Piling-Design-Re 1.pdf

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PIL

ING DESIGN

CALCULATIONS

PROPOSED 33 STOREY

OFFICE TOWER

Plo

Plot

t No. 0325126

No. 03251264 @ S

4 @ SEEF AREA,

EEF AREA,

BAHRAIN

JUL

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List of Contents:

1.0 1.0 Location plan

Location plan

2.0 2.0 Soil Report

Soil Report

3.0 3.0 Piling Design

Piling Design Calculation

Calculationss

3.1 3.1 900mm Bored Pile

900mm Bored Pile

4.0 4.0 Reinforcement Details

Reinforcement Details

5.0 5.0 Load Test Procedure

Load Test Procedure

6.0

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(4)

(5)

(6)

(7)

Diamater : 900 mm, pile diameter

Pile Capacity In Compression

FOS 1 : 3.00 factor of safety for skin friction

FOS 2 : 3.00 factor of safety for base resistance

Depth Ultimate Allowable Ultimate Allowable Wt. of Ultimate Allowable

friction friction end bearing end bearing Pile Capacity Capacity

0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1.5 0 0 0 0 0 0 0 2 2 1 126 42 8 128 35 2.5 6 2 207 69 15 212 55 3 14 5 2,032 677 23 2,046 659 3.5 23 8 1,017 339 31 1,040 316 4 34 11 892 297 38 926 271 4.5 48 16 1,052 351 46 1,099 321 5 63 21 1,199 400 53 1,262 367 5.5 79 26 905 302 61 984 267 6 98 33 1,087 362 69 1,185 326 6.5 124 41 3,904 1,301 76 4,027 1,266 7 150 50 2,731 910 84 2,881 876 7.5 179 60 3,027 1,009 92 3,206 977 8 211 70 3,330 1,110 99 3,541 1,081 8.5 247 82 5,707 1,902 107 5,954 1,878 9 286 95 5,224 1,741 114 5,510 1,722 9.5 333 111 5,726 1,909 122 6,058 1,897 10.5 672 224 5,726 1,909 137 6,398 1,995 11.5 1,011 337 5,726 1,909 153 6,737 2,093 12.5 1,351 450 5,726 1,909 168 7,076 2,191 14.5 2,029 676 5,726 1,909 198 7,755 2,387 15.5 2,369 790 5,726 1,909 214 8,094 2,484 16.5 2,708 903 5,726 1,909 229 8,433 2,582 18.5 3,386 1,129 5,726 1,909 259 9,112 2,778 19.5 3,726 1,242 5,726 1,909 275 9,451 2,876 20.5 4,065 1,355 5,726 1,909 290 9,791 2,974 21.5 4,404 1,468 5,726 1,909 305 10,130 3,071 22.5 4,744 1,581 5,726 1,909 320 10,469 3,169 23.5 5,083 1,694 5,726 1,909 336 10,808 3,267

L pile =

m, provided pile length below road level

=

m, pile length below Cut-off level

P prov.

kN, provided pile capacity

P req. =

kN, Required pile capacity

2,876

Since Pprov > Preq ---> OK Pile length is Ad equate

18.5 2,800

19.5 Pile Capacity (KN)

0 0 0 128 212 2,046 1,040 926 1,099 1,262 984 1,185 4,027 2,881 3,206 3,541 5,954 5,510 6,058 6,398 6,737 7,076 7,755 8,094 8,433 9,112 9,451 9,791 10,130 10,469 10,808 0 0 0 35 55 659 316 271 321 367 267 326 1,266 876 977 1,081 1,878 1,722 1,897 1,995 2,093 2,191 2,387 2,484 2,582 2,778 2,876 2,974 3,071 3,169 3,267

0

5

10

15

20

25

0 10,000

20,000

Pile Total Capacity

D e p t h b e l o w G L ( m )

Ultimate

Allowable

Project : Piling Work

Subject : Calculation of Bored pile Based on BH (3) REF pile: 1 Sheet 1 of 2

Input :

Diamater : 900 mm,pilediameter fb(max)= 9,000 kPa

Type : Bored Pile fs(max) = 120 kPa

FOS 1 : 3 factor of safety for skin friction WT = 1.0 m, water table below ground level

