Discussion and Conclusion

Chapter 6 Experimental results

6.3 Soil stress field

6.3.4 Discussion and Conclusion

- 115 -

From the model, we now know that the soil experiences very large transient stresses that will be largely dissipated since the static stresses are comparatively small. We expect therefore a lesser effect from pile driving on the soil than the linear assumption was previously telling us.

Figures 6.3.3.3.a and b present the values of the vertical distribution of the static radial stress field once the model has been applied (T90, PTl to PT6). The same test and transducers presented in Figures 6.3.1.2.a and b were chosen so that comparison would be facilitated. As stated above, the same global behavior for the driving history is observed, but sustantially lower stress levels are obtained. In Figure 6.3.3.3.b, the normalization of the static radial stress by the overburden stress is not meaningful anymore.

Figure 6.3.3.4 shows the comparison of the linear and model assumptions for a pair of transducers seeing radial and vertical stresses (TAO, PT2 and PT6). For both the vertical stress and the radial stress history, similarity in behavior is observed between the linear assumption and the soil-cell model results, with a reduction in the level of stress for both cases calculated by the use of the model.

Contours of the radial stress field are shown in Figures 6.3.3.5 a and b, for a pile depth of D / A

=

15 and D / A

=

25 respectively. The distortions observed in the linear case are accentuated in the non-linear case. The lobes on the side extend further up as the pile penetrates into the soil, which would indicate a larger importance of the side friction on the pile shaft. The compression and failure zone under the pile tip can be observed.

- 116 -

to obtain soil parameters. Those parameters relate to the dynamic properties of the soil, but are directly used to predict pile bearing capacity values. These are dependent on the static parameter values of the soil. The SCM assumption shows even more clearly than the linear assumption that the transient stresses in the soil are very large compared to the final static stresses. Therefore, a large discrepancy in the values obtained from dynamic measurements to predict static values is to be expected.

-117-

<t

I T70

z

PILE

PT

~ _ _ _ , _

R

CONTAINER

Figure 6.1 Definition of dimensions and positions

-118-

Cl)

I{) C\J

I

" _a

cf ;::

z ;::

0 a z

Cl)

0: a.

:::E 0 0 '-'

0 0:

0 LL

0 5

-119-

2L/C

to TIME (MSEC)

Figure 6.2.1 Response of the pile to the hammer impact

Force records from four strain gages along the pile D / A

=

16.0. Compression down

-120-

500

::

(a)

.

0 300 _ Force

...

^VNEA/C

R C

. .. . .... _. .

100

. . . . .

...

k 1

p -100

0 2 3 4 5 ^(L/C)

-300

0. 5 10 t!5

TIME ( L/C • msec ⁾

!500

(b)

0 300 _ Force ... VNEA/C

R C E

1 too

..

. . . ...

1 -100 p

0 2 3 4 5 ^(L/C)

-300

o. !5 to t!5

TIME ( L/C • maec )

Figure 6.2.2 Comparison of the force at the top of the pile obtained from strain gage record (Measured Force) and

acceleration record (V*EA/ C:calculated force) (a) D/A

=

14.7

(b) D/A

=

^25.6

~:/

Zone of

I- · \

lateral

I

compres~ion and sand densiflcdtlon ·.

~ - :

,~

l

\ "

-121-

f: .:

'Residua I friction

• · : · from hard driving

I

I - -

., '. · Lateral stress MJ-l~crease caused by ' - ,011 displacement n_:_Resldual friction

·: from hard driving

l /;

Resitlual point load from hard driving

Figure 6.3.0.1 Effect of placement of pile into a soil mass (from Vesic)

,,.,...

---

... ... _,,_.,

,,----

^...

/ ' '

,,

'

I ^\

I I

I plastic ^I

I I

zone

I I

m m

I I

' ' _' ^,,

^I^I

' _' ____

^,,,^,.^/

--

^{_ _}^.,.,,.,✓

Figure 6.3.0.2 Assumed failure pattern under pile point (from Vesic)

-122-

1 0 0 . . - - - . - - - " " " T " - - - . . - - - , - - - ,

(/)

a.

'-"

(/) (/)

....,

I-.

(j) 0 (j) 'O Q)

I-. :::,

(/)

ro

,-...

(/)

a.

'-"

(/) (/)

...., I-.

(j) 0 (j) 'O Q)

I-. :::,

ro

(/)

80 70

60 50

100 90 80

60 50

10 0

(a)

, I ,.

, I

,,

R/A=2.67

Rf

A= 5.33 R/A

=

^8.00

Rf

=

^16.0

Rf

A= 24.0

Non-dimensional Pile Depth (D/A)

(b)

,"'\

\ ' '

/ _,..

---- o-v

Non-dimensional Pile Depth (D/A)

Figure 6.3.1.1 Radial distribution of the radial measured stress (a) Z/ A

=

^16.00

(b) Z/A = 26.67

-

^CJ)

.._,,

a.

CJ) CJ) Q)

I...

...

(J) (J) 0

"O Q)

I...

CJ)

ro

100 90 ( C)

70 60

-123-

R/A

=

^2.67

--- R/ A

=

8.00

·--- R/A - 24 0

-

1/

/ /

.I ./\

_,,.. ----

I=---"""'"'---

...-,l'e•:::-..,.,,,,. ..

--#--~ -

Non-dimensional Pile Depth (D/A)

Figure 6.3.1.1 Radial distribution of the radial measured stress (c) Z/A

=

^37.33

-

^Cl)

.._,, Q.

