A STREETCAR SHELTER FOR THE ARBUTUS CORRIDOR A STUDIED SIMPLICITY: EXPRESSING THE W-SHAPE
BENJAMIN BYE | ARCHITECTURE 462 | THURSDAY NOON LAB | LAUREN GARVEY
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SIMPLICITY IN STEEL In the design of a steel streetcar stop for the Arbutus Corridor in Vancouver, B.C. the exploration of structure as ornament was made. Taking precedent from the structures of Mies Van Der Rohe, the streetcar station showcases the steel that makes its structure. To exemplify and showcase the steel, W-shape members where utilized for their clear identifiability as structural elements. To strengthen the purity and clarity of the Van Der Rohe influenced structure, a simple and clearly defined structural hierarchy and load distribution was designed. The structure contains four levels of member hierarchy. Purlins act as stiffening members, bracing the weak axis of the cantilevered joists. The joists, running cross sectionally, are the primary spanning members, collecting the initial snow load and material load on the structure. Two longitudinal girders direct loads from the joists into the four columns. The building is braced through the use of moment connections. Bents are created as the columns are connected by spanning joists and girders. To further brace the structure against strong lateral loads the columns are driven into the ground forming a moment connection at the base of the column. Through the process of designing with pure structural intention a truly simple and beautiful structure can be created. With the focus on clarity and purity of structure, a balance of structural efficiency and articulation was made. Some members were slightly oversized for this cause, giving more importance to the aesthetic possibilities of the structure than could have been achieved with a purely efficiency based design. The outcome is one of aesthetically reasoned structural design.
CLEAR HIERARCHY
PURLINS
JOISTS
GIRDERS
IIT Crown Hall. Mies Van Der Rohe. Structure as Ornament < EXPLODED AXON The axon brakes apart the streetcar stop and exemplifies the rational simplicity to which the structure was designed. The articulation of structural members becomes the ornament of the streetcar stop. COLUMNS
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AXONOMETRIC DRAWING: STRUCTURAL GEOMETRY
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STRUCTURAL ARTICULATION
MODEL PHOTOGRAPHS
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THE STRUCTURAL UNIT DRAWN 20ft
8ft
LONGITUDINAL ELEVATION 1/4”=1’
12ft
8ft
CROSS SECTION 1/4”=1’ 6
12ft
20ft
PLAN 1/4”=1” 7
EARLY DESIGN WORK: THINKING THROUGH DRAWING
left: many different formal and structural explorations where made at the beginning of the design process, and an evolution was made towards the current structural scheme. above: day dreaming a simple design detail was born that was to be the genesis of the structure. below: through drawing, geometries and porportions were tweaked until the final scheme was produced. thinking through drawing.
unsettling proportions early on...
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considered, balanced, and appropriate proportions...
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MULTIFRAME:
AN OVERVIEW OF THE MODEL
.75 snow load: w= .75k/ft dead load: w= .12k/ft
.75 snow load: w= .0375k/ft dead load: w= .06k/ft
.75 wind load: 1.8k
.75 wind load: 1.8k
note: the loads are placed on the joist members because ultimately in this design the purlins purposes is to brace the weak axis of the joists. In studying forces flow in the structure, it was most acurate to distribute loads in this manner.