FOS 2 : 3 factor of safety for base resistance ks: 0.90 coefficient of earth pressure

fcu : 40 N/mm2, concrete strength δ/φ : 0.67 ratio of sliding angle/friction angle

Preq : 2800 kN, Design Working Load COL = 1.0 m, cut off level below NGL

Ts = 0 kN, Design tension load SPT (max) = 200 max SPT allowed

Stc : 6,364 Structural Capacity Sv'(max) = 200 max allowable vertical overburden prusser

Wt : 189 kN, weight of pile

RL (m) Layer Thick. γ RQD quc SPT Sv' ks x Sv' tan(δ) (Nq-1) α β fs Ps fb Pb

blows penetration (kN/m3₎ _(%) _(MPa) _actual _(kPa) _(kPa) _(kPa) _(kN) _(kPa) _(kN)

(m) (mm) 0 0 0 0 1 1 2 SAND 19 300 17 16 19 0 0 0.34 31 0.13 0.65 0 0 0 0 1.5 0.5 2 SAND 15 300 17 16 15 0 0 0.34 31 0.13 0.65 0 0 0 0 2 0.5 2 SAND 3 300 17 16 3 4 3 0.40 55 0.13 0.65 1 2 198 126 2.5 0.5 2 SAND 1 300 17 16 1 8 7 0.37 41 0.13 0.65 3 6 325 207 3 0.5 2 SAND 39 300 17 16 39 12 11 0.53 264 0.13 0.65 6 14 3,195 2,032 3.5 0.5 1 CLAY 14 300 17 16 14 16 15 0.45 98 0.13 0.65 7 23 1,598 1,017 4 0.5 1 CLAY 8 300 17 16 8 21 19 0.42 68 0.13 0.65 8 34 1,402 892 4.5 0.5 1 CLAY 8 300 17 16 8 25 22 0.42 67 0.13 0.65 9 48 1,653 1,052 5 0.5 1 CLAY 8 300 17 16 8 29 26 0.42 65 0.13 0.65 11 63 1,885 1,199 5.5 0.5 1 CLAY 2 300 17 16 2 33 30 0.38 43 0.13 0.65 11 79 1,422 905 6 0.5 1 CLAY 3 300 17 16 3 38 34 0.39 45 0.13 0.65 13 98 1,709 1,087 6.5 0.5 2 SAND 23 225 17 16 31 42 38 0.49 147 0.13 0.65 18 124 6,136 3,904 7 0.5 2 SAND 18 300 17 16 18 46 41 0.45 93 0.13 0.65 19 150 4,293 2,731 7.5 0.5 2 SAND 19 300 17 16 19 50 45 0.45 95 0.13 0.65 20 179 4,758 3,027 8 0.5 2 SAND 20 300 17 16 20 55 49 0.45 96 0.13 0.65 22 211 5,234 3,330 8.5 0.5 2 SAND 27 225 17 16 36 59 53 0.49 152 0.13 0.65 26 247 8,971 5,707 9 0.5 2 SAND 31 300 17 16 31 63 57 0.48 130 0.13 0.65 27 286 8,211 5,224 9.5 0.5 2 SAND 50 150 17 16 100 67 61 0.55 255 0.13 0.65 33 333 9,000 5,726 10.5 1 4 ROCK 17 0 16 71 64 0.34 27 0.13 0.65 120 672 9,000 5,726 11.5 1 4 ROCK 20 0 20 81 73 0.34 26 0.11 0.65 120 1,011 9,000 5,726 For ROCK SPT For SOIL Soil Type

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Project : Piling Work

Subject : Calculation of Bored pile Based on BH (3) REF pile: 1 Sheet 1 of 2

Input :

Diamater : 900 mm,pilediameter fb(max)= 9,000 kPa

Type : Bored Pile fs(max) = 120 kPa

FOS 1 : 3 factor of safety for skin friction WT = 1.0 m, water table below ground level

FOS 2 : 3 factor of safety for base resistance ks: 0.90 coefficient of earth pressure

fcu : 40 N/mm2, concrete strength δ/φ : 0.67 ratio of sliding angle/friction angle

Preq : 2800 kN, Design Working Load COL = 1.0 m, cut off level below NGL

Ts = 0 kN, Design tension load SPT (max) = 200 max SPT allowed

Stc : 6,364 Structural Capacity Sv'(max) = 200 max allowable vertical overburden prusser

