measurements. The full-scale field tests comprised measurements during backfilling, under service and ultimate loads. One of the tested structures was an 11 m span single radius arch a railway bridge. The other 4 structures were box culverts with spans of 8 and 14 meters. Two of these four box culverts were reinforced by rib plates at the crown arch. The actual dynamic response of the railway bridge is studied during passages of a locomotive at different speeds. Service response and the ultimate bearing capactities of the structures were studied under different cover depths with a truck load, block weights and a hydraulic jack. Some of the measured results were compared with the theoretical design values. It was also possible to compare part of the results with results from a finite element model developed as a part of a master thesis using Plaxis, under supervision of the author. The field tests showed the effect of the depth of soil cover and soil confinement in the performance of soil-steel bridges. Under live loads, the structures became more vulnerable to applied loads as the soil cover decreased. The difference in moments and thrusts were 4 to 4.5 times when the depth of cover increased 3 times in structure with 8 m span. The moment and thrust ratios were higher for the structure with 14 m span. It was observed that the load bearing capacity increased linearly with increasing depth of cover. Finite element analysis results were conservative when live loading was concerned but the crown displacements and thrusts during backfilling were underestimated. Application of crown stiffening was more effective under shallow soil covers. The maximum crown displacement was reduced to half and the ultimate load capacity was doubled at the depth of cover of 45 cm by using crown stiffeners. Dynamic amplification factor, DAF, values as high as 1.45 were obtained for the moments at the quarter points and 1.25 for the crown displacements. The braking of the locomotive was found to increase dynamic displacements by 5% at the crown. DAF values were quite high compared to the values given in Eurocode and the Swedish bridge design code BV Bro. A revision in BV Bro’s method of the dynamic factor is suggested. The two measurements campaigns done on the 11 m long-span arch railway bridge, which were seven months apart (including the first winter), indicated that the structure has become more flexible in time. The Swedish design model calculates the thrusts due to backfilling with a safety margin of 2 for the arch cluvert bridge. The moments in the structures due to dead loads were found to be sufficiently predicted by the Swedish design method. The moments from the Canadian code, were conservative at zero depth of cover and then did not sufficiently increase with increasing soil cover. The design live load thrusts in the arch structrue calculated according to BV Bro loads was 50% higher than maximum thrust due to locomotive loading. If the real axle loads were used in the calculation the safety margin dropped to 1.25. The live load thrusts in the box culvert, however, were underestimated by the Swedish and Canadian bridge codes. Comparisons showed that the measured ultimate loads were considerably larger than what the design methods provide. The Canadian method, which is only applicable up to spans of 8 meters, was less conservative if the soil stiffness is high.

Abstract: Komurhan Highway Bridge is a reinforced concrete box girder bridge located on the 51st km of Elazig–Malatya Highway over the Firat River. Because of the fact that the Komurhan Bridge is the only bridge in this part of Firat, it has major logistical importance. So, this paper aims to determine dynamic characteristics such as natural frequencies, mode shapes, and damping ratios of the bridge using experimental measurements and finite-element analyses to evaluate current behavior. The experimental measurements are carried out by ambient vibration tests under traffic loads. Due to the expansion joint in the middle of the bridge, special measurement points are selected and experimental test setups are constituted. Vibration data are gathered from the both box girder and bridge deck. Measurement time, frequency span, and effective mode number are determined by considering similar studies and literature. The peak picking method in the frequency domain is used for the output-only modal identification. An analytic...

Abstract: Results of a recent bridge inventory evaluation indicated that about 50% of Turkish highway bridges have more than 30° of skew angle and can be classified as irregular bridges. During the recent major earthquake in Turkey, multisimple-span bridges with continuous decks and link slabs performed well even though these bridges were in the vicinity of the fault line. This study aims to evaluate the improvements in seismic response of skew bridges in terms of forces and displacements when link slabs are added as a retrofit tool. A series of elastic dynamic analyses and nonlinear time history analyses were conducted to investigate the seismic response of various standard highway bridges with different span lengths and skew angles. A new reinforcement design for edge zones of link slabs is proposed for bridges located in high seismic zones. In practice, link slabs can be implemented easily during a regular redecking of a bridge.