Cl) Cl) 0)

I..

+-'

(J) 0 (J)

I..

Cl) ('(j 0)

Cl) Cl) 0)

+-' I..

(J)

cu

Cl) C 0)

E

z

150 140 130 120 110 100 90 80 70 60 50 40 30 20

(a)

Z/A 10.67 21.33 26.67 32.00 37.33

-124-

Non-dimensional Pile Depth (D/A)

( b)

Non-dimensional Pile Depth (D/A)

Figure 6.3.1.2 Vertical distribution of the radial measured stress

Rf

^{A= 2.67}

(a) Measured stress

{b) Non-dimensional stress

-125-

-

^1/) 100 ⁹⁰ ^(a)

.._,, 0.

80 1/) 1/)

Q) ⁷⁰

Radial stress

---

+-'

(j) ₆₀ Vertical stress

(j) ⁵⁰

'O Q) ⁴⁰ _A•\

i \

en ³⁰

Cl!

i \

Q) j \

~ ²⁰

/ \

·,

.. "'-

_,,.

,/ ..

,

...

...___,_,

---·-

... ~ ...

Non-dimensional Pile Depth (D/A)

-

^en 100 ⁹⁰ ^(b)

.._,, 0.

en en

Q) ⁷⁰

+-'

(j) ₆₀

(j) ⁵⁰

'O Q) ⁴⁰ 1•"\

.

i

^I ^,\

en ³⁰ /

'

Cl!

·,.

Q) ,/

~ ²⁰

·,

/ ^...

·"'

.... , _ _ _ , _ _ _ JI"

10 _,,.. .. /

_

^..^__..^..^{.,,, ..}^,,,,

---·----

Non-dimensional Pile Depth (D/A) Figure 6.3.1.3 Comparison of radial and vertical measured stresses

R/A

=

5.33 (a) Z/ A

=

^21.33

(b) Z/ A

=

^26.67

-

^(/)

-

0. ^(/)

(/) Q)

I..

Cf) +-'

0 Cf)

I..

::J

(/) (IS Q)

100 90 80

20 10 0

(c)

-126-

Radial stress Vertical stress

Non-dimensional Pile Depth (D/A)

Figure 6.3.1.3 Comparison of radial and vertical measured stresses R/A=5.33

=

37.33

-

^VJ

_a.

100 ⁹⁰

.._,,

VJ VJ Q) ⁷⁰

... I..

(/) ₆₀

(/) ⁵⁰

u

Q) ⁴⁰

I..

VJ ::J ³⁰ Q)

cu

~ ²⁰

-

^VJ

_a.

100 ⁹⁰

.._,,

VJ (J)

Q) ⁷⁰

... I..

(/) ₆₀

(/) ⁵⁰

u

Q) ⁴⁰

I..

::J

(J) 30

cu

~ 20 10

-127-

(d)

/\

I \_

i

I \

i

I

/

,,,,.

-·-·-·-·-·-·-·

___

,,,,,,,,.

Non-dimensional Pile Depth (DIA)

( e)

Radial stress Vertical stress

Non-dimensional Pile Depth (D/A) Figure 6.3.1.3 Comparison of radial and vertical measured stresses

Z/A

=

^32.0

(d) R/A

=

2.67 (e)R/A=8.00

- ^en _a.

.._,,

en en

I,.

+-'

(/) 0 (/)

I,.

en

100 90

80 70

-128-

( f)

R/A

=

2.67 --- R/ A

=

8.00

Non-dimensional Pile Depth (D/A) Figure 6.3.1.3 Comparison of ra.dial and vertical measured stresses

(f) Z/ A

=

32.00

- ^en _a.

.._,,

en

(/) Q)

I- +-'

(/) 0 (/)

I-

(/)

(I)

100 90

80 70

50 40

(g) Z/A

=

^21.33

Z/A

=

26.67 Z/A

=

^37.33

Non-dimensional Pile Depth (D/A) Figure 6.3.1.3 Comparison of radial and vertical measured stresses

(g) R/ A

=

.5.33

- ~

- .c ....

a.

0 ni

C 0

(/)

C 0)

E

z

-129-

0 (a)

1.0

0.5

35 1.25

+ + +

1.125 + 45

1.0

~

Non-dimensional Radial Distance (A/A)

Figure 6.3.1.4 Measured vertical(left) and radial(right) stress contours (a) D/A

=

- ~

- .c ....

a.

0

"iij C 0

(I) Q) C

E

lJ I

z

-130-

0 (h)

1.5 1.0

+ ^♦

2 ♦ + +

Non-dimensional Radial Distance (A/A)

Figure 6.3.1.4 Measured verticaJ(left) and radial(right) stress contours (h) D/A

=

²⁵

-131-

Cl) ₂₀

Cl) Q) I.. 18

(J) +-'

::f. ¹⁶

ro

Q) ₁₄

n.

⁺

cij 12 + C

Cl) ¹⁰

C Q) 8

E

"O ⁶

C 0 4

z

Non-dimensional Radial Distance (R/A)

Figure 6.3.1.5 Non-dimensional peak-measured-radial stress variation with distance from the pile axis

-132-

- 1 0 0 ~ - - - . . . - - - ~ - - - . . . - - - , (/)

0. ⁹⁰

(/) (/) +-' ~

(/)

(/) (/)

u

w

u

I..

