National Steel Bridge Alliance

The Guide to Steel Highway Grade Separation Bridges provides practical guidance on the layout and detailing of steel overpass bridges.

The NSBA Steel Bridge Design Handbook is a comprehensive reference covering the selection, design, fabrication, and construction of steel bridges. It supports both practicing engineers and students and is fully aligned with the AASHTO LRFD Bridge Design Specifications, 10th Edition (2024), with updated chapters and design examples reflecting current practice.

Learn about site and location considerations, design recommendations, structural design, detailing, maintenance, and more! The Uncoated Weathering Steel Reference Guide is your one-stop shop for everything you need to know about UWS.

There are thousands of 100-year-old steel bridges spread across the nation. Some are grand. Some are not. Some span mighty rivers. Some span humble country roads. But all have lived through some of the most extraordinary events in modern history.

2014 article

2017 MSC article

The AASHTO LRFD Bridge Design Specifications are intended for use in the design, evaluation, and rehabilitation of bridges. The specifications employ the Load and Resistance Factor Design (LRFD) methodology, using factors developed from current statistical knowledge of loads and structural performance. This 10th edition includes updates to almost all sections of the specifications, with extensive revisions made to Section 5, Concrete Structures; Section 6, Steel Structures; and Section 3, Loads and Load Factors, which includes information on new risk-targeted design response spectra.

Accelerated bridge construction techniques combine innovative planning, design, materials, and construction methods in a safe and cost-effective manner to dramatically cut the time it takes to build a bridge onsite. For shorter spans, steel bridges or bridge elements can be fabricated elsewhere and carried into place during a brief closure for minimal interruptions.

Accelerated Steel: Achieving Speed in Steel Bridge Fabrication describes how each of these roles affects critical shop support activities, which can make or break the fabrication schedule. This guide describes the ideal schedule for every step of fabrication as well as the responsibilities for owners, designers, and general contractors.

Standard plans for four-span continuous bridges with spans ranging from 150 ft to 300 ft. End span lengths are optimized for the two middle span lengths. This document includes details for girders, cross-frames or diaphragms, bolted field splices, girder reactions, concrete deck, and the concrete deck placement sequence.

Standard plans for single span bridges ranging from 80 ft to 300 ft span lengths. This document includes details for girders, cross-frames or diaphragms, lateral bracing, bolted field splices, girder reactions, and the concrete deck. It also includes Link Slab details for those who need multi-span bridges while eliminating interior deck joints.

Standard plans for three-span continuous bridges with spans ranging from 150 ft to 300 ft. End span lengths are optimized for the center span length. This document includes details for girders, cross-frames or diaphragms, bolted field splices, girder reactions, concrete deck, and the concrete deck placement sequence.

Standard plans for two-span continuous bridges with equal spans ranging from 100 ft to 250 ft. This document includes details for girders, cross-frames or diaphragms, lateral bracing, bolted field splices, girder reactions, concrete deck, and the concrete deck placement sequence.

2015 article on understanding which steel bridge elements are fracture critical members will provide the required protection while saving on in-service inspection.

2013 article

Bridge Crossing Series No. 7

2021 article on the three girder straddle bent design. Focused on project in Connecticut.

Bridge Crossing Series No. 4

Determining bridge geometry is central to the work of bridge engineers and technicians. This Manual provides geometric parameters, characteristics, behaviors, and calculations for the evaluation and design of various bridge types. The Manual is organized in three parts: General, Concrete, and Steel.

This project was undertaken to investigate alternative Bridge Information Modeling standards. The process developed is called OpenBrIM. OpenBrIM is an alternative method for exchanging bridge information modeling data between different application platforms, organizations, and users. It is a community driven, free, open, on-cloud information modeling system designed for the bridge industry. With OpenBrIM, there’s one central data repository from which all participants operate. Participants are allowed to access information from and to contribute information into the repository. For this project, approximately 30 standard bridge component objects were developed. The OpenBrIM concept uses a standard XML data format to describe dimensions and other data parameters for bridge components. Bridge component library objects are defined parametrically, allowing repeated use for similar components by varying the geometric and/or physical property data. Common data can be defined globally within a project and automatically update all affected objects. In the future, new standards will be developed by the bridge community – the actual users of the information with the most knowledge about various bridge components.

This code covers welding requirements for bridges made from carbon and low-alloy constructional steels and designed to AASHTO or AREMA requirements.

