The diagonal lines of steel give support in all directions, helping to prevent the girder, which is one of the main support elements in a bridge design, from bending. The tetrahedral and pyramidal lattices have been fabricated by the folding of perforated sheet. Vertical loads from the crane, the eccentricity effects induced by the vertical loads, and the impact factors, internal surge thrust across the crane rail and. Conference paper pdf available september 2015 with 699 reads. Pdf evaluation of the structural performance of tetragonal lattice. 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 losses, concrete. Structural steel 1 of 18 rev plate girder design project. However, the present design method for the elements is based on empirical expressions and is believed to be over conservative. Eurocode 3 design of steel structures download ebook pdf. Contrary to standard solidweb girders, lattice girders are entirely integrated in.
Comprehensive design example for prestressed concrete psc girder superstructure bridge with commentary task order dtfh6102t63032 us customary units submitted to the federal highway administration prepared by modjeski and masters, inc. Analysis and design of prestressed box girder bridge by. What is the difference between plate girder and lattice. Longitudinal horizontal thrust along the crane rail. It was updated to illustrate the applicability of the revisions to the aashto. A beginners guide to simple plate girder design to ec3 part 15. Lattice girder joints design of joints in steel and. Experimental work, including fullscale tests of lattice girder structures and detail tests of grouted joints, was combined with finite element analyses. Siteblauvelt engineers cranberry township, pa pittsburgh, pa b s d i design. Tunnel, weak rock, ductile supports, time dependent properties of linings. Trusses and lattice girders are classified in accordance with the overall form and internal member arrangement. To design prestressed girders using line girder analysis. Hshaped steel ribs and triangular lattice girders have been widely used as a. Design guidelines for steel trapezoidal box girder systems.
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. When the order is placed, the lattice girder height h, lower chord diameter lc, upper chord size uc and diameter of diagonals d are specified. A plate girder is a beam that is made by welding 3 plates together to make an ibeam section. Analysis and design of prestressed box girder bridge by irc. Since the surface should be combed by a steel rake, design category 2 should apply. Lap splice, lattice girder systems, joint cast, nonlinear finite. Defined by the relationship of the roadway to the girder, these are deck girder bridges. Guidelines for modelling lattice girder structures with cantilever design. In this study, the structural behaviour of joints in lattice girder structures were investigated. The basic types of truss bridges shown in this article have simple designs which could. The example illustrates the design of a typical threespan continuous straight steel igirder bridge with spans of 140. Precast concrete lattice girder flat slabs are designed and manufactured in accordance with european standards 1,2 but the importance of the various design parameters in precast lattice girder floor systems are not fully understood 3. The lattice girder was used prior to the development of larger rolled steel plates.
Comprehensive design example for prestressed concrete. A test was conducted on two lattice girder elements in order to evaluate the mechanical behaviour in bending. Pdf evaluation of the structural performance of tetragonal. The recommended spandepth ratio for simply supported girder varies between 12 for short span and 20 for long span girder. It has been supplanted in modern construction with welded or bolted plate girders, which use more material. The units are typically 50mm to 100mm thick and 1200mm or 2400mm wide. Select a bridge and add information about your project using the line girder analysis panel. The terms are generally applied to the planar truss. Characteristics design of gantry girder is a classic example of laterally unsupported beam.
An open girder, beam, or column built from members joined and braced by intersecting diagonal bars. This chapter gives a short introduction to the design of hollow section joints. Steel bridge tutorials computers and structures, inc. The connected elements typically straight may be stressed from tension, compression, or sometimes both in response to dynamic loads. For the sake of this answer lets agree that a girder is what most people would call a beam. Design of prestressed concrete igirder bridge superstructure.
Fabrication, construction and assembly of the girderslab system and dbeam girder shall be in conformance with the girderslab system design guide v3. The lower chord already contains the complete reinforcement for floor loads commonly found in residential buildings. Lattice girder slabs function a floor system that serves as an alternative to conventional concreteinplace floors, in which a prefabricated slab with reinforcement serves as a permanent formwork for the final casting of the floors. Tecnica del acero, apta, madrid, spain, 2006 espdf. Ce 331, fall 2002 truss design example 2 1 4 design a typical steel truss girder to support the roof of the office building shown below. An image of a model taken from the sap2000 bridge examples document is shown in figure 1. Pantex lattice girders with the shotcrete has been determined by several pullout tests in terms of characteristic curves.