Abstract: In this paper the non-linear closed-form static computational model of the pre-stressed suspended biconvex and biconcave cable trusses with unmovable, movable, or elastic yielding supports subjected to vertical distributed load applied over the entire span and over a part (over the half) of the span is presented. The paper is an extension of the previously published work of authors [S. Kmet, Z. Kokorudova, Non-linear analytical solution for cable trusses, Journal of Engineering Mechanics ASCE 132 (1) (2006) 119–123]. Irvine's linearized forms of the deflection and the cable equations are modified because the effects of the non-linear truss behaviour needed to be incorporated in them. The concrete forms of the system of two non-linear cubic cable equations due to the load type are derived and presented. From a solution of a non-linear vertical equilibrium equation for a loaded cable truss, the additional vertical deflection is determined. The computational analytical model serves to determine the response, i.e. horizontal components of cable forces and deflection of the geometrically non-linear biconvex or biconcave cable truss to the applied loading, considering effects of elastic deformations, temperature changes and elastic supports. The application of the derived non-linear analytical model is illustrated by numerical examples. Resulting responses of the symmetric and asymmetric cable trusses with various geometries (shallow and deep profiles) obtained by the present non-linear closed-form solution are compared with those obtained by Irvine's linear solution and those by the non-linear finite element method. The conditions for the use of the linear and non-linear approach are briefly specified.

Abstract: The invention discloses a long continuous steel box girder or combined box girder construction method, including the following steps: 1, segment division and plate unit division; 2, butt welding the fulcrum segmental box girders and standard segmental box girders at a prefabrication plant, namely, pre-splicing the segmental box girders of a full span box girder and the first box girder segment of the adjacent span box girder through long line method on a segmental box girder moulding bed on which plane curves and pre-camber are arranged; marking the box girder segments, taking away the segmental box girders of the full span box girder, leaving the first box girder segment of the adjacent span box girder, and continuing to splice and weld the segmental box girders of the rest full span box girders; 3, generally assembling the full span box girders in the prefabrication plant. The invention adopts full span prefabrication and arrangement to construct a long continuous steel box girder or combined box girder, thus greatly reducing welding work load at the site. The invention ensures that the adjacent spans close smoothly after the steel girders are arranged and meets the requirements of light large span, precast assemblage and quick construction.

Abstract: There are a number of bridges which are designed according to codes without seismic provisions being considered. Such bridges are mostly found deficient and may need seismic retrofitting. Bridges that were built before the 1970s, either in the USA or Japan or Europe, were designed with little or no consideration for seismic demands. The majority of these bridges are supported on reinforced concrete bents at the abutments and pier walls that lack the ductility and strength to resist earthquakes. Besides most of these bridges have short spans (6–18 m) to medium spans (18–90 m). A bridge with a short span may be built with timber girders or with a concrete slab superstructure, whereas a bridge with a medium span is often built with steel girders, precast concrete girders, or cast-in-place box girders. Bridges in general consist of two structural components: a superstructure including the elements above the support and a substructure including the elements that sustain the superstructure.In this paper, the re...

Abstract: The invention discloses a visual examining device of cracks on railroad bridge surface, which mainly comprises of: an illuminating system which comprises an illuminating light source and a control circuit and used for illuminating on the front side of the bridge surface to be detected, a temperature control system which comprises a shield installed with optical glass, a heater and a fan and used for protecting a camera and a lens to work normally in an wild environment, a positioning system which is arranged on a wheel shaft of a bridge detecting vehicle and used for determining the defect position of the bridge, a data collecting and storing system which is arranged inside a control room of the rail-mounted bridge detecting vehicle, and an imaging system which comprises the camera and the lens and arranged inside the shield. The visual examining device of cracks on the railroad bridge surface runs in fixed working distance, can realize continuous high-speed detection, is applicable to the detection of railroad bridges especially to the detection of the elevated railroad bridges with large span and long distance distributed in the wild, and avoids the defects in the prior art that the artificial observation of the bridge surface to be detected which is carried out by the detecting personnel in the bridge detecting vehicle is easy to be influenced by subjective factors and weather factors, and other ground observation equipments are difficult to be mounted in the wild or under elevated bridges, and the like.

