Geotechnical - Notes on Design

Pile Design Report

Cawangan Jalan, Ibu Pejabat JKR, K.L

Sample Design CalculationsFor Micropiles in Kenny

Hill Formation

Generalized Subsoil Profile

- Generally flat terrain

- Subsoil profile:0-3m, silty SAND, SPT=1- 53-6m, silty SAND, SPT= 15 - 50 6-20m, highly weathered sandstone

FOR INTERNAL USE ONLY

Mild Steel Capping PlateL = 350mmB = 350mmThickness = 10mm

Mild Steel Stiffeners

Pile Boring

API Pipe

Cementitious Grout

Safe Working Load

Thickness = 10mm

Diameter = 200mm

O.D. = 127.0mmThickness = 9.2mmfy (min) = 552 MpaGrade = N-80

W/c = 0.45Fcu = 25 Mpa

Pa = 80 tonnesLsocket = 20m

Schematic Detail

Soil becoming weathered rock

L = 20.0m

Pile Design Report


Subject : Micropile Design

1.0 Material Properties1.1 Basic Dimensions and Properties1.1.1 Micropile Diameter, D = 200mm1.1.2 Pile Composite Modulus Ep = 41 GPa1.1.3 Moment of Inertia, Ip = 7.85E+07 mm^4

1.2 Cementitious Grout1.2.1 Max. water/cement ratio = 0.451.2.2 Anti-shrink / Additives = Adogroud 100g 150kg bag1.2.3 Grout Area. Ac = 45686 mm"21.2.4 28 day Comp. Strength, Fcu' = 25 MPa1.2.5 Density = 2000 kg /M^31.2.6 Elastic Modulus. Ec = 28 GPa

1.3 API Pipe Reinforcement1.3.1 Source =1.3.2 Outer Diameter, OD = 127 mm1.3.3 Wall Thickness. t = 9.19 mm1.3.4 Inner Diameter. ID = 108.62 mm1.3.5 Cross Sectional Area, As = 3401 mm^21.3.6 API Specification = 5A-801.3.7 Grade Designation = N-801.3.8 Mm. Yield Strength, fy = 552 MPa1.3.9 Elastic Modulus. Es = 210 GPa

1.4 Compliance with British Standards Designed Req. Min. Source (Max)

1.4.1 Working Grout/API Pipe Bond (MPa) 0.8 12 BS81101.4.2 Grout Characteristic Strength, fcu (MPa) 25 20 BS80041.4.3 Cement content (kg/m"3) 400 00 BS80041.4.4 Grout working compressive stress,0.4fcu/FoS 0.2 x fcu 0.25 x fcu BS8004

1.5 Minimum Factors of Safety1.5.1 Against Structural Failure = 2.001.5.2 Against Buckling Failure = 1.601.5.3 Against Geotech. Failure = 2.00 Skin Friction1.5.4 Against Geotech. Failure = 2.50 End Bearing

2.0 Structural DesignAssuming that the applied vertical load is carried by the API Pipe alone.

2.1 Ultimate Load Capacity Pu = 0.87 x fy x As = 1633450 N = 1633.5 kN = 163.3 tonnes

Use the Factor of Safety prescribed in Section 1.5 on Plate 22.2 Allowable Load Capacity Pa = 82 tonnes


Pile Design Report


2.3 Design Safe Working LoadSWL = 80 tonnes

3.0 Geotechnical DesignRefer Piler Analysis for derivation of Geotechnical Safe Working Load -Appendix ......

3.1 Design Length3.1.1 Safe Working Load per Pile P = 800 kN3.1.2 Nominal Diameter D = 200 mm3.1.3 Embedment Ls = 20.0 m

3.2 Grout l API Pipe Bond3.2.1 Ultimate Grout Pipe - Bond Stress, t (u) = 2.0 MPa3.2.2 Factor of Safety = 2.53.2.3 Working Bond Stress, t (w) = 0.8 MPa3.2.4 Req'd API Pipe Embedment in Grout = 2.5 m

< 20.0 mTherefore, adopted socket length is OK

4.0 Buckling (Pile Slenderness) Analysis not appropriate for Kenny Hill Formation

4.1 Pile End Conditions (Unfilled Cavities)4.1.1 Pile Top (at Pilecap Level) = Fixed4.1.2 Pile Base (at Rock Head Level) = Fixed4.1.3 Ass. length in unfilled cavity L assumed = 1 m4.1.4 Effective Length - 0.7 x L L eff. = 0.7 m

4.2 Eucler's Buckling Load (Unfilled Cavities)4.2.1 Effective radius r =41.84.2.2 Euler Critical Load Pe =@pi^2 - Ep l(Lelr)^2 = 1428 kN

FOS available =9.78 OK

4.3 Elastic Buckling Load of Pile embedded in Overburden (ie Winkler Medium)4.3.1 Average SPT in Overburden soils,N = 504.3.2 Est. Und. Cohesion Overburden soils, Cu = 6 ' N kPa 300 kPa 4.3.3 Modulus of Horiz. Subgrade Reaction, kh'c = 67*Cu

20100 kPa = 20.1 MPa 4.3.4 Elastic Buckling Load, Pcr = 2 x @sgrt (Ep x Ip x kh x d)

= 16014 kN4.3.5 FOS available = 20.02 OK

5.0 Rate of Corrosion of Reinforcement5.1 Ex Oil Drill API Pipe Reinforcement5.1.1 Outer Diameter O.D. = 127.0 mm5.1.2 Wall Thickness t = 9.2 mm5.1.3 Internal Diameter I.D. = 108.6 mm5.1.4 Cross sectional Area As = 3401 mm^25.1.5 API Specification = 5A-805.1.6 Grade Designation = N-805.1.7 Min Yield Strength fy = 552 MPa


Pile Design Report


5.1.8 Elastic Modulus Es = 210 GPa5.1.9 Allowable Axial Working Stress (Clause 7.4.6.3.1 BS8004)

Fa = 50% of Yield Strength = 276 MPa

5.2 Design for allowable corrosion as for sheetpiles w/o grout/concrete protection

5.2.1 Allowable corrosion rate = 0.01 mm/year5.2.2 Max. pile axial load Pa = 800 kN5.2.3 Req'd Steel Area Asc = 2899 mm^25.2.4 Min. OD of API Pipe O.D. = 124.5 mm5.2.5 Allowable Corrosion Period Tc = 255 years

Summary

No additional reinforcement required, Tc > Design Life of 50 years.

6.0 Pilehead Capping DetailsSafe Working Load = 800 kN

6.1 Capping Plate Size6.1.1 Assume characteristic strength of pileca f cu = 25 MPa6.1.2 Permissible direct compressive stress fcu13.65 = 6.85 MPa6.1 3 Req'd bearing area of capping plate = 116800 mm^2

Adopt plate of dimmensions (mm) 350 x 350 OK

6.2 Thickness of Stiffners6.2.1 Allowable Axial Compressive Stress = 155 MPa

(Table 17 (a). BS449 : Part 2: 1969)6.2.2 Contact Area of API Pipe on Capping Plate = 3401 mm^26.2.3 Stiffener projection beyond API pipe OD = 184 mm6.2.4 Required thickness of MS Stiffeners t(s) = 2.4 mm

Adopt 10 mm (4No. MS Stiffeners)

6.3 Thickness of Capping Plate6.3.1 Allow Shear Stress on Capping Plate = 125 MPa

(Table 10. BS449:Part 2:1969)6.3.2 Effect. Punching Shear Shear Perimeter = OD of API Pipe + Perimeter

- 8 x thickness of stiffeners = 1599 mm

6.3.3 Required Thickness of Capping Plate = 4.0 mm Adopt 10 mm

6.4 Allowable Bearing Stress on Capping Plate6.4.1 Allow. Bearing Stress on Capping Plate = 210 MPa

(Table 9. BS449:Part 2:1969)6.4.2 Proj. Bearing Area (API + Stiffeners) = 10761 mm^26.4.3 Actual Bearing Stress = 74 MPa

