Bowstring Arch Research Articles

Numerical and theoretical analysis of spatial shear lag effect in through wide box bowstring arch bridge main girder

The shear lag of the box girder section of a wide box bowstring arch bridge was investigated in this study. The finite element analysis software Midas Civil was used to discretize the bridge into separate entities, establish its spatial model, and analyze the law of shear lag effect in the longitudinal direction during the main construction stage and the completion stage separately. The shear lag effect is more prominent at certain key points due to the influence of the tension of the boom and the weight of the arch foot during the construction stage. After the bridge is completed, the axial pressure of the arch foot drives the shear lag effect near the midpoint of the main girder section to its maximum; the axial force is transmitted along the longitudinal bridge direction in a V shape along which it gradually decreases. Under the action of uniformly distributed load, the cross-section of the box girder near the middle fulcrum is affected by the axial force of the arch foot; there is both a positive and negative shear lag effect. Under the eccentric load, the positive and negative shear lag effects appear simultaneously at the end fulcrum. The shear lag coefficient is higher in the web on the eccentric load side than the non-load side. There is obvious and widely fluctuating positive/negative shear lag effect in the vicinity of the middle fulcrum. There is significant tensile stress on the roof under the action of the middle fulcrum. The cross-sectional stress of a single-box seven-cell box girder under compression-bending load action was analyzed according to the finite element analysis results. The stress was decomposed into a superposition of bending moment action and axial force action. The shear lag coefficient λM under the action of bending moment was also solved via energy variation method. Assuming that the axial force is only borne by the compressed area, the shear lag coefficient λN under the action of the axial force was obtained; λM and λN were superimposed to determine the comprehensive shear lag effect coefficient λ.

Real Geometrical Imperfection of Bow-String Arches—Measurement and Global Analysis

In order to analyse the buckling behaviour of existing bow-string arch bridges, it is necessary to deal with the imperfections that influence the global stability of their superstructures. Direct quantification of the material imperfections represents an extremely difficult task for this type of structure. On the other hand, the geometrical imperfections can be measured in more detail by using special scanners or high-accuracy surveying instruments. This contribution represents a beginning part of the research activities focusing on the real values of geometric imperfections of existing steel arch bridges using three-dimensional (3D) scanning. The possibility of using these data for further theoretical and numerical analysis based on the finite element method (FEM) and for further creating the building information modelling (BIM) of the bridges is proposed. When verifying the stability of bow-string arch bridges, much higher attention has to be paid to the out-of-plane stability of the arches. The numerical models of an existing bridge superstructure were developed to execute a nonlinear analysis with geometrical imperfections included. Both the theoretical and actual imperfections obtained by 3D scanning were taken into account. The obtained data, their comparison and the applicability of the presented method are finally discussed.

The "Bowstring Arch Bridge" Analogy to Guide Sequential Portal Placement during Needle Aponeurotomy in the Treatment of Dupuytren Contracture.

The "Bowstring Arch Bridge" Analogy to Guide Sequential Portal Placement during Needle Aponeurotomy in the Treatment of Dupuytren Contracture.

Design and Stability of Long Span Railway Arch Bridge

The bow-string arch bridge across the Vah River was designed on the main Slovak railway line. Total length of the bridge is almost 451 m, while the lengths of two main spans are 124.8 m. To analyse behaviour of the bridge, spatial transformation model was developed using FEM software. The Eurocodes were applied for all verification procedures. Bridge global analysis and verification of arches against buckling is discussed in more detail. The variation of upper bracing system and its influence on out-of-plane buckling of the arches is presented. Together with an architecture point of view, a minimum load amplifier to reach the elastic instability αcr is used to estimate the suitability of the bracings.

Analysis on In-Plane and Out-Plane Instability Coupling of Steel Bowstring Arch Bridge with Box Section Single Rib

Steel single rib box section arch bridge is established on the basis of secondary development using parametric language of large-scale finite element software ANSYS. On the premise of same sectional area A of arch rib,height breadth ratio h/b is changed, and both the spatial instability mode under the condition of arch bridges dead weight and the stability safety coefficient under the condition of the first step instability mode is calculated. With the aim to optimize distribution of stiffness and stability of single rib arch bridge, the target is to find out a height breadth ratio h/b which can make in-plane and out-plane instability mode coupling, that is to say, equivalent stiffness of in-plane and out-plane of the mode.

Design and construction of Shoreditch High Street Bridge, UK

The £500 million East London railway works contract in the UK includes the design and construction of a series of underline bridge structures, carrying the upgraded and extended railway between the refurbished Kingsland viaduct at its northern end and the former Great Eastern railway. One of these is Shoreditch High Street Bridge, a bowstring arch bridge forming a landmark where a new section of the railway crosses Shoreditch High Street just north-east of the City of London. It is an unusual form of railway bridge, chosen primarily for its appearance, having solid round bar hangers and no bracing between arch ribs above deck level. The East London railway Balfour Beatty–Carillion joint venture directed the design and constructed the bridge, while the bridge design was undertaken by URS. This paper describes the design and construction of Shoreditch High Street Bridge, highlighting some of the more unusual features.