The FHWA Bridge Welding Reference Manual, Publication No. FHWA-HIF-19-088, is a comprehensive reference for designers and owners that explains technical aspects and welding specifications for steel highway bridges.

2013 article

The FHWA cautions against the use of weathering steel in "tunnel-like" conditions of grade separate with certain geometric traits and is currently evaluating tunnel-like conditions using computational fluid dynamics models.

The Continuous Span Standards serve as a guide to state, county, and local highway departments in the development of suitable and economical steel bridge superstructures. Included are 88 unique solutions for three-span bridges with center spans between 150'-0" and 300'-0", girder spacings between 7'-6" and 12'-0", and plate girder designs utilizing both homogenous and hybrid steel options. Included on each conceptual solution are tables presenting girder plate sizes, diaphragm spacings, intermediate stiffener sizes and locations, shear connector spacings, camber, and girder weights.

Bracing behavior of cross frames and diaphragms in steel bridges with skewed supports.

2014 article

Bridge Crossing Series No. 2

This design example, plate girder shear and flexural strengthening, involves the addition of steel strengthening material to an existing steel plate girder. The existing bridge was designed for HS-20 live loading. The girder is to be strengthened due to section loss from corrosion. The design criteria is to strengthen the girder to obtain a HS-20 live load rating factor equal to or greater than 1.0.

Catastrophic damages--whether caused by natural disasters or other unforeseen events like vehicular impacts or fires--are a bridge owner's worst nightmare. When these damages cause bridge failure, the steel industry is there to mobilize and procure material in order to fabricate a new steel bridge at breakneck speed.

This manual is intended to serve as a reference. It will provide technical information which will enable Manual users to perform the following activities: • Describe typical erection practices for girder bridge superstructures and recognize critical construction stages • Discuss typical practices for evaluating structural stability of girder bridge superstructures during early stages of erection and throughout bridge construction • Explain the basic concepts of stability and why it is important in bridge erection • Explain common techniques for performing advanced stability analysis along with their advantages and limitations • Describe how differing construction sequences effect superstructure stability • Be able to select appropriate loads, load combinations, and load factors for use in analyzing superstructure components during construction • Be able to analyze bridge members at various stages of erection • Develop erection plans that are safe and economical, and know what information is required and should be a part of those plans • Describe the differences between local, member and global (system) stability

Bridge Crossing Series No. 11

2012 article

2021 report. Basis for Guide to Evaluating Details for Susceptibility to Constraint-Induced Fracture.

2017 article

This report summarizes the approach, findings and recommendations for the redundancy investigation of Bridge 69101 for the integral steel girder cap beams at Piers 10 and 11. This investigation was to determine if the noted pier caps in Bridge 69101 are truly fracture critical as currently designated, or if structural redundancy can be demonstrated through analysis in accordance FHWA Technical Memorandum, "Clarification of Requirements for Fracture Critical Members," and the application of criteria established in NCHRP Report 406, "Redundancy in Highway Bridge Superstructures."

This report summarizes the approach, findings and recommendations for the redundancy investigation of Bridge 69102 for the integral hammerhead cap beam at Piers 2 and 4, and the box beam straddle bent at Pier 3. This investigation was to determine if the noted pier caps in Bridge 69102 are truly fracture critical as currently designated, or if structural redundancy can be demonstrated through analysis in accordance with FHWA Technical Memorandum, "Clarification of Requirements for Fracture Critical Members," and the application of criteria established in NCHRP Report 406, "Redundancy in Highway Bridge Superstructures."

This report summarizes the approach, findings and recommendations for the redundancy investigation of Bridge 69839 for the integral steel box girder cap beam at Piers 1 and 2. This investigation was to determine if the noted pier caps in Bridge 69839 are truly fracture critical as currently designated or if redundancy can be demonstrated through analysis in accordance FHWA Technical Memorandum, “Clarification of Requirements for Fracture Critical Members”, and the application of criteria established in NCHRP Report 406, “Redundancy in Highway Bridge Superstructures.”

Drawings for Bridge 69839

This report summarizes the approach, findings, and recommendations for the redundancy investigation of Bridge 69840 for the integral steel box girder cap beam at Piers 1 and 2. This investigation was to determine if the noted pier caps in Bridge 69839 are truly fracture critical as currently designated or if redundancy can be demonstrated through analysis in accordance FHWA Technical Memorandum, "Clarification of Requirements for Fracture Critical Members," and the application of criteria established in NCHRP Report 406, "Redundancy in Highway Bridge Superstructures."