< All. Bearing Stress, OK


Pile Design Report


6.5 Check Stiffeners for Buckling6.5.1 Bearing Area of API Pile = 3401 mm^26.5.2 Bearing Area of 4No. Stiffeners = 7359 mm^2

Assume uniform distribution of Pile Axial Load,6.5.3 Compressive Load per Stiffener = 136.8 kN6.5.4 Pile head Embedment into Pilecap = 150 mm6.5.5 Assume Stiffener Depth, d = 140 mm

(Conservative Estimate)6.5.6 Slenderness Ratio of Stiffener

d ' @sgrt(3)1 thickness of stiffener = 24.26.5.7 Allow. Compressive Stress = 146 MPa

(Table 17(a). BS449)6.5.8 Allow. Buckling Load on Stiffener = 268.6 kN '

> Compressive Load of Stiffener, OK

6.6 Check Bearing on API PipeMoment equilibrium about intersection of Capping Plate and API Pipe,

6.6.1 Bearing Force on API Pipe = 180 kN6.6.2 Assume material for API Pipe to be equivalent to G55 steel,6.6.3 Allow. Bearing Stress = 320 MPa6.6.4 Allow Bearing Load = 448 kN

> Actual Bearing Force, OK

6.7 Fillet Weld Design (Stiffener to API Pipe)6.7.1 Weld Length per Stiffener = 2 x d

= 280 mm per stiffener6.7.2 Req'd Shear Load Capacity for weld = 0.49 kN/mm

Adopt 7 mm Fillet Weld


Pile Design Report


Design Report

1. IntroductionThis report presents the design criteria and design calculations for pile foundation for Interchange 3 of Project B 15 Road Upgrading Works.

Interchange 3 is a cloverleaf interchange with arch shaped R.C bridge as shown below

From structural analysis the compression load coming over the piles from one half of the bridge is 12600 ton while the other half is 2800 ton in tension.

2. Site ConditionThe topograph of the site is rolling to undulating. The subsoil condition is generalized as shown above.

The top 12m to 16m from the OGL of the residual soil is clayey silt with SPT 6-39 (average SPT=20): This is underlain by hard clayey silt sith SPT exceeding 50 up to 28m bgi.

3. AnalysisShallow foundation is not suitable because part of the formation is on filled ground and alsopart of the foundation is in tension or high compression.Driven spun piles cannot or not practical to provide adequate tension required. Large diameter bored piles are suitable for high compression and tension required.

4. Design Calculations4.1 Compression piles

The allowable compression load carrying capacity of the single pile has been calculated based on the SPT 'N" values, using the following formula.


Pile Design Report


Allowable load : Ab, af + As,fs3 2

Ab = base area (m2)

qf = unit base resistance= 400 Nb (in SI-unit), Meyerhof's Empirical Formula

Nb = average 'N' over 5m above and 3m below depth being considered (< 50)

As = Pile circumference area (m2)

fs = unit skin friction= 2 Nave (in SI-unit)

Nave = Average SPT value with depth

Factor of safety of base resistance = 3 to control settlementFactor of safety of friction resistance = 2

The detailed pile calculations are given in Appendix B.

4.2 Tension pilesThe allowable tension load carrying capacity of single pile has been calculated based on SPT 'N' values, using following formulaAllowable load = As . fs 2

As = Pile circumference area

fs = Unit skin friction= 2 Nave (in SI-unit)

Nave = Average SPT 'N' value with depth

Factory of safety against friction resistance = 2

The detailed pile calculations are given in Appendix B.

5. Design Calculations5.1 General Diameter of Compression pile : 1500 mm with design load of 900 ton Diameter of Tension piles : 1200m with design load of 400 ton Estimated pile length = 19m socketing 3 times diameter into hard stratum of SPT> 50

5.2 Preliminary Load Tests AnalysisCompression load tests and pull out tests were carried out at the Interchange bridge site to assess the performance of the piles installed to the design lengths.


Pile Design Report


(a) West AbutmentThe tension Test Piles (No.81) located on the west abutments satisfied the performance criteria. Based on Prof Chin's Stability Plot:

Ultimate load : 1141 tonne

Average Unit Shaft Friction : 16 tonne/m2

The compression Test Pile No. 15 located ont the west abutments satisfied criteria at work load and 2 x work load but just failed to satisfy the recovery criteria. Based on stability plot.

Ultimate capacity : 2,490 tonne

Ultimate Shaft capacity : 1,945 tonne

Mobilised Toe capacity : 548 tonne

Ultimate Unit Shaft Resistance : 39 tonne/m2

Mobilised Unit Toe Resistance : 310 tonne/m2

Based on these assessment, piles were constructed to following toe elevations: Compression Piles : RL 33.00(5m longer than Test Piles)

Tension Piles : RL 31.00 (same length as Test Pile)

(b) East AbutmentTension Pile No. 71 was tested. Pile satisfy the deflection criteria at working loadbut however failed to attain the 2 x working load without excessive movement. Based on Stability Plot, the following capacitities can be estimated:

Ultimate Shaft capacity : 624 tonne

Unit Shaft Resistance : 9 tonne/m2

This is much less than the 16.0 tonne/m2 value of tension pile No. 81. Based on the evaluated value of 9.0 tonne/m2, all remaining working tensionpiles are installed to RL 21.00 toe level, l O.Om longer than the test pile. Compression pile No. 65 was first tested. It failed to satisfy the performance criteria. Estimated capacities are:Ultimate capacity : 1600 tonne


Ultimate Toe capacity : 1041 tonne


Pile Design Report


Unit Shaft Resistance : 12 tonne/m2

Mobilised Unit Toe Resistance589 tonne/m2 Based on above results, Test Pile No. 2 (Pile No.66) located 4.50m from P65 was installed to toe level RL 33.00 (5.Om longer). Theoretical ultimate capacity should be of the order of 1,900 tonnes. The test showed the following:Ultimate capacity : 1520 tonne


Mobilised Toe capacity : 790 tonne

Ultimate Unit Shaft Resistance : 10 tonne/m2

Mobilised Unit Shaft Resistance : 447 tonne/m2

These are less than values obtained from P65, indicating significant variation in the subsoil strength. Concreting procedures are satisfactory and concrete batch recordsand test indicate supplied concrete complied with the requirements of the specification. Concreting volume of pile does not indicate occurrence of collapse of borehole or necking. Since the pile was concrete immediately after boring, strength relaxation due to aging should not occured.Based on above, all remaining piles are to be installed to toe levels 23. Pile No. P52 willbe test to assess amount of pile head movement at working load and 2 x working load. Estimated ultimate capacity of piles to toe level RL 23.00 is order 2,100 tonnes.

(c) Results of loads tests carried out at Interchange No. 3 are shown in Figure T1 to T.


Pile Design Report



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cla

yey s

ilt

SP

T 5

0

1.

Co

rrecte

d N

= 1

5 +

0.5

(N

-15),

fo

r N

up

to

and

eq

ual to

4 t

imes N

=50

22

4H

ard

cla

yey s

ilt

SP

T 5

0

02

6H

ard

cla

yey s

ilt

SP

T 5

0

BH

-13

(West

sid

e)

BH

-13

(Eest

sid

e)

RD

Level 2

5.7

5m

UL

TIM

AT

E S

HA

FT

RE

SIS

TA

NC

EU

LT

IMA

TE

EN

D B

EA

RIN

G R

ES

IST

AN

CE

AL

LO

WA

BL

E L

OA

D

BH

-11(

West

sid

e)

Pile Design Report



Ro

ad

B-1

5

A

pp

en

dix

B

PIL

E L

EN

GT

H E

ST

IMA

TIO

N A

LO

NG

TH

E I

NT

ER

CH

AN

GE

#3

(WE

ST

SID

E O

F T

HE

CE

NT

RE

LIN

E O

F T

HE

RO

AD

)

where

A

b =

b

ase a

rea (

m^2

)

q

f =

4

00

*Nb

(SI-

Unit

s)

N

b =

S

PT

valu

e at

base

A

s =

p

ile c

ircum

fere

nce (

m^2

)

f

s = 2

*Nave (

SI-

Unit

s)

N

ave =

a

vera

ge s

pt

valu

e w

ith d

ep

th

A

llo

wab

le lo

ad

= U

ltim

ate

lo

ad

alo

ng

base/3

.0 +

Ult

imate

lo

ad

alo

ng

shaft

/2.0

A

llo

wab

le lo

ad

= A

b*q

f/3

+ A

s*f

s/2

F

S f

or

base r

esis

tain

3.0

0

F

S f

or

fric

tio

nal re

s 2

.00

B

ore

d p

ile d

iam

ete

r 1.

