Design and Costs for Simple-Made-Continuous Rolled SteelGirder Bridges: Literature SurveyA. Stone, A.M.ASCE 1 ; J. W. van de Lindt, M.ASCE 2 ; and S. Chen, M.ASCE 3Abstract: The method of simple-made-continuous for steel bridges is becoming more popular throughout the United States because itenables signif i cant cost savings. Specif i cally, the method allows one to avoid steel bridge girder splices and design the steel sections forthe self weight and the weight of the slab as simply supported and then the addition of live load and remaining dead loads as continuous.This balances the moments between the positive and negative regions allowing for a prismatic section and even adds speed of constructionsince the f i eld splices are not needed. In 2006, the Colorado DOT sponsored a study to ?1? review current approaches to simple-made-continuous using standard rolled sections and ?2? develop design charts for rapid sizing of steel bridge beams and cost estimation forsimple-made-continuous. This paper presents a state-of-the-art review up until 2007 for this type of construction and focuses on severalof the most recent and successful transportation department projects.DOI: 10.1061/?ASCE?SC.1943-5576.0000045CE Database subject headings: Bridge design; Steel beam; Bridges, steel; Costs .Author keywords: Simple made continuous; Steel design; Bridge design; Rolled steel beam .IntroductionOver the past 50 years in the mid-western United States, construc-tion of short to medium span steel bridges has declined or, at best,remained constant, while prestressed concrete bridge constructionhas dominated the market ?Azizinamini et al. 2003?. The state ofColorado, in particular, has seen steel bridge construction virtu-ally disappear and the market dominated by prestressed bridges?Wang, T. ?2006? “Colorado Department of Transportation,” per-sonal communication?. One reason for this sharp decline is thelack of steel mills in the region combined with a strong presenceof precast concrete companies in the state. In addition, a lack ofreadily available economical and innovative procedures and toolsto design and construct steel bridges has hindered the industry incertain areas such as Colorado.During the bidding process for selection of the bridge type, itis mandated that accurate bidding of both steel and concrete bedeveloped. The precast concrete industry has worked to developtools to make this process easier and subsequently dominatedthe market in Colorado. These types of tools are not availablefor bidding steel bridges, thus more work by a design/buildcontractor is required for the steel option. The tendency is forbidders to go with the easier, and over time, more understoodoption and thus the type selection is routinely dominated by pre-stressed concrete.Simple-Made-Continuous: Economical Steel BridgeDesign MethodThe conventional approach for constructing multispan steelbridges is to design them as continuous girders to distribute theload over all members. In that method, the rolled girders arefabricated and shipped to the job site where they are assembled bythe contractor using a bolted or welded f i eld splice at low stresspoints. There is a relatively recent method where simply sup-ported beams are specif i ed by the designer and beams are thenmade continuous at the piers using a concrete diaphragm or aconnection plate ?Azizinamini et al. 2005?. In this approach, oncethe slab and diaphragm are poured, the simply supported beamaccounts for its weight along with the wet concrete deck. Asthe concrete diaphragm hardens, making the girders continuous,all other loads ?live, composite dead? are shared through the sys-tem of beams. This latter concept is called simple for dead load,continuous for live load, or simple-made-continuous ?Azizinaminiet al. 2005?. Some of the major advantages of the simple-made-continuous method over the f i eld splice method, hereafter referredto as the “conventional method,” are: ?1? it eliminates the needfor expensive f i eld splices; ?2? reduces the negative moment at thepier, while increasing the positive moment at mid span; ?3? main-tains a uniform cross section throughout span to reduce fabrica-tion effort; leading to minimum detailing of the steel beam; ?4?smaller cranes are required to assemble the beam system; ?5?erection time is reduced without the need for f i eld spices; and ?6?there is minimal traff i c interruption compared to the conventionalmethod. As of 2007, several states have begun to implement thistype of design and construction for some of their steel bridges.The list of states that have built simple-made-continuous steel1 Graduate Research Assistant, Dept. of Civil and Environmental En-gineering, Colorado State Univ., Fort Collins, CO 80523-2372.2 Professor and Drummond Chair, Dept. of Civil, Construction, andEnvironmental Engineering, Univ. of Alabama, Box 870205, Tuscaloosa,AL 35487-0202 ?corresponding author?. E-mail: jwvandelindt@eng.ua.edu3 Assistant Professor, Dept. of Civil and Environmental Engineering,Colorado State Univ., Fort Collins, CO 80523-2372.Note. This manuscript was submitted on August 5, 2008; approved onAugust 5, 2009; published online on July 15, 2010. Discussion periodopen until January 1, 2011; separate discussions must be submitted forindividual papers. This paper is part of the Practice Periodical on Struc-tural Design and Construction, Vol. 15, No. 3, August 1, 2010. ©ASCE,ISSN 1084-0680/2010/3-231–235/$25.00.PRACTICE PERIODICAL ON STRUCTURAL DESIGN AND CONSTRUCTION © ASCE / AUGUST 2010 / 231Pract. Period. Struct. Des. Constr. 2010.15:231-235.Downloaded from ascelibrary.org by Changsha University of Science and Technology on 06/05/13. Copyright ASCE. For personal use only; all rights reserved.