Attached is a model file and a pdf which outlines the procedure for modeling a concrete boxgirder bridge, a steelgirder bridge, and a cablestayed bridge. This bridge is the igirder design example presented in the appendix of the aashto guide specifications for horizontally curved steel girder highway bridges, 2003. The steel girder bridge is a structure in which a floor system and roadway, concrete or timber, is supported by girders, usually rolled section beams which are plain or encased in concrete. The mansard trusses can be used in the span ranges of 12 m to 30 m. Analyses of a lap splice in a lattice girder system semantic scholar. In many cases in the design of trusses and lattice girders, it is not necessary to consider secondary stresses. Lrfd design example for steel girder superstructure bridge. Threespan continuous straight composite i girder load and resistance factor design third edition customary u. Pdf lattice girder floor slabs tested application as a. While putting up lattice girder by means of textile slings the following rules have to be obeyed. Therefore, the purpose of this paper is to present information relative to the design criteria in addition to information on pre liminary plate sizes, design aids, and computeraided design of steel box girder bridges.
A lattice girder is a truss girder where the load is carried by a web of latticed metal. In the suggested innovative design and assemblies of lattice girder, rings, wire mesh and fixing devices provide first the temporary support in the tunnel and then the reinforcements of the. Llc requires design by a registered professional structural engineer. Distribution statement bridge design, steel girder, load and resistance factor this report is available to the public from the design, lrfd, concrete deck, bolted field splice, national technical information service in. The work was carried out from may 2004 to march 2005. The design shear forces and bending moments are shown in fig. A truss bridge is a bridge whose loadbearing superstructure is composed of a truss, a structure of connected elements usually forming triangular units. Pdf guidelines for modelling lattice girder structures with. Comparing bs5950 with ec3 part 15 in plate girder design design of plate girder bs5950 most design rules found in sections 4. Lattice truss structures from expanded metal sheet university of. They are cast with most, if not all, of the bottom reinforcement required. Lattice girder slabs act as permanent formwork and as precast soffits for robust, high capacity composite floor slabs.
Authors todd helwig, joseph yura, reagan herman, eric williamson, dawei li 8. Lattice girders with the complete reinforcement required for residential buildings are a special form of truss girder. Design to ec3 part 15 nanyang technological university. Tech structural engineering, mandava institute of engineering and technology, andhra pradesh s. Introduction box girders have become a prominent element in the con. The effect of cranes to be considered under the imposed loads should include the following. The tjoint in vierendeel girders, designed in accordance with en 199318, was analyzed because of its key importance when designing the overall frame. Sound resistance composite lattice girder floors are suitable for use at first floor level in domestic housing to create a quiet home for the benefit of home owners, their families and neighbours. Lattice girder definition and meaning collins english. Lattice girder article about lattice girder by the free. Lattice girders have been developed for special demands in the field of tunneling. Click download or read online button to get eurocode 3 design of steel structures book now. Lattice girder elements are used as permanent formwork in insitu concrete construction.
The system has been extensively tested and used successfully for numerous tunnel projects throughout the world. View initial results incanvas or purchase detailed girder design documentation in pdf format using cloud credits. With the aim to document the contribution of lattice girder to load carrying. A lattice girder is a type of girder with a crisscrossed web design, such as in gardening lattices, between the two edges of the girder. Draw steel joist girders as a 3dsolid by selecting a single line. Department, sri vasavi institute of engineering and technology, andhra pradesh. If capacity of crane is moderate, the gantry girders rest on brackets connected to roof column of industrial shed. You may hear the words girder and beam used interchangeably, but important differences distinguish the two from one another. Structural performance of precast concrete lattice girder. The lattice girders are used mainly as reinforcement of prefabricated slabs and beams, where concreting is performed in two stages, offering the advantage of avoiding scaffolding and formwork needed in traditional construction. The truss or lattice girder is a triangulated framework of members where loads in the plane of the truss or girder are resisted by axial forces in the individual members.
This horizontally curved steel box girder br idge design example was originally developed in the nchrp 1238 project using the 1993 aashto gu ide specifications for horizontally curved steel girder bridges. Therefore lattice girders are best suited when slab reinforcement is generally light, while at the same. Stateoftheart and conceptual design of steel and composite bridges. Figure 1 illustrates a simply supported lattice girder. Parallel chord lattice girders are used to support roofs and floors and for bridges, although in continuous bridges, additional depth is often required at the piers. Possible dimensions are stated below or can be found in the product range. Composite lattice girder floors are usually designed with a minimum 1hour fire resistance, although periods of up to 4 hours are possible.
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