Abstract: COWI recently prepared design for three long span suspension bridges: Halogaland Bridge in Norway (Basic Design, 1,345m main span), Messina Bridge (Tender Design, 3,300m main span) and Yemen-Djibouti Bridge (Sketch Design, multi span suspension bridge with four spans of 2,700m each. Huge tonnages of steel are required for cables, bridge decks and pylons. Innovative solutions were developed for all three bridges to overcome the challenges of spanning up to 3,300m for com- bined road and rail traffic and designing bridges with lifetimes up to 200 years. Pro- found water depths of up to approx. 300m require long spans. Application of high strength steel makes it possible to create economical designs. Dead load plays an im- portant role in the design of huge suspension bridges and it is therefore of utmost im- portance to apply the optimum steel grade in order to minimize weight and reduce the construction costs. As an example 1 ton saved in the bridge deck for Messina Bridge results in 1.2 ton less cable steel and related savings in pylons and anchorages. The paper focuses on bridge concepts, the utilisation of S420 and S460 in the design of bridge decks and pylons, application of cable wire strengths up to 1,860MPa and ad- vanced corrosion protection systems for cables.

Abstract: Spans occur when a pipeline is laid on a rough undulating seabed or when upheaval buckling occurs due to constrained thermal expansion. This not only results in static and dynamic loads on the flowline at span sections, but also generates vortex induced vibration (VIV), which can lead to fatigue issues. The phenomenon, if not predicted and controlled properly, will negatively affect pipeline integrity, leading to expensive remediation and intervention work. Span analysis can be complicated by: long span lengths, a large number of spans caused by a rough seabed, and multi-span interactions. In addition, the complexity can be more onerous and challenging when soil uncertainty, concrete degradation and unknown residual lay tension are considered in the analysis. This paper describes the latest developments and a ‘state-of-the-art’ finite element analysis program that has been developed to simulate the span response of a flowline under complex boundary and loading conditions. Both VIV and direct wave loading are captured in the analysis and the results are sequentially used for the ultimate limit state (ULS) check and fatigue life calculation.

Abstract: The present paper describes experiments carried out on IREQ 1 laboratory cable test bench. Test span arrangement is a 63.15m cable span with termination ends designed so as to minimize energy dissipation. A shaker provides a vertical alternating force to the conductor. During the experiments, a maximum of information on mode shape is collected: location of nodes, antinode amplitude of vibration, relative displacement at 44.5, 89, and 178mm from the last point of contact with the metallic clamp. Several configurations are studied: span equipped with an homogeneous steel cable, span equipped with an ACSR Crow conductor, sometimes in combination with other equipments such as a vibration damper or a local mass, to investigate how the presence of such devices impacts conductor vibrations. It results from these experiments an interesting comparison of two widely used fatigue indicators, the relative displacement Yb 2 (also called “bending amplitude”) and fymax (the product of antinode amplitude of vibration by frequency). Also, collected data gives indirect information on conductor variable bending stiffness.

Abstract: The invention relates to a construction method, in particular to a method for installing super-large crane beams, solving the technical problems of the prior art in the installation of large-span and large-mass crane beams. The method for installing the super-large crane beams comprises the following steps: a temporary bracket is first put up on the ground at one third of the span of a crane beam installation position; a crane beam is assembled on site; a left-segment crane beam component and a middle-segment crane beam component which are welded together are integrally lifted in place by use of two cranes; the left-segment crane beam component is partially fixed with a steel column connecting part; the other end of the middle-segment crane beam component falls on the bracket; a right-segment crane beam component is lifted to the height in accordance with the middle-segment crane beam component by use of another crane; and the right-segment crane beam component and the middle-segment crane beam component are paired and welded in the air. The method is applicable to the installation of the crane beam of which the length is over 60 meters and the mass is over 220 tons. The method has the advantages of high safety performance, short construction period, convenient construction operation and good engineering quality.