20

mete

rsS

UB

SO

IL P

RO

FIL

E A

LO

NG

TH

E B

RID

GE

LO

CA

TIO

N

Re

du

ce

d

Db

SP

TC

orr

ec

ted

Av

era

ge

Red

uced

Le

ve

l(m

)D

ep

thN

NN

av

efs

=2

NA

sQ

sN

bq

f=4

00

Nb

Ab

Qb

Ba

se

S

ha

ftT

ota

l(k

N)

Level(

m)

26

00

00

00

04

160

01.

131

1810

60

30

60

36

8B

ori

ng

B

ori

ng

25

18

63

63

.77

23

518

00

1.13

12

03

66

79

116

90

66

Dep

th(m

)R

D L

evel 6

4.8

9m

Dep

th(m

)R

D L

evel 6

6.5

0m

24

28

64

87.5

46

05

216

01.

131

24

43

814

30

84

46

40

0

23

36

64

.59

11.3

110

26

24

00

1.13

12

714

90

551

956

62

2M

ed

cla

yey s

ilt

SP

T 1

62

Med

cla

yey s

ilt

SP

T 1

0

22

49

95.4

10.8

15.0

816

37

26

86

1.13

13

03

710

128

110

94

60

4M

ed

cla

yey s

ilt

SP

T 1

74

Med

cla

yey s

ilt

SP

T 1

1

21

59

96

1218

.85

22

67

29

00

1.13

13

28

010

93

113

120

658

6S

tiff

cla

yey s

ilt

SP

T 2

36

Sti

ff c

layey s

ilt

SP

T 1

2

20

611

116

.71

13.4

32

2.6

23

04

93

450

1.13

13

90

213

01

152

1452

56

8S

tiff

cla

yey s

ilt

SP

T 2

98

V.S

tiff

cla

yey s

ilt

SP

T 3

9

197

1111

7.2

514

.52

6.3

93

83

104

050

1.13

14

58

015

27

191

1718

54

10V

.So

ft c

layey s

ilt

SP

T 2

10V

.Sti

ff c

layey s

ilt

SP

T 3

9

188

1111

7.6

715

.33

30

.16

46

212

46

50

1.13

152

59

1753

23

119

84

52

12V

.So

ft c

layey s

ilt

SP

T 2

12H

ard

cla

yey s

ilt

SP

T 5

0

179

21

188

.717

.43

3.9

359

014

550

01.

131

62

20

20

73

29

52

36

950

14V

.So

ft c

layey s

ilt

SP

T 2

14H

ard

cla

yey s

ilt

SP

T 5

0

1610

21

189

.55

19.0

93

7.7

72

016

62

25

1.13

170

40

23

47

36

02

70

74

816

Hard

cla

yey s

ilt

SP

T 4

716

Hard

cla

yey s

ilt

SP

T 5

0

1511

31

23

10.6

72

1.3

34

1.4

78

85

18710

01.

131

80

30

26

77

44

23

119

46

18H

ard

cla

yey s

ilt

SP

T 5

018

Hard

cla

yey s

ilt

SP

T 5

0

1412

32

23

.511

.65

23

.31

45.2

410

54

20

78

75

1.13

18

90

62

96

952

73

49

64

42

0H

ard

cla

yey s

ilt

SP

T 5

02

0H

ard

cla

yey s

ilt

SP

T 5

0

1313

38

26

.512

.71

25.4

34

9.0

112

46

22

89

50

1.13

110

122

33

74

62

33

99

74

22

2H

ard

cla

yey s

ilt

SP

T 5

02

2H

ard

cla

yey s

ilt

SP

T 5

0

1214

38

26

.513

.63

27.2

752

.78

143

92

510

02

51.

131

113

38

3779

72

04

49

94

02

4H

ard

cla

yey s

ilt

SP

T 5

02

4H

ard

cla

yey s

ilt

SP

T 5

0

1115

50

32

.514

.81

29

.63

58

.55

1675

27

10750

1.13

112

158

40

53

83

84

89

03

82

6H

ard

cla

yey s

ilt

SP

T 5

02

6H

ard

cla

yey s

ilt

SP

T 5

0

1016

50

32

.515

.85

31.

71

60

.32

1912

29

114

75

1.13

112

978

43

26

956

52

82

36

28

Hard

cla

yey s

ilt

SP

T 5

02

8H

ard

cla

yey s

ilt

SP

T 5

0

917

50

32

.516

.78

33

.56

64

.09

215

13

514

075

1.13

115

918

53

06

1075

63

81

34

So

il Investi

gati

on P

h:ll

So

il Investi

gati

on P

h:l

818

50

32

.517

.61

35.2

16

7.8

62

38

94

216

650

1.13

118

83

16

277

119

574

72

32

719

50

75

20

.48

40

.95

71.

63

29

33

48

190

75

1.13

12

1573

719

114

67

86

58

30

Bo

ring

62

050

75

23

.07

46

.14

75.4

34

79

54

215

00

1.13

12

43

168

105

174

09

84

52

8D

ep

th(m

)

52

150

75

25.4

350

.86

79

.17

40

27

59

23

62

51.

131

26

719

89

06

20

1310

92

02

60

42

250

75

27.5

955.1

78

2.9

44

576

64

25750

1.13

12

912

39

70

82

28

811

99

62

42

Med

cla

yey s

ilt

SP

T 6

32

350

75

29

.56

59

.13

86

.71

512

770

278

75

1.13

13

152

810

50

92

56

313

072

22

4M

ed

cla

yey s

ilt

SP

T 9

22

450

75

31.

38

62

.76

90

.48

56

78

75

30

00

01.

131

33

92

911

310

28

39

1414

92

06

Sti

ff c

layey s

ilt

SP

T 7

12

550

75

33

.06

66

.12

94

.25

62

31

75

30

00

01.

131

33

92

911

310

311

614

42

518

8S

tiff

cla

yey s

ilt

SP

T 1

1

02

650

75

34

.61

69

.22

98

.02

678

575

30

00

01.

131

33

92

911

310

33

93

1470

216

10V

.Sti

ff c

layey s

ilt

SP

T

-12

750

75

36

.05

72

.11

101.

79

73

40

75

30

00

01.

131

33

92

911

310

36

70

149

80

1412

V.S

tiff

cla

yey s

ilt

SP

T

-22

850

75

37.4

74

.79

105.5

678

95

75

30

00

01.

131

33

92

911

310

39

47

152

57

1214

V.S

tiff

cla

yey s

ilt

SP

T

-32

950

75

38

.65

77.3

109

.33

84

51

75

30

00

01.

131

33

92

911

310

42

26

1553

510

16H

ard

cla

yey s

ilt

SP

T 5

0

-43

050

75

39

.82

79

.65

113

.19

00

875

30

00

01.

131

33

92

911

310

450

415

814

818

Hard

cla

yey s

ilt

SP

T 5

0

62

0H

ard

cla

yey s

ilt

SP

T 5

0

No

te:

42

2H

ard

cla

yey s

ilt

SP

T 5

0

1.