::J (/)

ro

80 70 60 50 40 30 20

O t - - - - ' -10

(a)

Model Time (sec)

- 1 0 0 . - - - . . - - - . . . . - - - ~ - - - - - (/)

Q. 90

1/J 1/J Q)

I..

+-'

(/)

(/) (/)

u

w

u

I..

::J 1/J

ro

80 70 60 50

40 30 20

O i - - - ~ -10

(b)

Model Time (sec)

Figure 6.3.2.1 Measured transient stress following a blow (a) Z/A

=

26.67, R/A

=

2.67; D/A

=

24.1 (b) Z/A

=

26.67, R/A

=

2.67; D/A

=

26.8

-

^en

'-" 0.

en en

I,., +-'

(/)

en en

(I) 0 X

w u

(I)

I,.,

:J en cu Q)

-5

-133-

(a)

...

--

...

Rf

A= 2.67

Rf

A= 5.33

Rf

A= 8.00

Rf

A= 16.0

Rf

A= 24.0

... --

...

,--

^...^.,,.

' .,,.---

....

---~ ^'---, _____

^~ ^,

______ _

0.00-+,...,... _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ~..J,E-03

Model Time (sec)

Figure 6.3.2.2 Radial dynamic measured stresses, wave speed and stress decay (a) Z/ A = 26.67; D/ A =21.3

- en

.._,,

a.

en en

I-.

(/) +-'

en en

u w

I-.

en

(ll Q)

- en

.._,,

a.

CJ) CJ) Q)

I-.

+-'

(/)

CJ)

en

u

w

I-.

:J CJ) (ll Q)

-15

-25

-134-

Model Time (sec)

(b)

(c)

Z/A

=

^48.00

Z/A

=

^58.67

Figure 6.3.2.2 Vertical dynamic measured stresses, wave speed and stress decay

Rf

A= 0.0 (b) D / A

=

^19.4

=

^39.6

B 50 B 60 B 70

-135-

T70

B 80 ... ,.,.,_"'_ Z/A

=

26.67

B 90 B 100

Figure 6.3.2.3 Radial distribution of dynamic radial measured stress (a) Positions of the transducers,

and depth of the pile for the different blows

Increasing R/ A

T70B50;PT1 T70B50;PT2 T70B50;PT3 T70B50;PT4 T70B50;PT5

3 1

I I I

J

³⁵ ¹⁵

25 , 30

'iii

~ 2 0 t - t

.,

201- _--1 ¹⁰

(I)

(I) 15

01 ¹⁰

(I) (I)

ID Cl

w X

-•

•10 I _, b k I b L ^-5b _b I b L ^-5b _b I b L ^-5

T70B60;PT1 T70B60;PT2 T70B60;PT3 T70B60;PT4 T70B60;PT5

l

⁶⁰ Î Î Î

J

³⁵³⁰ ^I ¹⁵

~ iii

:~ ~

^{2s1-1 I} ^-l ¹⁰

..,:

... ^(I)

Q ^(I) ₂₀

bO ~

\ ]

⁵

_r1 I ¹ o~v~v~ o~ ^V ^\!VVVvV',

" 01 ^I-'

':3 ³⁰

1 5 ~ w

i': ^(I)

O"I

u ^(I) ₂₀

10 I

..s ^IDCl

...

w X ¹⁰

-10 I -5 _-5b b l b L -• i _b _l _b

l

^-5

T70B70;PT1 T70B70;PT2 T70B70;PT3 T70B70;PT4 T70B70;PT5

1 l

I I I

~

³⁶ ^ti ¹⁵

100 I

'iii

•o

~ ^(I)_ID

_..

^(I)

::~~ _~

²¹^26H^I ^-l ¹⁰

01 50H \ -l ¹⁶

(I) 40 (I)

ID ₃₀ Cl X

w ²⁰

10 0

-10 I Model Time (msec) - k l b L ^{.. b} Model Time (msac) " ~ l b L ·• b Model Time (msec) k l b L -• b Model Time (msec) b l b L ^-5 Model Time (msec)

Figure 6.3.2.3 Radial distribution of dynamic radial measured stress (b) Measured transient excess stress (Page 1 of 3)

Increasing R/ A

T70B80;PT1 T70B80;PT2 T70B80;PT3 T70BBO; PT4 T70BBO; PTS

'l

Î Î Î

^j

³⁵³⁰ ^,s

·;.; ^,9:

': I

^2si-1I ^-I ^,o

<I) ₇₀

<I) I IU'I I ²⁰

~ ⁶⁰

ui ^soU ^I .J ¹⁵

<I) ,o

<I)

I]) 11

'

^I ^'°

0 ³⁰

w X ²⁰ 10

_,:~ w·v

- , - , v -~ T

:r ^w

^\J

^{- - I}

^-⁵

l l ^{.. I} ^I

^-5

b k b • b I b • b I b

T70B90;PT1 T70B90;PT2 T70B90;PT3 T70B90;PT4 T70B90;PT5

20 ,s ,s

·;.; 15

< ^,9: ^mt_ ^.J ^{10L-11 I} ^-I ¹⁰

---

⁰ ^<I)^<I)

bO ~

" ui

-~

.:~/ \J~

~ - N \ ~ ^5~1 ^\

i l" ⁱ ^r'ilvl./ V'l\f v ~

⁰

1V\F~ vv vv1 ^~

\:! ^<I) u <I)

.s

^I])0 ^I

.

w X ^-,o -'5

-20

I

^I _k _b

l

^-5

l

b k b

l

^{·• 1} ^b ^k ^b ^L ^.5^b ^b ^k ^b ^L ^-5

T70BOA; PT1 T70BOA;PT2 T70BOA;PT3 T70BOA;PT4 T70B0A;PT5

20 '°

·;.; 15

,9: '°

<I)

<I) I])

..

