PILECAP DESIGN CALCULATIONS
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Design File	:	D:\Bentley\Common data\Bentley Communities\IS\Validation Sheets\IS code_Validation problem_Updated\Pile-cap\pilecap design.rcdx
Analysis File	:	D:\Bentley\000 RCDC 2010\10.0.0\Standard model for Demo\Staad\RCDC-Staad-Demo -with RCC wall.std
Analysis Last Modified	:	6/16/2020 4:07:28 PM

Definitions: 1. α = Coefficient of Thermal Expansion 2. ε1 = Strain at level considered, Calculated ignoring the stiffening of the concrete in tension zone 3. εm = Average steel strain at level considered 4. ρact = Percentage steel provided 5. ρcrit = Percentage steel critical as per code 6. A1 = Area of Base for Load Transfer 7. A2 = Area of Bearing under column 8. acr = Distance from the point considered to the surface of the nearest longitudinal bar 9. AsfrPrv = Area of face reinforcement provided 10. AsfrReq = Area of face reinforcement required 11. AstPrv = Area of tensile reinforcement provided 12. AstReq = Area of tensile reinforcement required 13. AsvPrv = Area of shear reinforcement provided 14. AsvReq = Area of shear reinforcement required 15. Av = Location of section of shear-check from Pile Center 16. Beff = Effective Width for design for bending and shear 17. Beffsfr = Effective Width for design for Face Reinforcement 18. BMux = Factored Bending Moment for pile-cap along column D 19. BMuy = Factored Bending Moment for pile-cap along column B 20. D = Depth of Pilecap 21. Deff = Effective Depth of Pilecap 22. DfCol = Distance of Pile center to face of column 23. Ec = Modulus of elasticity of concrete 24. Es = Modulus of elasticity of steel 25. Fst = Stress in steel 26. Mx = Bending Moment in column along Column D 27. My = Bending Moment in column along Column B 28. P = Axial load in pile due to Ptotal 29. Pcomb = Axial load in column for a load combination 30. Ppile = Axial Load on pile 31. Ptotal = Total vertical load on pile-cap for a load combination 32. Pmx = Axial load on pile due to moment Mx 33. Pmy = Axial load on pile due to moment My 34. sp = Spacing Between bars at outer most layer 35. Tc = Design Shear Strength of Concrete 36. Tce = Enhanced Shear Strength of concrete 37. Temp1 = Peak Hydration temperature 38. Temp2 = Seasonal Temperature Variations 39. Tv = Nominal shear stress 40. Vu = Design shear force 41. Vus = Design shear force for stirrups 42. Wcr = Surface Crack Width   Code References: IS 456 1. Ptmax : clause 26.5.1.1 2. Ptmin : clause 26.5.2.1 3. Pt : clause 38 4. Tc : clause 40.2.1 5. Tcmax : clause 40.2.3 6. AsvReq : clause 40.4 7. Min Shear Reinf : clause 26.5.1.6 8. Max Stirrup Spacing : clause 26.5.1.5 9. One Way Shear Criteria : clause 34.2.4.2 10. Load transfer : clause 34.4 11. Ptnominal : clause 34.5.2 12. crack width calculation : Annex-F 13. cracking : clause. 35.3.2   IS 2911 Part-1 Section 2 1. Pile capacity check : clause 5.10   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 : IS 456 + IS 13920 - 2016   Pilecap No : PC23   Column No : C23 (400mm X 700mm) Member Ref. No : 1901           Concrete Grade : M20   Steel Grade : Fe415   Clear Cover : 50 mm Top of pile-cap below ground : 3.3 m         Density of Soil = 18 kN/cum Founding Depth = 4 m Pile Capacity in Compression = 1000 kN Pile Capacity in Tension = 350 kN Pile Capacity in Shear = 250 kN Pile Capacity Reduction = 0 % Pile Overloading = 10 % Pile Group Overloading = 10 % Pile Capacity Increase for EQ = 25 % Pile Capacity Increase for Wind = 25 % Live Load Reduction = 0 %         Consider Capacity Design : No   Consider Overburden Pressure : No           No. of Piles = 3   Pile Diameter = 750 mm Pilecap Offset = 150 mm Pile Spacing = 2.5 x Ø Pilecap Size = 2481 mm (edge) Pilecap Depth = 700 mm Pile-cap Wt. = 95.029 kN                   Check for Maximum Load on One Pile: Critical Load Combination : [4] : (LOAD 1: LOAD CASE 1) +(LOAD 2: LOAD CASE 2) +(LOAD 4: LOAD CASE 4 EQ-Y) Pcomb = 2822.16 kN Ptotal = Pcomb + Pilecap Wt.   = 2917.19 kN Mx = -261.34 kNm My = -6.77 kNm P = Ptotal/ No. of Piles   = 972.4 kN Pmx = 160.947 kN Pmy = 0 kN         Maximum load on pile = 1133.34 kN Allowable load on pile = 1000 x 1.25   = 1250 kN   Check for Maximum Load on Pile Group: Critical Load Combination : [1] : (LOAD 1: LOAD CASE 1) +(LOAD 2: LOAD CASE 2) Pcomb = 2835.22 kN Ptotal = Pcomb + Pilecap Wt.   = 2930.25 kN Mx = -15.43 kNm My = -2.58 kNm         Maximum load on pile group = 2930.25 kN Allowable load on pile group = 3 x 1000 x 1.1   = 3300 kN   Check for Maximum shear on Pile Group: Critical Load Combination : [4] : (LOAD 1: LOAD CASE 1) +(LOAD 2: LOAD CASE 2) +(LOAD 4: LOAD CASE 4 EQ-Y) Pcomb = 2822.16 kN Ptotal = Pcomb + Pilecap Wt.   = 2917.19 kN Mx = -261.34 kNm My = -6.77 kNm Vx = 3.05 kNm Vy = -87.03 kNm Maximum shear on pile group = sqrt(3.052 + -87.032) = 87.09 kN Shear capacity of pile group = 3 x 250 x 1 x 1.25   = 937.5 kN   Check for Uplift Load on Pile: No uplift in any pile   Design for Bending: Bottom Reinforcement Along Parallel Edge Critical Load Combination : [6] : 1.5 (LOAD 1: LOAD CASE 1) +1.5 (LOAD 2: LOAD CASE 2) Pcomb = 4252.83 kN Ptotal = Pcomb + Pilecap Wt.   = 4395.373 kN Mx = -23.14 kNm My = -3.87 kNm Ppile = Max Load on pile   = 1460.06 kN         Deff = 620 mm Beff = 1050 mm DfCol = 0.74 m BMux = Ppile X DfCol   = 1076.8 kNm PtReq = 0.91 % AstReq (BM) = 5658 sqmm/m AstPrv = T32 @ 140 C/C   = 5744.64 sqmm/m   Top Reinforcement Along Parallel Edge D = 700 mm   <= 1000 mm, Hence AstReq (BM) = Min Pt for Top Reinforcement X D X 1000   = 0.06% X 700 X 1000   = 420 sqmm/m AstPrv = T10 @ 185 C/C   = 424.54 sqmm/m   Bottom Reinforcement Along Perpendicular Edge Critical Load Combination : [6] : 1.5 (LOAD 1: LOAD CASE 1) +1.5 (LOAD 2: LOAD CASE 2) Pcomb = 4252.83 kN Ptotal = Pcomb + Pilecap Wt.   = 4395.373 kN Mx = -23.14 kNm My = -3.87 kNm Ppile = Max Load on pile   = 1479.38 kN         Deff = 640 mm Beff = 1050 mm DfCol = 0.73 m BMuy = Ppile X DfCol   = 1083.69 kNm PtReq = 0.85 % AstReq (BM) = 5426 sqmm/m AstPrv = T32 @ 145 C/C   = 5546.55 sqmm/m   Top Reinforcement Along Perpendicular Edge D = 700 mm   <= 1000 mm, Hence AstReq (BM) = Min Pt for Top Reinforcement X D X 1000 = 0.06% X 700 X 1000   = 420 sqmm/m AstPrv = T10 @ 185 C/C   = 424.54 sqmm/m         Design for One Way Shear: Along Parallel Edge Critical Load Combination : [6] : 1.5 (LOAD 1: LOAD CASE 1) +1.5 (LOAD 2: LOAD CASE 2) Pcomb = 4252.83 kN Ptotal = Pcomb + Pilecap Wt.   = 4395.37 kN Mx = -23.14 kNm My = -3.87 kNm Ppile = Max Load on pile   = 1479.377 kN         Location of critical section is at d/2 from face of column Section Location from column center = 510 mm         Data for Piles       Pile No Load (kN) % covered Shear (kN) P1 1479.38 0 0 P2 1460.06 100 1460.06 P3 1455.94 100 1455.94   Design Shear Force (Vu) = Max. of (Shear due to P2, P3)   = 1460.06 kN Deff = 620 mm Beff = 2315.45 mm Tv = Vu/(Beff x Deff)   = 1.02 N/sqmm Tc = 0.6 N/sqmm Av = 427.5 mm Shear enhancement factor = 2 X Deff / Av     = 2.9 Enhanced shear strength (Tce) = 1.75 N/sqmm Tv < Tce, Hence Shear Reinforcement is not required   Along Perpendicular Edge Critical Load Combination : [6] : 1.5 (LOAD 1: LOAD CASE 1) +1.5 (LOAD 2: LOAD CASE 2) Pcomb = 4252.83 kN Ptotal = Pcomb + Pilecap Wt.   = 4395.37 kN Mx = -23.14 kNm My = -3.87 kNm Ppile = Max Load on pile   = 1479.377 kN         Location of critical section is at d/2 from face of column Section Location from column center = 670 mm         Data for Piles       Pile No Load (kN) % covered Shear (kN) P1 1479.38 100 1479.38 P2 1460.06 67.16 479.42 P3 1455.94 67.16 478.06   Design Shear Force (Vu) = Max. of (Shear due to P1, P2+P3)   = 1479.38 kN Deff = 640 mm Beff = 1688.79 mm Tv = Vu/(Beff x Deff)   = 1.37 N/sqmm Tc = 0.59 N/sqmm Av = 412.53 mm Shear enhancement factor = 2 X Deff / Av     = 3.1   Enhanced shear strength (Tce) = 1.82 N/sqmm Tv < Tce, Hence Shear Reinforcement is not required   Design of Face Reinforcement: AsfrReq = SFR % X D X Beffsfr = 0.05 X 700 X 500 / 100 = 175 sqmm Asfr Prv = 3-T10 = 236 sqmm   Check for Load Transfer from Column to PileCap Critical Analysis Load Combination = Critical Load Combination : [6] : 1.5 (LOAD 1: LOAD CASE 1) +1.5 (LOAD 2: LOAD CASE 2) P = 4252.83 kN A2 = 0.28 sqm A1 = 5.43 sqm Base Area = 5.43 sqm A1 < Base Area   Modification Factor = SquareRoot(A1/A2) < = 2 SquareRoot(A1/A2) = 4.4   Thus, Modification Factor = 2   Concrete Bearing Capacity = 0.45 X Fck X Modication Factor X Column Area   = 5040 kN Concrete Bearing Capacity > P, Hence Safe.