Co

rrecte

d N

= 1

5 +

0.5

(N

-15),

fo

r N

up

to

and

eq

ual to

4 t

imes N

=50

22

4H

ard

cla

yey s

ilt

SP

T 5

0

02

6H

ard

cla

yey s

ilt

SP

T 5

0

BH

-13

(West

sid

e)

BH

-13

(Eest

sid

e)

RD

Level 2

5.7

5m

UL

TIM

AT

E S

HA

FT

RE

SIS

TA

NC

EU

LT

IMA

TE

EN

D B

EA

RIN

G R

ES

IST

AN

CE

AL

LO

WA

BL

E L

OA

D

BH

-11(

West

sid

e)

Pile Design Report



Ro

ad

B-1

5

A

pp

en

dix

B

PIL

E L

EN

GT

H E

ST

IMA

TIO

N A

LO

NG

TH

E I

NT

ER

CH

AN

GE

#3

(WE

ST

SID

E O

F T

HE

CE

NT

RE

LIN

E O

F T

HE

RO

AD

)

where

A

b =

b

ase a

rea (

m^2

)

q

f =

4

00

*Nb

(SI-

Unit

s)

N

b =

S

PT

valu

e at

base

A

s =

p

ile c

ircum

fere

nce (

m^2

)

f

s = 2

*Nave (

SI-

Unit

s)

N

ave =

a

vera

ge s

pt

valu

e w

ith d

ep

th

A

llo

wab

le lo

ad

= U

ltim

ate

lo

ad

alo

ng

base/3

.0 +

Ult

imate

lo

ad

alo

ng

shaft

/2.0

A

llo

wab

le lo

ad

= A

b*q

f/3

+ A

s*f

s/2

F

S f

or

base r

esis

tain

3.0

0

F

S f

or

fric

tio

nal re

s 2

.00

B

ore

d p

ile d

iam

ete

r 1.

20

mete

rsS

UB

SO

IL P

RO

FIL

E A

LO

NG

TH

E B

RID

GE

LO

CA

TIO

N

Re

du

ce

d

Db

SP

TC

orr

ec

ted

Av

era

ge

Red

uced

Le

ve

l(m

)D

ep

thN

NN

av

efs

=2

NA

sQ

sN

bq

f=4

00

Nb

Ab

Qb

Ba

se

S

ha

ftT

ota

l(k

N)

Level(

m)

48

050

32

.53

2.5

65

00

33

130

00

1.13

114

70

34

90

10

49

01

68

Bo

ring

B

ori

ng

47

150

32

.53

2.5

65

3.7

72

45

33

130

00

1.13

114

70

34

90

112

350

23

66

Dep

th(m

)R

D L

evel 6

4.8

9m

Dep

th(m

)R

D L

evel 6

6.5

0m

46

250

32

.53

2.5

65

7.5

44

90

33

130

00

1.13

114

70

34

90

12

45

514

66

40

0

45

350

32

.53

2.5

65

11.3

173

54

015

83

31.

131

179

07

59

69

36

86

33

76

22

Med

cla

yey s

ilt

SP

T 1

62

Med

cla

yey s

ilt

SP

T 1

0

44

450

32

.53

2.5

65

15.0

89

80

45

178

57

1.13

12

019

66

73

24

90

72

22

60

4M

ed

cla

yey s

ilt

SP

T 1

74

Med

cla

yey s

ilt

SP

T 1

1

43

550

75

39

.58

79

.17

18.8

514

92

48

193

75

1.13

12

1913

73

04

74

68

050

58

6S

tiff

cla

yey s

ilt

SP

T 2

36

Sti

ff c

layey s

ilt

SP

T 1

2

42

650

75

44

.64

89

.29

22

.62

20

20

54

215

00

1.13

12

43

168

105

1010

911

556

8S

tiff

cla

yey s

ilt

SP

T 2

98

V.S

tiff

cla

yey s

ilt

SP

T 3

9

41

750

75

48

.44

96

.88

26

.39

2558

59

23

62

51.

131

26

719

89

06

1278

1018

554

10V

.So

ft c

layey s

ilt

SP

T 2

10V

.Sti

ff c

layey s

ilt

SP

T 3

9

40

850

75

51.

39

102

.78

30

.16

310

06

42

5750

1.13

12

912

39

70

815

50

112

57

52

12V

.So

ft c

layey s

ilt

SP

T 2

12H

ard

cla

yey s

ilt

SP

T 5

0

39

950

75

53

.75

107.5

33

.93

36

47

70

278

75

1.13

13

152

610

50

918

24

123

32

50

14V

.So

ft c

layey s

ilt

SP

T 2

14H

ard

cla

yey s

ilt

SP

T 5

0

38

1050

75

55.6

811

1.3

63

7.7

419

875

30

00

01.

131

33

92

911

310

20

99

134

09

48

16H

ard

cla

yey s

ilt

SP

T 4

716

Hard

cla

yey s

ilt

SP

T 5

0

37

1150

75

57.2

911

4.5

84

1.4

74

752

75

30

00

01.

131

33

92

911

310

23

76

136

86

46

18H

ard

cla

yey s

ilt

SP

T 5

018

Hard

cla

yey s

ilt

SP

T 5

0

36

1250

75

58

.65

117.3

14

5.2

453

07

75

30

00

01.

131

33

92

911

310

26

53

139

63

44

20

Hard

cla

yey s

ilt

SP

T 5

02

0H

ard

cla

yey s

ilt

SP

T 5

0

35

1350

75

59

.82

119

.64

49

.01

58

64

75

30

00

01.

131

33

92

911

310

29

32

142

42

42

22

Hard

cla

yey s

ilt

SP

T 5

02

2H

ard

cla

yey s

ilt

SP

T 5

0

34

1450

75

60

.83

121.

67

52

.78

64

21

75

30

00

01.

131

33

92

911

310

32

1114

52

04

02

4H

ard

cla

yey s

ilt

SP

T 5

02

4H

ard

cla

yey s

ilt

SP

T 5

0

33

1550

75

61.

72

123

.44

56

.55

69

80

75

30

00

01.

131

33

92

911

310

34

90

148

00

38

26

Hard

cla

yey s

ilt

SP

T 5

02

6H

ard

cla

yey s

ilt

SP

T 5

0

32

1650

75

62

.512

56

0.3

2754

075

30

00

01.

131

33

92

911

310

3770

150

80

36

28

Hard

cla

yey s

ilt

SP

T 5

02

8H

ard

cla

yey s

ilt

SP

T 5

0

31

1750

75

63

.19

126

.39

64

.09

810

075

30

00

01.

131

33

92

911

310

40

50

153

60

34

So

il Investi

gati

on P

h:ll

So

il Investi

gati

on P

h:l

30

1850

75

6..8

212

7.6

36

7.8

68

66

175

30

00

01.

131

33

92

911

310

43

30

156

40

32

29

1950

75

64

.38

128

.75

71.

63

92

22

75

30

00

01.

131

33

92

911

310

46

1115

92

13

0B

ori

ng

28

20

50

75

64

.88

129

.76

75.4

978

475

30

00

01.

131

33

92

911

310

48

92

162

02

28

Dep

th(m

)

27

21

50

75

65.3

413

0.6

879

.17

103

46

75

30

00

01.

131

33

92

911

310

517

316

48

32

60

26

22

50

75

65.7

613

1.52

82

.94

109

08

75

30

00

01.

131

33

92

911

310

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Pile Design Report



Pile Design Report


5) Check for buckling load

Qub = Cu ElWhere = = 10

CU = 15 kPa

E = 210 kN/mm2

I = 1/64 B (d14 - d24)

Qub = 10 15 x 210 x B (101.64 - 85.444) 64 106

= 907 kN

Allowable Qb = 907___ 2

= 454 kN > 300 kN

OK

6) Check for elastic compression

e = PL P = 300 kNL = 10m

EP A = 31416 mm2

Ep = 35.3 kN/mm2

= 300 x10 x103

31416 x 35.3

= 3 mm


Pile Design Report


Sample Pile Design Calculations

1. Project : KKS Road ProjectPiled Embankment for the approaches to Sg. Likas Bridge.

2. Generalized subsoil profile.

* Flat alluvial formation

* Top 24m consists of soft to very soft alluvium with few localized sandy lenses (Cu =10-20 kPa with an average of about 15 kPa except at lenses of sand). Stiff to hard strata of about 2 - 4m thick overlying on highly to moderately weathered sandstone/shale bedrock. WT is near the ground surface.

