Design verifications for simple steel plate girder bridges, consider spot checking computer program design and analysis output by rough hand calculations if practical for complicated steel plate girder bridges curved, consider verifying design with a second designanalysis program no two programs will match exactly of course. Lecture series on design of steel structures by dr. Then design of web plate and then design of flange. The design criteria is to strengthen the girder to obtain a hs20 live load rating factor equal to or greater than 1. Design considerations for steel plate girder bridges. Introduction of the unified effective width approach the nominal compressive resistance, pn, is obtained by multiplying fcr based on the gross crosssectional area by an effective area, aeff. Crane girder is an assembly of steel plates, angle and rails. I270 carries a significant number of daily commuters between illinois and missouri with an average. Abstractplate girder bridges are the most common type of steel bridges generally used for railway crossing of streams and rivers. This example is based on aashto lrfd bridge design specifications, 7th edition. The box girder normally comprises either prestressed concrete, structural steel, or a composite of steel and reinforced concrete. But before watching this part, please watch the 1st part of gantry girder for better understanding. The design shear forces and bending moments are shown in fig.
Wisdot bridge manual chapter 24 steel girder structures. The girders that fractured at the ttc were designated in the design drawings as tpg3 girders, where tpg refers to tapered plate girder. Seshu adluri plate girders recall compression field action in reinforced concrete beams compression struts develop because of the presence of stirrups plate girder tension field action develops because of the placement of vertical and horizontal stiffeners. In buildings, when large columnfree spaces are designed to be used as an assembly hall, for example, the plate girder is often the economical solution. Key words steel bridge, steel i girder, aashto lrfd, moment redistribution, cross frame design 18. Pdf this study concerns with finding the geometric dimensions of a plate girder which minimize the total weight and satisfy the design. Stiffened plate girders may or may not be designed for tensionfield action to resist the shear.
However, for plate girder roadway bridges the range may be. Design of plate girders for deck type railway bridges. Steel plates are also used as diaphragms of the girder. Structural steel 1 of 18 rev plate girder design project. Plate girder bridges details and design requirements. Aeffis generally computed as the summation of effective areas of the crosssection based on reduced effective widths, be, for each slender element in the crosssection article 6. Thus, the cross sections are not optimized for weight savings as is a plate girder but are cost effective due to lower. The span is 36 m and carries two concentrated loads as shown in fig. It carries a udl of 50 knm and two concentrated loads of 800 kn at 4 m from each support. Wisdot bridge manual chapter 24 steel girder structures july 2019 245 24. Design of plate girders for deck type railway bridges ijiet. Structural steel design, fabrication, and construction. A beginners guide to simple plate girder design to ec3 part 15. Plate girder shear and flexural strengthening design.
The girder is effectively supported in the lateral direction. The web plates of plate girders resist the shear force and the shear stress is uniformly distributed over entire cross sectional area of the web. For plate girders, only the girder web measured between the inside faces of the flanges is used to resist shear. For railway bridges, the girder depth will usually be in the range l o 12 to l o 8, where l o is the length between points of zero moment. Design, analysis and optimization of crane girder via. For these beams, readymade i sections are not suitable since selection from design of steel structures book. The design of a plate girder element is the responsibility of the building structural engineer just as is the design of a rolled section beam. The degree of continuity of the steel girders over. Design of roof truss notes click to download design of stiffners notes click to download design of plate girders notes click to download design of gantry girders click to. You can easily design any plate girder on the basis of these steps with a simple process of design by following our given steps in the pdf file provided below. We have shared the detailed design of steel structures lecturer notes in topic wise pdf. I270 bridge over chain of rocks canal introduction i270 is a fourlane interstate expressway that serves. Structural steel design, fabrication, and construction jamie f. Hs20 live load rating factor equal to or greater than 1.
Design to ec3 part 15 nanyang technological university. Buckling due to shear 7 vertical buckling the compression flange alateral. Plate girders are used in both buildings and bridges. Plate girder literature af area of compression flange af as area of transverse stiffener as aw area of web aw a panel length measured from centerline to a centerline of transverse stiffener b width of comp. Design verifications for simple steel plate girder bridges, consider spot checking computer program design and analysis output by rough hand calculations if practical for complicated steel plate girder bridges curved, consider verifying design with a second design analysis program no two programs will match exactly of course. Design recommendations for plate girders lehigh university fritz engineering laboratory rep. For complicated steel plate girder bridges curved, consider verifying design with a second design analysis program. There are two major steps required in the design of the post connection plates. Buckling of the compression flange due to inadequate stiffness of the web 3. Key words steel bridge, steel igirder, aashto lrfd, moment redistribution, cross frame design 18. Flange design flange is a solid plate of width b and thickness t f. Assumptions for the design of plate girder bridges following assumptions are made in the design of plate girder bridges.
