this document downloaded from vulcanhammer · pdf filethe soil rezcti~n in the embedded porbun...

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Terms and Conditions of Use: this document downloaded from vulcanhammer.info the website about Vulcan Iron Works Inc. and the pile driving equipment it manufactured All of the information, data and computer software (“information”) presented on this web site is for general information only. While every effort will be made to insure its accuracy, this information should not be used or relied on for any specific application without independent, competent professional examination and verification of its accuracy, suit- ability and applicability by a licensed professional. Anyone making use of this information does so at his or her own risk and assumes any and all liability resulting from such use. The entire risk as to quality or usability of the information contained within is with the reader. In no event will this web page or webmaster be held liable, nor does this web page or its webmaster provide insurance against liability, for any damages including lost profits, lost savings or any other incidental or consequential damages arising from the use or inability to use the information contained within. This site is not an official site of Prentice-Hall, Pile Buck, or Vulcan Foundation Equipment. All references to sources of software, equipment, parts, service or repairs do not constitute an endorsement. Visit our companion site http://www.vulcanhammer.org

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Page 1: this document downloaded from vulcanhammer · PDF fileThe soil rezcti~n in the embedded porbun 32 the pile is ... buckling load. ... for partially enbedded long flexible piles in cohesive

Terms and Conditions of Use:

this document downloaded from

vulcanhammer.infothe website about Vulcan Iron Works Inc. and the pile driving equipment it manufactured

All of the information, data and computer software (“information”) presented on this web site is for general information only. While every effort will be made to insure its accuracy, this information should not be used or relied on for any specific application without independent, competent professional examination and verification of its accuracy, suit-ability and applicability by a licensed professional. Anyone making use of this information does so at his or her own risk and assumes any and all liability resulting from such use. The entire risk as to quality or usability of the information contained within is with the reader. In no event will this web page or webmaster be held liable, nor does this web page or its webmaster provide insurance against liability, for any damages including lost profits, lost savings or any other incidental or consequential damages arising from the use

or inability to use the information contained within.

This site is not an official site of Prentice-Hall, Pile Buck, or Vulcan Foundation Equipment. All references to sources of software, equipment, parts, service or

repairs do not constitute an endorsement.

Visit our companion sitehttp://www.vulcanhammer.org

Page 2: this document downloaded from vulcanhammer · PDF fileThe soil rezcti~n in the embedded porbun 32 the pile is ... buckling load. ... for partially enbedded long flexible piles in cohesive

P r i g ~ r o u s f l e x u r a l a n a l y s i s f : ~ r p a t i a l l y enlbedded

p i l e s s u b j e c t e d t o v e r t i c a l dnd l a t e r a l l a a d s i s p resen ted .

The s o i l r e z c t i ~ n i n t h e embedded p o r b u n 32 t h e p i l e i s

o b t d n e d u s i n g ~ o d u ~ ~ s 3f suugr.s.de r e a c t i a n t ! l c ~ r y . k i l e . . s

~xbedcfed i n bs th c3hes ive and c o h e s i o n l e s s s o i l s have t e e n c ~ n = i d e r e d . The r e s u l t s 3f t h e a n a l y s i s s h ~ w +hat t h e ver-

t i c a l l o a d can i n c r e ~ s e trle l ~ i t e s a l d e f l e c t i : > n t o arl e x t e n t o f about 7 t o 16 p e r c e n t dese f id in~ ; on the degree 3f fixity i f the v e r t i c a i l ~ ~ u i s ~f t r ~ ; ~ ; . t e r 3 f 10 gezcen t 3f the b u c k l i n g load. A c o o ~ p a i s s n 3f t k i € reec; lts ?f t ~ e a~ la lys i s

v.1 th t hose o b t a i n e d using ' i c i ~ i i v ~ l e n t Cant i l e v e r i \ .ethodl

h a s been nlade. i h e con:; 2 r i . 3 2n sl;:k:c;ea t s Lhat t he 'Lc;uiv2.1ent C m t i l e v e r c etii od ' needs mou i l i c ~ ~ t i o n s even v i ! l e n ~ ~ ~ s e d t o

anz lyse a 2 i l e sub2 e c t e d on ly 1:-._teral load . .