3. AnalysisStability and settlement analysis have concluded that simple ground treatments by partial sand replacement with high strength woven polyester geotextile reinforcement or vertical drains are not possible to achieve FOS = 1.5 and or post construction settlement to be less than 200mm for the first 5 years of service if height of embankment exceeds 4.2m.

Piled raft embankment is adopted in preference to EPS, elevated structure and stone columntreatment because:a) EPS embankment is technically not acceptable because the site is subject to flooding

& the cost is high.

b) Elevated structure is about 30% more expensive (separate analysis)

c) Though treatment by stone columns is cheaper, it requires longer time to consolidate and technically less superior

4. Design calculation Analysis has shown that driven R.C piles will be the most cost effective.

The site has no vibration or noise or ground heave constraints. Pile capacity of about 600 kN is chosen to get optimum pile spacing of 2 to 3m and raft thickness of 350 - 450mm for pile depth of about 30m.

Use 250X250 R.C piles at spacing "x" bothways Max design capacity - 625 kN.


Piled embankmentBridge

V.soft to soft clay

Sandstone/shaleStiff to hard

Sand Lenses

CL

Pile Design Report


Load on each pile = x2.d.h, where x = spacingd = soil density

= 20kN/m3 hh = embankment height

625 = x2.20.h

x = (31.25/h)1/2 For h = 6.5m, x = 2.19m, say 2.0m

For h = 6.0m, x = 2.2m, say 2.0m For h = 5.5m, x = 2.38m, say 2.25m For h = 5.0m, x = 2.50m, say 2.25mFor h = 4.5m, x = 2.64m, say 2.25m (allow some traffic load of 10 kPa)

Conclusion:Use 250x250 R.C x 30m long at 2.0m spacing for h=6.5 - 6.0m & 2.25m spacing for h = 4-6m(Pile capacity calculations enclosed).

R.C piles (MS 1314, Class 1) are designed as end bearing piles driven to set.


Pile Design Report



Pile Design Report


Design of Micropile

a) Design load per pile = 800kNb) Diameter of micropile = 200mmc) Main reinforcement = 3 Nos of 50mm diam. deformed bars of yield

stress fy = 410N/mm2.d) Factor of safety = 2.5 (min)e) Grout characteristic strength, fcu = 20N/mm2.

Check Structural Capacity

Area of reinf, Asc = B/4 x 502 x 3 = 5892mm2

fcu = 20N/mm2

Area of grout, Ag = B /4 x 2002

= 31,416mm2..Area of net grout = 31,416 - 5892

= 25,524mm2According to BS 8110, clause 3.8. 4.3Ultimate axial load, Pu = 0.4 fcu Ac + 0.75Asc fy

= 0.4x20x25,524 + 0.75x5892x410 = 2,016kN.

.. Factor of safety = Pu/800= 2.53> 2.5 O.K.

Check Bond Length Required- Depth of micropile = 20m

At least l0m will be embedded in very hard decomposed granite SPT, N > 50.

- Bond between grout & hard formation = 0.4N/mm2

.. Min required bond length in hardformation, Ib = 800 x 2.5 x l 000NB x 200 x 0.4

= 7958mm = 8.0m.< 10m provided O.K.

Design of M.S. Plate for Pile HeadUse 250mm x 250mm x 20mm M.S. plate Stress on plate = 800 x l03N

250 x 250 = 12.8N/mm2< 155N/mm2 O.K. (allowable stress BS449)

Details of Micropiles & works specification are encl


Pile Design Report


Works Specification for Design and Installation of 200mm Diameter Micropiles1. Scope of work shall include design & installation of 200mm diam micropiles of 20m provi

sional length. The micropiles shall be reinforced with 3 Nos. of 50mm diam deformed bars (fy = 410N/mm2) The working load of the micropile is 800KN.

2. DrillingInitial drilling involves installation of 242mm diam conductorcasing through loose soil (about 1.5m) by means of rotary boring or equivalent. Upon reaching hard/stiff formation down the hole hammer will be used to advance the borehole till a minimum penetration of 10m in very hard decomposed granite. The drilled hole will be flush clean by compressed air before the reinforcement bars are inserted into the hole. Suitable coupling device will be used. During drilling, a complete record of soil strata will, be taken for Engineer's inspection.

3. Grout MixOrdinary Postland cement with water cement ratio of 0.5 will be used Non-shrink cement admixture will be added to improve bonding.

4. Grouting ProcedureA high speed Koken grout mixer is used for the mixing of the cement grout. The capacity of the grout mixer is about 25-0 litres.

For grout mixing, 100 litres of water with some non shrink admixture is poured into the mixer follow by 4 bags of 50 kg. ordinary Portland cement then allow to mix throughly, normally a few minutes. After mixing, the cement grout, a pressure hose is connected to thegrouting pipe which acts as tremie pipe for grouting. The other end of the pressure hose is connected to a diesel engine high pressure pump.


Pile Design Report



Pile Design Report


Micropile Design Calculations

Micropile design for underpinning works for an old building is shown as follows. The subsoil con-sists of about 3m of very soft clay, 5m to 8m of stiff to hard sandy clay with gravels (SPT = 11 to42). The bedrock generally consists of highly weathered and fractured sandstone/shale (RQD = 0 -25%, UCS = 7.5 Mpa).

1) Micropile detailsDiameter of micropile = 200 mmDesign load of micropile = 300 kNPipe diameter = 101.6 mmPipe wall thickness = 8.08 mmSteel grade (API pipe) = N80Yield strength = 500 N/mm2

(a) Check for structural capacity Ultimate structural capacity

PU = B (101.62 -85.44 2) X 500 kN

4 1000

= 1187 kN

Applying factor of safety of 2.5.

Allowable structural capacity.

PA = 1187

2.5

= 475 kN > 300 kN

OK

(b) Check for geotechnical capacityBased on boreholes BH1 and BI-12, the depth of bedrock (sandstone/shale) varies from 8.7 m to 11.0 m b.g.l. Since the overburden soil consists of about 3.0 m of verysoft soil, the shaft friction on the remaining overburden soil (5 to 8 m) with N value of 11 to 42 should be ignored and the micropiles are designed to be socketed into thebedrock.

The socketing length in rock, L, is worked out as follows:

FS Qa = 0.05 qa B D x L + 0.5qa B D2

4

where FS is the factor of safety = 2.5


Pile Design Report


Qa = Allowable geotechnical capacityqa = Unconfined compressive strength of rock

= 7.5 Mpa for sandstone/shale

Bond stress = 5% of UCS of rock

D = Diameter of micropile hole

2.5 x 300 = 0.05 x 7.5 x 103 x B x0.2 L + 0.5 x 7.5 x 103 x B x 0.22

4

750 = 235.6 L + 117.8

L = 2.68 m

Designed socketing length of pile = 3.0 m

2) Check overall underpinning pile supportEstimated total load of the whole building (3 storey). = 2,000 tons

No. of micropile points = 95Load on each pile = 2,000

95

= 21 tons

Working load for each micropile provided = 30 tons

OK

3) Check for anchorage bond between underpinning pile and the existing foundatic Since epoxy grout is used to fill the hole formed by the micropile in the existir foundation and the strength of epoxy grout is much higher than the concrete strength, it can be considered as monolithic for the whole foundation.


Pile Design Report


4) Check for shear failure of existing foundation.

Perimeter for shear check, p = 1900 mm

Effective depth of foundation, d = 1050-50-10= 990 mm

Maximum reaction load, V = 300 kN

Shear stress, V = V

Pd

= 300 x 103

1900 x 990

= 0.16 N/mm2

From Table 3.9, BS 8110 for d > 400 mm and100As/bd = 0.25 (nominal reinforcement), allowable shear stress Vc = 0.40 N/mm

2

V

Pile Design Report



ItemNo.

