I • Deck can be screwed to structural out of the screw or pullover of the steel, bar joists, or light gage steel deck will nonmally control. The framing. The lowest strength was values are based on the equations used to produce the tabulated provided by the AISI Specifica values. For bar joists and structural tions (1986 with addenda). These steel, a tensile strength (Fu) of 58 specifications call for a safety ksi was used ....nich is the lowest factor of 3 to be applied to the value for A36 steel. For gage table values. However, for tem- supports, F u porary wind = 45 ksi was Uplift Values for loads, a one used which third load SCREWED DECK is the lowest increase is provided in appropriate. ASTM A653 Structural dw If it is known that the Quality grade 33. Deck tensile strength of the materials fumished in gages support steel or the sheet 24, 26 and 28 are usually steel is greater than the grade 80 steels ....nich use a values used for the tables, tensile strength (Fu) of 60 the tabulated ultimate ksi as limited by the AISI strengths may be increased specifications. Either pull by a straight line ratio. • SCI cv. d d" A\.CfD(3C tc..,tcd te""" C d,. Size nOttl r1t'ad d'a ~tlt'Il(Jth. ~(lr" #10 0.190 0.415 or 0.400 2.56 #12 0.210 0.430 or 0.400 3.62 114 0.250 0.480 or 0.520 4.81 No": In our ~ catalog ·Steel Decks for Floors and Roofs·, the tables on pages 33 and 35 are in the wrong place Contact us for the needed corrections or contact us for a copy of the corrected publication. • • NICHOLAS J. 8011IIAS. INC. ~ PO. BOX 662. 47l SPRlJ',UflEWA\'E. (~. ) SUMMIT. NEW JERSEY 07902'-2 I • (908) 277-1617 Please circle # 33 Grades 50 and 65. 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For complete information, availability, literature and floppy disc, e ntact one of our TradeARBED offices at the following locations: o 825 Third Ave., New York, NY 10022. 1-800-272-3369, FAX (212) 355-2159. o 60 E. Sir Francis Drake Blvd., Larkspur, CA 94939. (415) 925-0100, FAX (415) 461-1624/8257. o 390 Brant Street, Suite 300, Burlington, Ontario, Canada L7R 4J4. (905) 634-1400, Fax (905) 634-3536. Please circle # 35 ,, MODERN STEEL • CONSTRUCTION Volume 35, Number 6 June 1995 FEATURES 24 ESSENTIALS OF LRFD (PART 1 OF 3) An overview of LRFD as found in Part 2 of the Manual of Steel Construction (1994) 30 THE IMAGE BEHIND THE DESIGN Richard Weingardt's firm has designed more than 3,000 projects during the past 30 years-and he's not shy about telling the world 40 .AN ALTERNATIVE To JOIST GIRDERS Talk of slow deliveries has prompted consideration of using rolled shapes in • place of roofj oist girders The expansion of the Cowboy Hall of Fame in Oklahoma gar nered an ACEC Excellence Award for Richard Weingardt Associates, a firm known not only for its engi neering prowess, but also for its marketing acumen Modern Steel Construction (Volume 35, Number 6/. ISSN 0026-8445. Published monthl)' by the Americ.lO Instllute of Steel D EPARTMENTS ConstructIon, Inc., (AISc), One fast Wacker Dr" Sullt' J 10 0, Chicago, It 6060 '·200 I. 6 EDITORIAL • Work 011 cOlillections Advertising office: The R.lmage Group. garners T.R. Higgills O'Hare L.lke Office Plaza, 2400 E. Devon Ave., Des Plaines, Il 606/81708/699-6049. 9 STEEL iNTERCHANGE Award • Fire wall cOllstruc • AlSC names IU!W VP Subscription price: tion of engineering Within the U.S.-single Issues 53; J yea" S85. • Enlarging an exist • Metric guide for steel Outside the U.S.-single issues S5; ing footing fabricators I year 536; 3 years S 100. • Flexural design • New price for LRFD Ple.lSc fax any clddresscs changes to strength of a single angle 011 CD J 121670·5403 or to the address below. • Environmental com Postmaster: Please send address changes to 12 STEEL NEWS pliallce workshops Modem Steel Construction, One East • Letters to the editor • Focusing on practi- • WJC~erDr. • SuiteJlOO. Chicolga, It 60601· • Teaching about steel cal steel design 2001. connections Second class posti1ge fJi1.ld at ChIC.lgO, IL and 50 STEEL MAIUlli"'TPLACE at addltion.l' mailing offices. 41 Modem Steel Construction 1 June 1995 , , ,~:-rj It's to D ••• ,0 t•'" in Computerized Structural Engineering PlAH[ R[SPOHS[ SP[CTRU" UHIT FEET IC I PS JOIHl COD.llDlHAJ[S 1 ••• ; 2 2 ••• S:I •• 11 • ; 6_, ,.22 . .." 1q1: :r• -___ 2' • ; ..:teCR I He I Ul 113;22_; S 3 tI ; 6 S 6 ..:teER !'Ro,n T ,10_HlST S If' S1 V12K .... 6 H' SI VllCtai SUPPORlS 1 2 FIX[D UHIT IHeM COHSHlHlS E 291 ... ALL 0[" •.