(2) pile cap design_columns
TRANSCRIPT
Project Job ref
Part of structure Calc sheet no rev
/ 0
Drawing ref. Calc by Date Check by Date
Apr-23 Nov-09
Ref Calculations Output
Design of pile cap - PC4
Line of critical shear
Dia. Of pile = 450 mm B
Offest from pile = 150 mm
Column width = 600 mm
Pile spacing (2L) = 1350 mm
Depth of pile cap = 750 mm
Width of pile cap (B) = 750 mm 2L
Bottom cover = 75 mm
Side cover = 50 mm
Ultimate axial load (N) = 1800 kN
Materials
= 35
= 500
= 1.25 (partial saftey factor for concrete - shear)
= 1.15 (partial saftey factor for steel)
Design for main reinforcement:
Effective depth of pile cap (d) = 653 mm
According to Truss theory:
Tension to be resisted by main reinforcement, T = (N x L) / (2 x d)
= 1800 x 675 / (2 x 653)
= 930.3 kN
According to Flexural theory:
Moment parallel to X axis = 607.5 kNm
K = = 0.054
Z = d(0.5 + √(0.25 - K / 0.9)) = 611.14 mm
Therefore Tx = 994.0 kN
Area of steel required = T / (0.87 x fy)
= 994040 / (0.87 x 500)
= 2286
Dia. Of bars using for main reinforcement = 20 mm
No. of bars required = 7.277
Provide No. of bars = 9 Nos
Area of steel provided = 2827 OK
BS 8110 Spacing of main bars = 78.25 mm
Table 3.25 Percentage of steel = 0.503 % > 0.13 % OK
Φ/5
fcu N/mm2
fy N/mm2
Gm
Gm
M / fcu b d2
mm2
mm2
Project Job ref
Newport Station Regeneration 5074908
Part of structure Calc sheet no rev
Car Park - Design of Pile Caps for Columns 9 / 9 / 0
Drawing ref. Calc by Date Check by Date
SJ Jun 08 CMN Jun-08
Ref Calculations Output
Check for shear:
Shear stress along critical section (v) = (N / 2) / (B x d)
= (1800 / 2) / (750 x 653)
3.4.5.2 = 1.838 < 5 OK
BS 8110
Table 3.8 100 As / bv d = 0.577 %
Design strength of concrete for shear resistance = 35
= 0.885
= 0.52
Critical section from face of the column (av) = (675 - 300 - 0.3 x 450)
= 240 mm
3.4.5.8 Enhanced shear stress = 2.834 > 1.838 OK
Hence, shear links are not required. However provide nominal T12 links @ 200 c/c.
Side face reinforcement:
3.12.5.4 Dia. Of bar used for side face reinforcement = 16 mm
Spacing of bar =
= 256 mm
Hence, provide side face reinforcement - 2 nos. T16 bars
N/mm2 N/mm2
N/mm2
(400 / d) (1/4)
Design shear resistance ( vc) N/mm2
N/mm2
( ϕ2 x fy ) / b
Project Job ref
Part of structure Calc sheet no rev
/ 0
Drawing ref. Calc by Date Check by Date
BVR Apr-23 Nov-09
Ref Calculations Output
Design of pile cap - PC2 (For 750x300 column) Y
Dia. Of pile ( Φ ) = 450 mm
Offest from pile = 150 mm
Column width in X-direction = 600 mm
Column width in Y-direction = 600 mm
Effective length of pile cap (2 Lx) = 1350 mm 2100 2Ly 750
Effective length of pile cap (2 Ly) = 1350 mm Φ
Depth of pile cap = 750 mm
Bottom cover = 75 mm
Side cover = 50 mm
Ultimate axial load (N) = 3500 kN 2Lx X
Reaction of each pile (N/3) = 1167 kN
2100
Materials
= 35 = 1.25 (partial saftey factor for concrete - shear)
= 500 = 1.15 (partial saftey factor for steel)
Design for main reinforcement:Effective depth of pile cap (d) = 637.5 mm
According to Truss theory:
Effective length of pile cap (2 Lxy) = 1509.4 mm
Tension to be resisted by main reinforcement, Txy = (2N x Lxy) / (9 x d)