A. Design and install cast in-situ 800kN workingcapacity micropiles complete withreinforcement as shown on the drawings inprovisional lengths 20.0m and pressure-grouted with and including approved groutingmaterial, drilling in all types of soils androck and all coring casings, linings, plugs,etc. and disposal of all excavated materialand debris from site.

Design information:-

a) Diameter of piles: 200mmb) Main bars: 3Y50c) Links: R05 helical link @ 100mm c/cd) Steel casings: 292mm O.D x 9mm thicke) Grout: Cement grout, w/c = 0.5, fcu = 20N/m2

f) Grout additives: Non shrink admixtureg) Factor of safety : 2.5h) Bond strength: 0.9N/mm2

i) Bond length: 10mj) Ultimate load: 2016kNk) Capacity: 800kNl) Working load: 800kNm) etc

Design and install all capping plates andstarter barsDesign information:-

Plate size: 250 x 250mmPlate thickness: 25mm

B. Starter bar size: 3Y50 or 8Y25

$ Description Quantity Unit Rate

Pile Design Report


Projek : Cadangan Blok Tambahan pada HospitalBersalin di Hospital Besar, K.Lumpur.

1.0 TujuanLaporan ini bertujuan untuk menyampaikan laporan penyiasatan tanah dan syor-syor asas yang sesuai bagi:Projek blok tambahan pada hospital bersalin, Kuala Lumpur.

2.0 Skop ProjekPerlaksanaan projek ini melibatkan pembinaan blok tambahan 2 tingkat di Hospital Bersalin. Blok yang dicadangkan ini dikelilingi oleh bangunan sedia ada.

3.0 Keadaan Tanah3.1 Sebanyak 3 ujian gerekan dalam telah dijalankan. Hasil ujian menunjukkan

keadaan lapisan tanah seperti berikut :-Ukurdalam(m) Jenis Tanah SPT (blows/ft.)0 - 4.5 Very soft CLAY 0 - 44.5 - 9/10.5 Loose SAND 1 - 79/10.5-13.5/16.0 Stiff silt or CLAY 1 - 913.5/16.0 Limestone RQD = 73 - 100%.>16.0 Limestone -

3.2 Kedudukan aras air bawah tanah ialah 1.45m.

4.0 syor-syor Asas4.1 Penapak konkrit tetulang adalah tidak sesuai kerana keupayaan galas yang rendah

dan jugs paras air bawah-tanah adalah tinggi.

"Driven R.C. or steel piles" adalah juga tidak sesuai kerana masalah "noise & vibration" dikawasan Hospital sukar diterima. "Inclined bedrock" juga mungkin mengakibat "excessive pile deviations".

Syor-syor asas yang dicadangkan adalah seperti berikut :-

Jenis Bangunan Jenis Asas Saiz Panjang Keupayaan Geseran Beba (mm) (m) galas yg Kulit Ujian

dibenarkan negatif

Blok Tambahan Cerucuk 200 16.5-19 200kN - 400kNmikro with 102 (micropile) API paip

(4)

4.2 Cerucuk mikro hendaklah digerudi sehingga ke paras batukapur dan dikunci (key) minima 3m ke dalam batukapur.

4.3 Sekurang-kurangnya 2 bilangan cerucuk digunakan untuk setiap tiang.

4.4 Jack pile (200x200xl5m) juga boleh diterima sebagai cerucuk gantian.


Pile Design Report


5.0 Syor-syor Tambahan5.1 Jika rongga (cavity) ditemui, cerucuk hendaklah dipanjangkan

melebihi rongga dan dikunci (keyed) minima 3m ke dalam batukapur tanpa rongga. (rujuk Fig. 1).

5.2 Untuk mengatasi masalah penanaman micropile dirongga, penender mestilah diarah mengemukakan cadangan sistem 'micropile installation' dan teknik-teknik 'grouting' dirongga semasa tawaran dibuat.

6.0 Hal-hal lainSatu set rekod penanaman cerucuk-cerucuk yang diuji berserta ujian beban hendaklah dihantar ke Unit Makmal bagi tujuan dokumentasi.


Pile Design Report


Lampiran A

Micropile Specfication

1. GeneralThe work involves the construction of 200mm (8") diameter micropile. The micropile shall be fabricated using steel tube and the bond length of micropile shall be 16m or directedby the S.O. The working load of micropile is 200 kN and factor of safety used in design is 2.0. The whole of work and materials shall be in, accordance with curreht Malaysian or British Standard or other National Standards approved by the S.O.

2. ReinforcementSteel grade - HFS 16 (BS: 1775 - 1964) External diameter 139mm (51/2)Thickness - 9.5mm (3/8") 2Yield strength - 250 N/mm (16 Tsi)

3. GroutThe grout shall be thcFoughly mixed with Ordinary Portland Cement (MS522) and water (MS28). The grout shall be Antishrink cement grout. The water cement ratio shall be 0245 -0.50. The 28 days. Strength for cement grout shall be 25N/mm (3570 psi). The representative cubes shall be collected on each day of grouting works for testing on the 28th days. Details of admixture shall be submitted to the S.O. for approval before commencement of works. The use of the admixture shall comply with instruction by the manufacturer & MS 922. The grout shall be free from segregation, slumping, & bleeding of water and fine materials during and after placing.

4. Installation a) Drilling

The drilling for installation of micropile shall guarantee the absence of Vibration which may cause damage to the existing building. Adequate precaution must be taken to ensure boreholes for micropile do not collapse during drilling.

If necessary, temporary casing shall be used. During drilling of borehole, the contractor shall maintain complete record of soil profile. The logging shall include depth of soil and water table. This drilled hole Viand! soil bore log shall be signed by contractor's site representative and a copy of which shall be deposited with the S.O. The contractor shall be required to keep representative sample of soil for each soil profil in plastic bag for inspection by.the S.O. Sample may only be disposed after the S.O. is satisfied that the logging has been properly done. The type-of drilling equipment shall be approved by the S.O. The drilled hole shall be flushed ckean.with air or water.

b) Fabrication of micro pileMethod of splicing of bars or pipes shall be approved by the S.O. Centralisers at about 3m centre must be used to ensure a minimum cover of 25mm or directed by the S.O.


Pile Design Report


c) GroutingThe contractor shall also provide details on method and equipment used in grout mixing. Further information such as grouting pressure, grouting procedure, grouting equipment and techniques employed in grouting under water shall also be furnished and approved by the S.O.

'To prevent deterioration of strength of soil, soil coring, installation of reinforcement and cement grouting shall be carried out in one continous operation.

5. Load TestingMicro-pile shall be load tested to 2 times design load using the Maintain Load Test. Minimum of one (1) load test shall be carried out. The contractor shall also specify and provide details of the method of load testing. Micropile shall be constructed only after the preliminary pile pass the load test requirements of JKR standard specification for building Works.


Pile Design Report



Bil. Unit Quantity Rate $

1 MICROPILES

(ALL PROVISIONAL)

A. Allow for Preliminaries Item

B. Provide all necessary pilingequipment on site, maintain on site,dismantle and remove from site oncompletion, allow for all standingor idling time and cost of operationfor the whole of piling works. Item

C. Installation of 200mm diameterMicropiles in soil, including coring,4" diameter pipe, steel plate head,jointing and extension and grouting MRin cement, all as specified (50positions)

D. Provide all necessary pile testingequipment on site, dismantle andremove from site on completion.Test 200mm diameter Micropiles in soilas specified. NO

Contoh Jadual Sebut Harga

Description

Pile Design Report


Lampiran E1

Pile Designfor

SMK (Perempuan Raja Zarina) Kelang

1. This project consists of construction of one additional 3-storey school block.

2. Max column load = 57 ton

3. This is a typical coastal alluvium site where first 60ft to 100 ft consists of very soft clay

4. Deep Sounding is very suitable and 4 nos of D/S results give consistent results as shown in Lampiran E-1

5. The site is a flat land and the first 4 ft is imported fill (about 5 years ago) Negative friction has to be checked.

6. Selection of piles (Refer to Fig. 1)6.1 Non displacement piles not suitable because of low column load and very soft clay

near the first 100 ft.