<I) I]) -5

X -,o t..i I .J ^-5t..l -I ^-5

-'5 -20

I -·

b k b

l

^{·" I} ^b ^k ^b ^L ^{·" b} ^b ^k ^b ^L ^·•

Model Time (msec) Model Time (msec) Model Time (msec) Model Time (msec) Model Time (msec)

Figure 6.3.2.3 Radial distribution of dynamic radial measured stress (b) Measured transient excess stress (Page 2 of 3)

--

«: ^i:::i₀₀ -~ =

~ V

·oo

f/) f/)

U) ~

f/) f/) I]) u

X lJJ

·oo

f/) f/)

U) ~

f/) f/) I]) 0 X lJJ

S: vi

f/) f/)

U) ~

f/) (I) I])

u X lJJ

T70B1A; PT1 ,0,--,,--,---,----,.---,

T70B2A;PT1 ,0,----,---,---,.---,

·'0 i,---,,----+----4----l

T70B3A;PT1 ,0,----,---,----,.---,

.,o ),----,,----+---.--;---!.

Model Time (msec)

T70B1A;PT2 , 0 , - - - - , - - - , - - - . . . , . - - - ,

.,o 1 r - - - - 1 r - - - + - - - - I - - - - I

T70B2A;PT2

.,o 1 r - - - - 1 r - - - + - - - - 1 - - - - 1

T70B3A;PT2

,.,---,---,----,.----,

.,o l , - - 4 . - - - - ¼ - - - l . - - - - l

Model Time (msec)

Increasing R/ A

T70B1A;PT3 ,0,----,----.----,---,

.,o lr----,,,---+---!.----1

T70B2A;PT3 , 0 , - - - - , - - - , - - - , . - - ~

.,o l,--4.---➔--+---l.

T70B3A;PT3 ,0,----,----,---,---,

.,o l,--4,---➔---+----L Model Time (msec)

T70B1A;PT4

.5 ,,_ _ _ _,,, _ _ _ + - - - - 1 - - - - 1

T70B2A;PT4

.5 1r----1r----l---l---l

T70B3A;PT4

·• !r-''--➔---+----;----1.

Model Time (msec) Figure 6.3.2.3 Radial distribution of dynamic radial measured stress

(b) Measured transient excess stress ( Page 3 of 3)

T70B1A;PT5

.5 lr---1---1---l

T70B2A;PT5

.5 /,---!,---¼---+---!.

T70B3A;PT5

Model Time (msec)

w I-'

(/) (/) Q)

....

.._.

Cl)

(/) (/) Q)

....

.._.

Cl)

(/) (/) Q)

....

.._.

Cl)

(/) (/) Q)

....

.._.

Cl)

, ,

-139-

---

S2

--- ---

S3

---

S4

---

Figure 6.3.2.3 Measured transient excess stress ( c) Typical transient record shapes

Time

-140-

B20

B 40

B 60

B 80

B 100 --L:.:li-

B 120 B 140 B 170

B 200

::c::> :

;::y

> / <

B 230

Figure 6.3.2.4 Vertical distribution of dynamic radial measured stress

(a) Positions of the transducers, and depth of the pile for the different blows

Increasing Z/ A _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __,_ Verlica.l Stress

T90B30; PT2 T90B30; PT3 T90B30; PT4 T90B30; PT5 T90B30; P11

1

Î Î Î

J '

⁵¹ Î Î Î

I

⁵¹ Î Î Î

I

^•1 Î Î Î

I ::

·;;

,3: 20L ...J 10L- ...J I I I I 20

~ ,sL , . A ..J I I I I II I I I I ,.

Ul ,oL r I ..J sL ..J oi.-. 11 11 11 f\,JL_iT \Jn. J""..N>II oil... 11 11 11 I\. .J\.JJ/11"'\A "'-'--"'•J '°

'1 '1 ll) () X

+ ~ ^{.I ' '} ~ .l '

^I ^I

l .l '

^I ^•

l .:

T90B40; PT2 T90B40; PT3 T90B40; PT4 T90B40; PT5 T90B40; P11

'~:~ ' ' I

~

^,sl Î Î Î Î Î ^2s

· - 80

< '1

N 8, 7oL J \ ..J ,oL -l I I I I I 20

IH~I

⁽⁾ ²⁰

~·~M i·~·µJ~::th H

wj~ ^V

^I ^I

~

^•

l

^S ^I ^I

l • l

^S ^I ^!

l • l

^S ^I ^I

l ::

T90B50; PT2 T90B50; PT3 T90B50; PT4 T90B50; PT5 T90B50;P11

, :~ ' ' ' ~ 1 ' ' ' J ^·1 ^' ^' ^' I ^·1 ^' ^' ^' I :

,f;: 10 flt\_ 2s1- ...J I I I I I I 20

~ I I \ I 201- I -I I A IL I I I II I I ,.