Wt : 189 kN, weight of pile

RL (m) Layer Thick. γ RQD quc SPT Sv' ks x Sv' tan(δ) (Nq-1) α β fs Ps fb Pb

blows penetration (kN/m3₎ _(%) _(MPa) _actual _(kPa) _(kPa) _(kPa) _(kN) _(kPa) _(kN)

(m) (mm) 0 0 0 0 1 1 2 SAND 19 300 17 16 19 0 0 0.34 31 0.13 0.65 0 0 0 0 1.5 0.5 2 SAND 15 300 17 16 15 0 0 0.34 31 0.13 0.65 0 0 0 0 2 0.5 2 SAND 3 300 17 16 3 4 3 0.40 55 0.13 0.65 1 2 198 126 2.5 0.5 2 SAND 1 300 17 16 1 8 7 0.37 41 0.13 0.65 3 6 325 207 3 0.5 2 SAND 39 300 17 16 39 12 11 0.53 264 0.13 0.65 6 14 3,195 2,032 3.5 0.5 1 CLAY 14 300 17 16 14 16 15 0.45 98 0.13 0.65 7 23 1,598 1,017 4 0.5 1 CLAY 8 300 17 16 8 21 19 0.42 68 0.13 0.65 8 34 1,402 892 4.5 0.5 1 CLAY 8 300 17 16 8 25 22 0.42 67 0.13 0.65 9 48 1,653 1,052 5 0.5 1 CLAY 8 300 17 16 8 29 26 0.42 65 0.13 0.65 11 63 1,885 1,199 5.5 0.5 1 CLAY 2 300 17 16 2 33 30 0.38 43 0.13 0.65 11 79 1,422 905 6 0.5 1 CLAY 3 300 17 16 3 38 34 0.39 45 0.13 0.65 13 98 1,709 1,087 6.5 0.5 2 SAND 23 225 17 16 31 42 38 0.49 147 0.13 0.65 18 124 6,136 3,904 7 0.5 2 SAND 18 300 17 16 18 46 41 0.45 93 0.13 0.65 19 150 4,293 2,731 7.5 0.5 2 SAND 19 300 17 16 19 50 45 0.45 95 0.13 0.65 20 179 4,758 3,027 8 0.5 2 SAND 20 300 17 16 20 55 49 0.45 96 0.13 0.65 22 211 5,234 3,330 8.5 0.5 2 SAND 27 225 17 16 36 59 53 0.49 152 0.13 0.65 26 247 8,971 5,707 9 0.5 2 SAND 31 300 17 16 31 63 57 0.48 130 0.13 0.65 27 286 8,211 5,224 9.5 0.5 2 SAND 50 150 17 16 100 67 61 0.55 255 0.13 0.65 33 333 9,000 5,726 10.5 1 4 ROCK 17 0 16 71 64 0.34 27 0.13 0.65 120 672 9,000 5,726 11.5 1 4 ROCK 20 0 20 81 73 0.34 26 0.11 0.65 120 1,011 9,000 5,726 12.5 1 4 ROCK 20 67 20 91 82 0.34 25 0.11 0.77 120 1,351 9,000 5,726 14.5 2 4 ROCK 20 43 20 101 91 0.34 24 0.11 0.65 120 2,029 9,000 5,726 15.5 1 4 ROCK 20 83 20 121 109 0.34 23 0.11 0.88 120 2,369 9,000 5,726 16.5 1 4 ROCK 20 70 20 131 118 0.34 23 0.11 0.79 120 2,708 9,000 5,726 18.5 2 4 ROCK 20 82 20 141 127 0.34 22 0.11 0.87 120 3,386 9,000 5,726 19.5 1 4 ROCK 20 69 20 161 145 0.34 21 0.11 0.79 120 3,726 9,000 5,726 20.5 1 4 ROCK 20 31 20 171 154 0.34 21 0.11 0.65 120 4,065 9,000 5,726 21.5 1 4 ROCK 20 97 20 181 163 0.34 21 0.11 0.98 120 4,404 9,000 5,726 22.5 1 4 ROCK 20 60 20 191 172 0.34 20 0.11 0.72 120 4,744 9,000 5,726 23.5 1 4 ROCK 20 83 20 200 180 0.34 20 0.11 0.88 120 5,083 9,000 5,726