6.2 Timber pile also not suitable bacause its max length is about 40 ft. only.

6.3 Use 12" x 12" x 100 ft R.C. piles Design load = 30 Ton/pile (max)

7. Check Pile Capacity (Refer to Lampiran E-1) From D/S results

Qu = Qs + Qp

where Qu = ultimate capacity

Qs = skin friction

Qp = end resistance


Pile Design Report


7.1 Skin friction, QsBased on total friction (remoulded)

At 30m (100ft), total friction = 3,000 kg.

Qs = tube friction x-pile perimeter

tube perimeter

= 3,000 x (12" x 2.54 x 4)

11.3

= 32,300 kg

= 30 Ton.

Based on local friction (undisturbed)

Qs = (8.5 x 0.05 + 7.5 x 0.13 + 13 x 0.27 + 0.9) x 3.28 x 4 x 0.92

= 70 Ton

Sensitivity = Qs (undisturbed)

Qs (remoulded)

= 70

30

= 2.3, within usual range

Q's = " Qs, where " = 0.7 (Bjerrum)= 0.7 x 70= 49 Ton

7.2 End Resistance, Qp,

Qp = 80 (kg/cm2) x 1 ft2 x 0.92

= 73.6 Ton

Qu= 49 + 73.6 = 122.6 Ton


Pile Design Report


7.3 Negative frictionNegative friction for piles at spacing more than 3 x diameters is

fn = 0.2 Po (Bjerrum)where Po = effective overburden

= h= 100' (100psf - 62.4 psf) = 3760 psf

Max. fn = 0.2 Po= 0.2 x 3760 = 752 psf

Average fn = (0 + 752)/2 = 376 psf

Total negative friction = fn x As= 376 x (100 x 4) = 150,400 lb= 67 Ton

7.4 Allowable load, QsThe negative skin friction, QN should only considered in combination with dead load because QN acts mainly at the lower portion of the pile and would only affect the settlement.2.5 QD.L = Qu- QN

QD.L = 70% Qa

2.5 x 0.7Qa = Qu - QNQa = (Qu - QN) /1.75

= (122.6 - 67)/1.75 = 31 Ton

say 30 Ton/pile

Notes : The filling is done about 5 years ago. At least 60 - 70% consolidation completed.

fn used is about the same as the undrained shear strength. Hence QN estimated is on the light side.To prevent tensile stress and buckling during driving, free drop hammers is preferred.

8. RecommendationUse 12" x 12" x 100 ft R.C. pilesFriction piles, driven to the required pene:,tration and load test to verify the capacity. (No "set" required).# Load tests after 4 weeks of driving.


Pile Design Report



Pile Design Report


Memo

Daripada: Penolong Pengarah Makmal,Caw. Rekabentuk & Penyelidikan, IP. JKR

Kepada: Penolong Pengarah(Binaan), Ibu Pejabat JKR, K.L.

Bil surat: (X) dlm. PKR.RB 4112 Tarikh : 26.3.1983

Per: Cadangan Masjid Baru di Batu 31/2, Jalan Cheras, K.L.Berhubung dengan perkara yang tersebut di atas, sukacita dimaklumkan bahawa cadangan asas yang disyorkan adalah seperti berikut:-

1. Keputusan penyiasatan tanahSebanyak 28 Nos. Proba JKR dan 5 Nos. Deep Boring telah dijalankan ditapak projekitu. Keputusan - keputusan yang diterima menunjukkan bahawa kawasan projek ini adalah terdiri daripada batu kapur. Paras batu kapur adalah daripada 2.5m hingga 14m daripada paras permukaan tanah sedia ada. Oleh kerana keadaan batu dasar yang susah untuk diramalkan, langkah-langkah pengawasan dan faktor keselamatan yang lebih tinggi perlu diambil di dalam rekabentuk asas.

2. Syor-syor asas2.1 Jenis - jenis asas yang disyorkan adalah seperti dicatitkan di dalam Lampiran A.

Sebelum kerja - kerja piling dimulakan sekurang - kurangnya satu ujian Proba JKR perlu dijalankan di setiap kedudukan tiang untuk menentukan paras batu dasar (>400 blows/kaki). Sekiranya paras batu dasar didapati kurang daripada 4.5m dibawah permukaan bumi, adalah dicadangkan supaya menggunakan R.C.cylinder foundation (sila lihat Lampiran A & B)

2.2 Sekurang - kurangnya 2 cerucuk perlulah digunakan ditiap-tiap kedudukan tiang kecuali jika R.C.cylinder foundation digunakan. Tiap - tiap tiang hendaklah diikat dengan rasak bawah dikedua - dua arah. Ini adalah sebagai langkah awas oleh kerana terdapat rongga - rongga dan kemungkinan masalah surutan.

2.3 Untuk memperolehi pengawasan yang lebih baik semasa memacu cerucuk tukul jatuh bebas(free drop hammer) dicadangkan supaya digunakan. Ini ialah supaya cerucuk tidakmenerima hentaman dan menyimpang berlebihan (overdriving and excessive deviation) oleh kerana keadaan batu dasar yang mencerun (inclined bedrock surfaces).

2.4 Hujung cerucuk keluli hendaklah dikelulikan dengan plat yang lebih. Ini adalah perlu untuk menahan tegasan yang berlebihan (withstand overstressing) apabila cerucuk sampai ke paras batu dasar.

2.5 Sekurang - kurangnya 2 nos. kumpulan cerucuk (pile group, NCT single pile) perlulah dipilih untuk ujian beban. Satu set driving records dan keputusan ujian beban hendaklah dihantar kepada Unit Makmal ini untuk analisa dan sebagai rekod di Unit Makmal.

2.6 Perhatian hendaklah diberi kepada pengalaman yang lepas iaitu cerucuk - cerucuk tambahan mungkin diperlukan untuk menggantikan cerucuk - cerucuk yang menyimpang


Pile Design Report


berlebihan dan cerucuk - cerucuk yang masih tidak set diparas yang dalam (>10m). Adalah dicadangan supaya tambahan sebanyak 25m disertakan didalam B.Q.

2.7 Oleh kerana keadaan tanah yang rumit (tricky) jurutera tapak bina hendaklah selalu rujuk kepada keputusan penyelidikan tapak semasa menyelia kerja - kerja pembinaan asas. Apabila cerucuk dijangka sampai paras batu dasar, kejatuhan pemukul (drop of hammer) hendaklah dikurangkan. Tujuan langkah ini ialah untuk better keying & bedding effect on rock surface. Langkah ini juga akan mengurangkan cerucuk daripada menyimpang berlebihan.

Sekian disampaikan ulasan kami untuk tindakan tuan selanjutnya.

Berkhidmat Untuk Negara

......................................................(Ir. Neoh Cheng Aik),Jurutera Kerja Kanan (R1),bp. Penolong Pengarah (Makmal),Ibu Pejabat JKR, K.L.


Pile Design Report


Lampiran A

Cadangan Asas Untuk Pro jekMas jid Batu 31/2, Jalan Cheras,K.L.

1. Bangunan Masjid (13T - 105T)Sila gunakan cerucul; keluli 203mm x 203mm x 45kg/m (Grade 43A9 BS 4360) dengan beban keupayaan 210 0/eerucuk. Untuk tujuan tawaran, panjang cerucuk ialah 8.5m(27ft) ATAU "R-C- cylinder foundation".Sila lihat Para 2.1

2. Bangunan Quarters Kelas G(9T - 16T)Sila gunakan eerucuk I-,yu berubat (treated timber pile) 125m x 125m dengan beban keupayaan 5W/oerucuk. Untuk tujuan taviarany panjang cerucuk ialah 8.5m (27 ft).


Pile Design Report



Pile Design Report


Lampiran E 5

Extension of Terminal Building, Subang Airport

1. GeneralThe project consists of extension of International and Domestic Transper Corridor for Subang International Airport. The proposed-site is situated approximately 13 miles west of Kuala Lumpur.

