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FFoundation oundation EEngineeringngineering

..

:: 33 (DEEP FOUNDATION : THEORY AND DESIGN)(DEEP FOUNDATION : THEORY AND DESIGN)

3.1 3.1

(Skin friction) (End bearing)

2

1) (Friction/Floating pile)

2) (End bearing pile)

3.1 3.1

3.2 3.2

)

(Filled)

) (Cast-in-situ piles)

(Precast or Prefabricated piles)

3.2 3.2

) (Bored piles) (Driven

piles) (Pre-auger piles)

(Vibrating or Ramming)

)

(Very large displacement pile) ()

(Small displacement pile) ( H)

(No displacement pile) ()

3.2 3.2

Uncased pile Step-Tamper pile Base pile

3.3 3.3

(Reinforced concrete pile)

(Pre-stressed pile)

Solid square

Steel pile Hollow square Steel box

Circular (bored pile) Hexagonal

Hollow circulaIWide flange,I or H

3.3 3.3

()

3.3 3.3

Drop Hammer

( 2.5

- 12 )

(Free drop)

()

3.3.1

Drop Hammer

Ram

Hammer cushion

Pile cap

Pile

Pile cushion

3.3 3.3

Single-Acting Hammer (Steam)

(Air pressure) (Hydraulic

pressure)

2.5 - 20

3.3.1

Single-Acting Hammer

Exhaust

Cylinder

Intake

Ram

Hammer cushion

Pile cap

Pile cushion

Pile

3.3 3.3

Double-Acting Hammer

Single-Acting Hammer

3.3.1

3.3 3.3

Diesel Hammer

() Diesel Hammer

( 1.8 - 4.5 )

3.3.1

Diesel Hammer

Ram

Hammer cushion

Pile cap

Pile cushion

Pile

Anvil

3.4 3.4

(Cohesive soils)

(Boiling)

3.4 3.4

Casing

1) 1 - 2 (

)

3.4 3.4

2) (Drill rig)

3.4 3.4

3) 0.5

( .)

3.4 3.4

4) Drop chute

3.4 3.4

5)

3.4 3.4

6) 5-10

2-3

3.4 3.4

7) (Seismic test)

3.4 3.4

8)

3.4 3.4

9)

3.4 3.4

40-60

1 2

(Caving)

3.53.5

3.53.5

3.53.5

1)

2) (Drilling fluid)

1) ()

2)

50-150

3.53.5

3.53.5

3)

4)

VibratoryDriver

Water Table

Caving Soil

Cohesive Soil

3.53.5

(Slurry method)

1) 3

2) /

(Drilling slurry)

3)

Cohesive Soil

Caving Soil

SoilSlurry

3.53.5

(Slurry method)

4)

5) Tremie

Cohesive Soil Sump

Caving Soil

Cohesive Soil

Caving Soil

3.6 3.6

(Hydraulic jack)

1.0

10-20

3.6 3.6

1)

3.6 3.6

2)

5-10

(Corrosion)

3.6 3.6

Reaction beam

Reaction column

Hydraulicjack

Steelpile

3) (Hydraulic jack) (Reaction

beam)

3.6 3.6

4)

3.6 3.6

5)

3.6 3.6

6)

3.6 3.6

7)

3.6 3.6

ShoringI-Beam

Existing pier

Shoring

8)

(Shoring)

9) I

3.7 3.7

(Skin friction)

(End bearing)

(Adhesion)

1L

2L

3L

4L

3.7 3.7

1)

2)

3) (Pile load

test)

3.7 3.7

1)

2)

(Shear failure)

3)

3.83.8

(

) (Total shear

strength analysis)

3.83.8

(Failure load, Qf)

(Qs) (Qb)

sf bQ Q Q= +

( )p s s c uf b bP W c A N A S qA+ = + +

Pf Wp As

Ab Su cs

Nc q

(Overburden pressure)

3.83.8

(Wp) qAb (Pf)

sf bP P P= +

s s s ufP Q c A S= = =

c ub bP N S A=

(Adhesion factor) Pb Nc 9.0

5.0 Nc

5.0

3.83.8

Nc (Skempton, 1951)