';hc l3:-.ds 9n p i l e f . ~ u n ! l . . t i o n s ESJ be ver. tica.1, - - . - I l : : t e r a l , c y c l i c D r d j rnmic Q r 12 2 c?n!bined n. '..ire. kl-?

f o u n c i a t i 2 n s s u p p o r t i r g ~ f f s h I; :: z t ~ : u c ? ~ r e c zr? r e q c i r e d to . t :a.rlsf~r I n t e r 3 1 l : ~ z d ~ i n v i l l i ';;i~n t o s i c l i l lo-..ris. yha

~.!.r-:? ;z foun6zt i :Jn f o r +.ej,e r . t ruc t t s . - s h3ve c>n:ider2blc=

f r e e b t a d i n g i u n s u s j o r t e d ) ltni,".h. 2he ; . resent rl:?*h?d :7f

f l e x u r a l , m z l y s i s z ~ f f r e e stc$lc!inp p i l e s n a be grouped as

f ollotr!~:

c i> :, e t h ~ d ~ ( b r 3 ~ 1 ~ . , 1964, e n , P, 7 2 ) :.;:i-b 'cqnsider ..;.flu.ive,l:..nt lo;-..i.ing zt t9.e g r ~ u n d l e v e l :xld ana1ys.e

Page 3: this document downloaded from vulcanhammer · PDF fileThe soil rezcti~n in the embedded porbun 32 the pile is ... buckling load. ... for partially enbedded long flexible piles in cohesive

"the ernbedaed p o r t i ~ n o f t n e 2 i l e usirig aoc~ulus o f

~ u b g r a d e r e t i c t i ~ n t i l ~ q r y . I n ttqie n e t h ~ d the def le- :q, --.L~

c t i on a t t i le k i l e head i s de termined as the sum of ( 3 - 0 e i l e c t i o n ,IL' g i l o a t the ground l e v e l . (b ) Def- l e c t i 3 n of p i l e head considered as c a n t i l e v e r f ixed

a t tne ground l e v e l ~ n d sub iec ted t o a l a t e r a l load

' 6 ' a t the p i l e head m d ( c ) D e f l e c t i o n of the p i l e , head due ts the s l q e a t the ground l e v e l .

( i i ) I\i.et.i qds (33visson -ad kobinson, 1569, 0 teo , 1S;t 1)

based on f i e p r i n c i p l e o f equ iva len t c a n t i l e v e r wherein i t i s a a s u ~ e d t h a t ~ a r t i a l l y ercbedded p i l e EW be r e p r e ~ e n t e d a:: a c m t i l e v e r with a f i x e d base below t h e grov-na su r face .

( i ) The e f f e c t o f v e r t i c a l l ~ a d on the f l e x u r a l behavi-

cur 3f p i l e s h a s n o t been c o m i d e r e d . Tile l a t e r a l d e f l e c t i 9 n a t t h e he;.c ~ f a f r e e s tanding p i l e can be l a g e and t h i s m~,lll r e s u l t i n the v e r t i c a l load

czusing an sddi t i o n a l c i x e n t ( 2 i g . 1) vktich tends

t o rxagnify the l s t e r a l d e f l e c t i o r . i .lij de,th of fixity of g ec;:iiv,lent cctnt i lever

coniguted b z . s ~ d on bending c r i t e r i a di:Pers fro^ -the

one c g q u t e a based on bu.ckling c r i t e r i a . I t a l s o depends on the f r e e ::t~.ndi~ng l e n g t n s and &he V j ~ e

3f loc,d.~;2i.:: (when bcnding. c r i t e r i 3 n i s used) i . e .

rvhether g i l e i c sub jec ted t o a, l a t e r a l load o r a

c~oxcnt. i h ~ s i n a genera l i sed si t u a t i ~ n m a u ~ n g a

p a r t i c u l a r va lue T o r d e ~ t h o f f i x i t y m g y r e s u l t i n ce r . t i2n a ~ : m n t 3f e r r o r i n t h e computed d e f l e c t i o n .

( i i i ) -e msinua n;onent i n a p i l e s h a f t i s no t equa l t o

t h e f i x e d end rnmien-1; o f the c a n t i l e v e r . The loca-

ti32 2 f the maximun; Eom~nt i n a p i l e x i 11 n o t corre- spond ~3 t h e 2 o s i t i o n of f i x e d en3 o f the c a n t i l e v e r . f'Y I n view of tne DOVE, ;: r i g o r o ~ s a n a l y t i c a l s o l u t i o n

Page 4: this document downloaded from vulcanhammer · PDF fileThe soil rezcti~n in the embedded porbun 32 the pile is ... buckling load. ... for partially enbedded long flexible piles in cohesive

f ~ r ~ , s t l a l l y ecitedcied long r'lexll3.e p i l e sub; e c t e d t o ver- -- Li c 1 IO~U, l d t e r a l l o :J -ylc; n i ~ r i , l L n t, i)d~t:d o:: o , ; d u l u s .;)f ~ u b -

I. ~ i e reac t i3 -n 23prodch is .,esent=d,

A u n i f c r ~ c r a ~ a - s i i c t i 12 p i l e & c r t i 2 l l y :~bedij.ed i n

c s h c s i - v e i c ~ h e s i - ~ n l e s s 2311 rnci s u b j e c t e d t3 lg:,~C.ing ? ~ l d

bou2cltzy con2ii ic?nz 2.2 shown in .Ti$;. 2 csni , iceref i .