.. 50

{n ◄OL- I I ...J 15

~ ³⁰

8

²⁰

i~

Model Time (msec)

Y ~:J :~

Model Time (msec)

Y:::=i.l

Model Time (msec) Î Î Î

l .l

Model Time (msec) ^I ^I ^• ^{[ , :} Model Time (msec) Figure 6.3.2.4 Vertical distribution of dynamic radial a.nd vertical measured stress

(b) Measured transient excess stress (Page 1 of 7)

--

bl)

::! u

.iii

00 00

ui ~

00 00

0 X

.iii

00 00

ui ~

00 00 m

w X

.iii

00 00

ui ~

00 00 ID 0

w X

T90B60; PT2 ,0,----,----,---,---,

.,o

1,---l.---➔--+---l.

T90B70; PT2 , 0 , - - - - , - - - - , - - - - , - - - ,

.,o

i r - - - i , - - - + - - + - - - l . T90B80;PT2 , 0 , - - - - , - - - - , - - - - , - - - -

-,o L---4---¼----;,----i,

Model Time (msec)

Increasing Z/ A T90B60;PT3 7 0 , - - - - , - - - - . - - - - . - - - ,

.,o k - - - - + - - - + - - - - l - - - - l . T90B70;PT3

-20 1,----<,---,---+----I

T90B80;PT3

-201.---➔----r---;,,---i, Model Time (msec)

T90B60;PT4

_, l,---!,---r----4---..J.

T90B70;PT4

·• 1r---,,---+----4---..J.

T90B80;PT4

1.---1,----+---+---l.

Model Time (msec)

T90B60; PTS

., 1.---➔---+----J,----i.

T90B70; PTS

_, 1r----+---+----l---l

T90B80; PTS

i r - - - i , - - - t - - - . - - - - l . Model Time (msec)

Figure 6.3. 2.4 Vertical distribution of dynamic radial and vertical measured stress (b) Measured transient excess stress (Page 2 of 7)

V,•rliral Str',•ss T90B60; P11 3 0 , - - - - , - - - - , - - - - , - - - ,

.,o lr----+---+----1----l.

T90B70; P11 3 0 , - - - - , - - - - , - - - - , - - - ,

.,o Ir---+---+----!---!

T90B80; P11

-,o 1 r - - - 1 , - - - - + - - - ; , - - - 1 , Modal Time (msec)

I ..:,. I-' N

"' in ~

]

"iii

.e,

00 00

in ~ 00 00 Q) ()

w X

"iii

.e,

00 00

in ~ 00 00 w

()

w X

"iii

.e,

00 00

in ~ 00

w 00 ()

w X

T90B90;PT2

.5 1 , - - - - < , - - - , - - - 1 , : - - - - 1 ,

T90BOA;PT2

/,---.----+----➔----!.

T90B1A;PT2

.5,._ ________ ,_ __ ➔----1.

Model Time (msec)

Increasing Z/ A T90B90;PT3

35---

_________

^..,_

__

^----,

___

^...,

T90BOA;PT3

20---

-20 i.---.----+---1----1.

T90B1A;PT3

20---,---~

-5

________

^..,_

__

^----,

___

^....

Model Time (msec)

T90B90;PT4

,.,---~---

-5 Jr----➔----,----1----1,

T90BOA;PT4

35..---~

.5,..__ __ _.,. ___ ,----➔---1.

T90B1A;PT4

35---

---<

Model Time (msec)

T90B90; PT5

,oc----,----,---~--~

.,o k---+---1---1.

T90BOA; PT5

rn.---.---,----,---~

T90B1A;PT5

rn---~---,---,---~

.,o

---<

Model Time (msec) Figure 6.3.2.4 Vertical distribution of dynamic radial and vertical measured stress

(b) Measured transient excess stress (Page 3 of 7)

Vertical Stress T90B90; P11

.5 /,---1,----.;,---.---!.

T90B0A; P11

/,----➔----r----1----1,

T90B1A; P11

Model Time (msec) f---0

...:,.

Increasing Z / A Vertical Stress

T9OB2A;PT2 T9OB2A;PT3 T9OB2A;PT4 T9OB2A; PT5 T9OB2A; P11

I

Î Î Î

^] l

Î Î Î

^j

^"°

^..

·oo

I I I

⁶⁰

.3: ^I ^I ^so ^l ²⁰

(I)

(I) I

ID IR II

.

ÎI ¹ Î Î ^l"lÎIÎI Î ^•oL ¹¹ ^...J ^,.

ui '- o!-ll,..,,ullllJI II I I/ I (\J II\ I VI\ /¹l.J oj...JI I V II \/ I A ✓ 1/\ r-..,.,. A.J 30L I I ...J 10 (I)

(I) I V I I \M .,

I]) I I I I I 20

w X

I

^-5^I ^\J ^I ^{I I} ^\

.

^/'\.~^{~ ~ ~ ~}

_,

_·•

·•1 _b _l !, l ^.JO~ b k !, l ^,o^I b l ^!, l ^-JO^I b k ^!, l ^-s

T9OB3A;PT2 T9OB3A;PT3 T9OB3A;PT4 T9OB3A;PT5 T9OB3A; P11

JOI Î Î Î

:[

Î Î Î

J

³⁰²⁵

.ii

< .3: ^I I I I •L I ...J SOL ~I ...J 20

---

^(I)

Q (I)

~ ^~~ ^\ ^j

..

^ID

=t

-~ ui ^'- ⁰

't ^~A ^j

^{o ! V}

^~w ^V-w v\/1

^...