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Moment Diagram: Because of the high level of wind load on the structure, the columns provide the most lateral resistance so they have the highest moments. The moment graph also illustrates the clear necesity for member hierarchy with the columns needing to resit the most force, and the purlins the least. The only member with noticeable weak axis bending is the column, which will be illustrated in the column design check. Mmax for the structure: 4.825k-ft (column)
Axial Stress Diagram: As tributary members for all loading on the structure, the columns are the main members that need to take compression and tension stresses in mind. The joists between the columns also contain higher compression stresses, acting as bracing members reacting against the high wind load. Pmax for the Structure: 3.017k (column)
Deflection Diagram: Deflection in the structure is most prominant in the columns with a total deflection of 0.052 inches. The deflection is well below the maximum allowed deflection factor. This graph also illustrates how there is a slight torsional effect in the girder due to the support of the joist cantilever. The actual deflection is negligable, it is just exagerated in the deflection diagram. Total Deflection For Structure: 0.052in
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TYPICAL CANTILEVER JOIST: A-36 Steel | W6 x 9 Shape | Spanning Member
Mx-max : 1.021k-ft
The weak axis My-max is negligable at 0.002k-ft
Pmax : 0.00k
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Max Deflection: 0.005in
Deflection Check: Allowable Deflection =
l = 4ft x 12in/ft 180 180
= 0.26in
Allowable Deflection: 0.26in > Max Deflection: 0.005in passes deflection check
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DEPARTMENT OF ARCHITECTURE School of Architecture and Allied Arts University of Oregon
Architecture 462/562 Mark Donofrio Winter 2012
Designer: Ben Bye
GTF: Lauren Garvey
Material Properties: Steel Type: A36 F y: Fu : E:
Section Properties: Section: W6X9 36 ksi 58 ksi 29000 ksi
Area: Axis X-X (Strong Axis) I x: S x: r x:
2.68
in2
16.4 5.56 2.47
in4
Member Data: Member ID: Typ. Cantilever Axial Properties (Column Buckling): Unbraced Length - X-Axis: K-Condition: e K-Value: 2.1 Member Loads:
Axial Tension Moment - Strong Axis: Moment - Weak Axis:
Axis Y-Y (Weak Axis) I y: S y: r y:
in3 in
4 ft
2.2 1.11 0.905
in4 in3 in
2 ft
Unbraced Length - Y-Axis: K-Condition: e K-Value: 2.1 0 kips 1.021 kip-ft 0.002 kip-ft
P: Mx MAX: My MAX:
Axial - Tension Check [AISC Spec D1]: f t:
0.00 ksi
<
F t:
22 ksi
Utilization: 0.0%
OK
Axial - Compression Check [AISC Spec E2]: Strong Axis - X: KL/rx:
40.8
C c:
126.1
Weak Axis - X: KL/rx:
Governing Effective Slenderness Ratio: KL/r = 55.7
fc: N/A
Cc = 126.1
ksi
Flexure Check - Strong Axis [AISC Spec. F1]: fbx:
<
Flexure Check - Weak Axis [AISC Spec. F2]:
Utilization: N/A
F c:
17.8 ksi
Fbx:
22 ksi
OK
Utilization: 10.2%
Fby:
27 ksi
OK
Utilization: 0.1%
Fby = 0.75Fy
0.02 ksi
<
Designer: Ben Bye Member ID:
Therefore, use EQN E2-1 [AISC]
Fbx = 0.6Fy
2.20 ksi
fby:
55.7 <-- Governs
GTF: Lauren Garvey Typ. Cantilever
Combined Stress Check: Axial Compression and Bending [AISC Spec H1]: F'ex: Cmx:
W Shapes
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89.7 1
ksi
F'ey: Cmy:
48.1 1
ksi
Structural Design - Steel Design Spreadsheet Copyright Š 2011 by Mark Donofrio
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DEPARTMENT OF ARCHITECTURE School of Architecture and Allied Arts University of Oregon
Architecture 462/562 Mark Donofrio Winter 2012 AISC EQN H1-1
AISC EQN H1-2
AISC EQN H1-3
Axial Tension and Bending [AISC Spec H2]:
AISC EQN H2-1
0.00
+
0.10
+
0.00
=
0.10
<
1.0
OK
Section is satisfactory
W Shapes
