Posttensioned box girder bridge an analysis approach. In this document, a lightweight concrete without natural sand is termed alllight. Mar 27, 2019 attached is a model file and a pdf which outlines the procedure for modeling a concrete box girder bridge, a steel girder bridge, and a cablestayed bridge. The use of 8 ksi concrete for prestressed i girders. Substitution of cip conventional concrete in the contract document with. Bridge design to eurocodes worked examples worked examples presented at the workshop bridge design to eurocodes, vienna, 46 october 2010 support to the implementation, harmonization and further development of the eurocodes y. This document includes detailed flowcharts outlining the design steps for all components of. Rehabilitating concrete box girder bridges designed to show you bridge design example of them should extend at cantilever method, designed such sections are. Reinforced and prestressed concrete are used extensively in bridge projects. Design step 5 design of superstructure prestressed concrete bridge design example task order dtfh6102t63032 510 design step 5. In addition to the beam design, the design of the concrete deck is also included.
Upon the curing of the deck slab concrete any further loading, both superimposed and live loads, is sustained by the compound section of the beam as well as the slab. The substructure consists of integral end abutments and a multicolumn intermediate bent. Section a6 flexural resistance sample calculation from opis to compare with. Modeling of box girder bridge the tendon profile considered for the design of post tensioned box girder bridge is parabolic and mathematical model is shown in figure 6. The integral wearing surface is considered in the weight calculations. Chapter 5 concrete structures bridge design manual m.
The design example and commentary are intended to serve as a guide to aid bridge design engineers with the implementation. Posttensioned box girder design manual this manual contains information related to the analysis and design of castinplace concrete box girder bridges prestressed with posttensioning tendons. The purpose of this document is to illustrate how the pgsuper computer program performs its computations. The document also includes instructional commentary based on the aashtolrfd. Sep 03, 2020 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. September 20 lrfd bridge design 124 minimum top slab thickness is 9 inches, and the minimum bottom slab is. Future infrastructural replacement through the smart bridge concept. Mar 27, 2019 attached is a model file and a pdf which outlines the procedure for modeling a concrete boxgirder bridge, a steel girder bridge, and a cablestayed bridge.
The first portion of this report contains a general description of the design features peculiar to this type of bridge and the background material necessary to make design calculations. The bridge was a posttensioned concrete box girder bridge with a main span of 315 ft. This document consists of a comprehensive design example of a prestressed concrete girder bridge. Design step 4 design of deck prestressed concrete bridge design example task order dtfh6102t63032 43 for this example, a slab thickness of 8 in. T or i girder bridges are the most common example under this and width of the rib in the case of t, i and l beams design of reinforcement in box girder bridge concrete tbeam bridge design free download as pdf file.
Key words steel, box girders, trapezoidal, torsional 18. The closed cell which is formed has a much greater torsional stiffness and strength than an open section and this is the main reason why box girder configuration is usually adopted in long span bridges. Concrete boxgirder bridge model tutorials computers and. See bridge design manual volume 1, article 611 stresses. Prestressed concrete box girders unsymmetrical sections. A box girder is formed when two web plates are joined by a common flange at both the top and the bottom. The centretocentre spacing between main girders is 7 m and the slab.
Failure of pier head during construction sent eight bridge girders onto road. Pgsuper is a computer program for the design, analysis, and load rating of precast, prestressed concrete girder bridges. Table 28 bridge outline 1 bridge name lawakha bridge basochu bridge nyarachu bridge bridge type simple composite steel i girder bridge pc box girder bridge pc box girder bridge bridge length 45. Designers knew that as they increased the pier size, the box girder prestressing requirements would increase. Wisdot bridge manual chapter 19 prestressed concrete. Analysis of box girder bridges using staad pro structville. California has been dominated by concrete for nearly 100 years. Bridge design guide 32 txdot january 2020 section 1 general recommendations prestressed concrete beam and girder design txdots policy is held firmly to a 6. Pdf precast segmental box girder bridge manual serhat. Behaviour of concrete box girder bridges of deformable crosssection. The example illustrates the design of a typical threespan continuous straight steel i girder bridge with spans of 140. The earliest examples in the united states date to the 1930s. Finally, an example of the analysis of a bridge composed of a continuousspan, posttensioned concrete box girder superstructure and a concrete pier is also demonstrated using the approximate equivalent load method. Hueste, mohammed safi uddin adil, mohsin adnan, and peter b.
Analysis and design of reinforced concrete bridge structures 10. Example on design of slab bridge design data and specifications superstructure consists of 10m slab, 36m box girder and 10m t girder all simply supported. Key words prestressed concrete, lrfd, design, bridge girders. Design of steel elements is covered in part 3 and of concrete elements in part 4. The concrete compressive strength or class of concrete should be specified in the contract doc. Bridge engineering handbook superstructure design segmental.
Worked examples presented at the workshop bridge design to eurocodes, vienna, 46 october 2010. For prestressed box girders, the use of concrete with strength greater than 5 ksi is only allowed with prior approval of the bos development section. The aims of this project is to develop a series procedure of box girder bridge using cantilever method design based on prestressed concrete design procedure. The box is typically rectangular or trapezoidal in crosssection.
