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Column (House)

This document summarizes the design of columns and footings for a house, garage, and balcony. It specifies the dimensions, reinforcement, and load capacities of 450mm x 450mm and 400mm x 400mm columns for the house and garage with 6-16mm bars and 10mm ties spaced 450mm and 400mm respectively. A 250mm x 300mm column for the balcony is designed with 6-12mm bars and 10mm ties at 250mm spacing. A 1.5m x 1.5m x 0.3m footing is designed to support the house and garage columns, using 11-16mm bars spaced 450mm on center.

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Ivy Al
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217 views5 pages

Column (House)

This document summarizes the design of columns and footings for a house, garage, and balcony. It specifies the dimensions, reinforcement, and load capacities of 450mm x 450mm and 400mm x 400mm columns for the house and garage with 6-16mm bars and 10mm ties spaced 450mm and 400mm respectively. A 250mm x 300mm column for the balcony is designed with 6-12mm bars and 10mm ties at 250mm spacing. A 1.5m x 1.5m x 0.3m footing is designed to support the house and garage columns, using 11-16mm bars spaced 450mm on center.

Uploaded by

Ivy Al
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
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COLUMN (HOUSE)

Use 16mm diameter bar

450mm X 450mm

𝑓𝑐 = 20.70𝑀𝑃𝑎

𝑓𝑦 = 276𝑀𝑃𝑎

𝑃 = 0.06(𝑎𝑙𝑙𝑜𝑤𝑎𝑏𝑙𝑒)

Tied Column:

Axial Load Capacity: Nominal Load

𝑃𝑛 = 0.85𝑓𝑐 (𝐴𝑔 − 𝐴𝑠𝑡 ) + 𝑓𝑦 𝐴𝑠𝑡


𝜋 2 𝜋
𝐴𝑠𝑡 = 𝑑 𝑁 = 162 (6) = 1206.372𝑚𝑚2
4 4
𝐴𝑔 = 450 ∗ 450 = 202500𝑚𝑚2

𝑃𝑛 = 0.85(20.70)(202500 − 1206.372) + 276(1206.372)

𝑃𝑛 = 9,400,167.181𝑁

𝑃𝑢 = ∅𝑃𝑛 =0.70(9,400,167.181)

𝑃𝑢 = 6,580,117.181𝑁

Max. Steel Ratio:


𝜋 2
𝐴𝑠𝑡 4 16 (6)
𝑃𝑠𝑡 𝑚𝑎𝑥 = = = 0.0059574 < 0.06( 𝑂𝐾 )
𝐴𝑔 202500

Therefore, use 450mm X 450mm column w/ 6-16mm bars

Spacing Ties:

a. 16 ∗ 𝑑𝑏 = 16(16) = 256
b. 48(𝑡𝑖𝑒 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟) = 48(10) = 480

c. 𝐿𝑒𝑎𝑠𝑡 𝑑𝑖𝑚𝑒𝑛𝑠𝑖𝑜𝑛 𝑜𝑓 𝑐𝑜𝑙𝑢𝑚𝑛 = 450𝑚𝑚


Therefore, use 10mm tie at 450mm O.C

COLUMN (GARAGE)

Use 16mm diameter bar

400mm X 400mm

𝑓𝑐 = 20.70𝑀𝑃𝑎

𝑓𝑦 = 276𝑀𝑃𝑎

𝑃 = 0.06(𝑎𝑙𝑙𝑜𝑤𝑎𝑏𝑙𝑒)

Tied Column:

Axial Load Capacity: Nominal Load

𝑃𝑛 = 0.85𝑓𝑐 (𝐴𝑔 − 𝐴𝑠𝑡 ) + 𝑓𝑦 𝐴𝑠𝑡


𝜋 2 𝜋
𝐴𝑠𝑡 = 𝑑 𝑁 = 162 (6) = 1206.372𝑚𝑚2
4 4
𝐴𝑔 = 400 ∗ 400 = 160000𝑚𝑚2

𝜋 2 𝜋
𝑃𝑛 = 0.85(20.70) (160000 − 16 (6)) + 276 ( 162 (6))
4 4

𝑃𝑛 = 8,652,379.68𝑁

𝑃𝑢 = ∅𝑃𝑛 =0.70(8,652,379.68)

𝑃𝑢 = 6,056,665.777𝑁

Max. Steel Ratio:


𝜋 2
𝐴𝑠𝑡 4 16 (6)
𝑃𝑠𝑡 𝑚𝑎𝑥 = = = 0.00754 < 0.06( 𝑂𝐾 )
𝐴𝑔 160000

Therefore, use 400mm X 400mm column w/ 6-16mm bars

Spacing Ties:

a. 16 ∗ 𝑑𝑏 = 16(16) = 256
b. 48(𝑡𝑖𝑒 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟) = 48(10) = 480

c. 𝐿𝑒𝑎𝑠𝑡 𝑑𝑖𝑚𝑒𝑛𝑠𝑖𝑜𝑛 𝑜𝑓 𝑐𝑜𝑙𝑢𝑚𝑛 = 400𝑚𝑚


Therefore, use 10mm tie at 400mm O.C

COLUMN (BALCONY)

