1Steel structures Prof Schierle 1Steel StructuresSteel structures Prof Schierle 2SteelTypes:• Light gauge steel• Heavy steelChallenges:• Requires much energy to produce• Higher cost than other material• Requires fire proofing• Requires accurate workmanship• Limited availability in some countriesCompression TensionHysteresis loop(test stress-strain curve)E = Energy absorbed byductility-  Strain  +Advantages:• Can be recycled • Ductile (absorbs seismic energy)• Lighter than concrete and masonry(small seismic forces)• No limitation of height or floor areaSteel structures Prof Schierle 3Light-gauge steel (cold-rolled)Channel stud (2 ½ – 6“)1. C-stud (2 ½ – 6“)2. I-stud (3 5/8 –8“)3. C-joist (6 – 12”)4. I-joist (6 – 12”)2Steel structures Prof Schierle 4Light-gauge steel curtain wallAttached to steel frameSteel structures Prof Schierle 5http://www.dietrichmetalframing.com/ultrasteel/menu.aspSteel structures Prof Schierle 6Steel production3Steel structures Prof Schierle 719thCentury Train Station (3-hinge arch)Steel structures Prof Schierle 819thcentury hinge supportSteel structures Prof Schierle 9USC steel frame buildingMoment jointBeam flanges weldedDog-bone reduces joint stressPin jointFlanges not welded4Steel structures Prof Schierle 10Dog-bone moment frame Classic moment frameDog-bone joints – reduced size reduces joint stressSteel structures Prof Schierle 11Coalbrookdale bridge by Darby (first iron bridge, 1777-79)30 mSteel structures Prof Schierle 12by Gustav Eiffel5Steel structures Prof Schierle 13Heavy steel shapesProfiles: typical labels1. W-shape, light (W14x22)2. W-shape, heavy (W14x730)3. S-shape, Standard (S12x50)4. W-shape, wide flange (W16x40)5. C-shape, Channel (C10x30)6. T-shape Cut from S-shape (ST6x25)Cut from W-shape (WT8x20)7. Angle, unequal legs (L6x4x½)Double angle (DL6x4x½)8. Angle, equal legs (L4x4x½)Double angle (DL3x3x½)9. Pipe Standard (P4) Extra strong (XP4) Double extra strong (DXP4)10. Structural Tubing Square (ST6x6x½)Rectangular (ST8x4x½)Steel structures Prof Schierle 14Floor / roof framingA Concrete slab on steel deckB Steel Q-deckC Truss joistD Support bracketE Alternate prefab concrete slabF Wide-flange steel beamSteel structures Prof Schierle 15Steel joints1 Pin joint, transfers only beam shear to column2 Classic moment joint, transfers shear and bending moment3 Dog-bone moment joint, reduces seismic joint stress 4 Joist to beam joint with top flange cut back5 Beam to beam joint with both flanges cut backA ColumnB BeamC Connector angles, usually shop welded, field boltedD Machine bolts, usually installed in field to connect beamE Welded connection of beam flanges to columnF Stiffener plates resist bending stress from beam flangesG Secondary beam / joist supported by primary beam / girder6Steel structures Prof Schierle 16Steel moment frames(wood structure ocean front)Beam / column moment jointsprovide lateral resistance forwide ocean view Steel structures Prof Schierle 17Truss floorsX-braced towers provide lateral resistanceJoist / beam roofOptimal spacing:Joists ~ 10’Beams ~ 30’Posts ~ 30’x30’Steel structures Prof Schierle 18Expressed steelHillside houseArchitect: Helmut SchulitzBraced frameImos factoryArchitect: Richard RogersEngineer: Anthony HuntStayed roof7Steel structures Prof Schierle 19Currigan exhibit hall, DenverArchitect: Muchow, Ream, and LarsonThe space truss is expressed inside and alongthe roof edge outside. Inverted truss pyramidssupport define the organization. The space truss has four modules of 240’x680’combined length. The truss is two layers deep to reduce bucklinglength of web bars.Top and bottom grids, 10’x10’. are offset by halfa module and joined by pyramidal web bars.Truss bars consist of twin-Ls, joined by gussets.The span/depth ratio is 6.5, DL = 13 psf.Steel structures Prof Schierle 20Festival Plaza, Expo 70, OsakaArchitect: Kenzo TangeEngineer: Yoshitomi Suga• Six towers support the 108x292 m space trussproviding about equal span both ways• Equal spans assure equal deflection(both spans equally efficient) Steel structures Prof Schierle 21Larkspur Ferry Terminal, San FranciscoArchitect: Jacques De BrerEngineer: Kaiser Engineers8Steel structures Prof Schierle 22Olympic Arena BarcelonaArchitect: Arata Isozaki Engineer: Mamoru KawaguchiThe 1992 106x128 m Olympic Pentadomespace truss consists of 5 units assembled at ground and lifted to final position.Assembly at ground Erection Steel structures Prof Schierle 23Airport terminal StuttgartArchitect: Von Gerkan / MargEngineer: Weidleplan Features:• 12 trees, each 80’ x 80’• Four pipe stems, 48 branches• Skylights separate units Tree structureSteel structures Prof Schierle 24Airport Terminal Stansted, UK Architect: Norman Foster AssociatesEngineer: Ove Arup and Partners Steel lattice domes are supported by 36x36 m trees that integrate mechanical services. Four strands secure each dome to trunks for lateral stability.9Steel structures Prof Schierle 25Airport Terminal HamburgArchitect: Von Gerkan / MargEngineer: Kockjoy, Schwarz, WeberPrismatic trussAirport Terminal, ChicagoArchitect: Helmut JahnFolded trussSteel structures Prof Schierle 26IBM sports hall, UKArchitect: Nicholas GrimshawPrismatic truss frameSteel structures Prof Schierle 27Sainsbury Center, UK Architect: Norman FosterEngineer: Anthony HuntPrismatic truss frame10Steel structures Prof Schierle 28SPACE TRUSSJavits Convention Center New YorkArchitect: I M PeiEngineer: WeidlingerSteel structures Prof Schierle 29Currigan Exhibit Hall, DenverArchitect: Muchow, Ream, and LarsonSteel structures Prof Schierle 30Centre Pompidou, ParisArchitect: Piano and RodgersEngineer: Ove ArupThe Centre Pompidou features six levels exhibit space 60 x 166 m Warren Trusses span the 60 m width11Steel structures Prof