STRUCTURAL DESIGN OF PILE 400 MM DIA (TOP 12. 6 NO. ONLY) Diameter of pile = 400 mm Working Load (Compression) P = 1000 kN Load Factor (Ref.Table 2.2 of BS:8110 :1997, Page 9)= 1000 x 1.5 =1500 kN Structural Design of Pile I) Material properties : a) Characteristic cube strength of concrete = Fcu- 40 Mpa b) Characteristic strength of steel = Fy –Gr. 420– 420 Mpa II) Proposed Reinforcement: a) Main Reinforcement = 8T16 mm dia b) Shear Reinforcement = T10@ 150 c/c helical links (Ref. 3.12.7.1 & 3.12.7.2 of BSS 8110-1:1997, Page 79) III) Pile Details Pile size = 400 mm dia. Clear cover = 75 mm Working load = 1000 kN Fcu = 40 N/mm2 Fy = 420 n/mm2 Section Area = 125600 mm2 Main Reinforcement Dia. = 20 mm No. of Rods = 8 nos. Reinforcement area of 16 mm Dia = 2512 mm2

IV) Check for Stresses in Concrete: Referring to clause 7.4.4.3.1 of BS : 8004 – 1986, allowable compressive stress under working load should bot exceed 25% of the specified works cube strength at 28 days calculated on the total cross sectional area of the Working stress = 1000 x 1000 (3.14/4 x 400 ^2) = 4.906 N/ mm2

Allowable Stress = 0.25 x 40 = 10.00 N/mm2 4.906 N/mm2

Hence O.K. Check for compression capacity of piles referring to BS: 8110 (Part-I, Clause 3.8.1.3). Since the 'N' value of soil is high in top layers so there is no unsupported length of the pile Slenderness is not taken. BS 811-1 Cl. 3.8.1.3 Referring to BS: 8110 part-I, Clause 3.8.4.3 for nominal eccentricity of short columns resisting moments and axial forces, which stress that the column may be designed. So that the design axial load does not exceed the value of N given by. N = 0.4 x Fcu x Ac + 0.8 x Asc x Fy = 0.4x40x 125600+0.8x2512x420 2853632 N = 2853.632 kN Allowable compressive load

= 2853.6 > 1000 x 1.5 2500 kN Hence safe

V) Design of pile due to axial load and Bending: Axial Load Load Factor (Ref: Table 2.1 of BS:8110-1:1997, Page 8) Factored axial load, P = 1000 x 1.2 = 1200 kN Moment is taken from the graph = 39.0 =39.0 kN-m Factor Moment, = 39 x 1.2 = 46.8 kNm Design Moment M = 46.8 = 46.8 kNm (Referring to CP:110 Part-3 Page No. 132 for circular sections-Available lower grade chart is considered) Fcu = 40N/mm2 Fy = 420N/mm2 h = 400 mm hs = 400 – (2x75) – 2 x 10 = 230

Hs/h = 230/400 = 0.57 M/h3 = 46.8 x 10^6 / 400^3 0.73125 P/h22 = 1200 x 10^3 / 400^2 7.50 Hence O.K. Shear Check: Factor Moment, M = 46.80 kNm Factored vertical Load, P = 1200kN M/P = 46.8 / 1200 =0.039 m 0.6 h = 0.6 x 0.4 0..24 m M/P < 0.6 h Shear check is not required (As per BS:8110-1, 1997 Cl.3.8.4.6 shear check is not required) VI) Design Summary Diameter of Pile 400 mm Grade of concrete OPC40 Grade reinforcement steel 420 N/ mm2 Main reinforcement 8 T 20 Helical reinforcement T 10 @ 150 c/c helical links