Use 12mm diameter bar

250mm X 300mm

𝑓𝑐 = 20.70𝑀𝑃𝑎

𝑓𝑦 = 276𝑀𝑃𝑎

𝑃 = 0.06(𝑎𝑙𝑙𝑜𝑤𝑎𝑏𝑙𝑒)

Tied Column:

Axial Load Capacity: Nominal Load

𝑃𝑛 = 0.85𝑓𝑐 (𝐴𝑔 − 𝐴𝑠𝑡 ) + 𝑓𝑦 𝐴𝑠𝑡


𝜋 2 𝜋
𝐴𝑠𝑡 = 𝑑 𝑁 = 122 (6) = 678.58𝑚𝑚2
4 4
𝐴𝑔 = 250 ∗ 300 = 75000𝑚𝑚2

𝜋 2 𝜋
𝑃𝑛 = 0.85(20.70) (75000 − 12 (6)) + 276 ( 122 (6))
4 4

𝑃𝑛 = 4,603,038.571𝑁

𝑃𝑢 = ∅𝑃𝑛 =0.70(4,603,038.571)

𝑃𝑢 = 3,222,127𝑁

Max. Steel Ratio:


𝜋 2
𝐴𝑠𝑡 4 12 (6)
𝑃𝑠𝑡 𝑚𝑎𝑥 = = = 0.00905 < 0.06( 𝑂𝐾 )
𝐴𝑔 75000

Therefore, use 250mm X 300mm column w/ 6-12mm bars

Spacing Ties:
a. 16 ∗ 𝑑𝑏 = 16(12) = 192
b. 48(𝑡𝑖𝑒 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟) = 48(10) = 480

c. 𝐿𝑒𝑎𝑠𝑡 𝑑𝑖𝑚𝑒𝑛𝑠𝑖𝑜𝑛 𝑜𝑓 𝑐𝑜𝑙𝑢𝑚𝑛 = 250𝑚𝑚

Therefore, use 10mm tie at 250mm O.C

FOOTING (HOUSE/GARAGE)

Column Dimension = 450mm X 450mm

𝑓𝑐 = 20.70𝑀𝑃𝑎

𝑓𝑦 = 276𝑀𝑃𝑎

Footing Dimension = 1.5m X 1.5m

𝑃𝑢 = 1.4𝐷𝐿 + 1.7𝐿𝐿 = 1.4(7050.428) + 1.7(0.48)

𝑃𝑢 = 9872.42𝑘𝑁

9872.42
𝑄𝑢 = = 4387.30 𝑘𝑁⁄𝑚2
2.25
Soil Bearing Capacity

𝑞𝑒 = 190𝑘𝑃𝑎

Area of Footing

7050.428 + 0.48
𝐴=
190
2 2
𝐴 = 37.11 𝑚 ⁄9 𝑐𝑜𝑙𝑢𝑚𝑛𝑠 = 4.12 𝑚 ⁄𝑐𝑜𝑙𝑢𝑚𝑛

Weight of Footing

𝑊 = 0.06(783.434) = 47.006𝑘𝑁

∅0.85𝑓𝑐 𝛽1 600
𝑃𝑎𝑐𝑡𝑢𝑎𝑙 =
𝑓𝑦 (600 + 𝑓𝑦 )

(0,90)(0.85)(20.70)(0.85)600
𝑃𝑎𝑐𝑡𝑢𝑎𝑙 =
276(600 + 276)
𝑃𝑎𝑐𝑡𝑢𝑎𝑙 = 0.0334

Min. Reinforcement Ratio

𝑃𝑓𝑦 0.0334(276)
𝜔= = = 0.4454
𝑓𝑐 20.70

𝑅𝑢 = 𝑓𝑐 𝜔(1 − 0.59𝜔)

𝑅𝑢 = 20.70(0.4454)(1 − 0.59(0.4454))

𝑅𝑢 = 6.797𝑀𝑃𝑎⁄9𝑓𝑜𝑜𝑡𝑖𝑛𝑔 = 0.126 𝑀𝑃𝑎⁄𝑓𝑜𝑜𝑡𝑖𝑛𝑔

Using 16mm diameter bars

𝐴𝑆 = 𝑃𝑏𝑑 = 0.0334(1500 ∗ 1500) = 4050𝑚𝑚2

Number of bars
𝜋 2
4050 = 16 𝑁
4
𝑁 = 10.07 𝑠𝑎𝑦 11 𝑝𝑐𝑠

Adopt 1.5m X 1.5m X 0.3 footing with 11-16mm diameter bars spaced@ 450 on center both
ways

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