Due to the close proximity of the proposed site to the existing terminal building v where theControl Tower for the airport is located, severe vibration such as driving piles is unacceptabldo Bored and Cast-in-situ piles were considered most suitable.

2. Soil ConditionThe site consists of residual soils of granite.Lampiran E5-1 represents the generalised poil profile. The top layer of the soil consists of brown firm sandy silty clay with some organic matters. The depth of this top soil varies from 6" to 2ft. Beneath this top soil underlies the yellowish with patches of grey medium sandy clayey silt with some gravelse This medium sandy clayey silt extend to a depth of 40 to 85 ft. below R.L. 86.00'. Between these layers of medium sandy clayey silt and the fractured or slightly weathered granite bedrocksq lies the greyish very stiff decomposed granite residual soil. The thickness of this decomposed granite residual soil varies. Water table is about Oft. b.g.l.

3. Load Settlement CriteriaThe system of piling to be designed shall meet the followings:-a) Safety Factor

The factor of safety for the purpose of computing the working load shall be taken as 2.5.

b) Working LoadThe working load adopted for single pile shall not be greater than the ultimate load divided by the safety factor of 2.5 and the ultimate load is defined as:(i) Load at which the gross settlement continues to increase without any further

increase in load.

(ii) Load at which gross settlement is 10% of the pile diameter.

c) Settlement Criteria(i) Gross settlement of the pile at working load during the first cycle of load

ing, loading to one time working load, shall not exceed 0.5".

(ii) The residual settlement of the pile at the end of the first cycle of loading shall not exceed 0.10".

(iii) The gross settlement of the pile at twice the working load shall not exceed 1.5"


Pile Design Report


d) Group Effect

Negligible because of small group (2 or 3 pile per group) & large spacing 2.5 .

4. Structural Capacity of PilesSince piles are not fully reinforced, the structural capacity of the piles will be solely depend on the concrete section of the piles* In this case, the pile is reinforced for the top 40ft. only for the dispersion of the possible slight bending moment elperienced at the pile top.

The piles will be designed as short columns. According to CP 2004, the structural carrying capacity of Cast-in-situ concrete pile, that is, the safe working load per pile, W

W - 1/4 (Acc.Uw)

Where Acc = Gross cross section of the area of concreteUw = Specified cube crushing strength at 28 days.

= 3000 psi.

For d = 18, max. structural load = 80 Ton. d = 24, max. structural load = 150 Ton d = 30, max structural load = 230 Ton.

5. Check Pile CapacityUse 18" bored piles x85 ft max. Meyerhofs formula (modified) is applicable for bored piles in residual soilQu = Qs + Qp

= fs As.+ Op Ap

= N As + N. Ap50

where N = average SPT along pile shaft

N = average SPT near pile base (4 above pile base & 2 below pile base).

As = pile shaft area (ft2)

As = pile base area (ft2)


Pile Design Report


Based on DB1218" x 75'

N = 16 fs = N = 0.32 TSF50

N = 50 qp = 50 TSB

Qs = fs As= 0.32 x (1.5' x 3.1416 x 75) = 113 Ton

Qp = 50 x (1/4 x 1.52 x 3.1416) = 88 Ton

Qa = Qs/20 + Qp/3.0 = 56.5 + 29.3= 85.8 Ton say 80 Ton

Based on DB 1018" x 55ft

N = 20 fs = 0.4 TSF

N = 80 qp = 80 TSF= 0-4 x (1o5 x 301416 x 55) =104 Ton

Qp = 80 x (1/4 x 1o5 x 1o5 x 3o1416) = 141 Ton

Qa = Qs/2.0 + Op/3.0 = 52 + 47 = 99 Tonsay 80 Ton.

Based on DB 1318 x 80ft.

N = 23 fs = 0.46 TSF

N = 35 qp = 35 TSF

Qs = 0.46 x (1.5 x 3.1416 x 80) =173 Ton

Qp = 35 x (1/4 x 3o1416 x 1o5 x 145) =62 Ton

Qa = Qs / 2.0 + Qp / 3.0 =173/2 + 62/3.0 = 86 + 31= 117 Ton > 80 Ton.


Pile Design Report


6. Founding LevelFounding level should be determined by observing the soil type from the boring. Suitable founding soil should be weathered granite bedrock or oompacted/cemented clayey silt with gravels, or up to a max depth of eft'. In case of dou7gt, SPT should be carried in the bored base.

7. RecommendationUse 18 bored pile Vrith max capacity 80 Ton per pile. Site engineer should use the DB results to determine the founding level. Para 6 above can be used as a guide. 4 Nos load tests should be carried out to verify the capacity.


Pile Design Report



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Pile Design Report


Lampiran E 6

1. ObjectiveTo design the foundation system for the proposed Dewan Orang Ramai in Kampung Cheras Baru

2. Introduction2.1 The proposed.structure is a one-storey assembly-hall'situated on Lot 405 in

Kampung Ceras Baru, M11rim Ampang, Daerah Hulu Langat

2.2 Column loadsMaximum - 68TMinimum - 30T

3. Site Condition3.1 Surface Condition

The terrain is generally flat. It was formerly an old building site that has been cleared. Springs of water are visible which suggest the ground water table is very near the ground surface. The only visible form of undergrowth are bushes and shrubs.

3.2 Subsurface Condition3.2.1 Referring to the geological map of Kuala Lumpur District (after Ting

and Ooi 1972)2, Kampung Cheras Baru is located in the Granite region. Hence the soil is residual Gradite soil.

3.2.2 Scope of Site Investigation.Initially 6 Nos of JKR Probes were performed by the district office of JKR Hulu Langat. Due to the inconsistency of the probe results, a more elaborate method of sub-soil exploration in the form of 3 Nos. Deep Boring was done by the Unit Makmal Ibu Pejabat JKR. Borehole positions are as indicated in Appendix B. From the borelog results (APPENDIX C) the soil profile is not consistent along the threeboreholes. Generally) though, the sub-soil eonsists of interlayer between sand, clay and stilt. The first 9 metres Appears to be comprised of loose to medium dense sand and very soft-to firm clays (the variation occuring with depth). Below 9m the soil seems to improve from medium dense to very dense silts and sands as well as stiff to very hard clays. The groundwater is very near to the surface and the subsoil is assumed to be fully saturated.

3.2.3 Other Relevant Information.Near to the proposed site of the hall, in a north, easterly direction is situated a quarry. There is an access-road leading to the intended site but it is in a bad state.


Pile Design Report


4. Foundation Analysis and Recommendation

4.1 Selection of type of foundationWith reference-to the results obtained from the S.I. done the first 5 metres comprises of compressible material which is of insufficient strength to sustain the intended imposed loads. Hence an ordinary shallow foundation in the form of a pad footing would not suffice. A piled foundation system is warranted here in order to transfer the loads to the stronger material found below 15m of the ground-level. In selecting the particular type of pile'to be used, particular consideration has been made to(a) Cost.

(b) Driving lengths

(c) Resistance to hard driving.

(d) Strength mf pile as structural member

(e) Effectiveness in mobilising friction and end-bearing

From Table 1, the most apparent' choice would be to use steel piles. However, based on the soil variation (profile) and the intended loading system which is relatively small, the .use of steel' piles is overly conservative. Furthermore hard driving is not expected.RC piles would be more appropriate in this case because; (a) it is more economical

(b) RC piles would be able to mobilise sufficient safe end-bearing resistance at a much shallower depth than would be necessary fdv its steel counterpart.

(c) Due to its rougher surface texture RC piles can mobilise frictional resistance better than steel piles


(see Table 1)Table 1 : Selection of Pile TypeType

of pile

R.C. v 2 v 2 v 2 v 1 v 2 v 2

Steel v 1 v 1 v 1 v 2 v 1 X 3

Timber X 3 X 3 X 3 X 3 X 3 v 1

Figures in box represen

Documents

Geotechnical - Notes on Design