Structural Design - Steel Design Spreadsheet Copyright Š 2011 by Mark Donofrio
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TYPICAL COLUMN:
A-36 Steel | W8 x 31 Shape | Supporting Member
Mx-max: 4.825k-ft (strong axis)
My-max: 0.646k-ft (weak axis)
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P-max: 3.017k compression
Max Deflection: 0.052in
Deflection Check: Allowable Deflection =
h = 8ft x 12in/ft 500 500
= 0.192in
Allowable Deflection: 0.192in > Max Deflection: 0.052in passes deflection check
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DEPARTMENT OF ARCHITECTURE School of Architecture and Allied Arts University of Oregon
Architecture 462/562 Mark Donofrio Winter 2012
Designer: Ben Bye
GTF: Lauren Garvey
Material Properties: Steel Type: A36 F y: F u: E:
Section Properties: Section: W8X31 36 ksi 58 ksi 29000 ksi
Member Data: Member ID: Typ. Column
Area: Axis X-X (Strong Axis) I x: Sx: rx :
9.12
in2
110 27.5 3.47
in4
Axial Properties (Column Buckling): Unbraced Length - X-Axis: K-Condition: c K-Value: 1.2
Member Loads:
Axial Compression Moment - Strong Axis: Moment - Weak Axis:
Axis Y-Y (Weak Axis) I y: Sy: ry :
in3 in
8 ft
37.1 9.27 2.02
in4 in3 in
8 ft
Unbraced Length - Y-Axis: K-Condition: c K-Value: 1.2 3.017 kips 4.825 kip-ft 0.646 kip-ft
P: Mx MAX: My MAX:
Axial - Tension Check [AISC Spec D1]: ft: N/A
ksi
F t:
Utilization: N/A
22 ksi
Axial - Compression Check [AISC Spec E2]: Strong Axis - X: KL/rx:
33.2
Cc :
126.1
Weak Axis - X: KL/rx:
Governing Effective Slenderness Ratio: KL/r = 57.0
f c:
0.33 ksi
<
Cc = 126.1
<
Flexure Check - Strong Axis [AISC Spec. F1]: fbx:
<
Flexure Check - Weak Axis [AISC Spec. F2]:
F c:
17.7 ksi
OK
Utilization: 1.9%
Fbx:
22 ksi
OK
Utilization: 9.7%
Fby:
27 ksi
OK
Utilization: 3.1%
Fby = 0.75Fy
0.84 ksi
<
Designer: Ben Bye Member ID:
Therefore, use EQN E2-1 [AISC]
Fbx = 0.6Fy
2.11 ksi
fby:
57.0 <-- Governs
GTF: Lauren Garvey Typ. Column
Combined Stress Check: Axial Compression and Bending [AISC Spec H1]: F'ex: Cmx:
135.5 1
ksi
F'ey: Cmy:
45.9 1
ksi
AISC EQN H1-1
W Shapes
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Structural Design - Steel Design Spreadsheet Copyright Š 2011 by Mark Donofrio
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DEPARTMENT OF ARCHITECTURE School of Architecture and Allied Arts University of Oregon
Architecture 462/562 Mark Donofrio Winter 2012
AISC EQN H1-2
fa/Fa:
0.02
<
0.15
AISC EQN H1-3
0.02
+
0.10
+
0.03
=
0.15
<
1.0
OK
Section is satisfactory Axial Tension and Bending [AISC Spec H2]:
AISC EQN H2-1
W Shapes
Structural Design - Steel Design Spreadsheet Copyright Š 2011 by Mark Donofrio
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TYPICAL GIRDER CANTILEVER: A-36 Steel | W8 x 10 Shape | Spanning Member
Mx-max : 1.616k-ft
Pmax : 0k
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Max Deflection: .042in
Deflection Check: Allowable Deflection =
l = 6ft x 12in/ft 180 180
= 0.4in
Allowable Deflection: 0.4in > Max Deflection: 0.042in passes deflection check
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DEPARTMENT OF ARCHITECTURE School of Architecture and Allied Arts University of Oregon
Architecture 462/562 Mark Donofrio Winter 2012
Designer: Ben Bye
GTF: Lauren Garvey
Material Properties: Steel Type: A36 F y: Fu : E:
Section Properties: Section: W8X10 36 ksi 58 ksi 29000 ksi
Member Data: Member ID: Typ. Girder
Area: Axis X-X (Strong Axis) I x: S x: r x:
2.96
in2
30.8 7.81 3.22
in4
Axial Properties (Column Buckling): Unbraced Length - X-Axis: K-Condition: e K-Value: 2.1
Member Loads:
Axial Compression Moment - Strong Axis: Moment - Weak Axis:
in
Axis Y-Y (Weak Axis) I y: S y: r y:
3
in
6 ft
P: Mx MAX: My MAX:
2.09 1.06 0.841
in4 in3 in
4 ft
Unbraced Length - Y-Axis: K-Condition: e K-Value: 2.1 0 kips 1.616 kip-ft 0.01 kip-ft