In plate girder, the web is always slender, as dt w 126. The design criteria is to strengthen the girder to obtain a. The design of gantry girder is explained in this video step by step with full procedure. Crane girder design crane girder details proper detailing is the key to good fatigue performance the vast majority of crane girder performance issues occur at the crane girder to column connection. Use is made of a computer program to compare the behaviour of alternative girder support systems and the advantages and disadvantages of each is summarized. Additionally, the weld design for the webtoflange joint of the plate girders is demonstrated along with all applicable components of the stiffener design and cross frame member design. Design of plate girders 2 of welded plate girders in this book. Design of plate girder design of plate girder design principles design inputs span l, loadings, depth and width internal forces bmd and sfd bending resistance effective width method effective section area, a eff effect second moment of area, i eff elastic modulus w eff m y,rd modifiedflangesonly method. There was a total of four tpg3 girders in the ttc, and all four had nominally identical designs. Comparing bs5950 with ec3 part 15 in plate girder design design of plate girder bs5950 most design rules found in sections 4. Introduction welded plate girders, which are the most common form of plate girders, are builtup structural steel members that consists of flange plates welded to a web plate with fillet welds. If a ring girder is required, design the girder to resist all load conditions. Box girder, rolled girder and plate girder bridges are primarily flexural structures which carry their loads by bending between the supports.
Pdf design of plate girders mik wanul khosiin academia. Crane girder design 5 crane column cap plates allow girder end rotation avoid thick cap plates place the bolts outside of the column flanges. In such cases, the designer must choose between a plate girder and a truss. Girder design contd the first step in the design of plate girder section is to select the value of the web depth, d. Page 1 of 12 design and construction of a long span steel plate i girder bridge. The nominal shear strength for design without tension field action is given by lrfd appendix f2. For simple steel plate girder bridges, consider spot checking computer program design and analysis output by rough hand calculations if practical.
Curved plate girder design for safe and economical construction justify recommendations in preferred. Damodar maity, department of civil engineering, iit guwahati. It is more helpful to revise the basics in quick manner. Although there are preliminary steps, lrfd specification appendix g2 gives the flexural capacity for a plate girder, whereas appendix f1. Extend bearing stiffeners the full height of the girder. I270 bridge over chain of rocks canal introduction i270 is a fourlane interstate expressway that serves as a north bypass to the city of st. Use is made of a computer program to compare the behaviour of alternative girder support systems and the advantages and disadvantages of. Design of prestressed girder for bridge prestressed girder reinforcement details duration. This study concerns with finding the geometric dimensions of a plate girder which minimize the total weight and satisfy the design requirements using genetic algorithm ga, sequential quadratic. Aisc design of members for flexure about major axis 6 beam vs plate girder for doubly symmetric ishaped sections plate girder. The load effects such as bending moment and shear force are to be found using individual and unfactored load cases. Ikuerdesign suchasminimumthicknessofmaterialinwebplates, andminimumedgedistancesforpunching,theyfixalimit 10sizeofcertainpa.
Do not use knee braces allow for adjustment in placing the crane girder. The recommended spandepth ratio for simply supported girder varies between 12 for short span and 20 for long span girder. The flanges of plate girders resist the bending moment. Mar 22, 2018 design of plate girder part2 duration. Box girder bridges box girders are a particular form of plate girder, with two webs joined by common top and bottom flanges. They are used to support loads over long spans 60 ft. The design may be based on any one of the following assumptions. Based on these, the summation of load effects due to different load combinations for various load factors are obtained. Steel plates forms the flange and web of girder while the angle forms the stiffening part of the web plate.
Jun 09, 2017 we have shared the detailed design of steel structures lecturer notes in topic wise pdf. A stiffened plate girder with tensionfield action acts like a pratt truss, with the web plate resisting diagonal tension. The following note discusses the standard formula for the shear flow between web and flanges of a doubly symmetric beam which is used for weld design and gives the background to the formula in eurocode 3 part 51. Saq 2 1 design a plate girder of effective span 16 m and simply supported at ends. Feb 18, 2018 the design of gantry girder is explained in this video step by step with full procedure. The curtailment of the thicker plate is made by reducing thickness t f, keeping b the same. Cl stress modification coerficient depending on 01.
Recommendations to industry arising from investigation of. The difference is that plate girder design involves choosing explicitly the width and depth of the beam and also the thicknesses and arrangement of the constituent plates, including the connection. Pdf design of plate girders miftakhu zaim academia. Steel plate girder bridge design using indian standard. However, it is a necessary and important part of plate girder design when applying the load.
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