An advantage of constructing influence lines using the mullerbreslau principle is that the response function of interest can be determinedinterest can be determined directly. Savita maru2 1,2 department of civil engineering, ujjain engineering college ujjain, m. Aashtopciasbi segmental box girder standards for spanbyspan and balanced cantilever construction december, 1997, metric units including the following. Prestressed tendons system in a box girder bridge 7. Pdf influence lines of bridges with boxgirder crosssection. A box or tubular girder is a girder that forms an enclosed tube with multiple walls, as opposed to an ior hbeam. The boxgirder bridge using balance cantilever method design according to construction phase and loading. Launching the girder to the next span is usually a multistage process involving tiedowns, counterbalancing with precast segments and winches and the use of temporary support legs but the precise procedure to be followed will vary from one piece of equipment to another and must be clearly set out in method statements, and.
Skewed bridge design process design example check that design rates using pcbars. Draw the ild for bending moment at any section x of a simply. An influence line diagram with numerical values of its ordinates is known as a. Analysis and design of prestressed box girder bridge by. Specification 1041 i erection of precast prestressed. Load distribution factors of straight and curved steel. Influence line for first interior support, from spreadsheet. The aashto lrfr engine is then run for the traditional line girder analysis using the distribution factors computed by the distribution factor analysis. Wooden blocks supports to be placed underneath psc girder. The box beam ordinarily includes of prestressed concrete, steel or steel concrete. Initial girder size is determined using line girder analysis. In successive increments psc girder is to be lifted to a ht. Specifically, the example illustrates the design of selected critical sections from an exterior girder at the strength, service and fatigue limit states.
Now the psc girder is ready for placement of track and trolleys below it tofacilitate leading. The comparative study was conducted on two box girder road bridges illustrated in fig. Girder definition is a horizontal main structural member as in a building or bridge that supports vertical loads and that consists of a single piece or of more than one piece bound together. At present a number of innovations taking place in ontario and elsewhere. For instance, assume that the influence line of the support reaction at point a r ai of the beam is given as shown in the figure 3a. Grid model using crossframe beam elements all girders and crossframes are included in. An optimised box girder design had the potential to save up to 20% of structural steel compared to the original plate girder design, and the savings in structural steel would offset the additional cost of redesign and manufacturing. Built in 1902, the bridge consists of three equal simple spans that are supported on concrete and masonry piers and abutments. The side spans are 85 % of the length of the middle spans. Undergraduate student, department of civil engineering, ssn college of engineering, tamil nadu, india. Computerised design of boxgirder bridge using balanced. Posttensioned box girder bridge an analysis approach using. The design technique is applicable to both dead and live loads applied perpendicularly to the plane of the structure or as torsional moments applied along the longitudinal axis parallel to the plane. Wf girders are very efficient sections relative to the weight of the girders and are capable of.
Click the analyze toolbar button to initiate the distribution factorline girder analysis. Click the analyze toolbar button to initiate the distribution factor line girder analysis. When a given load system moves from one end to the other end of a girder. Launched steel girder bridge erection 2003 nova award nomination 21 launched steel girder bridge erection u.
Vertical loads primarily gravity loads are applied to the girder at its centerline, but the centerline of a curved girder is not coincident with a straight line chordline drawn between support points. Construct the influence linefor the shear at c 9 ft. Influence lines structural analysis theories slideshare. Ali, determination of load distribution factors of steelconcrete composite box and i girder bridges using 3d finite element analysis. Tubular girder is also used if the girder is round or oval in crosssection, such as the royal albert bridge. In some cases, the plate girders may be formed in a zshape rather than ishape. The box girder bridge using balance cantilever method design according to construction phase and loading. In order to have a reliable finite element model of these. Each span consists of two thrugirders and ballasted transverse troughs, all built from riveted steel plates and angles.