: ' i p r e 2 i ?Lj c h 3 v . ~ s f ree-fzee 2ile ( f r e e et 2ile he26 2 r ~ i i

f r t e s t t i p ) :.;ith vertical l g c d 3,' 1 ; : t e r d lozii C, i-nd r l

.n ' r:.311 ~ n t 1,. zt tl:c t~;.. ~ - f l p r e 2 j b j sn3.;,5 f i x e d f r e e \ f i x e d at,

p i l e ?fld y ~ c e at ti&, k i i e ..': ,,.- '-h > A +i b* r ., 2.- ..l l I-,'.! 2 ,. ?.c L C

-,: 1 - 7 l.L~c-2z,l :>,-? - . L - . ,- . ,.),--. . . , , , I . ,. . .z;i~uc.ed t~ be cgna tant

:;i- -;h depth f3r c:1h6sive s!)i 1,c :md i-ncreasin_r -fin. g r l y ;z;ith -.

, ~ K _ J 21 f.3r c31.,esi 2niess s3ils (i l ic: . 3 , .

f r i z t i 3 n -".;y t;e asS.;;rr,ed c o n s t z l t ;.,i't';i ce2t.h ;>rid hence t h e

C , ,

v c ; ~ t _ i c a l l o 2 1 is 2 s s u ~ : ~ d t o decreijse l i n e z l y v i i t n d~;it:b. . . -l in c:;~E. 3 1 ~ ~ ~ ~ e ~ i : 3 i l l e s s S ) L S k l e u : l i i = k i n f r i c t i o n incre3,-

s e s line,tr.iy :;.i.a dep+h m~ hence a e v s r i k c h l l ~ a d x~tri-

. ., -. ' Free-;Yee 1 i l - e i l l < - t ~ t i v ~ J ) ~ . L E ; - (i) >.Lee s t w o i n g ,oc t i c~n . - me governing bendin;. ; ~ s ~ i r i t e ~ u , ~ t i ; n f o r t h e

f l e e s t b r d i r ~ ; ( ~ n ~ u ~ p o r t e d Itn;-t&j 2 3 r t i 3 n oS t h e p i l e is : ' i 7 r 6 . r 1 v :A br; iT?'ig.

J 1) ,-.

Page 5: this document downloaded from vulcanhammer · PDF fileThe soil rezcti~n in the embedded porbun 32 the pile is ... buckling load. ... for partially enbedded long flexible piles in cohesive

( a ) FREE -FREE PILE ( ~ I F I X E D - F R E E PILE

f ig, 1. Beading of a part ial ly embedded p i 1s

Bfg.2. Loadiag and end I

aom%Ltitoru~ considered for &a snalyais

( 1 ) UWHORM ( ii) L INEAR ( 1 ) LINEAR ( i f ) PARABOLIC

P2g.4. Variat ion of v e r t i c a a load

Page 6: this document downloaded from vulcanhammer · PDF fileThe soil rezcti~n in the embedded porbun 32 the pile is ... buckling load. ... for partially enbedded long flexible piles in cohesive

-. ; ;!, ..z i;i j:f ere n t i al cciu I ti .:n ~ , i dl con:.:. t 2 1 . 2 ,",t

coefficicn.t- ,.,;1~ its ~-2;~lc;t;e : - j>lu t i : )n i~ . r i v c r i b;1:

' , - -- . - ' k

: , = a c2s j l : c A, c i n YLz + --- + / . . { 7 , 5 7 1 - t i J

Page 7: this document downloaded from vulcanhammer · PDF fileThe soil rezcti~n in the embedded porbun 32 the pile is ... buckling load. ... for partially enbedded long flexible piles in cohesive

cxaz ST aazc3 m a y s 3 q ( ~ 7 ) PTR cxaz S T

warnom ayz [ T ) - * a l e a ~ ~ f i 3% 10 d g aayl 7~ s u c ~ ~ r ~ m c 3 ayA

*pEaI TesalzT p a q d * cq l ~ n T 3 3 7~ . n a g s a n ( T T )

p m 3uamoT p a g d d s 0; ~ ~ n 5 a a ? $u3incio eyJ (7) - : a n a l ~ f i

a q . j c peaq ay% 3s s u o q y p n c a a q 2 - * s u o r q ~ ~ u c o Xnpunog

Page 8: this document downloaded from vulcanhammer · PDF fileThe soil rezcti~n in the embedded porbun 32 the pile is ... buckling load. ... for partially enbedded long flexible piles in cohesive