1 = CLAY 2 = SAND 3 = SILT 4 = Rock

For ROCK SPT

For SOIL Soil Type

Soil Parameters Rock Parameters

P

Pile Capacity in Soil

Skin Friction

As = surface area

End Bearing fs fs

Pile Capacity in Rock

Ab = area of base

Pile-Rock Frictional Resistance fb

Table 1: RQD vs. J

RQD J

Pile-Rock End Bearing Resistance %

0 - 25 0.2

25 - 50 0.2

Where: 50 - 75 0.2 - 0.5

quc : Mpa, average unconfined compression strength along shaft 75 - 90 0.5 - 0.8

quc : Mpa, average unconfined compression strength at base of pile 90 - 100 0.8 - 1.0

RQD : %, Rock mass Designation

fbr = kN/m2_{, ultimate end bearing in rock = 2.0 x quc(base) (Rowe and Armitage, 1987)}

*by Hobbs

Wt

Qs = 0.5 x Ks x Svb' x tan (δ) x As

Qb = (Nq – 1) x Sv' x Ab

Ultimate Pile Capacity = Qu = (Qb + Qs)/FOS- Wt

Figure ( 4.38 )

after williams & Pells

0

0.2

0.4

0.6

0.8

1

0.1

1

10

100

Unconfined compression strength (MPa)

r o c k s o c k e t r e d u c t i o n f a c t o r ( )

Figure ( 4.39 )

quc

fsr

=

α

.

β

.

Ab

fbr

Pbr

=

.

(9)

P

Pile Capacity in Soil

Skin Friction

As = surface area

End Bearing fs fs

Pile Capacity in Rock

Ab = area of base

Pile-Rock Frictional Resistance fb

Table 1: RQD vs. J

RQD J

Pile-Rock End Bearing Resistance %

0 - 25 0.2

25 - 50 0.2

Where: 50 - 75 0.2 - 0.5

quc : Mpa, average unconfined compression strength along shaft 75 - 90 0.5 - 0.8

quc : Mpa, average unconfined compression strength at base of pile 90 - 100 0.8 - 1.0

RQD : %, Rock mass Designation

fbr = kN/m2_{, ultimate end bearing in rock = 2.0 x quc(base) (Rowe and Armitage, 1987)}

*by Hobbs α = rock socket reduction factor

β = rock socket reduction factor

J = reduction factor for discontinuities in rock mass

Pile Capacity in Tensi on

Method (1) :

Method

(2)

:

ADOPTED

Wt

Qs = 0.5 x Ks x Svb' x tan (δ) x As

Qb = (Nq – 1) x Sv' x Ab

Ultimate Pile Capacity = Qu = (Qb + Qs)/FOS- Wt

Figure ( 4.38 )

after williams & Pells

0

0.2

0.4

0.6

0.8

1

0.1

1

10

100

Unconfined compression strength (MPa)

r o c k s o c k e t r e d u c t i o n f a c t o r ( )

Figure ( 4.39 )

after williams & Pellis

0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 Mass factor ( J ) r o c k s o c k e t c o r r e c t i o n f a c t o r ( )

Tension Pile Capacity = Qt = (Qsu)/FOS+ Wt

Tension Pile Capacity = Qt = (Qsu) x 0.75 / FOS+ Wt

quc

fsr

=

α

.

β

.

Ab

fbr

Pbr

=

.

1.0 Structural Pile Capacity:

Ref. Pile =

2 Dia =

900 mm, pile diameter

Qall =

2,800

kN, allowable maximum load on top of pile

Qt =

0 kN, allowable maximum tension load on pile

%H =

5%

% of horizontal force with respect to the vertical force on top of pile

FOS1 =

1.5 factor of safety for horizontal force

FOS2 =

1.5 factor of safety for tension force

L =

19.5 m, pile length below COL

Fcu =

40 N/mm2

Fy =

460 N/mm2

cover =

75 mm, steel cover for pile

Proposed Reinforcement:

Main reinforcement =

13 bars of

20 mm, diameter

(10)