A detailed finite element modelling of these bridge structures is used to calculate the load distribution factors. The comparative study was conducted on two boxgirder road bridges illustrated in fig. Study on behaviour of plate girder with plane the web and corrugated web r. Design guidelines for steel trapezoidal box girder systems 6. Boundary conditions considering crane parked at one position and lifting. The analysis progress dialog will appear showing the progress of the 3d and 2d finite element analyses. Saving half through girder bridges using nonlinear finite element analysis s. The figures on pages 5 and 6 show the elevation and typical. M at 1st interior support due to one truck two 1k loads separated by 6ft, from spreadsheet. The precast fabricator will load the girders onto the contractors hauling equipment. Optimization of spantodepth ratios in highstrength concrete girder bridges sandy shukyan poon master of applied science graduate department of civil engineering university of toronto 2009 abstract spantodepth ratio is an important bridge design parameter that affects structural behaviour, construction costs and aesthetics. Distribution factorline girder analysis tutorial aashto. Its a bridge that has its main beams comprising of girders within the form of hollow boxes. Where a large box girder contains more than two walls, i.
In such cases owners should adopt these documents with the. Comparative study of the analysis and design of tbeam girder and box girder superstructure amit saxena1, dr. Mncr harlem line and spans over the croton river near pawling, ny. Saving half through girder bridges using nonlinear finite. Department, sri vasavi institute of engineering and technology, andhra pradesh. This paper presents highlights of references pertaining to straight and curved box girder bridges in the form of singlecell, multiplespine, and multicell cross sections. These influence lines are then loaded with the axle weights of the vehicle traveling along. At present a number of innovations taking place in ontario and elsewhere have the potential of further enhancing the design, durability, constructibility and, by extension, the economics of steel box girder bridges. Ce 331, fall 2010 influence lines for trusses 1 7 an influence line shows how the force in a particular member changes as a concentrated load is moved along the structure. Days creek, or ii executive summary in january 20, bridge diagnostics, inc.
Many girder sections from 36 to 100 tall have been developed to accommodate a wide range of bridge spans. Pdf influence lines of torsion and distortion internal forces of large concrete and steel cablestayed bridges with continuous boxgirders. Heins september, 1937 december 24, 1982 during the past decade, there has been extensive use of steel box girders for straight and curved highway and transit. Pdf files, structural analysis influence line diagram, influence line diagram pdf, shaikh yunus, solved example of influence line diagram, technical civil leave a comment design of plate girder pdf february 22, 2019 february 22, 2019 shaikh yunus. Where the girder carries its content inside the box, such as the britannia bridge, it is termed a tubular girder. Study on behaviour of plate girder with plane the web and. Having multiple vertical webs, it can also carry more.
Supports to be provided at the bearing location areas only. Heins september, 1937 december 24, 1982 during the past decade, there has been extensive use of steel box girders for straight and curved highway and transit structures. Sketch the influence line for the vertical reaction at a. Design of prestressed concrete igirder bridge superstructure. Influence lines provide a systematic procedure of how. Both are symmetrical five span girders with constant girder height. The question is about the influence line for floor girder. Influence lines are very useful in the quick determination of reactions, shear force. In addition, the method is used for a comprehensive study of the behavior of these structures with geometrical configurations representing the. Authors todd helwig, joseph yura, reagan herman, eric williamson, dawei li 8. Effects of diaphragms in continuous slab and girder highway bridges katzreferenoe ro civil engineering bl06 c. A 2d finite element analysis is then performed for each girder. The behavior of box girder section for a general case of an eccentric load has been s tudied and presented its studies in chapter 2. Introduction in 1993, the american association of state highway and transportation officials aashto adopted the load and resistance factor design lrfd specifications for bridge design.
The maximum positive shear at x will occur when the point load of 105kn is located at x 615m, since this is the positive peak of the influence line, the ordinate peak is. A series of influence line tables and equations have been presented, which will permit an initial design of a two or three span continuous bridge. Duckett gifford and partners ltd, southampton, uk abstract in the uk there are a large number of half through girder bridges dating from the latter part of. Pdf files, structural analysis influence line diagram, influence line diagram pdf, shaikh yunus, solved example of influence line diagram, technical civil. Imia short paper provided by michael spencer, zurich.