~ ^(I) ^.i:,.

'-' (I) .i:,.

.s

^ID_(l ²⁰ I

w X ^-5 ¹⁰

_,:t V!::::j

^-5

-5 -JO -,o

T9OB4A;PT2 T9OB4A;PT3 T9OB4A;PT4 T9OB4A;PT5 T9OB4A; P11

101 I I I

I l

⁶⁰ Î Î Î

J

^"°²⁵

.ii

.3: Î ^{I. I} Î ^5L Î ^...J ^SOL ^...J ²⁰

(/)

(/) I nAII I II n I I II, II II I •0L I ...J ,.

ui ~

o r r \ t v v v v v v ·

v~

^{o r \ )}

^V 1

V"'

^V Tl

³⁰

(/) (/)

I]) 20

w X

I l ^l ^,:~

¹⁰

^V!::::j

^-5

-5 Model Time (msec) b l !, ^-10 Model Time (msec) b l !,

.

Model Time (msec) ^-JO Model Time (msec) Model Time (msec) Figure 6.3.2.4 Vertical distribution of dynamic radial and vertical measured stress

(b) Measured transient excess stress (Page 4 of 7)

..__

i::i

,9 i::

'iii

-9:

Cl) Cl)

iii ~

Cl) Cl) (]) 0

w X

'iii

Cl) Cl)

iii ~

Cl) Cl) (]) 0

w X

-9: iii

Cl) Cl)

iii ~

Cl) Cl) (]) 0

w X

T90B5A;PT2

.5 lr---l,----!r---+---J.

T90B6A;PT2

.51,---+----!r----J..----l.

T90B7A;PT2

.5 1 , - - - -... - - - + - - - , - - - ; .

Model Time (msec)

Increa.si ng Z / A T90B5A;PT3

,a,----,----,----,----

"'°1,---!,---!r---l,---l.

T90B6A;PT3

.5 1,---!,---Jr---+----L

T90B7A;PT3

·•1r---+----!r---!.---l.

Model Time (msec)

T90B5A;PT4

.,. lr--~,---!r---+----l.

T90B6A;PT4 , o r - - - - , - - - - , - - - - , - - - ,

.,a

1,---➔---+---!---l.

T90B7A;PT4 , a , - - - , - - - , - - - - , - - - ,

.,a

1 r - - - - < , - - - + - - - - l ! - - - - l . Model Time (msec)

T90B5A;PT5 7 0 , - - - , - - - - , - - - - , - - - ,

.,. 1 , - - - - -... ---+----1----l

T90B6A;PT5 7 0 , - - - - , - - - , - - - ~ - - - ~

.,a 1,----<,---+---1----l T90B7A;PT5

.,. )r----!r---+---1,----1, Model Time (msec)

Figure 6.3.2.4 Vertical distribution of dynamic radial and vertical measured stress (b) Measured transient excess stress (Page 5 of 7)

Vertical Stress T90B5A; P11

-5

ir----➔---+----+---i.

T90B6A; P11

-5

1 , - - - - -... ---+---!---l.

T90B7A; P11

Modal Time (msac) I-' I +» u, I

...

..,

::: _u

..:l

"iii .9,

(/) (/)

U) ~

(/) (/) Ql (J

w )(

"iii .9,

(/) (/)

U) ~

(/) (/) Ql (J

w )(

"iii .9,

(/) (/)

U) ~

(/) (/) Ql (J

w X

T90B8A;PT2

lr---➔----1----.----l

T90B9A;PT2

-5

1r---➔----1----.----l

T90B0B;PT2

·• 1r----,,---¼---+---!.

Modal Time (msac)

Increasing Z/ A T90B8A;PT3

.5 11---!,---+---1~---l

T90B9A;PT3

.5 1r----,,---,,---!,---I

T90B0B;PT3

·• J,----l,----+----1,---;.

Modal Time (msac)

T90B8A;PT4 20,---r---,----.,....---7

.,s

-20/,---,,.----!r---4----I.

T90B9A;PT4 2 0 , - - - - , - - - - ~ - - ~ - - -

-20 1r---!,----1---i.----1.

T90B0B;PT4 2 0 , - - - . - - - , - - - - , - - -

-20/,----1,----+----4----1.

Modal Time (msac)

T90B8A;PTS 70,---,----,----,----,

-,o i,---➔---..---i.----l

T90B9A;PT5 7 0 , - - - , - - - - ~ - - ~ - - -

.,o 1r----,,---¼----!,---L

T90B0B;PTS 70,---,---.---,---

Modal Time (msac) Figure 6.3.2.4 Vertical distribution of dynamic radial and vertical measured stress

(b) Measured transient excess stress (Page 6 of 7)

Vertical SI res,;

T90B8A; P11

.5 1r----,,---¼---+---!.

T90B9A; Pl 1

-5 1 , - - - - ! , - - - + - - - i . - - - - 1

T90B0B; Pl 1

Modal Time (msac)

...

~ O'I

--

..,

2:! u

,.s iii

iii ~

<n ID 0

w X

"iii

{/) {/)

iii ~

fl)

~ X

"iii

fl) fl)

iii ~

fl) fl) ID 0

w X

T90B1B;PT2

.5f,---.---'z---➔----i, T90B2B;PT2

.5 r---;---'z---➔----t

T90B3B;PT2

-51.---4----'z---➔----i, Modal Time (msec)

Increasing Z/ A T90B1B;PT3

-5 f , - - - . - - - - 4 - - - - l , - - - I .