Axial - Tension Check [AISC Spec D1]: ft: N/A
ksi
F t:
Utilization: N/A
22 ksi
Axial - Compression Check [AISC Spec E2]: Strong Axis - X: KL/rx:
47.0
C c:
126.1
Governing Effective Slenderness Ratio: KL/r = 119.9
f c:
0.00 ksi
Weak Axis - X: KL/rx:
<
<
Flexure Check - Strong Axis [AISC Spec. F1]: fbx:
2.48 ksi
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W Shapes
0.11 ksi
Therefore, use EQN E2-1 [AISC]
F c:
10.3 ksi
OK
Utilization: 0.0%
Fbx:
22 ksi
OK
Utilization: 11.5%
Fby:
27 ksi
OK
Utilization: 0.4%
Fbx = 0.6Fy <
Flexure Check - Weak Axis [AISC Spec. F2]: fby:
Cc = 126.1
119.9 <-- Governs
Fby = 0.75Fy <
Structural Design - Steel Design Spreadsheet Copyright Š 2011 by Mark Donofrio
1 of 2
DEPARTMENT OF ARCHITECTURE School of Architecture and Allied Arts University of Oregon
Architecture 462/562 Mark Donofrio Winter 2012
Designer: Ben Bye Member ID:
GTF: Lauren Garvey Typ. Girder
Combined Stress Check: Axial Compression and Bending [AISC Spec H1]: F'ex: Cmx:
67.7 1
F'ey: Cmy:
ksi
10.4 1
ksi
AISC EQN H1-1
AISC EQN H1-2
fa/Fa:
0.00
<
0.15
AISC EQN H1-3
0.00
+
0.11
+
0.00
=
0.12
<
1.0
OK
Section is satisfactory Axial Tension and Bending [AISC Spec H2]:
AISC EQN H2-1
W Shapes
Structural Design - Steel Design Spreadsheet Copyright Š 2011 by Mark Donofrio
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TYPICAL BRACING JOIST A-36 Steel | W6 x 9 Shape | Bracing Member
Mx-max : 2.735 k
Pmax : 0.768 k Compression
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Max Deflection: .02in
Deflection Check: Allowable Deflection =
l = 4ft x 12in/ft 360 360
= 0.133in
Allowable Deflection: 0.133in > Max Deflection: 0.02in passes deflection check
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DEPARTMENT OF ARCHITECTURE School of Architecture and Allied Arts University of Oregon
Architecture 462/562 Mark Donofrio Winter 2012
Designer: Ben Bye
GTF: Lauren Garvey
Material Properties: Steel Type: A36 F y: Fu : E:
Section Properties: Section: W6X9 36 ksi 58 ksi 29000 ksi
Area: Axis X-X (Strong Axis) I x: S x: r x:
2.68
in2
16.4 5.56 2.47
in4
Member Data: Member ID: Typ. Brace JoistAxial Properties (Column Buckling): Unbraced Length - X-Axis: K-Condition: a K-Value: 0.65 Member Loads:
Axial Compression Moment - Strong Axis: Moment - Weak Axis:
Axis Y-Y (Weak Axis) I y: S y: r y:
in3 in
4 ft
P: Mx MAX: My MAX:
2.2 1.11 0.905
in4 in3 in
4 ft
Unbraced Length - Y-Axis: K-Condition: a K-Value: 0.65 0.768 kips 2.735 kip-ft 0.02 kip-ft
Axial - Tension Check [AISC Spec D1]: ft: N/A
ksi
F t:
Utilization: N/A
22 ksi
Axial - Compression Check [AISC Spec E2]: Strong Axis - X: KL/rx:
12.6
C c:
126.1
Governing Effective Slenderness Ratio: KL/r = 34.5
f c:
0.29 ksi
Weak Axis - X: KL/rx:
<
<
Flexure Check - Strong Axis [AISC Spec. F1]: fbx:
5.90 ksi
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W Shapes
0.22 ksi
Therefore, use EQN E2-1 [AISC]
F c:
19.6 ksi
OK
Utilization: 1.5%
Fbx:
22 ksi
OK
Utilization: 27.3%
Fby:
27 ksi
OK
Utilization: 0.8%
Fbx = 0.6Fy <
Flexure Check - Weak Axis [AISC Spec. F2]: fby:
Cc = 126.1
34.5 <-- Governs
Fby = 0.75Fy <
Structural Design - Steel Design Spreadsheet Copyright Š 2011 by Mark Donofrio
1 of 2
DEPARTMENT OF ARCHITECTURE School of Architecture and Allied Arts University of Oregon
Architecture 462/562 Mark Donofrio Winter 2012
Designer: Ben Bye Member ID:
GTF: Lauren Garvey Typ. Brace Joist
Combined Stress Check: Axial Compression and Bending [AISC Spec H1]: F'ex: Cmx:
935.9 1
F'ey: Cmy:
ksi
125.6 1
ksi
AISC EQN H1-1
AISC EQN H1-2
fa/Fa:
0.01
<
0.15
AISC EQN H1-3
0.01
+
0.27
+
0.01
=
0.30
<
1.0
OK
Section is satisfactory Axial Tension and Bending [AISC Spec H2]:
AISC EQN H2-1
W Shapes
Structural Design - Steel Design Spreadsheet Copyright Š 2011 by Mark Donofrio
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