0 1 2 3 4 55

6

7

8

9

10

Bea

ring

capa

city

fact

or, N

c

Ratio of pile length to pile diameter

Nc 5.0

(Remolded state)

1.0

(Overconsolidation ratio)

3.83.8

3.83.8

Su (Horpibulsuk and Kampala, 2007)

3.83.8

(Visic, 1977)

3.83.8

American

Petroleum Institute (API)

1.0 =

25kPa1 0.5 50kPauS

=

0.5 =

Su < 25 kPa (500 lb/ft2)

25 kPa (500 lb/ft2) < Su < 75 kPa (15 lb/ft2)

Su > 75 kPa (1500 lb/ft2)

3.83.8

(Stiff to very stiff clay)

20

0.4 8 20

20

1.0 =

25kPa1 0.5 50kPauS

=

0.5 =

Su < 25 kPa (500 lb/ft2)

25 kPa (500 lb/ft2) < Su < 75 kPa (15 lb/ft2)

Su > 75 kPa (1500 lb/ft2)

3.83.8

Skempton (1966) = 0.45

0.45s u sP S A=

9 ub bP wA S=

w 0.8 0.75

1.0

(Wp) 0.5BN

3.93.9

sf bP P P= +

tans s s s vsP A f A K = =

qb b b b vbP A q A N= =

vb vs

K

Nq

3.93.9

/ / 1.0

/ 0.8 - 1.0

/ 0.7 - 0.9

/ 0.5 - 0.7

/ 0.8 - 0.9

(Stas and Kulhawy, 1984)

3.93.9

(Stas and Kulhawy, 1984)

K/K0

(Jetted pile) 0.5 - 0.67

(Cast-in-situ) 0.67 - 1.0

0.75 - 1.25

1 - 2

3.93.9

Berezantzev et al. (1961)

Berezantzev et al. (1961)

90 (

45 )

(qT)

(W)

(T)

3.93.9

Nq ( Berezantzev et al., 1961)

25 30 35 40 4510

50

100

500

1000

Nq

Internal friction angle (Degree)

Poulos (2001)

(Nq)

3.93.9

(Meyerhof, 1959)

Meyerhof (1959)

(Zone of

volume change, b) 6 8

(Failure zone, a) 4

3.93.9

(Kishida, 1963)

Kishida (1963)

3.5

Kishida and Meyerhof (1965)

3.93.9

01

402

+ =

1 0

40 40

3.93.9

25 30 35 40 4510

50

100

500

1000

Nq

Internal friction angle (Degree)

Poulos (2001)

Nq

(0 3)

01

402

+ =

3.93.9

(API 1984)

fsl (..) qbl (..)

4.8 190

/ 6.7 290

/ 8.0 480

/ 9.6 960

11.5 1200

API (1984) (qbl) (fsl )

qb qbl fs fsl

3.10 3.10

(Closed-section pile)

H (H pile) (Open-end pipe pile)

(Open-section pile)

H

3.10 3.10

Paikowsky and Whitman (1990) ; Miller and Lutenegger (1997)

Paikowsky and Whitman (1990)

10 20 25 35

3.10 3.10

H

H

Ab As

3.113.11

3.11.1

qc 4B 1B

(B ) 2.5

12

cb bP A q=

3.113.11

3.11.1

H

( ) 2kN/m200c av

sq

f =

( ) 2kN/m400c av

sq

f =

Meyerhof (1956) (fs)

(qb) SPT

Decourt (1982 1995)

3.113.11

3.11.2

260(2.8 10) kN/msf N= +

260( ) kN/mb b bq K N=

N60 1

0.5 - 0.6

60( )bN Kb

3.113.11

3.11.2

325 165

205 115

165 100

100 80

(Decourt, 1995)

3.123.12

Wh

Wp

Y

R

s

A

L

E

3.123.12

1

) (Impinging particle)

)

