PILECAP DESIGN CALCULATIONS Project Name : s Client Name : s Engineer Name : s Design File : D:\Working\RCDC\Documentation\ACI Pilecap 2014\PC ACI 318M-14.rcdx Analysis File : C:\Users\Sudeep.PM\OneDrive - Bentley Systems, Inc\Desktop\RCDC -SampleFiles\Staad-Samples\STAAD Sample file new\RCC Wall - RCDC STAAD Demo.std Analysis Last Modified : 22-Apr-21 12:57:14 PM
Definitions:
 1. α = Coefficient of Thermal Expansion 2. ρact = Percentage steel provided 3. A1 = Area of Base for Load Transfer in 'sqm' 4. A2 = Area of Bearing under column in 'sqm' 5. AsfrPrv = Area of face reinforcement provided in 'sqmm' 6. AsfrReq = Area of face reinforcement required in 'sqmm' 7. AstPrv = Area of tensile reinforcement provided in 'sqmm/m' 8. AstReq = Area of tensile reinforcement required in 'sqmm/m' 9. AsvPrv = Area of shear reinforcement provided in 'sqmm/m' 10. AsvReq = Area of shear reinforcement required in 'sqmm/m' 11. Av = Location of section of shear-check from Pile Center 12. Beff = Effective Width for design for bending and shear in 'mm' 13. Beffsfr = Effective Width for design for Face Reinforcement in 'mm' 14. BMux = Factored Design Bending Moment for pile-cap along column D in 'kNm' 15. BMuy = Factored Design Bending Moment for pile-cap along column B in 'kNm' 16. Cx = Width of column in 'mm' 17. Cy = Length of column in 'mm' 18. D = Depth of Pilecap in 'mm' 19. Deff = Effective Depth of Pilecap in 'mm' 20. DfCol = Distance of Pile center to face of column in 'mm' 21. Icr = Moment of Inertia of concrete crack section in 'mm4' 22. Mcr = Cracking Moment 23. Mx = Bending Moment in column along Column D (from analysis) in 'kNm' 24. My = Bending Moment in column along Column B (from analysis) in 'kNm' 25. P = Axial load in pile due to Ptotal in 'kN' 26. Pcomb = Axial load in column for a load combination in 'kN' 27. Ppile = Axial Load on pile in 'kN' 28. Ptotal = Total vertical load on pile-cap for a load combination in 'kN' 29. Pmx = Axial load on pile due to moment Mx in 'kN' 30. Pmy = Axial load on pile due to moment My in 'kN' 31. sp = Spacing Between bars at outer most layer in 'mm' 32. Temp1 = Peak Hydration temperature in Degree 33. Temp2 = Seasonal Temperature Variations in Degree 34. Vc = Nominal shear strength provided by concrete in 'kN' 35. Vs Capacity = Shear strength capacity of provided shear reinforcement 'kN' 36. Vu = Design shear force in 'kN' 37. Vus = Design shear force for stirrups in 'kN' 38. Vs = Nominal shear strength provided by shear reinforcement, in 'kN' 39. Vx = Shear in Column along major axis (from analysis) in 'kN' 40. Vy = Shear in Column along minor axis (from analysis) in 'kN' 41. y = Neutral axis depth in 'mm' 42. φ = Strength reduction factor in shear 43. φ1 = Strength reduction factor in concrete bearing 44. Φ1Pnb = Bearing strength of column in 'kN' Code References: ACI 318M - 14 1. Ptmax : 7.3.3.1, 8.3.3.1, 9.3.3.1 2. Ptmin : 7.6.1.1 & 8.6.1.1/7.7.2.3 3. Vc : 22.6.5 4. Vcper : 22.5.5, 22.5.6 5. AvReq : 22.5.10.5 & 22.6.7 6. Min Shear Reinf : 7.6.3, 9.6.3 & 10.6.2 7. Max Stirrup Spacing : 9.7.6 & 10.7.6 8. One Way Shear Criteria : 13.2 & 13.4 9. Load transfer : 22.8 10. fs,perm : 24.3.2.1 11. fc,perm : 22.2.2.4.1 12. Wcr : Eq 4.2(a) BS 8007 (For Early / Initial Thermal Cracking) 1. Surface Zone for suspended slab : Figure A.1 2. Surface Zone for ground slab : Figure A.2 3. Factors for the calculation of minimum reinforcement : Table A.1

Design Code : ACI 318M - 14
Pilecap No : PC4
Column No : C4 (700 mm X 700 mm)
Member Ref. No : 301

Clear Cover : 50 mm
Top of pile-cap below ground : 2.88 m

Density of Soil = 18 kN/cum
Founding Depth = 4 m
Pile Capacity in Compression = 1500 kN
Pile Capacity in Tension = 500 kN
Pile Capacity in Shear = 200 kN
Pile Capacity Reduction = 0 %
Pile Capacity Increase for EQ = 0 %
Pile Capacity Increase for Wind = 0 %
Live Load Reduction = 0 %