T90B2B;PT3

T90B3B;PT3

-5 J.----l,----+---1.----1.

Modal Time (msec)

T90B1B;PT4 2 0 , - - - - , - - - - r - - - - r - - - ,

-20f,---l,---'z---➔----i,

T90B2B;PT4 2 0 . - - - ~ - - - , - - ~

-20f,---l,---'z---➔----i,

T90B3B;PT4 2 0 ~ - - - r - - - - , - - - - , - - - - ,

-,o

-20 f,---.---'z---➔----i, Model Time (msec)

T90B1B;PT5 1 o r - - - , - - - - . , - - - - ,

.,o ,__

_________

^..,_

_____

T90B2B;PT5 3 5 r - - - , - - - - , - - - - ,

-5 r--~----:r---➔----t

T90B3B;PT5 30,----,----.,..---,---,

.,o 1.---1,---'z---➔----i, Model Time (msac)

Figure 6.3.2.4 Vertical distribution of dynamic radial and vertical measured stress (b) Measured transient excess stress (Page 7 of 7)

Vert it.:al St n·ss T90B1B; P11

-5 ,__

_________

^..,_

__

^_,,.

___

^..,

T90B2B; P11

T90B3B; P11

Modal Time (msac) I-' .+:>, '-J I

200 180 (a)

-

^fl) 160

- a.

fl) 140 fl) Q)

I... 120

...

(J)

"O ¹⁰⁰ Q)

I...

:, 80 fl) (1j

Q) ⁶⁰

.

20 0

125

-

^fl) ¹⁰⁰ ^(b)

-

fl)

a.

fl) 75

I...

...

(j)

cu

⁵⁰

...

C Q)

E

25 Q)

I...

u

-25

. .

. . .

' '

. . . . .

.

.•

. .

. . .

. . . _. _.

. .

. . . . .

. .

-148-

Static

Begining of blow End of blow

. _______ { Maximum during blow Minimum during blow

....

-

.. - -..

-

. ...

Blow Number

-

... --.... .. ...

....

-

10 1

Blow Number

Figure 6.3.3.1 Static and dynamic stress histories of a transducer, Z/ A

=

26.67, R/ A

=

2.67; linear assumption Recreating the missing blow history

( a) Stresses, (b) Incremental stresses

- ^en

_0.

..___,

en en

I..

(/) +-'

0 (/)

- ^en

..___, 0.

en en

I..

(/) +-' 160 140

120

100

20 0

160 150 140 130 120 110 100 90 80 70 60

30 20 10 0

I I I I

A' ^II ^I

...

B e'

::i

_{1I I}

!l •

I

\ ' ' ^II I I I I I I I

' ^II I I

' ' ^II

' ^I_I

' ' ^I

-149-

Linear SCM

' \ c' ,

c' ,,_.,/

Model Time (sec)

'

_____

/ / --

B 8¹

:

' '

I I I

' I

I I

' I

,' ,'

I I

,' ,'

Measured Stress (psi)

(c)

( d)

Figure 6.3.3.1 Implications of the SCM assumption for a blow Z/ A

=

26.67, R/ A

=

2.67; D/ A

=

^22.6

( c) Transient stress following a blow

( d) Stress paths for the linear and model assumption

CJ)

a.

' - ' CJ) CJ) Q)

I,..

+-'

(fJ 0 (fJ

a.

CJ) '-' CJ) CJ) Q) I..

+-'

(fJ

-150-

40---""""T---r---r---,

5 A

Linear SCM

Model Time (sec)

(e)

40.---""""T---""T""---r---,

(f) _C

Tr---,t,,.---,o!i~---~-~.,,---;10

Measured Stress (psi) Figure 6.3.3.1 Implications of the SCM assumption for a blow

Z/A = 26.67,

Rf

A= 2.67; D/A = 26.8 ( e) Transient stress following a blow

(f) Stress paths for the linear and model assumption

200

-

^fl) ₁₆₀180 '-'

a.

fl) 140 fl) Q)

I.. 120

....

(J)

"O ¹⁰⁰ Q)

I..

:J ⁸⁰ fl)

ro

Q) ⁶⁰

200

-

^fl) 180 ¹⁶⁰ ' - '

a.

fl) 140 fl) Q)

I.. 120

....

(J)

u

¹⁰⁰

....

ro

⁸⁰

:J () ₆₀ ('lj

0

40 20

-151-

(g)

:

.·, ^'

..

' ' ' ' ' ' '

---·

Non-dimensional

(h)

: .·. .

' '

.

' ' ' ' ' '

Non-dimensional

.

Static {

Maximum during blow Minimum during blow

- -

^..^"

.. -...

Pile Depth DIA

···

-

^{... -}....

Pile Depth DIA

Figure 6.3.3.1 Comparison between the linear (g) and SCM (h) assumptions, of the dynamic stress history of a transducer

Z/A

=

26.67, R/A

=

^2.67

-152-

200

-

^IJ) ¹⁵⁰ (i)

- a.

IJ) IJ) 100 (I) +-' I..

(fJ

-- '"'~--- ....

______

Non-dimensional Pile Depth DIA

- -------·---·-·--·-···--·----·-

100

80 (j)

-

^IJ)

- a.

^IJ) ⁶⁰

IJ) (I) 40 I..

+-'

(fJ

... _.__ .. ____ ...