••1 2.3 All cur orr HDDl -lOAD 1 WilL IE U"IT FEET LOAD 1 DUD AHD • Experience STAAD - III "Concurrent Engineering" on DOSlWindows/UnixlNT Welcome to tomorrow in Computeri7Cd Structural Engineering. The latest relea,e of STAAD-1I1, based on the principles of "Concurrenl Engineering". is redefining the way you engineer your structure. Whelher you are on DOS, WINDOW. U IX, or NT , STAAD-III is guaranteed to enhance the performance and productivity to a whole new level. STAAD-III, from Research Engineers, 's an Today's STAAD-ili. brings you the latest ,n modern acknowledged world leader in structural software. Computer A,ded Eng,neerlng Based on the State-of·the-art Static/Dynamic/ Nonlinear analysis, pnnclples of "concurrent englOeenng", it unifies IOnovatlve fIOlte element techniques, comprehensive leading-edge graphics and visualization techniques SteeliConeretelTimber des'gn, powerful graph,es and with proven and time tested analysis/design. A live seamless CAD Integra lion have always been our and unified associative data base provides seamless forte. Our deep rooted R&D base, spread over four integration across all mission cntlcal applications. continents, and our associatIon with the world's tram concept design and analysIs to detail design, leading institutions, have resulted 10 a solid simulat,on and visualozations. Today's STAAD-III-a technolog,ealfoundat,on for STAAD-ili. producllvlty concept for tomorrow • With over 10.000 installations, more than 30.000 engineers worldwide rely on STAAD-I11 for the state-of-the-art in technology. Experiellce tomorrow today - experiellce STAAD-1I1 I I . 22700 Savi Ranch Pkwy., Yorba LInda. CA 92687 Research Engineers, Inc. "'Ill! Tei: (714) 974-2500 Fax. (7t4) 974-477t Toll Free: (800) FOR-RESE • USA • UK • GERMANY • FRANCE • CANADA • JAPAN • KOREA • NORWAY • TAIWAN • fNDIA Please circle # 34 , , ED ITO R I A L • Beautiful Music Editorial Staff Scott Melnick, AFEW WEEKS AGO, A GOOD FRIEND HAD A COUPLE OF TICKETS Editor and Publisher TO THE CHlCAGO SYMPHONY ORCHESTRA that he couldn't Patrick M. Newman, P.E. use and asked if! wanted them. I gladly accepted. I had Senior Technical Advisor n't been to the symphony in a few years, and while I greatly Charlie Carter, enjoyed myself, I was struck by a difference in the way I Senior Technical Advisor approached the performance than I had back in my college Jacques Cattan, days. Technical Advisor When I was in college more than a decade ago, I often took advantage of the free symphonic performances put on by Editorial Offices Northwestern University's fine music school. Given the quality Modern Steel Construction One East Wacker Dr., of my dorm room stereo, it was the only way to really hear fine Suite 3100 music. In fact, even on the best of my friends' stereos, there Chicago, IL 60601-2001 was no comparison between the quality of a live performance (312) 670-5407 and recorded music. But today, with the ubiquity of compact Fax 3121670-5403 disc players, the best audio performances are in living rooms rather than in concert halls. Going to a concert, then, takes on Advertising Sales an entirely new dimension. Today, you go to a concert to experi- • Facinelli Media Sales 2400 E. Devon Ave., ence the music, to see the musicians, to partake of a public per Suite 267 formance. Des Plaines, IL 60018 As with the performance of music, the design of structures (708) 699-6049 has also shifted. A decade ago, few designers were making Fax 708/699-8681 extensive use of computers. And for steel design, you had no choice but to use Allowable Stress Design. But today, engineer AISC Officers ing has moved to a great reliance on computers and steel Frank B. Wylie, III, Chairman design has moved to the more advanced and more reliable Robert E. Owen, Load & Resistance Factor Design specification. First Vice Chairman Just as the phonograph has given way to the CD player, H. Louis Gurthet, ASD will soon give way to LRFD. 'Ib quote the AlSC Board of Second Vice Chairman Directors: "LRFD is a modern and technologically superior Robert D. Freeland, Treasurer steel design specification." Still, despite LRFD's introduction Neil W. Zundel, nine years ago, some engineers are not familiar with its basic President precepts. 'Ib help them out, beginning this month MSC is pub David Ratterman, lishing a three-part series on the "Essentials of LRFD." This Secretary & overview of LRFD, whjch starts on page 24, is taken from the General Counsel LRFD Manual of Steel Construction (2nd edition) and is basi Morris Caminer, Vice President, cally a primer on switching from ASD to LRFD. For even more Finance/Administration information, AISC's upcoming seminar series will include a session on "LRFD for the Practicing Engineer" (a schedule appears on page 23). 