This article relates experimental testing at Purdue University on large-scale bridge girders that showed that for built-up steel members with typical proportioned components, failures of a single component (e.g. single cover plate) do not propagate into adjacent components. Furthermore, guidance was developed on how to evaluate built-up flexural members to ensure the appropriate application of member-level redundancy.

G4.1-2025 sets potential minimum requirements for a fabricator's quality control program and an owner's quality assurance program. G4.1 puts emphasis on the development and implementation of a comprehensive program for fabricators. This document supersedes S4.1 and provides information that is complementary to applicable welding codes and AISC standards and will be useful for developing a Fabricator Quality Control (QC) System and corresponding Quality System Manual.

The G4.2-2024 guidelines are intended to assist owners with the development of individual training and qualification programs for structural bolting inspectors.

2012 article

This guide provides comprehensive guidelines on heat-straightening repair techniques for damaged steel bridge members. This Guide is a condensed and updated version of the previous FHWA Report, FHWA-IF-99-004, "Heat-straightening Repairs of Damaged Steel Bridges, A Manual of Practice and Technical Guide."

This Guide provides bridge engineers and owners with general information and typical details to help standardize orthotropic steel deck (OSD) bridge design/fabrication to make it more competitive. This document does not intend to set a national standard but to help inform the effort through reduced parametric variations. OSD bridges can be either closed- or open-rib systems, and this Guide begins with background information regarding OSD bridge design. General considerations with respect to OSD bridges are discussed, followed by specific instructions for closed- and open-rib systems including rib geometry, size, and fabrication methods. Suggestions for deck plate selection are provided followed by a discussion of wearing surface types and selection considerations. Lastly, suggestions for floorbeam/diaphragm design are provided. Throughout the document, short summaries on the performance of several in-service OSD bridges are provided.

This AASHTO guide specification offers direction on overall modeling, element selection, and material models suitable for nonlinear FEA with the purpose of identifying system-level redundancy. Two reliability-based load combinations referred to as Redundancy I and Redundancy II are given along with performance criteria for the strength and service limit states to help determine if a bridge demonstrates sufficient performance after the hypothetical failure of a primary tension member.

This AASHTO guide specification offers provisions for an engineer to evaluate mechanically-fastened built-up steel members (either existing or new designs) for member-level redundancy. It provides several simplified solutions for flexural and axial member types, a reliability-based load combination, fatigue resistance categories, performance criteria for strength and limit states, and information necessary to develop an inspection protocol linked to the damage tolerance of the member, as appropriate.

While there are some similarities between highway and railroad bridges, there are key differences in design and construction that designers need to be aware of. This guide describes special considerations for railroad bridges in the areas of design, girders, boxes, trusses, floor systems, decks and walkways, bolts, corrosion protection, and construction. This document is intended to be used in conjunction with the AREMA Manual for Railway Engineering, Chapter 15--Steel Structures, and other referenced documents for further clarification on specific issues.

This is the original guide for heat-straightening repair techniques, that was condensed into FHWA-IF-08-999. This manual is divided into three parts. Part I provides a background and overview of the heat-straightening process. Part II is a technical guide to heat straightening directed primarily to engineers. Part III contains guides, specifications and reference material.

Bridge Crossing Series No. 14

Bridge Crossing Series No. 16

2017 article

2014 WSBS conference proceeding

2013 article

You don’t have time to babysit your bridge inventory. If there’s a problem, you need to know about it fast, so you can fix it fast. Steel is the ultimate choice for superior inspectability and repairability.

Bridge Crossing Series No. 8

This article from the Journal of Bridge Engineering discusses findings from large-scale experimental fracture tests and finite element parametric studies investigating the fracture criticality and after-fracture load redistribution behavior of built-up steel axially loaded members. The article summarizes conclusions about these member types including Cross-Boundary Fracture Resistance (CBFR), localized stress amplifiers, and the evaluation of existing members and design of new members for member-level redundancy.

This implementation guide is intended to provide an overview of background information, requirements for built-up members found in the AASHTO Guide Specifications for Internal Redundancy of Mechanically-fastened Built-up Steel Member (hereafter referred to as Guide Spec.), and example evaluations to help illustrate implementation. This document supplements the IRM (internally redundant member) Evaluator spreadsheets produced by the National Steel Bridge Alliance (NSBA), which are spreadsheets developed to facilitate the calculations involved in the evaluation of internal redundancy.

