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Vierendeel girder and frame - Engineering Class Home Pages

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<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong><br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 1


= American Society of Civil Engineers<br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 2


<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 3


<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 4


<strong>Vierendeel</strong> bridge<br />

HBF Berlin: <strong>Vierendeel</strong> <strong>frame</strong> <strong>Vierendeel</strong> elevator shaft<br />

<strong>Vierendeel</strong> detail<br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 5


<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong><br />

Named after 19 th century Belgian inventor, <strong>Vierendeel</strong> <strong>girder</strong>s <strong>and</strong> <strong>frame</strong>s are bending resistant<br />

1 1-bay <strong>girder</strong><br />

2 Gravity load<br />

3 Lateral load<br />

4 Articulated<br />

Inflection points<br />

5 3-bay <strong>girder</strong><br />

6 Gravity load<br />

7 Lateral load<br />

8 Articulated<br />

Inflection points<br />

1 Base <strong>girder</strong><br />

2 Global shear<br />

3 Global moment<br />

4 Bending �<br />

5 Chord forces<br />

6 Pin joints<br />

7 Strong web<br />

8 Strong chord<br />

9 Shear �<br />

10 Chord shear<br />

One-way <strong>girder</strong>s<br />

1 Plain <strong>girder</strong><br />

2 Prismatic <strong>girder</strong><br />

3 Prismatic <strong>girder</strong><br />

Space <strong>frame</strong>s<br />

4 2-way<br />

5 3-way<br />

6 3-D<br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 6


Salk Institute, La Jolla<br />

Architect: Louis Kahn<br />

Engineer: Komendant <strong>and</strong> Dubin<br />

Viernedeel <strong>girder</strong>s of 65’ span, provide adaptable<br />

interstitial space for evolving research needs<br />

Perspective section <strong>and</strong> photo, courtesy Salk Institute<br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 7


Yale University Library<br />

Architect/Engineer: SOM<br />

1 <strong>Vierendeel</strong> facade<br />

2 <strong>Vierendeel</strong> elements<br />

3 Cross section<br />

• The library features five-story Vierndeel <strong>frame</strong>s<br />

• Four concrete corner columns support the<br />

<strong>frame</strong>s<br />

• Length direction span: 131 feet<br />

• Width direction span: 80 feet<br />

• Façades are assembled from prefab steel<br />

crosses welded together at inflection points<br />

• The tapered crosses visualize inflection points<br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 8


Commerzbank, Frankfurt<br />

Architect: Norman Foster<br />

Engineer: Ove Arup<br />

Floors between sky gardens are<br />

supported by eight-story high<br />

<strong>Vierendeel</strong> <strong>frame</strong>s which also<br />

resist lateral load<br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 9


<strong>Vierendeel</strong> elevation / plan<br />

<strong>Vierendeel</strong> / floor <strong>girder</strong><br />

<strong>Vierendeel</strong> / floor <strong>girder</strong><br />

joint detail<br />

Commerzbank, Frankfurt<br />

Architect: Norman Foster<br />

Engineer: Ove Arup<br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 10


Hong Kong Shanghai Bank<br />

Architect: Norman Foster<br />

Engineer: Ove Arup<br />

Gravity / lateral load support:<br />

• Hanger / belt truss<br />

• <strong>Vierendeel</strong> towers<br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 11


<strong>Vierendeel</strong> steel <strong>girder</strong><br />

Assume:<br />

10” tubing, allowable bending stress F b = 0.6x46 ksi F b= 27.6 ksi<br />

Girder depth d = 6’, span 10 e = 10x10’ L = 100’<br />

DL= 18 psf<br />

LL = 12 psf<br />

� = 30 psf<br />

Uniform load w = 30 psf x 20’ / 1000 w = 0.6 klf<br />

Joint load P = 0.6 x 10’ P= 6 k<br />

Max shear V = 9 P/2 = 9 x 6/2 V = 27 k<br />

CHORD BARS<br />

Shear (2 chords) V c = V/2 = 27/2 V c = 13.5 k<br />

Chord bending M c = V c e/2 = 13.5 x (10’x12”)/ 2 M c = 810 k”<br />

Moment of Inertia<br />

I = M c c/F b = 810 k” x 5”/27.6 ksi I = 147 in 4<br />

2nd bay chord shear V c = (V–P)/2 = (27-6)/2 V c = 10.5 k<br />

2nd chord bending M c = V c e/2 = 10.5 x 120”/2 M c = 630 k”<br />

WEB BAR (2nd web resists bending of 2 chords)<br />

Web bar bending M w = M c end bay + M c 2nd bay<br />

M w = 810 + 630 M w=1,440 k”<br />

Moment of Inertia<br />

I = M w c/F b = 1440 k” x 5”/27.6 ksi I = 261 in 4<br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 12


Chord bars<br />

Moment of Inertia required I= 147 in4 Use ST10x10x5/16 I= 183>147<br />

Web bars<br />

Moment of Inertia required I= 261 in4 Use ST10x10x1/2 I= 271>261<br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 13


Sport Center, University of California Davis<br />

Architect: Perkins & Will<br />

Engineer: Leon Riesemberg<br />

Given the residential neighborhood, a major objective was to<br />

minimize the building height by several means:<br />

• The main level is 10’ below grade<br />

• L<strong>and</strong>scaped berms reduce the visual façade height<br />

• Along the edge the roof is attached to bottom chords<br />

to articulates the façade <strong>and</strong> reduce bulk<br />

Assume<br />

Bar cross sections 16”x16” tubing, 3/16” to 5/8” thick<br />

Frame depth d = 14’ (max. allowed for transport)<br />

Module size: 21 x 21 x 14 ft<br />

Width/length: 252 x 315 ft<br />

Structural tubing F b = 0.6 Fy = 0.6x46 ksi F b = 27.6 ksi<br />

DL = 22 psf<br />

LL = 12 psf (60% of 20 psf for tributary area > 600 ft 2 )<br />

� = 34 psf<br />

Note: two-way <strong>frame</strong> carries load per relative deflection ratio:<br />

r = L1 4 /(L1 4 +L2 4 ) = 315 4 /(315 4 +252 4 ) r = 0.71<br />

Uniform load per bay<br />

w = 0.71 x 34 psf x 21’/1000 w = 0.5 klf<br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 14


Design end chords<br />

Joint load<br />

P = w x 21’ = 0.5klf x 21’ P = 10.5 k<br />

Max. shear<br />

V = 11 P /2 = 11 x 10.5 / 2 V = 58 k<br />

Chord shear (2 chords)<br />

Vc = V/2 = 58 k / 2 Vc = 29 k<br />

Chord bending<br />

Mc = Vc e/2 = 29x 21’x12”/2 Mc= 3654 k”<br />

Moment of Inertia required<br />

I = Mc c /F b = 3654 x 8”/27.6 ksi I = 1059 in 4<br />

Check mid-span compression<br />

Global moment<br />

M = w L 2 /8 = 0.5 x 252 2 /8 M = 3969 k’<br />

Compression (d’=14’–16”=12.67’)<br />

C = M/d’= 3969 k’/ 12.67 C = 313 k<br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 15


Chord bars<br />

Moment of Inertia required I= 1059 in4 Use ST16x16x1/2 I =1200 > 1059<br />

Check mid-span chord stress<br />

Compression C = 313 k<br />

Allowable compression Pall = 728 k<br />

313


Z U G S P T Z E<br />

<strong>Vierendeel</strong> <strong>girder</strong> <strong>and</strong> <strong>frame</strong> Copyright Prof Schierle 2012 17

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