Simulation Analysis of Shrinkage and Creep for Bowstring Arch Bridge Steel Tube Concrete in Different Specification

The actual bowstring arch CFST is taken as the background,the paper using finite element analysis method, researched the shrinkage and creep of combination of steel and concrete structure. Through the use of different countries regulation of shrinkage and creep of concrete, the effects of the structure deflection separately were studied ,then explain the different influence degree of different norms in the calculation of the creep and shrinkage of concrete; The paper also has also put forward the doubt about accurate calculation concrete filled steel tubular structure shrinkage and creep of concrete, it puts forward new requirements for the research and standards about steel tube concrete shrinkage and creep at last.

Structural Analysis and Load Test of a Nineteenth-Century Iron Bowstring Arch-Truss Bridge

A structural study examines the oldest remaining metal bridge in the Commonwealth of Virginia, a wrought-iron bowstring arch truss, designed and manufactured by the King Iron Bridge Company. Finite-element analysis is used to evaluate the interaction between the arch and truss, and the results are compared with field measurements from a live-load test. The study reveals that diagonal truss elements decrease arch bending by distributing concentrated vertical loads along the arch toward the abutments in a way consistent with that of modern network arch bridges. When the truss diagonals are absent, the vertical bridge-deck deflection is doubled. Underslung portal frames provide lateral stiffness to the arch, an innovation that accommodates a shallow arch profile conducive to transportation and erection.

Research on Overall Stability of Concrete-Filled Steel Tubular Bowstring Arch Bridge

Based on the finite element theory, the computational model, one through concrete filled steel tube tied-arch bridge was established under the considerations of both geometrical non-linearity and material non-linearity. And using the ANSYS software to study the bridge's arch rib construction process and the overall stability after the complete construction, the results show that the full-bridge’s stability coefficient are larger than other concrete-filled steel tube arch bridge; the in-plane stiffness is larger than the out-plane stiffness, and the influence of material non-linearity on the stability is notable. The results provide a good reference for the similar bridge's design and construction.

Design and Construction of Composite Tubular Arches with Network Suspension System: Recent Undertakings and Trends

The use of Network hanger arrangement, a development of the classical Nielsen V-hanger system, in steel bowstring arch bridges allows for important steel saving, with very slender main elements, owing to the remarkable reduction of bending stresses in the arches and tie beams. The present paper describes the main features of the design and construction of several long-span arch bridges of this typology in Spain: the three pedestrian footbridges for the Madrid cycling ring track, with spans of 52, 60 and 80 m, the Bridge over River Deba in Guipuzcoa with a span of 110 m and Palma del Rio Bridge over River Guadalquivir in Cordoba, 130 m long. In all cases, two inclined arches linked at the crown were implemented, a very effective disposition to reduce the out-of-plane buckling length. The multiple crossings of the hanger system, consisting of prestressed bars in the case of Deba Bridge and the footbridges, and locked coil cables for Palma del Rio Bridge, were dealt with by means of crossing devices which led to a technically satisfactory solution with minimal visual impact. An innovative approach to bowstring arches was introduced in Valdebebas Bridge over M-12 motorway in Madrid, next to the new T-4 Terminal of Barajas Airport, with a span of 162 m, where the hangers are replaced by a structural steel mesh -diagrid- which acts as the web of a simply-supported beam whose compression head is the arch and the tie beam is the deck.

Procurement, design and construction of the Clyde Arc, Glasgow

The design and construction of the Clyde Arc has created a new landmark structure on the River Clyde waterfront in Glasgow. The construction of the £20·3 million project commenced in May 2005 and was completed in September 2006. The bridge is a three-span structure, the central span comprising a tied bow string arch with a single steel diamond-shaped arch rib spanning the long diagonal of the span. The main deck consists of a composite steel ladder beam arrangement with two longitudinal plate girders and cross girders at 4 m centres acting compositely with a reinforced concrete deck. The centre span is supported directly from 14 hanger bars, each 110 mm in diameter. The lower hanger connections are attached to outriggers from the main longitudinal girders, which are connected longitudinally with tubular members. The back spans are supported at the pier cross girders and are integral with the reinforced concrete abutments, which are in turn supported on reinforced concrete piles of small diameter. The centre span is supported on tubular steel piles of large diameter, within the river. This paper describes the procurement, design and construction of this structure.

T5A roof: the abutment first run study

The abutment structures provide the support for the main span of the dramatic 176 m free-spanning roof of Heathrow's Terminal 5 (T5) main terminal building. The abutments contain many complex engineered components, which are replicated 22 times throughout the roof structure. The roof modules were essentially made up of the central portion of the span containing the majority of the roof cladding supported by a 107 m bow-string arch structure, which was in turn supported by the end abutments which form the subject of this paper. The programme for the construction of T5 was time-critical and relied heavily upon constructing the roof in a series of modules to an extremely ambitious cycle time. The construction of the abutments was key to achieving these rapid cycle times. In order to ensure that the cycle times could be achieved, BAA embarked upon what was termed the abutment first run study (AFRS) essentially to determine, ahead of the construction on site and offline from the critical path, that these crucially important cycle times could be achieved. The current paper describes the rationale behind the study and the preparations made for the construction of the AFRS at Severfield Rowen's facility in North Yorkshire. The paper focuses on how practical refinement of complex installations can contribute to savings of both time and cost and how attention to detail during the design and manufacturing phases ensured that the components successfully fitted together. The effectiveness of the AFRS helped to guarantee that when the roof module was suspended from the strand jacks some 30 m in the air, the support points on the abutment structure were correctly aligned.