) R

WhY Rs

hW Y Rs=

3.123.12

2


)

) R

(Rebound)

3.123.12

s

OE C

c

D

BA

Displacement

R

= OABD

= OABC + BDC

( /2)hW Y R s c= +

c

Drop Hammer:

Single Acting-Hammer:

( 1.0)hW Y R s= +

( 0.1)hW Y R s= +

3.123.12

3

2

OAE

Y0 WhY0

OAE = CBD = Rc/2 WhY0 = Rc/2 ( /2)hW Y R s c= +

0h hW Y Rs W Y= +

Y0

(Y) (s)

3.123.12

Y0

Hei

ght o

f fal

l of h

amm

er (

H)

Set (s)

H0

Y0 y

3.123.12

Morrison (1868) (s1 s2)

Y1 Y2

1 1 /2hW Y Rs Rc= +

2 2 /2hW Y Rs Rc= +

1 2 1 2( ) ( )hW Y Y R s s =

3.123.12

4


(Coefficient of restitution) er

)

hW Y Rs U= +

U

3.123.12

)

M m V

v M = Wh/g, m = Wp/g, V = (2gY)0.5

v = 0

2 2(1 ) ( )2( )re Mm V v

M m

+2(1 )

( )r p h

ph

e W W YU W W

=

+ hW Y Rs U= +

2( )( )

r ph hph

W Y W e W RsW W+

=+

2

( )h

ph

W Y RsW W =+ er = 0 Dutch Eytewein

3.123.12

5

) WY = Rs + U

)

R

RL/AE R2L/2AE U

= R2L/2AE

2

2hR LW Y Rs AE= + Weibach (1850)

3.123.12

6

) kWhY k

1.0

) 5

) 4

Janbu (1953 )2

2(1.5 0.3 / )h

p h

kW Y R L RsAEW W = ++

3.123.12

hu

W YR K s=

1 1u dd

K C C

= + +

0.75 0.15 pdh

WC W= +

2hW YL

AEs =

3.123.12

7

) kWhY

) (2kWhYL/AE)0.5

Danish 0.5

22

hh

kW YLRkW Y Rs AE

= +

3.123.12

8

)

)

) (cp)

) (cc)

) (cq)

L, A, E

2 2 2(1 )2 2 2( )

qph h ph

Rce R L R LkW Y Rs kW YW AE A EW W = + + + ++

3.123.12

2 2 2(1 )2 2 2( )

qph h ph

Rce R L R LkW Y Rs kW YW AE A EW W = + + + ++

pRL cAE = c

RL cA E =

Hiley

2( ) 1( )2( )ph h p c qph

k W e W W Y R s c c cW W

+= + + +

+

3.123.12

Hiley

/2h

c p q

W YRs c c c

=+ + +

2( )/( )r p ph hk W e W W W = + +

0.72p

RLc A=

21.8cRLc A=

3.60q Rc A=

L2 ()

R, L A

3.13 3.13

Whitaker and Cooke (1966)

(Load cell)

0.5

10 - 20

3.13 3.13

Total

Shaft

Base

Settlement

Load

Total

Shaft

Base

SettlementLo

ad

(a) (b)

3.13 3.13

s bas b

PPP FS FS +

FSs 1.2 1.5

FSb 3.0

s baP PP FS

+

FS 2.0 2.5

3.14 3.14 ( (Negative Skin Friction Negative Skin Friction : : NFNF))

(Highly compressive soil)

(Neutral point)


3.14.1 (Cause of Negative Skin Friction)

1)

(Neutral point)

2)

(Pore pressure)

3)

(Excess Pore Pressure)

(Sensitivity)


(Longterm)

(Negative skin friction) (Burland, 1973)

3.14.2 (Negative Skin Friction Analysis)

( )v avNF L =

v(av) (Overburden) (Fill)

(Perimeter of pile)

L


3.14.2 (Negative Skin Friction Analysis)

(Burland, 1973)

0.25 0.20 0.15 0.10

3.15 3.15

()

National Building Code (1991)