Consider Capacity Design : Yes
Consider Overburden Pressure : Yes

No. of Piles = 4
Pile Diameter = 600 mm
Pile Spacing = 2.5 x Ø
Alternate Pile Spacing = 2.5 x Ø
Pilecap Size = 2400 X 2400 mm
Pilecap Depth = 1125 mm
Pilecap Offset = 150 mm
Soil Wt. + Pile-cap Wt. = 434.72 kN

Check for Maximum Load on One Pile:
Pcomb = 1640.76 kN
Ptotal = Pcomb + (1 x Soil Wt.) + (1 x Pilecap Wt.)
= 2075.48 kN
Mx = 10.39 kNm
My = -77.44 kNm
P = Ptotal/ No. of Piles
= 518.87 kN
Pmx = 3.46 kN
Pmy = 25.81 kN

Maximum load on pile = 548.15 kN
Allowable load on pile = 1500 x 1.1
= 1650 kN

Check for Maximum Load on Pile Group:
Pcomb = 1616.98 kN
Ptotal = Pcomb + (1 x Soil Wt.) + (1 x Pilecap Wt.)
= 2051.7 kN
Mx = 7.87 kNm
My = -16.72 kNm

Maximum load on pile group = 2051.7 kN
Allowable load on pile group = 4 x 1500 x 1.1
= 6600 kN

Check for Maximum shear on Pile Group:
Pcomb = 1390.09 kN
Ptotal = Pcomb + (1 x Soil Wt.) + (1 x Pilecap Wt.)
= 1824.81 kN
Mx = 100.88 kNm
My = -14.14 kNm
Vx = 8.12 kN
Vy = 38.76 kN
Maximum shear on pile group = sqrt(8.122 + 38.762)
= 39.6 kN
Shear capacity of pile group = 4 x 200 x 1 x 1
= 800 kN

Check for Uplift Load on Pile:
No uplift in any pile

Design for Bending:
Bottom Reinforcement Along Column-D
Ppile = Capacity of pile
= 1500 x 1.5
= 2250 kN

Deff = 1065 mm
Beff = 900 mm
DfCol = 0.4 m
BMux = Ppile X DfCol
= 900 kNm
PtReq = 0.24 %
AstReq (BM) = 2560 sqmm/m
AstPrv = #19 @ 110 C/C
= 2604.73 sqmm/m

Top Reinforcement Along Column-D
D = 1125 mm
AstReq = 2025 sqmm/m
AstPrv = #19 @ 140 C/C
= 2046.57 sqmm/m

Bottom Reinforcement Along Column-B
Ppile = Capacity of pile
= 1500 x 1.5
= 2250 kN

Deff = 1045 mm
Beff = 900 mm
DfCol = 0.4 m
BMuy = Ppile X DfCol
= 900 kNm
PtReq = 0.25 %
AstReq (BM) = 2612 sqmm/m
AstPrv = #19 @ 105 C/C
= 2728.76 sqmm/m

Top Reinforcement Along Column-B
D = 1125 mm
AstReq = 2025 sqmm/m
AstPrv = #19 @ 140 C/C
= 2046.57 sqmm/m

Design for One Way Shear:
Along Column-D
Ppile = Capacity of pile
= 1500 x 1.5
= 2250 kN

Location of critical section is at d/2 from face of column
Section Location from column center = 882.5 mm

Data for Piles
 Pile No Load (kN) % covered Shear (kN) P1 2250 72.08 628.12 P2 2250 72.08 628.12 P3 2250 72.08 628.12 P4 2250 72.08 628.12

Design Shear Force (Vu) = Max. of (Shear due to P1+P3, P2+P4)
= 1256.25 kN
Deff = 1065 mm
Beff = 2400 mm
φVc = 1450.03 kN
Vu < φVc,  Hence Shear Reinforcement is not required

Along Column-B
Ppile = Capacity of pile
= 1500 x 1.5
= 2250

Location of critical section is at d/2 from face of column
Section Location from column center = 872.5 mm

Data for Piles
 Pile No Load (kN) % covered Shear (kN) P1 2250 70.42 665.63 P2 2250 70.42 665.63 P3 2250 70.42 665.63 P4 2250 70.42 665.63

Design Shear Force (Vu) = Max. of (Shear due to P1+P2, P3+P4)
= 1331.25 kN
Deff = 1045 mm
Beff = 2400 mm
φVc = 1425.87 kN
Vu < φ Vc, Hence Shear Reinforcement is not required

Design of Face Reinforcement:
AsfrReq = SFR % X D X Beffsfr
= 0.05 X 1125 X 500 / 100
= 281 sqmm
Asfr Prv = 4-#10
= 284 sqmm

Check for Load Transfer from Column to PileCap
P = 2046.89 kN
A2 = 0.49 sqm
A1 = 5.76 sqm
Base Area = 5.76 sqm
A1 < Base Area
Modification Factor = SquareRoot(A1/A2) < = 2
SquareRoot(A1/A2) = 3.43
Thus, Modification Factor = 2
Φ1Pnb = Φ1 x 0.85 x Modification Factor x A2 x Fck x 1000
= 0.65 x 0.85 x 0.49 x 2 x 20 x 1000
= 10829 kN
Φ1Pnb > P, Hence Safe.