; ' o l l ~ w i n g ti] c s -.r:,e ~ r o c e d ~ t r . 3 s.s f ~ r free- i'r.i:e p i l e , "&.e

e:,u a ti 3n 15 c an 1:) e tr ansferre~ 11 'c, ti! 5 YI~J a- ci.~ rr.? t z ~ i o n 2 f 2rn,

in m i ch , hi,-, = I,.?/LB . . .( 21)

'i 'ht c ~ ~ n ~ p l e t ~ s 3 h a c ; n ~f EL. 2G i s given by

'Yhe governirlg u f f e r e ~ t i a l ecju,tian and i t s s o l u t i ~ n f l~r .

-Ae e~bec i aea le::;,tri 35 tne silt? sr'e s x e as given by ;.;~s.

4 hi12 13

bounazry c o n a i t i 3 n s - i t i = 3 , i t he s 1 0 ~ c is zero i . e .

dkv/dz = 0 ana ( i i ) 'Lhe c!3meilt i s equal t~ t h e fixed. end J

'I -, ronient, i. e. d ' b /de2 = -bbp 3'

The c o n d i t i ~ n s zt b e ti2 s.nci tle c o n t i n u i t y c3nr i i t ior ls a t

Page 9: this document downloaded from vulcanhammer · PDF fileThe soil rezcti~n in the embedded porbun 32 the pile is ... buckling load. ... for partially enbedded long flexible piles in cohesive

gra7ilnd l e v e l are same as g iven ~y h q s . 13 t o It?. /s i

( c ) 2ree-Free P i l e i n C o h e s i ~ n l e s s b3ils.- Yhe governing d i f f e r e n t i a l - equat i3n i n nan-dimensional form may be g i v e n

f o r 0 \( Z 4 Z2

2 i n which @' = v/(z,) ; and %he r e l a t i v e s t i f f n e s s f a c t o r

C

R 51 B I / n , . The c o ~ p l e t e so l u t i o n of Eqs. 23 and 24 a r e

g iven by, r e s p e c t i v e l y

Batcl Z $ = A1 cos V U s + A2 s i n VUz + --- U

.&To +i

( d ) 2ixed-Free P i l e i n Cohesionless Soi l . - m e governing (1 d i f f e r e n t i a l equat ion and i t s s o l u t i 3 n f o r tne fkee stand-

ing (unsupported) p o r t i o n o f t h e p i l e a re same as given by Eqns. 20 and 22. S i m i l a r l y the governing d i f f e r e n t i a l equa- t i m and i t s s o l u t i o n for the ercbedded length o f t h e p i l e are same as g iven by Eqns. 24 and 26.

R U u LTS BND DISCUSSIONS

m e a n a l y s i s has been p rogramed and t h e r e s u l t s a re

obta ined u s i n g DEC-20 systeni. The r e s u l t s a re presented

f o r p a r t i a l l y enbedded long f l e x i b l e p i l e s i n cohesive and

cohes ion less s o i l s . Z f f e c t ~f a i a l load on d e f l e c t i o n and beyLd.dir?g EoEent 3f t he p i l e s i s discussed. C h a t s are prese- n t e d f o r top d e f l e c t i o n c o e f f i c i e n t , $t and maximum morrent

c o e f f i c i e n t , AIYm which a r e g e n e r a l l y r e q u i r e d f o r design. A comparison sf the l L q u i v d e i ~ t Cant i lever Lethod1 and t h e

proposed r i g o r o u s a n a l y s i s is n;ade. f-4

I t h a s been repor ted by various i nves t iga to r s (Reese -

Page 10: this document downloaded from vulcanhammer · PDF fileThe soil rezcti~n in the embedded porbun 32 the pile is ... buckling load. ... for partially enbedded long flexible piles in cohesive

U E

MB

ED

DE

D

LE

NG

TH

, Z2

k,

P .

(39

0

U

0, h

0

P.

