A beginners guide to simple plate girder design to ec3 part 15. Girder design contd the first step in the design of plate girder section is to select the value of the web depth, d. In india, industries usually have quality range of gantry girders for industrial sheds. However, for plate girder roadway bridges the range may be. For plate girders, only the girder web measured between the inside faces of the flanges is used to resist shear. Key words steel bridge, steel igirder, aashto lrfd, moment redistribution, cross frame design 18. Hs20 live load rating factor equal to or greater than 1.
A girder may be of longer spans, take greater load. Then design of web plate and then design of flange. Steps with formulars to design of plate girders beam structure. 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. Generally rolled girders are used for web depths less than 36. Recommendations to industry arising from investigation of. Structural steel design, fabrication, and construction jamie f. For curved girders, use above and increase by 10 to 20 percent, or use lrfd equation 2. 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. However, it is a necessary and important part of plate girder design when applying the load. This document consists of a comprehensive steel girder bridge design example, with instructional commentary based on the aashto lrfd bridge design specifications second edition, 1998, including interims for 1999 through 2002.
The span is 36 m and carries two concentrated loads as shown in fig. This includes the criteria and the allowable stresses used in the design, as well as alternative types of girder with advantages and disadvantages given for each. There was a total of four tpg3 girders in the ttc, and all four had nominally identical designs. A plate girder is a deep builtup beam consisting of plates or plates and angles meant for carrying heavy loads on large spans. I270 carries a significant number of daily commuters between illinois and missouri with an average. Design considerations for steel plate girder bridges. Recently many steel plate girder bridges have had design and construction issues. The curtailment of the thicker plate is made by reducing thickness t f, keeping b the same. Thus, the cross sections are not optimized for weight savings as is a plate girder but are cost effective due to lower. In plate girder, the web is always slender, as dt w 126. Design, analysis and optimization of crane girder via. Beam the term beam is a general term and means a horizontal member supported at its ends and subjected to loading perpendicular to its longitudinal axis.
Zahn what differentiates a beam from a plate girder. For heavily loaded girders of large spans single isections even with cover plates do not provide the necessary moment of resistance and shear resistance. Design recommendations for plate girders lehigh university fritz engineering laboratory rep. Introduction to the design of steel and composite bridges. 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. Design optimization and structural performance evaluation of plate.
Buckling due to shear 7 vertical buckling the compression flange alateral. The design shear forces and bending moments are shown in fig. Buckling of the compression flange due to inadequate stiffness of the web 3. Crane girder design 5 crane column cap plates allow girder end rotation avoid thick cap plates place the bolts outside of the column flanges. Steel plates forms the flange and web of girder while the angle forms the stiffening part of the web plate. Plate girder worked example 1 made by sssr date 150400 structural steel design project calculation sheet checked by pu date 250400 problem. The girders that fractured at the ttc were designated in the design drawings as tpg3 girders, where tpg refers to tapered plate girder. Abstractplate girder bridges are the most common type of steel bridges generally used for railway crossing of streams and rivers. Curved plate girder design for safe and economical construction justify recommendations in preferred. Structural steel 1 of 18 rev plate girder design project. Wisdot bridge manual chapter 24 steel girder structures july 2019 241. However, it is a necessary and important part of plate girder design when applying the load and resistance factor design lrfd specification.
Design of plate girders for deck type railway bridges ijiet. 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. The box girder normally comprises either prestressed concrete, structural steel, or a composite of steel and reinforced concrete. Steps with formulars to design of plate girders free download as pdf file. Flange design flange is a solid plate of width b and thickness t f. Plate girder design using lrfd american institute of. E1 is fully restrained against lateral buckling throughout its span.
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. 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. Steel plates are also used as diaphragms of the girder. Stiffened plate girders may or may not be designed for tensionfield action to resist the shear. Plate girder design using lrfd university of maryland.
Ikuerdesign suchasminimumthicknessofmaterialinwebplates, andminimumedgedistancesforpunching,theyfixalimit 10sizeofcertainpa. Comparing bs5950 with ec3 part 15 in plate girder design design of plate girder bs5950 most design rules found in sections 4. Plate girder shear and flexural strengthening design. The design criteria is to strengthen the girder to obtain a. Steel plate girder bridge design using indian standard. To discuss bridge components and structural systems. Pdf the behaviour of plate girders under in plane loading has been intensively. A plate girder structure is selected over a rolled girder structure for longer spans or when greater versatility is required. Assisted by skilled workers in india, companies have been able to successfully grow towards the zenith, but.
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. Pdf design of plate girders miftakhu zaim academia. Previously in korea, multiple girder plate bridges were constructed more frequently, because. Design considerations for steel plate girder bridges the texas. Lrfd design example for steel girder superstructure bridge. Saves the bridge description in this window and its tabs to memory and closes the window. 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. Pdf this study concerns with finding the geometric dimensions of a plate girder which minimize the total weight and satisfy the design. The design may be based on any one of the following assumptions. The recommended spandepth ratio for simply supported girder varies between 12 for short span and 20 for long span girder.
Aisc design of members for flexure about major axis 6 beam vs plate girder for doubly symmetric ishaped sections plate girder. Design of prestressed girder for bridge prestressed girder reinforcement details duration. Design to ec3 part 15 nanyang technological university. Design of plate girders for deck type railway bridges. For these beams, readymade i sections are not suitable since selection from design of steel structures book. Box girder bridges box girders are a particular form of plate girder, with two webs joined by common top and bottom flanges. Four span simply supported steel plate girder input. Structural steel design, fabrication, and construction. This publication provides guidance on the design of composite box girder bridges, generally in accordance with bs 5400. Plate girder design using lrfd, engineering journal, american institute of steel construction, vol. 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. Extend bearing stiffeners the full height of the girder. 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.
The flanges of plate girders resist the bending moment. Assumptions for the design of plate girder bridges following assumptions are made in the design of plate girder bridges. To describe the common types of steel bridge plate girder, box girder and truss girder bridges. Crane girder is an assembly of steel plates, angle and rails. The design example and commentary are intended to serve as a guide to aid bridge design engineers with the implementation. Do not use knee braces allow for adjustment in placing the crane girder.
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