250

3.15 3.15

3.15 3.15

() ()

0 1,800 0

1,800 3,000 1

3,000 6,000 2

6,000 9,000 3

9,000 12,000 4

Engel (1988)

3.15 3.15

30 90

ASTM D-1143 7

1) Standard Loading Procedure Slow Maintained Load Test

25

200

2.0

2) Cyclic Load Test Standard Loading Procedure

50, 100 150

3.15 3.15

3) Loading in Excess of Standard Test Load

Standard Loading Procedure

25

4) Constant Time Interval Loading Standard Loading

Procedure 1

5) Constant Rate of Penetration Method

0.25 0.5

3.15 3.15

6) Quick Load Test

4 6

7) Constant Settlement Increment Loading Method

(

) 1

Standard Loading Procedure,

Cyclic Load Test Quick Load Test

3.15 3.15

) Standard Loading Procedure

1) 200 %

150%

2) 25 %

3)

25%

1

-

0.25 ./. 2

-

12

0.25 .

24

-

15%

3.15 3.15

) Cyclic Loading

1) .

2) 50 , 100 150 %

50

100% 1

20

3)

50 %

20

-

)

3.15 3.15

) Quick Load Test

1) 10 15 %

2.5

2)

5

-

-

4

5

3.16 3.16

30.5 19.0

200

3.16 3.16

Davission (1972)

INCHES 0.25 XINCHES 12 D

120D0.15 X

==

+=

=L

AE P

PSI 610-4.3 E =

0.15

(4 ) D/120 D

3.16 3.16

Chin

(Hyperbolic shape)

1 2P c c

= +

21

1P cc=

+

P

c1 c2

3.16 3.16

De Beer

0.05 0.10 0.15 0.20 0.30 0.40 0.50 1.00 1.50 2.00

40

50

100

30

150

200

300

186

EXAMPLE 1DE BEER'S METHOD

MOVEMENT (INCHES)

Construction of De Beer's yield limit

De Beer

log P log

3.16 3.16

90% Brinch Hansen

Brinch Hansen (1963)

90

(Trial and error)

3.16 3.16

80% Brinch Hansen

P

1 2C CP

= +

21 CCP

+

=

80 Brinch Hansen

(Pu) (u)

1 2

12u

PC C

=

2

1u

CC =

3.16 3.16

Mazurkiewicz (1972)

Mazurkiewicz (1972)

( X)

3.16 3.16

Fuller and Hoy Butler and Hoy

Fuller

and Hoy (1970)

0.05 (0.14 )

Butler and Hoy (1977)

Fuller and Hoy (1970)

0.05

3.16 3.16

Vander Veen

ln1

Ass

umed

u

PP

Vander

Veen (1953)

(Assumed Pu)

ln (1 P/Assumed Pu)

3.17 3.17

(Pile cap)

2

(Piled foundation)

(Free

standing group of pile)

3.17 3.17

3.17 3.17

(Efficiency, )

( )f group

f

Pn P =

n

Pf(group)

3.17 3.17

(Free

standing group of pile) Whitaker (1976)

Whitaker

3.17.1

3.17 3.17

3.17.1

3.17 3.17

3.17.1

S = 2D

3.17 3.17

3.17.1

Whitaker (1976)

(Block

failure) (Individual

failure of piles)

(Critical spacing)

3.17 3.17

3.17.1

( ) 2 ( )c g g u g g gf group block ub fP N S B L S H B L nP = + + Lc) ( )0.5

2 29 1.5 1.59

yieldu u

u

MH S D e D e D

S D

= + +

3.18.23.18.2

2) (Fixed-Head Piles)

(L < Lc) ( )

3

2p

u

DK LH

e L

=+

( )3 22 0ululc cp p

H eHL L

DK DK =

(L > Lc) 23

yieldul

MH

e f=

+

0.821.5

ul

p

Hf

DK

=

3.18.23.18.2


(L < Lcs) ( )9 1.5u uH S D L D= 292

18 16yield

csu

ML D

S D

= +

( cs clL L L ) ( )