Y p

l 4 nF

J

m a

w

hm

O

YH

,

P- e F

J P

O@

J

0 - d P

C*

P

O

D

Page 11: this document downloaded from vulcanhammer · PDF fileThe soil rezcti~n in the embedded porbun 32 the pile is ... buckling load. ... for partially enbedded long flexible piles in cohesive

i t i s observed t l&t ifi t h e case of p a r t i d l y e ~ b e d d e d p i l e s ,

t h e v e r t i c a l load i n c r e a s e c the top d e f l e c ~ o n and m s i m m 43 , 4 -J

moment s i g n i f i c a n t l y . ? o r e x w p l e , f o r a p i l e having a un- -. supported length = 2 t9y d e f l e c t i o n c o e f f i c i e n t

?Yt . i n c r e a s e s f r o & 13.7'3 t3 1 2 .CJL ( i n c r e a s e i s a b m t 15.68 per- cent) and .rr.simIc rr.orrAsnt c a e f f i c i e n t , Ah., i n c r e a s e s from

2.17 t o 2.55 ( i n c r e a s e i s a b X t 17.5 percent ) when v e r t i c a l *

load i n c r e a s e s f r o n 6 = Q.3 1;2 L = 3.03. T h i s i s due t o +Ae \

f a c t t i1: i t thc l : . teral d e f l e c t i a n a t t n s 2 i l e head i s l a r g e

cind the addi t i ~ n a l n:Drrent, cziused due t o t h e e c c e n t r i c i t y ~f v e r t i c a l Igad a4i the d e f l e c t e d p o s i t i o n (Fig . lj i s sig-

nificant.

Pigures 7 a d t sh3-iv r e s p e c t i v e l y , t y p i c a l d e f l e c t c

i o n and ~ o m e n t curves f o r g i l e s ' h a v i n g f i x e d f r e e end condi-

t i ~ n s . The r e s u l t s a r e p r e s e ~ ~ t e d f g r U = 0.0 and U = 0.06. U = 3.06 corresiJonds t o n e a i 2 10 p a c e n t of buckl ing load

f o r a f i x e d f r e e p i l e having L1 = 2.0. 1-t can be seen from -

Zig. 7 a d t, t h a t though the ve rLdca l load i n c r e a s e s the 9 top d e f l e c t i o n a?d n-mimum r, o l ~ e n t s i g n i f i c z n t l y the i n c r e a s e

i s no t as ruch as gbserved i-1 the case of p i l e $ having free- f r e e end condi t ions . F3r exa lq ie f o r a p i l e having an unsu-

pported length Z1 = 2.0 tne ~ o p d e f l e c t i o n c3efrJ icient '4Jt increase^ from 3.51 t o 4.97 ( i n c r e a s e i s abou t 6.62 percent )

and niixinun, o.on.ent c o e f f i c i e n t , q , , from -.1.71 t o - l . t 2

( i n c r e a s e i s abaur 6.26 percent ) when v e r t i c a l lohd i s inc-

c r e ~ s e d from b = 0.0 t o u = 13.06.

Tigures 5 t o t a l s o silow that as Zl i n c r e a s e s , -the

13 in t o f zero d e f l e c t i o n and tile p o i n t of aurimnl m n e n t

s h i f t u p r a r d s . ?or e x a q l e I i ~ e ;orit i . .n o f n#imrn noment rrovee fronl z2 = 1.0& t3 0 .jG a s Z1 i s - i n c r e a s e d from O t o 2

f ~ r f r ee - f ree s i l e v , i t h U = 0 . 0 .

F i x i t y a t the h e ~d 3 '. t h ~ f l c n . : . n l ' lerbsr s t r q n ~ l y influences b 3 t h c ief lec t ion :::d xonent . Yhc dec r t e of f i x i t y

B, zt the k i l e h b ~ d c m be d t 2 i n e d a s t h e r a t i o s f We (1 -

Page 12: this document downloaded from vulcanhammer · PDF fileThe soil rezcti~n in the embedded porbun 32 the pile is ... buckling load. ... for partially enbedded long flexible piles in cohesive

V) Z z W

DEFLECTION COEFFICIENT, A~

F O R Um0.06 FOR U-0.0 y = 1.0

BMQ-0.0

f r e e

k = CONSTANT FOR U*0-0 6

B M a= 0.0

Fig *&

MOMENT COEFFICIENT 8 - AM,

T y p i c a l moment curve f o r f ixed m free p i l e in eoheaive soil 5 4~

Eorrent a t -the p i l e head t3 t n2L t sf t h e rcm,ent a t tine ;Fie head 3f a f i x e d h e s d e d 2ile ( n o i ~ t ~ . t l , n a t t h e & i l e head; . k c c o r b n g l y t h e zer3 p e r c e n t f i x i t j - co= . r e s i ;~nds ta t h e ca se 2 : f r ~ c headed ~ i l e a i lOO ;er.'ccnt fixit;;: cr)y7:ezxqnd, t,3

the C ~ E E of f i x e d heaaed p i l e . g ~ v i s s o n (1573) s c g g e s t s t h a t -tine ciegree of f i x i t y *-st can u s u a l l y b e d e v e l 3 p e d between