Abstract: Ice removal device and controller thereof for power line relate to a ice removal device and controller thereof. The device prevents infection of the prior power line ice removal method on production and daily life, reduction of power line life and potential safety hazard. The power line ice removal device and controller thereof hanging the whole ice removal device on power line by three mechanical arms, knock down the ice layer adhered on the power line by mechanical arm installed at from, an object detecting sensor for detecting obstacles is installed at the front of the device, and controller can control the three mechanical arms to span the disorder as required. The controller of the utility model can be added a remote control function convenient for on-site operation, and is suitable for ice removal operation for power line in various environment. The power line ice removal device and controller thereof of the utility model can remove ice without breaking the power transmission, move conveniently, and are suitable for ice removal for power line in various areas.

Abstract: The utility model discloses the a support structure of an escalator or a moving pavement, comprising a large angle steel which is fixedly connected with the girder of the escalator or the moving pavement The large angle steel consists of a horizontal side wall and a vertical side wall A projecting part is connected to with the horizontal side wall of the large angle steel The bottom surface of the projecting part leans against a building and is not fixedly connected with the building The utility model has the following advantages: 1 the support structure can span across the dilatation joint on the building; 2 when an earthquake or other strong impacts happen, the support structure can have fine adjustment in the horizontal direction and the vertical direction to guarantee the safety and the stability of the escalator or the moving pavement

Abstract: A multi-span continuous bridge using a prestressed concrete girder and the construction method thereof are provided to balance the moment between the central part of a span and a continuous support and to reduce the girder height using structural efficiency for extending the cross section of a continuous support, thereby to reduce the amount of materials used such as concrete reinforcing bars, etc. and to improve economical efficiency, and to make a superstructure lightweight and to promote the size reduction of a substructure. A multi-span continuous bridge using a prestressed concrete(PSC) girder is formed by continuing a plurality prestressed concrete girders with a plurality of spans, wherein the PSC girder is composed of a single-sided board(12) having an end located in a continuous support to have the larger width than the width of a web, a through hole is formed in the single-sided board to penetrate when the ends of the adjacent PSC girders face with each other in the bridge axis direction, a cross beam is installed between the PSC girders in the perpendicular direction to the bridge axis in the middle of the span and the continuous support while the PSC girder is placed between the support, the ends of the adjacent PSC girders are connected to each other by inserting a steel bar to the through hole formed on the ends of the adjacent PSC girders and anchoring at the continuous support, and an end cross beam is installed to the outer end of the PSC girders adjoining each other in the perpendicular direction to the bridge axis, and concrete is placed to make the end cross beam buried, thereby to form a bridge deck.

Abstract: The invention relates to a fastening method of a T-shaped beam bridge. The T- shaped beam bridge comprises a plurality of T-shaped beams with the sections being T-shaped; the T-shaped beams comprise a wing plate positioned in a horizontal part and a ventral shield positioned in a vertical part; the fastening method comprises the following steps: reinforcing steel bars are embedded between the ventral shields of the adjacent T- shaped beams and concrete is poured thereinto so that the at least one concrete cross beam along the T-shaped beam span direction is arranged between the ventral shields of the adjacent T- shaped beams. The fastening method of the T-shaped beam bridge solves the problems existing in the prior art fastening the hinge T- shaped beam that the articulation connection is lacking; the jointing position of the articulation seam is easy to weaken and even fails; the whole rigidity of the bridge is not high.