0 ^_,......

1 ⁰

IJ)

a.

-

IJ) IJ) (I)

I..

+-'

(/)

Non-dimensional Pile Depth DIA

100.---.---

(k)

Linear --- SCM

Non-dimensional Pile Depth DIA

Figure 6.3.3.l Comparison between the linear and SCM assumptions, of the dynamic stress history of a transducer

Z/A

=

26.67, R/A

=

^2.67

(i) Maximum dynamic stress history (j) "Static" stress history

(k) Minimum dynamic stress history

T90B20; Linear & Model

20 18 16

(J) 14

.e:

(J) 12

(J)

~ ¹⁰

iii

(fJ 6

T90B30; Linear & Model

20 18 16

'iii ₁₄

.e:

(J) 12

(J) I]) ₁₀

I,.

iii

(fJ

T90B40; Linear & Model

20 18 16

iii ₁₄

.e:

(J) 12

(J)

~ ¹⁰

iii

·•· ... ~:

(fJ

Model Time (sec)

Figure 6.3.3.1

Implications of the SCM assumption Z/A = 26.67, R/A = 2.67

(I) Evolution throughout driving of the transient stress following a blow, linear and SCM assumptions

Linear --- SCM

E-03

(J) a.

(J) (J) I])

I,.

iii

(fJ

-153-

T90B60; Linear & Model

1 0 0 . . - - - . - - - , - - - ,

120

100

20 .···

T90B70; Linear & Model

140

T90BBO; Linear & Model

140

120

T90B90; Linear & Model

160

140

120

100

Model Time (sec)

T90BOA; Linear & Model

4 0 , - - - " T ' " - - - , - - - ,

;;,.:

....

,,,,

~ ·:

... _··..

T90B2A; Linear & Model

4 0 . . - - - . - - - , - - - ,

T90B5A; Linear & Model

4 0 . . - - - , - - - . - - - ,

T90B0B; Linear & Model

40 r - - - , - - - . - - - ,

Model Time (sec)

-

^(J)

_a.

-

(J) (J) Q)

I,..

CJ) +-

0 CJ)

"O +-Q) (1j ::J 0

"iij

0

100 90

10 0

-154-

R/A

=

2.67 --- R/ A

=

5.33 --- R/ A

=

^8.00

· · · - - - · R/ A

=

16.0 - - - R/ A

=

^24.0

10 2

Non-dimensional Pile Depth (D/A)

Figure 6.3.3.2 Radial distribution of the radial calculated stress Z/A

=

26.67

-

^UJ

.._,,

a.

UJ UJ Q)

I...

...,

(fJ

0 (fJ 'O

...,

co :,

(.}

(tj ()

UJ UJ Q)

I...

...,

(fJ (tj

0 UJ C Q)

E

'O I

z

150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0

5 4.5

3.5 3 2.5

1.5

0.5 0

-155-

Z/A

=

^10.67

Z/ A

=

^21.33

Z/A

=

^26.67

Z/A

=

^32.00

Z/A

=

^37.33

Z/A

=

42.67

Non-dimensional Pile Depth (D/A)

(a)

(b)

Figure 6.3.3.3 Vertical distribution of the radial calculated stress

Rf

A= 2.67

(a) Calculated stress (b) Non-dimensional stress

50 45

-

^(J) 35

0. ³⁰ ...

(J) 25

(J) Q)

....

I.. 20

Cl)

5 0

-156-

Measured stress Radial stress

Vertical stress ~---.,.-\

. \

Non-dimensional Pile Depth (D/A)

Figure 6.3.3.4 Comparison of radial and vertical, measured and calculated stresses; Z/ A

=

32.0, R/ A

=

^8.00

-157-

5r-.---.---

(a)

-5

10 ,-...

<( ₁₅

N

.._,,

.c ^0.5

+' 20

a.

0 ni

⁺

C 0

u, ³⁰

C + +

E

³⁵

u

_I +

C 0 ⁴⁰

z

₊

65 0

Non-dimensional Radial Distance

Figure 6.3.3.5 Calculated radial stress contours (a) D/A

=

-

(

N -

.c ....

a.

i

C 0

(/)

C Q)

E u

z

-158-

10 +

+ +

35 + 40

+ 45

65 J , - - - h - - - , f , , c - - - ~ ₀

Non-dimensional Radial Distance

Figure 6.3.3.5 Calculated radial stress contours (b) D/A

=

- 159 -

Dalam dokumen SOIL STRESS FIELD AROUND DRIVEN PILES (Halaman 130-174)

Chapter 6 Experimental results

6.3 Soil stress field

6.3.4 Discussion and Conclusion

=

=

<t

I T70

z

PILE

PT

R

CONTAINER

-118-

I

=

-120-

::

.

...

. .. . .... . .

. . . . .

...

..

. . . ...

=

=

~:/

I- · \

I

,~

l

\ "

-121-

f: .:

I

l /;

---

,,----

,,

'

zone

m m

' ' ' ,,

' ' ____

--

a.

....,

ro

a.

ro

,,

Rf

=

Rf

=

Rf

---- o-v

=

-

a.

ro

=

=

-

1/

.I ./\

_,,.. ----

I=---"""'"'---

--#--~ -

=

-

cu

E

z

Rf

-

---

i \

i \

. .. . .... _. .

' ' _' ^,,

' _' ____

_a.

_a.

- ^en _a.

- ^en _a.