The NSBA IRM Evaluator automates much of the process for evaluating built-up axial and flexural steel members for internal redundancy. The tool follows the provisions of the AASHTO Guide Specifications for Internal Redundancy of Mechanically-Fastened Built-up Steel Members to establish internal redundancy and prescribe a special inspection interval.

2023 Engineering Journal article.

Weathering steel is a particular type of steel that develops a higher level of atmospheric corrosion protection than non-weathering grades of steel. While uncoated weathering steels have the appearance of being rusted, there are many forms of ferric oxyhydroxides (aka. rust) that can form on steel. The predominant ferric oxyhydroxide that gives uncoated weathering steel its tightly adherent patina is goethite. The atmospheric corrosion protection comes from alloying, primarily with a copper composition greater than 0.20 percent and also small amounts of chrome, nickel, and silicon. Bare atmospheric corrosion resistant steels have been recognized as far back as 1905 with very early editions of the American Society for Testing and Materials (ASTM) A 7 Standard Specification for Steel for Bridges and Buildings [. Uncoated weathering steel (UWS) is the lowest cost corrosion protection system possible for a steel bridge based on the first cost. Provided the UWS is used in an optimal environment that allows the protective patina to form, UWS also provides the lowest life cycle cost. The protective patina on UWS does not form or degrades in continuously damp conditions, forming a higher proportion of lepidocrocite, or in the presence of a concentration of chlorine ions that is too high, forming a higher proportion of akageneite.The use of UWS for bridges began in the mid-1960s. The steels were first marketed under proprietary names falling under the ASTM A 242 specification (first published in 1941) [, and by 1968 they fell under the ASTM A 588 specification [. The first uncoated weathering steel bridge was built over the New Jersey Turnpike in 1964 [. Shortly thereafter, Michigan began wide use of the product due to the potential advantage of much lower maintenance and life cycle costs compared to using steel in bridges that requires periodic painting. Between 1964 and 1980, Michigan built 513 uncoated weathering steel bridges, with an additional 100 bridges built by counties [. One of these was the Eight Mile Road Bridge in Detroit, Michigan. A portion of this bridge interchange was a depressed roadway with a low, 147 clearance and vertical retaining walls very near the shoulder. After an eight-year exposure study, it was found the corrosion rate never tapered off and in general their overall experience with uncoated weathering steel was poor [. This led the Michigan DOT to issue a total moratorium on uncoated weathering steel in 1980, leading other states to also question their use of uncoated weathering steel. To facilitate a national discussion on the performance and use of UWS, the Federal Highway Administration (FHWA) held a forum of 131 participants comprised of federal, state, and industry representatives in July 1988 [. An outgrowth of this forum was Technical Advisory (TA) 5140.22, to provide recommendations to bridge owners and designers on conditions and locations that appeared to be associated with increased corrosion risk for existing bridges and to identify situations in which the use of uncoated weathering steel should be avoided for new designs [. In particular, the TA advised against using UWS in grade separations, produced by the combination of narrow depressed roadway sections between vertical retaining walls, narrow shoulders, bridges with minimum vertical clearances and deep abutments adjacent to the shoulders. This particular part of the TA became known as the tunnel effect.

The Lean-on Bracing Reference Guide provides design criteria, commentary, and example designs. It is also intended to show bridge designers how to implement lean-on bracing in routine bridge designs with confidence and with minimal computational effort beyond that required for a traditional bracing system.

Bridge Crossing Series No. 5

This document presents the theory, methodology, and application for the design and analysis of both steel and concrete highway bridge superstructures. The manual is based on the AASHTO LRFD Bridge Design Specifications, Seventh Edition, 2014, with Interim Revisions through 2015. Design examples and commentary throughout the manual are intended to serve as a guide to aid bridge engineers with the implementation of the AASHTO LRFD Bridge Design Specifications.

This article from the Journal of Bridge Engineering discusses the results of large-scale experimental fatigue tests along with the results of an analytical parametric study investigating the localized stresses near a partially failed component in built-up steel flexural members. This information is critical in determining the strength capacity of members that have experienced a failure in one of the components (e.g. single cover plate), as well as determining the remaining fatigue life of built-up girders subjected to vehicular loads.

2020 article outlining Texas DOT research and implementation of redundancy.