= 2 x 3500 x 754.675 / (9 x 637.5)
= 920.74 kN
Tension to be resisted by main reinforcement, Ty = (2N x Ly) / (9 x d)
= 2 x 3500 x 675 / (9 x 637.5)
= 823.53 kN
Net tension to be resisted by main reinforcement, Tx = 2 x Txy cos 26.57
= 2 x 920.74 x cos 26.57
= 1647.1 kN
Net tension to be resisted by main reinforcement, Ty = 2 x Txy sin 26.57 + 823.53
= 1647.1 kN
According to Flexural theory:
Moment parallel to X axis = 700 kNm
K = = 0.023
Z = d(0.5 + √(0.25 - K / 0.9)) = 605.63 mm
Moment parallel to Y axis = 437.5 kNm
K = = 0.015
Z = d(0.5 + √(0.25 - K / 0.9)) = 605.63 mm
Therefore Tx = 1155.8 kN
Therefore Ty = 722.39 kN
In X-direction
Area of steel required in X-direction = Tx / (0.87 x fy)
= 1647100 / (0.87 x 500)
= 3786.4
Dia. Of bars using for main reinforcement = 25 mm
No. of bars required = 7.7137
Provide No. of bars = 14 Nos
Area of steel provided = 6872.2 OK Provide
BS 8110-1 Spacing of main bars = 153.8 mm 14 Nos. T25 bars
Table 3.25 Percentage of steel = 0.44 % > 0.13 % OK
av
Φ/5
av
fcu N/mm2 Gm
fy N/mm2 Gm
M / fcu b d2
M / fcu b d2
mm2
mm2
Project Job ref
Newport Station Regeneration 5074908
Part of structure Calc sheet no rev
Car Park - Design of Pile Caps for Columns 5 / 9 / 0
Drawing ref. Calc by Date Check by Date
SJ Jun 08 CMN Jun-08
Ref Calculations Output
In Y-direction
Area of steel required in Y-direction = Ty / (0.87 x fy)
= 1647100 / (0.87 x 500)
= 3786.4
Dia. Of bars using for main reinforcement = 25 mm
No. of bars required = 7.7137
Provide No. of bars = 14 Nos
Area of steel provided = 6872.2 OK Provide
Spacing of main bars = 150 mm 14 Nos. T25 bars
Percentage of steel = 0.44 % > 0.13 % OK
Check for shear:
Shear stress along critical section (v) = (2 N/3) / (B x d)
= 2 (3500000 / 3) / (2100 x 637.5)
3.4.5.2 = 1.74 < 5 OKBS 8110
Table 3.8 100 As / bv d = 0.52 %
Design strength of concrete for shear resistance = 35
= 0.89
= 0.51
= (2/3)x1350 - 600/2 - 0.3x450
= 465 mm
3.4.5.8 Enhanced shear stress = 1.4 < 1.74 0
Hence, shear links are required
Check for punching shear:
At column face:
Punching stress = N / (u d)
Perimeter of column (u) = 2400 mm
Punching stress = 2.29 < 5 OK
At Φ/5 from pile face:
Punching stress = N / (u d)
Critical perimeter (u) = 3558.7 mm
Punching stress = 1.54
Enhanced shear stress = 1.39 0
Hence, shear links are required
Side face reinforcement:
3.12.5.4 Dia. Of bar used for side face reinforcement = 16 mm
Spacing of bar =
= 256 mm
Hence, provide side face reinforcement - 2 nos. T16 bars
mm2
mm2
N/mm2 N/mm2
N/mm2
(400 / d) (1/4)
Design shear resistance ( vc) N/mm2
Critical section from face of the column (av)
N/mm2
N/mm2 N/mm2
N/mm2
N/mm2
( ϕ2 x fy ) / b
Project Job ref
Part of structure Calc sheet no rev
/ 0
Drawing ref. Calc by Date Check by Date
Apr-23 Nov-09
Ref Calculations Output
Design of pile cap - PC1 Y
Dia. Of pile ( Φ ) = 450 mm
Offest from pile = 150 mm
Column width in X-direction = 600 mm
Column width in Y-direction = 600 mm
Pile spacing in X-direction (2 Lx) = 1350 mm 2100 2Ly
Pile spacing in Y-direction (2 Ly) = 1350 mm
Depth of pile cap = 750 mm
Bottom cover = 75 mm
Side cover = 50 mm
Ultimate axial load (N) = 4300 kN 2Lx X