The box girder normally comprises prestressed concrete, structural steel, or a composite of steel and reinforced concrete. Reinforced concrete bridges concrete reinforcing steel. This three span precastprestressed girder example features a single long span in the middle along with two short side spans, as shown in. March 8th, 2018 eurocode 2 box girder bridge design example pdf free download here concrete bridge design example nocread com gopdf concrete bridge design example pdf lrfd design example for steel girder superstructure bridge april 28th, 2018 contentlrfd design example for steel girder superstructure bridge aashto lrfd design example. Design examples are presented in appendices to this manual. September 20 lrfd bridge design 121 buried structures serve a variety of purposes. Learn about the csibridge 3d bridge analysis, design and rating program and the comprehensive suite of tools it offers for the design of prestressed concrete.
A threespan castinplace concrete box girder bridge shown in figure b. A method for the design of intermediate external diaphragms is presented herein. The examples cover the principal steps in the verification of the. Detailed design examples for an aashto type iv girder and a texas u54 girder using both the aashto standard specifications and aashto lrfd specifications were also developed and compared. Design guide for composite box girder bridges steelconstruction.
Csibridge 05 design of prestressed concrete box girders. Posttensioned box girder design manual federal highway. Steel bridge tutorials computers and structures, inc. Analysis and design of prestressed concrete box girder bridge. This document follows the steel bridge design handbook sbdh design example 3.
It gives two worked examples, one for a multi girder bridge and one for a. Construction failure an overview sciencedirect topics. A box girder bridge, or box section bridge, is a bridge in which the main beams comprise girders in the shape of a hollow box. Introduction this example illustrates new mexico department of transportation nmdot design procedures for a threespan prestressed concrete girder bridge. Twin girder composite bridge 60 m 80 m 60 m c0 p1 p2 c3 note. Comprehensive design example for prestressed concrete psc girder superstructure bridge with commentary in us customary units this document consists of a comprehensive design example of a prestressed concrete girder bridge. Each bridge is formed by steel girders acting compositely with a reinforced concrete deck slab. Appropriate rounding should be made to comply with section 4 of astm e380. Enter the charts with a n ultimate axial design load and an ultimate design bending moment and determine the reinforcement required. Concrete bridge lrfd specifications parsons brinckerhoff page 1 1. Only the design of slab bridge will be used for illustration.
Doc calculations bridge design gichane gikonyo academia. This example illustrates the design of a two span castinplace posttensioned concrete box girder bridge. Transverse design of adjacent precast prestressed concrete box. Nov 12, 2019 specifically, the design of a continuous steel wideflange beam bridge is presented using a standard shape rolled ibeam, as an alternative to the plate girder design. As with the first example, the side spans are far shorter than the end spans while the depth of the bridge is constant. Box girder bridges are commonly used for highway flyovers and for modern elevated. This publication presents worked examples of the detailed design of two composite highway bridges. The first example is of multi girder form, the second is of ladderdeck form. The design procedure was developed through an investigation of torsion in curved girders and the effect of torsion on twintrapezoidal box girder bridge systems. The use of 8 ksi concrete for prestressed i girders and 6. The first steel bridge to be launched in the united states is believed to be a kansas city southern. Analysis of posttensioned concrete boxgirder bridges diva.
Concrete box girder bridge, prestress force, eccentricity, prestress losses, reinforcement, flexure strength, shear strength, sap model. Elevation, plan and typical cross section of precast box girder bridges in the united states. This type of superstructure is generally used for spans between 20 to 40 m. In that example, girder design and detailing is evaluated extensively. The publication of the document is at the request of the relevant centc250 sub. Impact of lrfd specifications on design of texas bridges. This document is available to the public through the national technical. A threespan cast inplace concrete box girder bridge shown in. T or i girder bridges are the most common example under this.
Lrfd design example for prestressed concrete girder. Mathematical modeling the mathematical model of a box girder bridge having a span of 30 m is shown in figure6. Furthermore, the optional moment redistribution specifications will be invoked. Based on the findings and results of nchrp project 121, the. The superstructure consists of two simple spans made continuous for live loads. Design of reinforced concrete bridges department of civil. This example illustrates the design of a two span precast prestressed i girder bridge. Posttensioned box girder bridge an analysis approach using. To avoid this circular dilemma, only the end spansat 157 feet long, the longest in the new bridge. In addition to general design guidance and information on detailing practices, this section contains three design examples. Design step 5 design of superstructure prestressed concrete.
The torsional properties of the closed section are. Lrfd design of double composite box girder bridges core. Caltrans, bridge design aids manual, california department of. Large cracks, failure of epoxyfilled joint not hardened to take design shear force. Comprehensive design example for prestressed concrete psc. Computerised design of boxgirder bridge using balanced.
Standard adot 42inch fshape barriers will be used resulting in a bridge configuration of 17 barrier, 120 outside shoulder. In these cases, straight steel box girders are used in regions where the clear span requirements preclude the use of the concrete ubeams. The types of girders covered by this section include castinplace, posttensioned girders as described below. Lrfd design example for steel girder superstructure bridge. Threespan continuous horizontally curved composite steel i girder bridge rivera and chavel 2015. An image of a model taken from the sap2000 bridge examples document is shown in figure 1. The manual is targeted at federal, state and local transportation departments and private company personnel that may be involved in the analysis and.
Design guidelines for steel trapezoidal box girder systems. Example of a common fourspan plate bridge type in the netherlands. Each class has specified wall and slab thicknesses, reinforcement areas, concrete strength, and fill 12. The construction of this bridge was considered so successful that the launching method was utilized to construct a nearly identical bridge a few years later. Precast, prestressed girder design example pgsuper training 242020 1. Concrete boxgirder bridge model tutorials computers. Final design calculations of timedependent prestress losses shall be based on the.
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