2014 article

Pop quiz: What item you encounter daily is 100+ years old? For thousands of American drivers, the answer is simple: “the steel bridge on my commute.” That’s right: There are more than 2,400 steel bridges in service today that have carried traffic for more than a century! Talk about leaving a legacy--and making life easier for the next generation of bridge owners.

The AASHTO LRFD Bridge Construction Specifications are intended for use in the construction of bridges. The specifications employ the Load and Resistance Factor Design (LRFD) methodology, and are designed to be used in conjunction with the AASHTO LRFD Bridge Design Specifications. Revisions from the 3rd edition of this title include a complete revision of Section 3, Temporary Works, and changes to Section 10, Prestressing; Section 11, Steel Structures; Section 19, Bridge Deck Joint Seals; and Section 27, Concrete Culverts.

These Guide Specifications address the design and construction of typical pedestrian bridges which are designed for and intended to carry primarily pedestrians, bicyclists, equestrian riders, and light maintenance vehicles, but not designed and intended to carry typical highway traffic. Pedestrian bridges with cable supports or atypical structural systems are not specifically addressed.

This publication provides comprehensive LRFD design specifications for highway movable bridges, including structural, seismic, vessel collision, mechanical, hydraulic, and electrical design, as well as establishes requirements for movable bridge operation and control. The specifications cover several types of movable bridges, including bascule, swing, and vertical lift.

Simon is line girder analysis software intended for preliminary analysis and design of steel I-girder highway bridges, providing an efficient alternative when full 3D finite element modeling is unnecessary and hand calculations are too cumbersome for practical design exploration.

These specifications govern the fabrication of vehicular steel bridges to include the furnishing and fabrication of steel structures and the structural steel portions of other structures. Their objective is to achieve quality and value from a common specification that standardizes vehicular steel bridge fabrication in the United States. Specifically, the specifications: minimize variations among projects; provide economy, because individual fabricators would not have to change their methods and production variables; allow expertise in steel bridge fabrication to be shared among states; and enable owners to share resources, minimizing the effort each would, otherwise, spend to maintain their individual bridge fabrication specifications. Includes the 2024 and 2025 Interim Revisions.

This document provides guidelines for the maintenance actions to address fatigue cracking and details at risk of constraint-induced fracture (CIF) in steel bridges. It is a synthesis of best practices from published literature, project reports, past and ongoing research projects, as well as input from industry professionals gathered through a web-based survey. Intended to be a very practical reference text, it is written with everyone in mind from a maintenance contractor to an asset manager and design engineer, providing detailed descriptions of the driving causes of fatigue cracking and CIF in steel bridges and accepted methods for repair or retrofit. A number of case studies are discussed giving context for the different detail susceptibilities and utilizing a mixture of real-world and rendered images to illustrate the problems and solutions. For each case, a suggested sequence of steps is also provided as a ‘‘how-to.”

The objective of this manual is to provide a comprehensive reference on aspects of heat straightening, heat curving and cold bending as they pertain to steel bridge components. This manual is targeted towards both engineers and steelwork practitioners. This manual is an updated version of FHWA Report, FHWA-IF-99-004, “Heat Straightening Repairs of Damaged Steel Bridges: A manual of Practice and Technical Guide” and FHWA Report, FHWA-IF-09-999, “Guide for Heat-Straightening of Damaged Steel Bridge Members” and includes various updates and suggestions developed from recent studies and investigations.

This manual provides technical guidance on using refined methods of analysis for design and evaluation of highway bridges, to supplement the provisions and commentary of the AASHTO specifications. The application of refined methods is needed when a bridge design falls outside of the limits for the approximate methods in the AASHTO specifications or when refined methods can provide a more rigorous treatment to appropriately account for unique details and/or behaviors. Refined methods can also be used to achieve a more effective design or a more accurate load rating. To generate confidence, this manual includes seven case study analysis examples and provides trusted results that can be used by software providers and engineers to verify their modeling techniques.

2014 article

This document provides guidance to help steel bridge designers working on mid-Atlantic state projects to achieve optimal quality and value in steel bridges.

The Navigating Routine Steel Bridge Design guide complements the 10th Edition AASHTO LRFD Bridge Design Specifications and focuses on the design of steel superstructures for routine steel I-girder bridges. Organized as a series of hyperlinked checklists, it guides engineers step by step through the design process while identifying which provisions of the AASHTO Specifications apply to these bridges and which provisions are not applicable or only partially or conditionally applicable.