+he p i l e head a d tine g i l e eas i s 31 t n e orde r ~f 50 yer- c e n t . A c o m p a i s o n of r e s ~ l t s f )l: 'ii = 0.0 ar,d iT = i) .03 shoq~vs

that f o r a 2 i l e having an u n s u ~ ~ o r t e d length Z - 2.0 and a 1 -

degree of f i x i t y , ? 3f 30 ijercenQ6-1 the sile head, t h e top

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c o e f f i c i e n t & ~ n , 4 . E 2 5 w -Ci.kLO \ i n c r e ; i ~ e i s about 2.5 - .

e n ) md a i x i ~ u r , ; i s ~ i l.i-zt. rr.onlen t c x f f i c i c n t fron 1.375. t o 1.575 ( i n c r e z s e i s a b w t 1G.6 gercen t ) when v e r t i c a l load

i n 5 p r s c t i z a l si- tuati Jn, tt .c e f f e c t 3f vertical 13.12 rray ,

r L f l ~ f ~ c t + L , t t h e ;fcrl;ical l ~ s 6 sl ; ' ruf icc~ntly h f f e c t s

tLie f l k x u r a l iri;r?c~vi3ur 32 pc . r t id . ly e~~.-ced[-ied p i l e s hiis two

i m p l i f i c a t i 3 n viith I c g d d ~ ts tile p e s e a t day p r a c t i c e i n a n a l y s i s mu des ign ~f 2ilt~.

(i) ,file ' L q u i v d e n t Czn t i l eve r a -e t i l~d ' v,hich is used i n tile a ~ a l y s i s 3f y ~ ~ t i - , . l l ~ a:-Gedded p i l e s do n g t t & e i n t o

5ccJunt t h e e f f e c t ~f s c i a l load , Therefs re the use of

' Ec_uivaifnt C m t i l e v e r i. et~;:>u' f a r m a l y s i s of v e i t i c a l l y

~ n i l i , t e r a l l y loaded p xtidl) eabeaaed 3ile.s w i l l r e s u l t

i n under e s t i l ~ a t i o n o f t o p d e f l e c t i o n aad Piaximrn monents.

( i i j i t s h ~ z i l d b e enslcrc-d t h z t t h e l L ~ t e r . s i d e f l e c t i x l

under the con;bined v e r t i c a l and l a t e r a l loads does n o t exceed the perr r i ~ s i b l e lird ts.

(b) Sohes ionleYs 6oi.l.- k e s ~ l z s f p r tk ie c a s e :)f 2 i l e s i~

cohes ionleas s ~ i l a r e alss g b t d n e d and faund t o be sf the

s s e n;;ture 2s 3f tLe p i l e i n c2hesive s a i l s . The g e n e r a l

conc lus ians a r r ived aith r e g a d s t o the e f 3 c t of v e r t i c a l l3ad a r e v a U d f o r p i l e s i n cohes i3niess s ~ i l s d s 3 .

N 9 n - D i ~ ~ n s i ~ n a l D e f l e c t i ~ n C 2 e f f i c i e n t at t h e Y i l e Head

Il'hk ; t ~ x i , s i k l e 1 ~ t e r ~ l load is g e n e r a l l y based 3rr o e 2 ~ y r L ~ s i b l e l a t € l c ~ l clc;icc-L;~~n Qt t h e d i l e head. The

der" lec t l3n st LTe k i l e he,d i s d e p n d e n t 3n a p s t f r~7~1 t h e

n ~ ~ n i t u a e 3 2 1 , terz l l ~ n d , xhe u n ~ u p p o r t e d length , the

dc,ree 3f flxiTJr 2.t t h e p i l e ht-ad , ~ n d the n ~ ~ ~ g n i t u d e of l o d d . ' /nerer 'art : tde r e s l t s f o r d e f l e c t i o n at t h e

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r l l ~ he,td a e 21 e s e n - ~ e d in tiie ; , Y E 3f c h a t s f ~ r - J ~ , ~ ~ ~

v d u e s ~f u n ~ u p p o r t e c l Len; ti: U1, " (?ecrce o f f i x i t j ; , 3 dr,d

~ l ; z l -. l ~ ~ d f a c tsr, b . dll;u;.e CJ t h e t~~ d e f l e c t 8 a n

c o e z f i c i e n t ;3-t f o r p i l t i z l $ ~:.;sBded y i l r s i n c ~ k i ~ i v e s o i l . The r e s u i t s a r e pressn--c b -' f3r ir = 0.0 arid U = 0.3; 2nd

de:~rec o f fixity, E = v .O1 u;?d 1.0. a i r i . 1 ~ r e s a l t c f o r

FREE STANDING LENGTH 821 Fig.5 .Uef lec t ion at the pile

head for p i l e in c3hesive s o i l

-FOR U-0.03 FOR U-0.0 y = 1.0

FREE STANDING LENGTH $21

Pig, ,y .Def lec t i2n at t h e p i 1 head for p i l e s in c* hes i3n less soi 1