'Ibday, stereo albums are mostly found only in old collections. It won't be much longer before ASD manuals also are only a • collector's item. 8M 61 Modern Steel Construction I May 1995 Imagine",a software sy tem that automatically gives you: oShop Drawings olAlbor for Estimating oCNC Data for Shop Equipment oOrdering & Inventory Data oConnection Design Calculations Re\;sion Management 0 oJ ob, member status and much more With SDSI2 imagination becomes reality, You get details, estimates and ordering infollllation on eve!), piece of steel in the job- right down to the nuts, bolts and washers, SDSI2 is the only comprehensive software S) tem for eve!)' phase in the steel industry, With SDSI1, each phase of a project creates and stores infollllaLion that is integrated and utilized in the next project phase, eliminating costly data re-ent!)' time, Project schedules, job status, drawing submittal! approval and erection planning can all be easily done using SDSI2, Whether you are an owner, engineer, fabricator or detailer, you will be able to see the money saving benefits of using SDS/2, Don't leave anything to the imagination on your next project. C:lil today for more infonnation or to set up your own personal demonstration of the SDSI2 products that include: [II. Estimating [II. eNC Interface Ill_ Engineering Design '". Production Control "• • Detailing '". DeslgnLiNK • DESIGN III DATA "First in",software, solutions, service" 402-476-8278 or 1-800-443-0782 Please circle # 32 Please circle # 43 .- .Il ',0 • S N T TEE L E R C H ANGE Stttl Intrr~hange is an open forum for Modun ttel Answers andlor questions should be typewritten and double Construdlon readers to exchange useful and practical profes spaced. Submittals thnt have been prepared by word-proc('sslOg sional ideas and mrannalian on all phases of steel building and an> appreciated on computer dlsk£'tte (either as 8 Wordperfect bridge construction. Opinions and suggestions are welcome on file or in ASCII formal). any subject covered in thiS maganne. If you have 8 quelilian or The opinions expressed in Sl"llllt('rchang~ do nol necessar· problem that your fellow readers might help you to solve, plea~e Ily represent an official poSition of the American Institute of forward it to Modern Steel Construction. At the some time. feel Steel Construction, Inc. and have not been reviewed. It is recog free to respond to any of the questions that you have read here. nized that the design of structures is within the scope Rnd Please send them to; expertise of n competent licensed structural engineer. architect Steel lnterchange or other licensed professional for the application of prinCipals to Modern Steel Construction n particular structure. One East Wacker Dr., Suite 3100 Information on ordering AISC publications mentioned in Chicago, IL 60601·2001 this article enn be obtained by calling AlSC al3121670-2400 ext. 433. The following responses from previous Steel lnterchange columns have been received: For fire wall construction, building codes say tbe wallshall have sufficient stability to allow for collapse on either side of the wall without collapse of the wall. What is the opti mum detail for this type of connection. T he sketch provided with the question submit ted is applicable for a specific type of tied fire • wall; non-load bearing, constructed between two double-column lines, structural members on rigure 12 Through Wall Tic PrimJry Stl"'('1 P.lr.llld To rtr(' W~lll each side of the wall at the same elevation and pri mary framing members parallel to th wall. For a scenario such as this the recommendations of for the slack provided in the through-wall ties. Factory Mutual Loss Prevention Data Book 1-22 This slack insures that the collapsing frame on the are very specific and are as follows. fire side of the wall will not pull on the wall before The anticipated horizontal component of the there is resistance provided from the frame on the force resulting from the collapse of the structural unexposed side of the wall via the through-wall frame on one side of the wall should be resisted by ties. the remaining structure on the opposite side of the The Factory Mutual recommendations also wall. This is accomplished through the use of include provisions