0.522918 0.75 0.5

9 2 8yield

u uu

M LH S D D D LS D

= + + +

0.5 0.5

2 42.259 9 2.25

yield yieldcl

u u

M ML D

S D S D

= + +

(L > Lcl) 0.5

2 49 2.25 1.59u u yield

H S D D M D = +

3.18.23.18.2


(L < Lcs) 21.5u pH DK L =

1/ 3

yieldcs

p

ML

DK

=

( cs clL L L ) 0.5yieldu p

MH DK

L = +

3 00.5 0.5

yieldulcl cl

p p

MHL L

DK DK + =

(L > Lcl) 2

23

yieldul

MH

e f=

+

0.821.5

ul

p

Hf

DK

=

3.18.23.18.2

1) (Tension failure)

2) (Compression failure)

3) (Balanced failure)

3.18.23.18.2

Interaction diagram D/D = 0.90

3.18.23.18.2


1.61.5

1.4

1.3

1.2

1.1

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

00.05 0.10 0.15 0.20 0.25 0.30 0.350

DD

0.25

MuD3fc

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

pm = 1.0

0

3.18.23.18.2


3.18.23.18.2


e/D

= 0

.05

0.10

0.15

0.20

0.25 0.3

0

pm = 1.00.9

0.80.7

0.60.5

0.40.3

0.20

0.1

P u D2 f

c

3.19 3.19

c st iS S S S= + +

St (Total settlement)

Si (Immediate settlement)

Sc (Consolidation settlement)

Ss (Secondary settlement)

3.19 3.19

(Immediate settlement)

(Secondary

settlement)

(Consolidation settlement)

3.19 3.19

Terzaghi

2/3

2/3

(Hard soil)

3.19 3.19

3.19 3.19

g gVq B L=

q

Bg

Lg

V

3.19 3.19

q

30 z (Bg + z)(Lg + z)

( )( )v g gV

B z L z = + +

v z

3.19 3.19

H Cc e logv (p) (Compression index) Cs e - logv

(Swell index) v

000

log1vc vc

v

C HS e

+= +

000

log1vs vc

v

C HS e

+= +

000 0

log log1 1vps c vc pv

C H C HS e e

+= + + +

0 v pv +

0 v pv + >

3.19 3.19

2 10 (St)

US. Department of Navy (1982)

0g

tBS S B=

S0

Bg

B

33..11

0.40 x 0.40 14

API

33..11

1.0 =

s u sP S A=

(1)(2)(0.4 4 3.5) 11.2sP = =

-

Su < 2.5

-

33..11

-

3.5 : 0 (1.6 1) 3.5 2.1v = =

0 2.1 (1.9 1) 2 3.9v = + =

-

5.5 :

0 1 sin 1 sin30K = =

0 0.5K =

33..11

-

tans vsf K =

2.1 3.9(0.5 1) tan(0.8 30 )2sf

+=

0.67sf = < fsl (6.7 )

-

s s sP A f=

(0.4 4 2)(0.67)sP =

2.1sP =

33..11

s u sP S A=

-

Su > 7.5

-

0.5 =

(0.5)(9)(0.4 4 5.5)sP =

39.6sP =

33..11

-

11 :

-

14 :

0 3.9 (1.9 1) 5.5 8.8v

= + =

0 8.8 (2.1 1) 3 12.1v

= + =

0 1 sin 1 sin41K = =

0 0.34K =

33..11

-

tans vsf K =

< fsl (9.6 )

-

s s sP A f=

8.8 12.1(0.34 1) tan(0.8 41)2sf

+=

2.3sf =

(0.4 4 3)(2.3)sP =

11.1sP =

33..11

-

-

12.1vb =

qb vbq N= 040 40.52

+ = =

12.1 200 2420bq = =

Nq = 200

qb = 960

> qbl (960 )