I t cm be a o v m t h a t t h e l t i t e r a . l de r ' l c c2Lm v ~ x i e s

l i n e a r l y v , i t . h degree 0 5 fixit;:. 3 ihere fore fro:!. t,",~: r e s u l t s rr .ecente6 d e f i ~ ~ t i 3 n v ~ ~ l u e ~ c;ll 't\e 3 k ~ t c i c e d f ~ r an3; o t h e r

Ciegree o f f i x i t y bj- i irle;lr in ' ier201L+L m. it is ;;so T x n d J . - 1 .

. t ,?1 .ti3nU:~,,, :,etv,hen i _lm.cJ '"; ' t i s a > g r n x i ~ x t c l y l l n c ; ~

';kt:, 3 3 o i l t 13 p e r c e n t s7f -the b~ci(1i.w load. i h e r ~ f 3 1 . e ~ ~ i n g -- .

the c n 3 z t s yreae-n-ted i:- i i g . 5 .31d 13 f a r .L = 0.0 mil L&.u;~

i h - A v a l u e s f3r 0th:~ ~ i i l i l e 31' L u2- t~) 13 2ercen-t 32 buck- Y b

-I. a n g 1 ~ ~ 2 can b e obta i f i e6 usin:; l i n e a x inter ;oiazidn ( o r

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Non-diniendsnal Laxinun: i:.or.ent C o e f f i c i e n t

F o r t he structural design sf y i l - e s i t i s necebsary

t3 .ltn.on. the -lr!: juin?~;u) mar-cat i n the p i l e s h a f t . ca,se of

frc-t-free p i l e a , i c e mzxinrdn siorjent ( pos i t i v e nomen t ) occurs

st SoLie dep th 5~jlox7 t n e ground leve, i . l n t i e c m e of f i x e d

f r e e ~ i l e s tne m r : e n t 2% tfie p i l e head i s n :a : inum (negat ive

monent) . 3'31. s i l e s h i u i n g in termedia te f i x i t j i c snh i t i3ns a t tine p i l e head, t h e ~ . J i n ? c m~r ren t occurs e i ~ e r . at t h e p i l e Gejd j nagati-ue rn3centj. 3r at s3i1ie depth be low t h e

gr-,und l e v e l ( y o r i t i v e n3r.entj depenbcg upDn ~e hearee of fixi t y .

Figure i1 a d 12 z i v e r e s y e c t i v e l y -!he max ix run i 33si-

t i v e i~~scient i+ and EiOi i lCn t 5% t h e gi l e head, -&. . fsr p a r t i - AWL 3 *L1

1 5ri:bedded & l e s i n co!le;ive s o i l . l h e results a e p:,asen- t e d f o r LI = 0.0 ;fnd :! = 2 . 5 3 a d ciegree 3f f i x i t y , F = 0,0.5 3~ 1.0. Sil idlTz r e s u l t L fs;. ~ i i r ; s in c o h e s i s n l e u ~ s o i l a r e

=reden ted in 2i.c. 13 :>-i12- 14.

;i cfoc.p.zison !I.:-' ike r e s u l t s o b t a n e d sing the gz, ;2dvalen t c',~J--~-; l eve r 1, e:.. od* ( T C ' ! 1 '. ~i t h those ob t d n e d

s s i n g t h e yr.~i;;sed rigsi 'ove ;i1cJ;h3d i s ~.. : ide i n 9r.iler t o b r i n g

'32 t t!': F :z$ ,$ ~ ~ i r i ! a t i :3n i :.?-u:> lved ~ f i d L. mi ta.t l dnz of ti1 e ' LqLki-

embedded y i l e s .

. . 1 . 5 1 e V L ~ . ., i,9 3 f ,A ;? t , ined g s i n g ' 5 ~ : ~ i v ~ i e n t Cant i -

J L l e v e r Ze-&xi' as g r 9 2 ~ s e d Sjr 3av i s san and 2,fobinson (1565)

t n , t fJr :i r^r~t--r 'r€e 2 i l c , t h e dnf l e c a ~ n vskdes o b t d n e d by 1. t,?th t i l e r e t h ~ d s a c . ~ $ y r 3 X i ~ , ~ . t e l y t h e s a l e vjhen "

dl is gre3.- t e ~ . ti-1s.n 2 . 371 viil~*es ~f L7 l e s s UL-a 2.0, ~ A e u ~ e af

