Project Title : VG800 Machine at 51 Calshot Road

Designer : RAM Date : 26/6/2023

Bore Ref : ABH-2
Type of Pile : Bored Pile
Size of Pile (d) : 300 mm Diameter
Penetration Depth : 22.0 m from COL COL = 100.300 m
Penetration Depth : 22.100 m from BHL BHL = 100.400 m
Cut-Off Level : 0.100 m from BHL TL = 78.300 m
Perimeter of Pile (ls) : 0.942 m
Area of Bearing Point (Ab) : 0.071 m2
Ks (Skin Friction)= 2 N (<200kPa)
Ks (Skin Friction)= 2 N(Rock)
Ref: Bored piles: Old Alluvium (OA) Ks = 2N to 3N <= 300 kPa
Bt Timah & Jurong Formation Ks= 1.5N to 2.5N <= 150kPa
Other soil type Ks = 1N to 1.5N <= 150 kPa
Drivel pile All soil Type Ks = 2N to 5N <= 200 kPa
fb = 100 Nb ≤ 10000 kPa
= 8000 kPa for N > 100
= 11000 kPa for Rock
Density of Soil (W) : 17.0 kN/m3

Combination Design Capacity (kN) FOS

1 263.66 3.17
2 220.32 2.33

Table of Partial Safety Factors Design Approach 1 - Alternative Method { EC7-1 7.6.2.3(8) }
Parameters Combination 1 Combination 2
A1 R1 ADOPT A2 R4 R4+test ADOPT
UnFavourable 1.35 1.35 1.0
Permanent actions (G) gG 1.0
Favourable 1.0 1.0
UnFavourable 1.5 1.5 1.3
Variable actions (Q) gQ 1.3
Favourable 0 0
Soil Properties SEE □□) Above □□) □□)
Driven 1.0 1.0 1.5 1.3
Shaft resistance (Rs) gs 1.6
Bored 1.0 1.6 1.4
Driven 1.0 1.0 1.7 1.5
Base resistance (Rb) gb 2.0
Bored 1.0 2.0 1.7
Driven 1.0 1.0 1.7 1.5
Total resistance (Rt) gt 2.0
Bored 1.0 2.0 1.7
Tensile resistance (Rs;t) gs;t 1.0 1.0 2.0 1.7 2.0

Model factor gRd = 1.4 { NA to SS EN 1997-1 A.3.3.2 Para 3 }

Pile Capacity Calculations
Calculation of Skin Friction Resistance by Meyerhof's Method :

Layers Depth (m) Thickness (m) SPT (N) fs (kN/m2) Qs (kN)

Ground 0.080
1st layer up to 5.08 5.00 5 10 47
2nd layer up to 10.08 5.00 6 12 57
3rd layer up to 15.08 5.00 11 22 104
4th layer up to 18.08 3.00 17 34 96
5th layer up to 21.08 3.00 100 200 565
6th layer up to 22.08 1.00 100 200 188
7th layer up to
8th layer up to
9th layer up to
10th layer up to
11th layer up to
12th layer up to
13th layer up to
14th layer up to
Total Qs = 1057 kN

Note 1 : The cut-off level should be within the 2nd layer.

Note 2 : The penetration depth should reach at least the 3rd layer.

Negative Skin Friction :

Depth of Water Table = 1 m below GL

Depth of Marine/Peaty Clay (Ls)= 22.5 m below GL
Depth of neutral plan for NSF= 18 m below GL
QNSF = fsneg x C x Ln
fsneg = b x sv'
Efficiency of mobilised NSF, h = 0.67
C: Circumference of Pile Ln : Depth of Embedment Within layer in Consideration
Layers Depth (m) Thickness (m) b sv' fsneg (kN/m2) Qn (kN)
Ground
1st layer up to 0.00 0 0.00 0 0
2nd layer up to 0.00 0 0.00 0 0
3rd layer up to 0.00 0 0.00 0 0
4th layer up to 0.00 0 0.00 0 0
5th layer up to 0.00 0 0.00 0 0
6th layer up to 0.00 0 0.00 0 0
7th layer up to 0.00 0 0.00 0 0
8th layer up to 0.00 0 0.00 0 0

Total QNSF (kN) = 0

 Calculation of End Bearing Resistance :

qb = Kb(40Nb)
SPT blow count at pile base (Nb): 100
Kb: 1
Ultimate base resistance, (qb): 1600 kN/m2 Rock
End Bearing Resistance (Qb) : 113 kN
Note: Pile socket less than 4d into founding layer (Soil), adjustment has been made to Base stress