1.0 Structural Pile Capacity:

Ref. Pile =

2 Dia =

900 mm, pile diameter

Qall =

2,800

kN, allowable maximum load on top of pile

Qt =

0 kN, allowable maximum tension load on pile

%H =

5%

% of horizontal force with respect to the vertical force on top of pile

FOS1 =

1.5 factor of safety for horizontal force

FOS2 =

1.5 factor of safety for tension force

L =

19.5 m, pile length below COL

Fcu =

40 N/mm2

Fy =

460 N/mm2

cover =

75 mm, steel cover for pile

Proposed Reinforcement:

Main reinforcement =

13 bars of

20 mm, diameter

1.1 Forces in Concrete:

Based on B.S. 8004 , the maximum load in Concrete should not exceed

0.25 x Fcu x Area of pile

Maximum design load = 0.25 x fcu x 0.25 x(Dia)

2 x

π

x 1000

=

6,359

kN

>

2,800

kN

<--- OK

1.2 Checking Minimum Reinforcement:

Minimum percentage of compression steel reinforcement according to BS 8110 Part 1 is:

Asc = 0.4% x Acc ….. for 460 N/mm2

Where:

Asc = area of steel in compression

Acc = area of concrete in compression

Asc = 0.4% x 0.25 x

π

x (Dia)

2 =

2,543

mm

2 Area of steel provided =

4,082

mm

2 >

2,543

mm

<---OK

1.3 Checking Pile Compression Capacity:

The maximum eccentricity loading due to deviations during piling construction,

should not exceed the value of N (according to B.S 8110, part 1, section 3.8.4.3) given by:

Ac =

635,850

mm

2 As =

4,082

mm

2 N =

10,174

+

1502.176

=

11,676

kN

Taking factor of safety =

1.5 then,

(11)

=

7,784

kN

>

2,800

kN <---OK

Therefore the pile section can take the applied load.

1.4 Checking Reinforcement for Tension Force:

Tension force on pile =

0 kN

Ts = 0.95 x Fy x As / FOS2

Where:

Ts = Tensile Force in Reinforcement

As = Area of steel provided =

4,082

mm

2 Ts =

1,189

kN

>

0 kN

```

OK ----> Steel Reinf. Is Adequate

1.5 Additional Forces on Pile

According to B.S 8004, section 7.4. 2.5.4. considering out of position tolerance of 75 mm

and out of plumb tolerance of 1:75, the loads acting on the piles can be calculated as follows:

Maximum

vertical

load =

2,800

kN

Horizontal load from out of

Plumb condition =

H

N

= Qall x FOS1

56 kN

75 Assumed horizontal load =

5%

x vertical load on pile

=

140 kN

Total horizontal force =

196 kN

1.6 Spacing between the vertical bars:

Maximum spacing between steel bars should be > 100 mm

Dia of steel cage =

2,356

mm

Spacing between bars

181 mm

OK spacin g between bars > 100 mm

1.7 Determination of Maximum Bending Moment:

The pile behavior shall be assumed as an elastic beam on soil, the maximum bending moment is calculated as below:

Assuming fixed pile head.

Where,

M

f

= bending moment in the pile.

Fm = coefficient of bending moment (figure 6.39b)

(12)

T = stiffness factor = (E.I/N

h

)

1/5

E =

26,000

MPa, for concrete

I =

π

x d

4 /64

N

h

= coefficient of sub grade modulus

=

45 kN /m3, for weathered Roc k

For Pile Diameter =

900 mm

I =

π

x d

4 /64 =

_3.22E-02

m

4 T =

1.79 m

H max =

196 kN, total horizontal force

Zmax = L/T ( L = pile length)

Zmax =

10.87

≈

11.0 Depth

T

X(m)

(m)

0

0 -0.85

0.5

0.28 -0.67

1

0.56 -0.41

1.5

0.84 -0.17

2

1.11

0.01

2.5

1.39

0.14

3

1.67

0.21

3.5

1.95

0.25

4

2.23

0.25

4.5

2.51

0.23

5

2.79

0.20

5.5

3.07

0.16

6

3.34

0.12

6.5

1.79

3.62

0.09

7

3.90

0.05

7.5

4.18

0.03

8

4.46

0.01

8.5

4.74

0.00 Max. Bending Moment =

299 kN.m

Use

maximum

B.M

=

299 kN.m

-61

81

3

48

75

87

88

69

56 -299

-237

-143

Z

=

X/T

Fm

Mf

=fm

x

H

x

T

(kN.m)

2

0

42

30

19

10

(13)

Using BS 8110 Chart for circular columns with:

Fcu =

40 N/mm2

Fy =

460 N/mm2

h =

900 mm

hs = h – (2xcover) – (2 xDia of shear steel reinf.) =

730 mm

hs/h =

0.81 Using the above mentioned chart:

M =

2.99E+08

=

0.41 h

3 7.29E+08

N =

4.20E+06

=

5.19 h

2 8.10E+05

use

100Asc =

0.60 %

Acc

Area of steel needed =

3,815

mm

2 Area of steel provided

4,082

mm2

<---Area of steel pro vid ed > area required

<--- OK

0

5

10

15

20

25

30

35

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

5.5

6 M/h

3 (N/mm

2 )

N

/

h

2

(

N

/

m

2

)

0.40

1

2

3

4

5

6

(14)

1.8 Check for Stirrups:

Shear reinforcement =

10 mm @

150 mm c/c

Fyv = characteristic strength of the link r einforcement =

460 N/mm2

100 Asc (provided) =

0.64 %

Ac

from table 3.9 of B.S 8110 Part 1,

Design concrete shear stress (vc) =

0.64 N/mm

2 The ultimate shear force =

196 kN

Ultimate shear stress =

0.31 N/mm2 <

0.64 N/mm2

<---OK

<

5.1 N/m m2, 0.8 x (f c u)^ 0.5

<---OK

<

5.0 N/mm2

<---OK

Minimum shear reinforcement :

Asv/Sv =

0.4 x b

0.95 Fyv

where :

Asv = cross-section area of stirrups

Sv

=

spacing

of

stirrups

=

150 mm

b

=breadth

of

pile

=

900 mm

Asv =

124 mm2

vc =

0.64 N/mm

2 v

=

0.31 N/mm

2 For normal section, Asv/Sv can be calculated as below:

Asv/Sv =

(v - vc ) x b

0.95 Fyv

If, v > 0.5 x vc

---> use the above equatio n

If, v < vc

---> nomi nal lin k must be pro vid ed

If, v < 0.5 x vc ---> no need for sh ear reinfo rcemen t

Since

:

v

<

0.5 x

vc

(15)

(16)

Reinforcement Details:

NGL

COL (Cut-off Level = -1m)

13T20

T10@150mm

19.5m

Full Length

Longitudinal bars

Spiral bars

900 mm Diameter

Bored Pile

(17)

(18)

Static Load Test Procedure:

The piles shall be tested by applying loads for a specific time intervals or until the rate

of settlement falls to a specific value.

The test will be carried out in accordance with B.S 8004-1986.

a.

Load Measurement:

The load will be applied by a hydraulic jacks and the pressure will be

recorded with a calibrated pressure gauge. The hydraulic jacks will act

against a reaction system. The reaction system consists of concrete blocks

arranged carefully on top of the tested pile or a tension piles to be used

instead of concrete blocks.

b.

Measurement of pile settlement:

During loading the pile, the settlements are recorded with dial gauges with

accuracy of 1/100.

c.

Working load test:

Pile Dia

(mm)

Working load

(kN)

Testing load

(1.5 x working load)

(kN)

Type of

load

900 2,800

4,200

Compression

(19)

d.

Performance of the Test according to B.S 8004:

Load

(%)

Reading

(min.)

25% of working load

50%

75%

100%

50%

0%

50%

100%

125%

150%

100%

50%

0%

0, 5, 15 min

6 hrs.

0, 10 min

0, 5, 15 min

6 hrs.

0, 10 min

1 hr.

Note:

The next load step shall be applied only if the rate of settlement has

become less than 0.25 mm per hour.

(20)

A

Counter weight

Plate

main girder

Girder

Hydraulic

jack

support

Dial guage

A

Reference beam

6.0m

Counter weight

Plate

main girder

support

Dial

guage

Hydraulic

jack

(21)

Counter weight

Plate

main girder

support

Dial

guage

Hydraulic

jack

Reference beam

Section (A-A)

6.0m

(22)