Abstract: The invention discloses a machinery-driven foldable trestle bridge, which mainly comprises a base, a platform wagon, a walking mechanism, a portal support, a rotating mechanism, a winch, a hydraulic system, an electrical system and the like, wherein the hydraulic system and the electrical system form a trestle bridge control system. The bridge span is foldable, and can consist of two, three or four segments; a hydraulic turnover mechanism is arranged among the bridge segments; and when the bridge is used, the hydraulic turnover mechanism unfolds or folds the bridge span. The foldable machinery-driven trestle bridge has the advantages of small occupied area, low labor intensity, convenient operation, quick bridging and folding, and the like.

Abstract: Structural identification (St-Id) offers wide ranging benefits to infrastructure owners by providing insight into the safety and performance of their bridges. St-Id generally refers to the construction of field calibrated models of a structural system by correlating simulated and measured responses. The Drexel Intelligent Infrastructure Institute (DI3) has applied St-Id to numerous bridges over the past decade. These applications have ranged from long span (arch, suspension, and truss) landmark bridges to undocumented short span reinforced concrete slab, t-beam, and arch bridges. Through these experiences, DI3 researchers have gained an appreciation of the benefits of St-Id related to decision-making, and the distinctions between applications to short and long span bridges. The application of any St-Id begins with the formulation of a specific objective that will drive the study along with the structure type, which may limit the experimental and analytical tools to be employed. St-Id, founded in the model of the scientific method, is applicable to a wide range of structures and can inform a range of objectives. Every bridge/owner combination presents a unique situation which will have its own characteristics, requirements and deliverables. There are several other factors that can affect the feasibility and reliability of any St-Id, and these include: (a) relevant responses used to assess safety and performance, (b) owner motivation and resources, (c) impact of structural and population scales, and (d) reliability of results and owner expectations. The objective of this paper is to highlight how a St-Id is defined by the constraints set forth through the owner, structural type (long or short span), and expected life of the structure, and how these constraints delineate what type of modeling, experimental methods and potential outcomes that are applicable. This comparison will be presented an illustrated through a discussion of two St-Id case studies: a concrete arch bridge and a long span truss bridge.

Abstract: The invention discloses a method for processing a main cable saddle of a suspension bridge. A side span (1) and a midspan (2) of the main cable saddle are respectively processed, then a bolt (3) is used to connect the side span and the midspan, and a joint surface of the side span (1) and the midspan (2) is provided with a positioning pin hole (6). The method guarantees the consistency of the size of a rope groove after the side span (1) and the midspan (2) are butted, has no alternate edges, high butting accuracy and small error, unifies processing reference, has low requirement on processing equipment, is more convenient for clamping and calibration of workpieces, is easy to guarantee processing accuracy, and improves processing efficiency.

Abstract: A method for spans launched, as self-supporting bridge beams, approximately horizontally from support structure to successive support structure without significant temporary false work or scaffolding between permanent support structures. Bridge spans assembled atop previously constructed roadbed are launched individually onto supporting structures or columns spaced at span widths beyond said roadbed. 3 individual spans are placed or assembled with a longitudinal girder into a unit atop the roadbed surface, the assembly becoming a launching truss. Load moving air cushion pallets are placed upon the roadbed beneath and before the 3 spans. The launching truss moves forward one span length beyond the roadbed end placing one span and assembled girder in cantilever. That span is disconnected from the truss and emplaced upon supporting structures, at eventual roadbed level, beyond the previously constructed roadbed. Repeated, the process completes the bridge.

Abstract: A tapered cross section U-type support girder beam of the temporary bridge is provided that the construction cost can be cut down since the steel amount can be minimized and the span can be lengthened. A tapered cross section U-type support girder beam of the temporary bridge comprises a pair of cover plate(11) connected to a pair of central part I-beam girders, a tapered cross section web plate(12) in which one of more fixing plates(124) are equipped, and which fixes a cross beam(30), and a bottom plate(13) in which an incline(131) and a bottom part are equipped. The tapered cross section web plate move span central part moment to the support since the cross section of tapered cross section web plate is larger than the cross section in the web of central part I-beam girders. The bottom part of the bottom plate is fixed to the upper end of the support bent.