This report summarizes the results of a project to establish limits, based on fatigue and fracture performance, on the number of damage and repair cycles to which damaged steel bridge girders may be subjected using the heat-straightening procedure. A key product if this research are suggested revisions to the FHWA manual of practice for heat straightening.

Bridge Crossing Series No. 15

For horizontally curved steel rolled beam and constant depth welded I-section plate girders, the AASHTO LRFD Bridge Design Specification Article 6.7.7.2 requires that Engineers indicate on the contract documents whether heat curving is permitted in accordance with Article 14.3.2.2 of the AASHTO LRFD Steel Bridge Fabrication Specification. However, evaluation and interpretation of this article can be challenging for even the most seasoned engineers. This spreadsheet is intended to help simplify that task.

2019 paper

2014 article

2014 article

2018 article

2012 article

This document provides guidance to help steel bridge designers working on Texas Department of Transportation (TxDOT) projects to achieve optimal quality and value in steel bridges.

Effective and efficient redundancy in design can be achieved through system or member-level mechanisms utilizing engineered damage tolerance that is linked to the structure's inspection intervals.

2020 article on twin tub girder systems.

2018 paper

2019 paper

2019 article focus on system redundancy. This is part 2 to a 3 part series.

2019 Engineering Journal article.

S18.1 establishes material requirements for duplex stainless steel bridge plates, following a framework consistent with ASTM A709. It is part of a coordinated set of specifications intended to support the use of duplex stainless steel in plate girder bridge applications.

S18.2 provides design provisions for I-girder bridge superstructures fabricated from duplex stainless steel. It is structured to align directly with the AASHTO LRFD Bridge Design Specifications, using the same article numbering and organization.

2011 article

Provides an overview of structural steel products used in bridge construction, with emphasis on ASTM A709 steels, mechanical properties, fracture toughness, and atmospheric corrosion resistance, including weathering steel requirements.

Describes the development and application of strength, service, fatigue-and-fracture, and extreme-event limit states used in LRFD bridge design.

Highlights erection methods and construction-stage behavior, focusing on stability and critical stress conditions that may govern design during bridge erection.

Provides background on fatigue and fracture behavior in steel bridges and guidance on applying AASHTO LRFD fatigue design provisions, including member classification and detailing considerations.

Covers the design of bracing systems for straight and curved girder bridges, including I-girders and tub girders, with emphasis on stability, stiffness, and construction-stage performance.

Discusses the design and detailing of bolted field splices for steel girders, addressing factors influencing splice layout, strength and service limit states, and practical detailing considerations.

Provides practical guidance for selecting, designing, and detailing steel bridge bearings, including elastomeric, high-load multi-rotational, and mechanical bearing systems.

Presents an overview of substructure and foundation design for steel bridges, including abutments, piers, shallow and deep foundations, and related design considerations.

Reviews deck systems used in steel bridges, including concrete slabs, metal grid decks, orthotropic steel decks, and other alternatives, with discussion of design and detailing considerations.

Explains load rating concepts and the LRFR methodology used to evaluate the live-load carrying capacity of existing steel bridges.

Discusses corrosion mechanisms and protection strategies for steel bridges, with guidance on selecting systems based on environment, life-cycle cost, and long-term performance.

Provides comprehensive guidance on the layout, design, and detailing of composite trapezoidal steel box girder bridges, consolidating previously scattered guidance into a single reference.

Explains the preparation and use of steel bridge shop drawings, including detailing practices, fabrication requirements, and the translation of contract drawings into fabrication-ready documents.

Presents the fundamental behavior and strength principles of steel bridge systems and members, with guidance on applying the AASHTO LRFD Specifications to member and system-level design.

Provides guidance on selecting appropriate steel bridge types based on site conditions, cost, and performance, covering common systems such as rolled beam, plate girder, truss, arch, cable-stayed, and suspension bridges.

Addresses the detailed design of composite steel I-girder bridges, with emphasis on welded plate girders and practical detailing considerations applicable to most modern steel bridges.

Discusses bridge loads, limit states, and load combinations in the AASHTO LRFD Specifications, with additional guidance to help designers identify governing combinations and avoid non-controlling cases.

Provides an overview of analysis methods for steel girder bridges, including modeling considerations, available tools, and guidance on selecting appropriate analysis approaches based on bridge complexity.

Explains redundancy concepts and their implications for design, fabrication, inspection, and management of steel bridges, including considerations for nonredundant steel tension members.