Geotechnical Compression Resistance of Pile

▪ Combination 1:
Rc;d = 836 kN { = Rs;d + Rb;d } Rs;d = 755.33 kN { = Rs;k / gs /gRd }
Rb;d = 80.784 kN { = Rs;b / gs /gRd }
▪ Combination 2:
Rc;d = 512 kN { = Rs;d + Rb;d } Rs;d = 472.08 kN { = Rs;k / gs /gRd }
Rb;d = 40.392 kN { = Rs;b / gs /gRd }
Design Compressive Actions:
▪ Combination 1:
Factored Permanent action Gk +
Variable actions Qk under A1 = 263.66 kN
Design Compressive Force, Fc,d = 263.66 kN

Over Design Factor (Rc,d/Fc,d) = 3.17 OK

▪ Combination 2:
Factored Permanent action Gk +
Variable actions Qk under A2 = 220.32 kN
Design Compressive Force, Fc,d = 220.32 kN

Over Design Factor (Rc,d/Fc,d) = 2.33 OK

□□ Geotechnical Tensile Resistance of Pile
▪ Combination 1:
3
W'p = 19.79 kN { = (gp - gw)Vp/gg , gp = 24 kN/m , Vp = 1.55509 m3, gg = 1.10 }
Rt;d = 775 kN { = Rs;k / gs;t / gRd + W'p } *Pile r/f cage to be full length of pile
▪ Combination 2:
W'p = 19.79 kN { = (gp - gw)Vp/gg }
Rt;d = 397 kN { = Rs;k / gs;t / gRd + W'p }

Design Tension Actions:

▪ Combination 1:
Factored Permanent action Gk +
Variable actions Qk under A1, Ft,d = 0 kN

Over Design Factor (Rt,d/Ft,d) = NT OK

▪ Combination 2:
Factored Permanent action Gk +
Variable actions Qk under A2, Ft,d = 0 kN

Over Design Factor (Rt,d/Ft,d) = NT OK

□□ Check Structural Compressive Capacity of Pile

2
Dnom = 300 mm fcd = 20.606 N/mm { = acc fck / gm;c , EN 1992-1-1 3.1.6(1)P }
2
Deff = 280 mm { EN 1992-1-1 2.3.4.2(2) } fck = 40 N/mm { = fck;cyn OR 0.80 fck;cube }
2
As = 04H32 3216.99 mm acc = 0.85 { NA to SS EN 1992-1-1 Table NA.1 }
2
Ac = 58358 mm gm;c = 1.5 { EN 1992-1-1 Table 2.1N }
Pc;d = 2601.22 kN { = fc;d Ac + fs;d As } fs;d = 434.783 N/mm2 { = fyk / gm;s }
2
Fc;d = 264 kN < 2601.22 kN O.K.! fyk = 500 N/mm { Characteristic strength of reinf bars }
gm;s = 1.15 { EN 1992-1-1 Table 2.1N }
kf = 1.1 { EN 1992-1-1 cl2.4.2.5(2) }

□□ Check Structural Tensile Capacity of Pile

2
fctd = 1.49 N/mm { = act fctk,0.05 / gm;c , EN 1992-1-1 3.1.6(2)P }
Tension Capacity Ptd = 1485.56 kN { = fctd Ac + fs;d As } act = 1
Ft,d = 0 kN < 1485.56 kN O.K.! fctk,0.05 = 2 N/mm2 { Table 3.1 EC2 }
□□ Crack Control due to direct tension (cl 7.3.2 EC2-1 & 7.3.3 EC2-3)
Tensile force @ SLS = 1
Allowable crack width, wk,all = 0.3 mm
2
Stress in tension steel, ss = 0.31 N/mm
kc = 1
k= 1
kt = 0.6
2
fct, eff = fctm = 3.51 N/mm {fctm=0.3xfck(2/3) <=C50/60, or 2.12xln(1+(fck+8)/10) >C50/60}
2
Area of Concrete within tension zone, Act = 0.07 m
2
Minimum reinforcement area, As,min = 496 mm {As,min.σs = kc k fct,eff Act}
OK!
pile effective dia, deff = 300 mm
hc,eff = 50.00 mm
2
Ac,eff = 36052.92 mm
rp,eff = 0.089 {=As/Ac,eff}
Rebar elastic modulus, Es = 200 GPa
Ecm = 35 GPa {22[fcm/10]^0.3, table 3.1 EC2}
Effective modulus ratio, ae = 5.68 {=Es/Ecm}
esm-ecm = 9.33E-07 {[σs- kt (fct,eff/ρp,eff)(1+αe.ρp,eff)]/Es≥0.6σs/Es}
Cover to rebar, c= 75 mm
Max crack spacing, Sr,max = 376.9325 mm {3.4*c+0.34*f/rp,eff}

Crack width, wk = 0.0004 mm OK!