-

b b vbP A =

(0.4 0.4)(960) 153.6bP = =

33..11

- FS = 2.5

11.2 2.1 39.6 11.1 64sP = + + + =( ) 64 153.6 217.6sf bP P P= + = + =

- FSs = 1.5 FSb = 3.0

217.6 87.02.5allP = =

64 153.6 93.91.5 3allP = + =

87

33..22

400 250

100

40 x 40

29 9 100 0.4 144ub bP S A= = =

0.5 100 4 0.4 80s u sP S A L L= = =

33..22

10.7

80 144400 1.5 3L= +

6.60L=

80 144400 2.5L+=

10.7L=

80250 2.5L=

7.81L= 10.7

33..33

Hiley Janbu

20 4.0 4.5 60

21 3.4 676

( 26 x 26 ) 10

350

80 er 0.25

33..33

) Hiley

2 20.80 4.5 3.4 0.250.484.5 3.4

p rh

ph

k W W eW W

+ + = = =+ +

0.72 20 4 21 1.79676pc = =

1.8 20 4 0.10 0.02676cc = =

3.6 20 4 0.43676qc = =

0.48 4.5 6020 41.79 0.02 0.43

2s

=+ +

+

0.50s =

33..33

) Janbu

1.52.323 4270 350 282836.67E = =

282.8E =

3.40.75 0.15 0.864.5dC

= + =

2

4.5 6020 44.5 60 21000.86 1 1

676 282.8 0.86s

s

= + +

0.84s =

10 5.0 8.4

Hiley Janbu

33..44

1.5 m

4.0 m

5.5 m

4.0 m

1.2 m

1.2 m

0.4 m-diameter-spun pile

Soft claysat = 1.6 ton/m

3

Su = 1.7 ton/m2

Stiff claysat = 1.8 ton/m

3

Su = 7 ton/m2

Very stiff claysat = 2.0 ton/m

3

Su = 15 ton/m2

33..44

Spun () 20

API

Soft clay 1.0 =

Stiff clay70 251 0.5 0.5550

= =

Very stiff clay 0.5 =

33..44

-

Soft clay Stiff clay Very stiff clay( ) ( ) ( )s s s s s s sP A f A f A f= + +

( 0.4 4)(1 1.7) ( 0.4 5.5)(0.55 7) ( 0.4 4)(0.5 15)sP = + +

8.5 26.6 37.7 72.8sP = + + =

-

-

9 ub bP S A=

2(9)(15) 0.4 17.04bP

= =

72.8 17.0fP = +

89.8fP =

33..44

- FS = 2.5

89.8 35.92.5allP = =

72.8 17.0 54.21.5 3.0allP = + =

- FSs = 1.5 FSb = 3.0

35.9

33..44

-

-

143.6

-

,( )1

2( )n

c u g g g g u i if group blocki

P N S B L B L S H=

= + +

( ) (9)(15)(1.6)(1.6) 2(1.6 1.6) (1.7 4) (7 5.5) (15 4)f group blockP

= + + + +

( ) 345.6 673.9 1019.5f group blockP = + =

( )1019.5 407.82.5all group blockP = =

( ) aall group individualP P n =

( ) 35.9 4 143.6all group individualP = =

33..55

A =

0.5 H/B = 6.0/1.6 = 3.75 c = 0.64 ()

33..55

(Stiff clay)

(Medium dense sand) L 5

(L) = (1.5 + 8 + 2 5/3) = 12.8

z () v (..) v0 (..) p (

..)

vf (

..)

Sc(1-D)

(.)

4.7 50/(1.6 + 4.7)2 = 1.26 (1.51.5) + (0.58) + (0.83) +

(0.94) + (0.91) = 21.25

38.25 22.51 0.43

6.7 0.72 21.25 + (0.92) = 23.05 41.49 23.77 0.23

8.7 0.47 23.05 + (0.92) = 24.85 44.73 25.32 0.14

0.80

(1 ) 00log1

vfsc D v

C HS e

= +

(1 ) 0.64 0.80 0.51c c DS = =

33..66

1, 6, 8 9

250 A 40

Boring log

y (+)

1 2 3

4 5 6

7 8 9

1.20 m

1.20 m

1.20 m 1.20 m

x (+)