Illustrates the LRFD design of a three-span continuous straight composite steel I-girder bridge, including strength, service, fatigue checks, and constructability considerations.

Demonstrates LRFD design procedures for a two-span continuous steel I-girder bridge, including optional moment redistribution and detailed limit-state checks.

Presents an alternative design using rolled wide-flange beams for a two-span continuous steel bridge, including deck design and wind analysis.

Illustrates the design of a three-span continuous horizontally curved composite steel I-girder bridge, including analysis of curved girder behavior and design checks for major structural components.

Demonstrates the design of a straight three-span composite steel tub girder bridge, including flexure, shear, bracing, and bearing design considerations.

Illustrates the LRFD design of a curved composite steel tub girder bridge, including torsion, distortion, field splices, diaphragms, and bracing design.

2016 paper

2012 article

Its unmatched span-to-depth ratio means smaller girders--in fact, the AASHTO Bridge Design Specification’s recommended minimum depth for a continuous steel girder is 33% shallower than the recommendation for precast concrete!

These plans are intended to serve as a guide to state, country, and local highway departments in the development of suitable and economical steel bridge superstructure designs.

Steel is an efficient, economical, elegant solution for every bridge design.

(AISI D432-07) This article dispels some of the "myths" or misconceptions surrounding the use of steel in bridge construction.

Check out the latest bridge innovations.

MSC bridge articles from 2009

MSC bridge articles from 2010

MSC bridge articles from 2011

MSC bridge articles from 2012

MSC bridge articles from 2013

MSC bridge articles from 2014

MSC bridge articles from 2015

MSC bridge articles from 2016-2018

MSC bridge articles from 2019-2020

Showcasing bridges more than 100 years old that are still in service today. 

The information listed in this article is not intended to be an all-encompassing summary of available plates that a mill may be able to produce. It is intended to provide an overview of where the thicknesses, widths, and lengths produced by each mill intersect with one another resulting in the greatest dimensional availability.

The Steel Span-to-Depth Ratio charts are the quickest way to estimate steel girder depth and total superstructure depth for straight, low-skew, plate girder bridges. The charts are organized by span arrangement (single span, two-span, three-span, or four-span continuous bridges) and represent typical girder spacings used in practice.

2013 article

2016 paper

Uncoated weathering steel has been used in Connecticut for over 50 years. These structures often have both long-term and short-term cost effectiveness as they do not require initial painting, nor is repainting needed throughout the service life. This report reviews the current state of practice for the implementation of weathering steel bridges in the state of Connecticut followed by a review of a large group of weathering steel bridges in the state.

Steel's circular supply chain means that it stores carbon for generations, unlike other materials. Instead of going to the landfill or an incinerator, decommissioned bridges and buildings go right back to the mill to become new steel again and again.

This document is a technical summary of the Georgia Institute of Technology report, Evaluation of Large-Format Metallic Additive Manufacturing (AM) for Steel Bridge Applications: Final Report of Tensile, Impact, and Fatigue Testing Results (GT-SEMM-23-01), available at https://rosap.ntl.bts.gov/view/dot/72366[1]. This report is a deliverable from a research study sponsored by the Federal Highway Administration (FHWA).

This technical brief by FHWA summarizes a field-based research project performed by Rob Connor, Lindsey Digglemann, and Ryan Sherman at Purdue University wherein they used explosives to instantaneously sever a fracture critical tension chord of an approach span to the Milton-Madison Bridge. The approach span was loaded with sand to simulate live load, and while measuring strain and deflection, they severed the first half of the tension chord and then the entire chord.

2020 article advising on classifying system redundancy.

2011 article

2011 article

Bridge Crossing Series No. 13

Bridge Crossing Series No. 17

2011 article

Bridge Crossing Series No. 1

Bridge Crossing Series No. 10

Bridge Crossing Series No. 9

2014 WSBS conference proceeding

This document gave broad guidance on situations where uncoated weathering steel (UWS) should not be used or else used with caution. As stated in the technical advisory (TA), "Further work is needed to quantify and understand the performance of UWS in a variety of circumstances and conditions." This report details a study conducted with the FHWA Long-Term Bridge Performance (LTBP) Program that contributes toward that goal, particularly considering longer term performance of UWS structures than was available at the time of the writing of the 1989 TA.

Bridge Crossing Series No. 12

Bridge Crossing Series No. 6

Bridge Crossing Series No. 18