K' = 0.156
2100
Materials
= 32
= 500
= 1.25 (partial saftey factor for concrete - shear)
= 1.15 (partial saftey factor for steel)
Design for main reinforcement:
Effective depth of pile cap (d) = 662.5 mm
According to Truss theory:
Reynolds Tension to be resisted by main reinforcement, Ty = (2 N Ly)/(4 d)
Hand book = 2 x 4300 x 675 / (4 x 662.5)
= 2191 kN
Tension to be resisted by main reinforcement, Tx = (2 N Lx)/(4 d)
= 2 x 4300 x 675 / (4 x 637.5)
= 2276 kN
According to Flexural theory:
Moment parallel to Y axis = 806.25 kNm
K = = 0.027
Z = d(0.5 + √(0.25 - K / 0.9)) = 629.375 mm
Moment parallel to X axis = 806.25 kNm
K = = 0.03
Z = d(0.5 + √(0.25 - K / 0.9)) = 605.625 mm
Therefore Ty = 1281 kN
Therefore Tx = 1331.3 kN
In Y-direction
Area of steel required in Y-direction = Ty / (0.87 x fy)
= 2190570 / (0.87 x 500)
= 5036
Dia. of bars for main reinforcement = 25 mm
No. of bars required = 10.259
Provide No. of bars = 12 Nos
Area of steel provided = 5890 OK Provide
BS 8110-1 Spacing of main bars = 181.82 mm 12 Nos. T25 bars
Table 3.25 Percentage of steel = 0.37 % > 0.13 % OK
av2
av1
fcu N/mm2
fy N/mm2
Gm
Gm
M / fcu b d2
M / fcu b d2
mm2
mm2
Project Job ref
Newport Station Regeneration 5074908
Part of structure Calc sheet no rev
Car Park - Design of Pile Caps for Columns 3 / 9 / 0
Drawing ref. Calc by Date Check by Date
SJ Jun 08 CMN Jun-08
Ref Calculations Output
In X-direction
Area of steel required in X-direction = Tx / (0.87 x fy)
= 2276470 / (0.87 x 500)
= 5233
Dia. of bars for main reinforcement = 25 mm
No. of bars required = 10.661
Provide No. of bars = 14 Nos
Area of steel provided = 6872 OK Provide
BS 8110-1 Spacing of main bars = 150.00 mm 14 Nos. T25 bars
Table 3.25 Percentage of steel = 0.44 % > 0.13 % OK
Check for shear in Y-direction:
Shear stress along critical section (v) = (N / 2) / (Bx x d)
= (4300000 / 2) / (2100 x 662.5)
= 1.55 < 5 OK
Table 3.8 100 As / bv d = 0.42 %
Design strength of concrete for shear resistance = 32
= 0.88
= 0.45
= 1350/2 - 600/2 - 0.3*450
= 240 mm
3.11.4.4.a = 2.5 > 1.55 OK
Hence, shear links are not required.
Check for shear in X-direction:
Shear stress along critical section (v) = (N / 2) / (By x d)
= (4300000 / 2) / (2100 x 637.5)
3.4.5.2 = 1.61 < 5 OK
BS 8110
Table 3.8 100 As / bv d = 0.52 %
Design strength of concrete for shear resistance = 32
= 1
= 0.55
3.11.4.4.a = 1350/2 - 600/2 - 0.3*450
= 240 mm
3.4.5.8 = 2.93 > 1.61 OK
Hence, shear links are not required.
Check for punching shear:
At column face:
Punching stress = N / (u d)
Perimeter of column (u) = 2400 mm
Punching stress = 2.76 < 5 OK
Side face reinforcement:
3.12.5.4 Dia. Of bar used for side face reinforcement = 16 mm
Spacing of bar =
= 256 mm
Hence, provide side face reinforcement - 2 nos. T16 bars
mm2
mm2
N/mm2 N/mm2
N/mm2
(400 / d) (1/4)
Design shear resistance ( vc) N/mm2
Critical section from face of the column (av)
Enhanced shear stress = 2 d vc / av N/mm2
N/mm2 N/mm2
N/mm2
(400 / d) (1/4)
Design shear resistance ( vc) N/mm2
Critical section from face of the column (av)
Enhanced shear stress = 2 d vc / av N/mm2
N/mm2 N/mm2
( ϕ2 x fy ) / 500