The support reaction at point a r a due to applied loads as shown in figure 3b can then be obtained using eqn. Bridge lines, bridge fonts pdf, 267kb bridge font true type font format. For a particular girder span and bridge width, a large number of parameters control the design of the bridge such as girder spacing, cross sectional dimensions of girder, deck slab thickness, number of strands per tendon, number of tendons, deck slab reinforcement, configuration of tendons, anchorage system, prestress. Gamble issued as a documentation report on the field investigation of prestressed reinforced concrete highway bridges. Originally constructed of riveted wrought iron, they are now made of rolled or welded steel, aluminium extrusions or prestressed concrete compared to an ibeam, the advantage of a box girder is that it better resists torsion.
Construct the influence linefor the moment at c 5 ft. Wideflange girders the wf girders series is wsdot premier and preferred girder series for bridge jobs in the state of washington. Comparative study of the analysis and design of tbeam girder. Dec 09, 2015 the question is about the influence line for floor girder. The design procedure is based on the relative behavior of a single isolated curved girder to the response of the same girder when acting in conjunction with a system of curved girders. Influence line diagram pdf influence line diagram pdf march 17, 2019 march 30, 2019 shaikh yunus. Construct influence lines r ai, m ai, v bi, m bi, g bi, t bi of a cantilever beam solution consider the beam subjected to a moving unit load as shown below. The moving loads are never carried directly on the main girder but are transmitted across cross girders to the joints of bottom chord. The example illustrates the design of a typical threespan continuous straight steel i girder bridge with spans of 140. Lrfd 3rd edition threespan continuous straight igirder 1. In addition, the method is used for a comprehensive study of the behavior of these structures with geometrical configurations representing the majority of commonly built box girder bridges. For the beam shown below, draw the influence lines for. Load distribution in simply supported concrete box girder.
The purpose of present study is the design of bridge structure for 25 m of span. The purpose of present study is the design of bridge structure for 25 m. Oct 26, 2012 wooden blocks supports to be placed underneath psc girder. Comparative study of the analysis and design of tbeam.
Posttensioned box girder bridge an analysis approach. Price composite steel box girder bridges have become an effective alternative to more conventional plate girder bridges and concrete girder bridges in north america in the past 25 years. The wf girders series is wsdot premier and preferred girder series for bridge jobs in the state of washington. I managed to plot the influence line but i failed to get the max negative live shear as the answer given.
In design specification, maximum bending moment at pier from construction phase are the concerns since the results to determine prestressed force, number of strand and cable arrangement. A boxgirder cross section could take the shape of single cell one box, multiple spines separate. Tech structural engineering, mandava institute of engineering and technology, andhra pradesh s. Local buckling influence on the moment redistribution for continuous. Analysis and design of prestressed box girder bridge by irc. Threespan continuous straight composite i girder load and resistance factor design third edition customary u. Design guidelines for steel trapezoidal box girder systems. In a plate girder bridge, the plate girders are typically ibeams made up from separate structural steel plates rather than rolled as a single crosssection, which are welded or, in older bridges, bolted or riveted together to form the vertical web and horizontal flanges of the beam. The simplysupported, posttensioned concrete girder shown in fig. Comparison of the amount of reinforcement for a boxgirder.
The line girder analysis method uses load distribution factors to isolate a. The weight of the structural steel for the plate girder option was more than 900t. Therefore, by applying appropriate factors, the system response can be determined from the single girder forces as computed from the influence line charts. In the final design, all girders should meet line girder design requirements at a minimum. The first girder is internally prestressed, the second is externally prestressed. Design optimization of box type girder april 2015 ijst, transactions of mechanical engineering, volume 39, number m1 103 3. C b influence lines since beams or girders are usually major load carrying members in large structures, it is important to draw influence lines for reaction.
Mukul anand associate professor, department of civil engineering, ssn college of engineering, tamil nadu, india. Moreover, the plate girder solution required heavy crossframes and bottom lateral bracing due to its tight curvature. Do not reduce the strength of the girders based on refined analysis results. Figure 3 plan view of the development of torque in a curved girder. All statically determinate beams will have il that. Site location is assumed to be near socorro, new mexico, with the bridge crossing a waterway on a normal perpendicular alignment.