0.35 m

0.45 m

33..66

(Stiff clay)

(Medium dense sand) L 5

(L) = (1.5 + 8 + 2 5/3) = 12.8

2 2y xVe y Ve xVP ny x

=

226 1.2 8.64x = =

226 1.2 8.64y

= =

250 0.45 112.5yVe = =

250 0.35 87.5xVe = =

-

-

33..66

1

1

112.5 1.2 87.5 1.2250 09 8.64 8.64P

= + + =

6

87.5 1.2 112.5 0250 39.99 8.64 8.64P +

= + + =

8

87.5 0 112.5 1.2250 43.49 8.64 8.64P

+= + + =

9

87.5 1.2 112.5 1.2250 55.69 8.64 8.64P + +

= + + =

6

8

9

33..66

9

3

1.0

( 55.6 )

7

1.5

33..66

1.5-3.0

3.0-5.5

5.5-7.0

7.0 ()

1 1.96 2.73 1 sin28.2 tan28.2 0.40 1.50 1.22sP

= + =

1 2.73 4.70 1 sin32.5 tan32.5 0.40 2.50 3.42sP

= + =

1 4.70 7.47 1 sin44 tan44 0.40 2.50 5.62sP

= + =

144 40 422

+ = =

7.47 300 2241v qN = =

21200 0.4 150.84bP= =

> qbl (= 1200 )

33..66

1.2 3.4 5.6 150.8 161.0fP = + + + =

161.0 64.42.5allP = =

1.2 3.4 5.6 150.8 57.11.5 3.0allP

+ += + =

57.1

40 7

33..77

40 80 9

(Free head

pile) 28 (fc) 280 (fy) 4000

33..77

28 2.5 39.34stA

= =

2min

0.5 80 25.13100 4stA= =

32 2

4 4 39.3 7.82 1080

stApD

= = =

4000 16.810.85 2800.85y

c

fm f= = =

37.82 10 16.81 0.13pm = =

... 0.5%

< Ast OK.

33..77

D/D = 0.65/0.80 = 0.815, pm = 0.13 Pu = 0

3 0.025u

c

MD f

=

30.025 80 280 0.7 2,508,800yieldM = =

25.1yieldM =

-

-

33..77

0.59( ) 1.5 2.25

yieldc

u u

ML ft D S D S D

= + +

1000.80 2.6730D= =2

304 2.2 0.79100uS

= =

10025.1 2.2 1857.430yieldM = =0.5

9 1857.41.5 0.79 25.232.25 0.79 2.670.79 2.67cL

= + + =

3025.23 7.57100cL = =

(Lc)

-

< 9.0

(Long pile)

33..77

0.52 2

9 1.5 1.59yield

u uu

MH S D e D e DS D

= + +

0.52 2 1857.49 0.79 2.67 0 1.5 2.67 0 1.5 2.679 0.79 2.67uH

= + +

0.518.98 16.04 195.68 4.00uH

= +

200.25uH =

200.25 91.022.2uH = =

33..88

3.6 x 100

Myield

12 -

y (+)

1 2 3

4 5 6

7 8 9

1.20 m

1.20 m

1.20 m 1.20 m

x (+)

0.35 m

0.45 m

33..88

x () 6

1.0

0.7

100 14.39H = =

1/3yield

csp

ML DK

=

33..88

10012 2.2 8830yieldM = =

0.51 1.5 0.79 2.5 1.11 1.50.805.5

+ + = =

3300.80 2.2 0.048100

= =

1000.40 1.3330D= =

28.2 1.5 32.5 2.5 44 1.534.55.5

+ + = =

2 34.5tan 45 3.612pK

= + =

88 381.840.048 1.33 3.61csL

= =

30381.84 114.55100csL = =

-

> L

33..88

21.5u pH DK L= 2

1001.5 0.048 1.33 3.61 5.5 116.230uH

= =

116.2 52.82.2uH = =

52.8 0.7 2.5814.3FS= =

ออกแบบเสาเข็ม

Engineering

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