for adequate separation between through-wall ties. The ties are designed based on the double-column line and the fire wall to prevent the horizontal pull "H" calculated from the formula damage to the unexposed structure during the ini provided in Recommendation #3 of the referenced tial stages of the fire. FM Data Book, using an allowable stress of not D. Matthew Stuart, P.E. mor than 10 ksi. A detail of the recommended The Stellar Group installation of the through-wall tie at each column Jacksonville, FL line is shown in Figure 12 of the same FM Data Book. For the situation indicated by the sketch in What is the most efficient way to enlarge question, it may be necessary to also install ties an existing footing, when new loading condi more often than every column line. In either case, tions are applied? T enough slack should be provided in the tie connec here is a good article dealing with this prob tion to allow for normal buiJding movement. lem. It was published in the fourth quarter While the through-wall ties insure the continu AISC Journal 1980 and was authored by • ity of the opposing framework at the fire wall, flexi Agrawal and Stafiej. The parameters required to ble masonry anchors should be provided at approx solve the problem include ratios of the respective imately 2 to 4 feet on center to brace the wall moments of inertia of the two column sections, laterally (see Figure 13 of the referenced FM Data ratios of axial loads applied at the top of the col Book). It is important to note that enough slack umn to loads at the lower section, and ratios of the should be provided in the anchors to compensate upper length to the lower length. Using these Modern Steel Construction I May 199519 '. S • TEE L NTERCHANGE ratios, one then uses a chart which gives equiva lent effective lengths factors for the composite col umn for six different end condition cases, pin-pin, flx-free (Steel Interchange question case), fix-pin, fIx-slider, fIx-fix, fIx-pin, and pin-slider. From the determined effective length factors, the effective lengths of the upper and lower column sections are easily obtained for use in the Euler buckling for mula. James F. McCarthy Folsom, CA Fran M. Lacsina Melrose Metals Is the method of determining the flexural Freemont, CA design strength of a single angle given in the Manual appropriate for unequal legs not Is there a more efficient and cost-effective loaded through the shear center? way to connect a masonry shear wall to struc M ood reference for this question is a paper tural steel framing? The most common prob by Tide, Raymond H. R. And Norbert V. lem with the following detail is that once the rogstad, Economical Design of Shelf masonry is built up to the bottom flange of Angles, Masonry: Design and Construction, the beam, there is not enough room to install Problems and Repair, ASTM STP 1180, John the grout and continuous reinforcing bars in Melander and Lynn R. Lauersdorf, Eds., American the bond beam at the top of the wall. If the Society of Testing and Materials, Philadelphia, PA, bond beam is dropped a course in elevation, • 1993, p. 60. the masonry to steel beam connecting angle R. H. R. Tide vertical leg or bent plate vertical leg becomes Wiss, Janney, Elstner Associates, Inc. excessively long. Northbrook, IL EEAM New Questions TEQCX)E~ Listed below are questions that we would like the readers to answer or discuss. ~.. . ~ -1----- If you have an answer or suggestion please send it to the Steel Interchange Editor, Modern Steel Co '. nstruction, One East Wacker Dr., Suite 3100, Chic ' \r'~'~" ago, IL 60601-2001. Questions and responses will be printed in EE:XO'l(')e (E)E RAEMN •" . SNEr£O W311'-2I.4 ' ' I0 o 1.c1).(7 avFa-A.Sm· TEc'B>AC'I PLT O ~9 .o..0.Tu WATI future editions of Steel Interchange. Also, if you SME'ECtTF.. IfI SGIOR OFJCTQ F WUA LJ.. •C MAIJ.. T WERANlAL TE EA 5I)E CF have a question or problem that readers might S' DEIP u-a..c:x:x 80NJ EEAM WI (2) • !I c;o.rr. CSLCR: TO help solve, send these to the Steel Interchange MATO< BEAM> Editor. ef o.u SJ-EARW.Ail. Given a wall of sheet metal or plate sub jected to fluid pressure and stiffened by same size parallel members spaced regularly, what Charles L. Bowman section (or width) of the wall shall be used • Morrison and Sullivan Engineers that contributes to the section of a stiffener? Raleigh, NC The stiffening member may be a flat bar, an angle, a channel (see figure) or any other sec tion. 10 I Modern Steel Construction I May 1995