L

" i ~ ~ ~ i v r i l e n t Carrt-~lever. i e t i ioLi > ; i t h averGze va,lues 3f d e p ~ & ... o f f i x i t y (1.4 i. f o r c3hes ive s o i l s and l.bY ffor c3hesion-

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FOR UxO.03

, FREE

k :CONSTANT

. FOR U = 0.0 = 1.0

F I X E D H EAD

FREE STANDING LENGTH 3 21 F R E E STANDING LENGTH,Z1

i?ig. 11 .h.i.axiRun; p s s i t i v e molilent r ' ig. 12.b.3nent at t he p i l e f ~ r p i l e s i n cohes ive hedd P a r d i l e s i n cohe. s o i 1

0

FOR Uo0.03 ----- FOR U.O.0

F R E E - HEAD

I I I

F R E E HEAD

0 1 2 3 L 1

o 1 I I I J 0 1 2 3 L

FREE STANDING LENGTH, Z1

2ig. 13 .b~aximum p o s i t i v e rnD- nent f ~ r p i l e s i n c o h e s i a n l e s s s o i l

k : ? h ' X

FOR U=O.O

y - 1.0

FIXED

/HEAD

0

F R E E

* I I I

0 1 2 3 L FREE STANDING LENGTH 3 Z1

Fig .14 .h~ment a t the pile ' head f3r p i l e s i n

c o h e s i ~ n l e s s s o i l

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, l o s s s o i l s ) u ~ l i l result i n s i g n i f i c a n t e r r o r . T o r z1 use of sxac t v a l u e s o f de2th C I ~ f i x i t y g iven by i lavisson and Sobsnson ( 15 69 hhowever re;- It;, in r e ~ s q n a b l e qreernent bet-

l oad , t h e use ~f 'Gquivalerlt ' C antilever BLetnodl h w e v e r , w i l l r e s u l t i n 'under. esJdr:.;.;tion ~f d e f l e c t i g n 5s the meth~d does

n ~ t t a k e i n t o , zcc~u i~- t the e i ' l e c t of vertical load .

t i a-L, 1 1 - C3n.pzrison gf d e f c c t i g n s obt-nrd u ~ i n g ILqciv* l e n t S~~ , .n t i l ever l:.stl,qd' (LCL) 2nd ",.:e p g ~ o s ~ d s a l y s i s

u = 0.3 b~~.< = 0.0 -- - -- - Unsup-INhon-~1~-ensional d e f l e c t i o n c o e f f i c i a t a t t h e p i l e 3:tod hfi.d: iiyt length/-,

I rogosed ana g s i s Yercentage m- zl u s:rlg, ~ L ~ ~ ~ e y e --- oheslve voneslan ~ 3 n ~ ; s l v e oneslon o l e s lve o e s l o G

l e s s l e s s l e s s s o i l s o i l s o i 1 -- s o i 1 s o i l s o i 1 - -

0 0 -3 15 1.944 1.432 2.441 36.1 29 . 3 (1.365j ( 2 . 3 5 6 ) (4.62) ( l .63j

1 4.KIt 7.317 5.151 7 0765 11.2 5 e b C 4.943) (7.7161 (3.61) j 0.66)

2 13.1 l b .251 l j .791 lL .593 5 .O 1 .6 i 13.27) ( l~ .5%j (3.74) ( 0.15)

4 5 2 05 65.04 53.214 64.762 1.5 -0 04 10 453.E; 547.7 497 01 543.6 0 * 7 -G .& -- -----

( ~ h e ~ ~ d u e $ g i v e n i n b racke t s e thoLe obta ined using exac t de2th of f i x i t y )

( i i ) Fixed-Tree pi le . - The v a i u e s of %t, obtained us ing 'E$uiv;lent Ca++'i i lever hletho?' m e g iven i n 'I'zble 2 f o r U=i)

a l o n s x i t h til3ee s k t a i s e d u s i ~ ~ . the p r e r e n t ana ly s i s f o r

c o ~ , p a r i s ~ n . it is o ~ s e l v e d ̂&at i n the case sf f i x e d f r e e

~ i l e t h e r e i b a s i g n i f i c a n t c i i l e r e n c e i r ; the top d e f l e c t i 3 n

v n l u e s up to Z1 < 1.0. Keiuo:?i:cle agrsen.ent i s obt;;i.ned only f 3 ~ . z1 2 4. h ' ~ r example i n t h e czse of cohesive s o i l s , the

percentage d i f f e r e n c e betiyeen the L$-t v a l u c s i n as h i g h as

& .39 pe rcen t -;,hen Z1 = O .i) s d 14 p e r c e n t a t Z1 = 3. yhe

corresponding v a l c e c for cohes iunle-s s o i l s a re 4t .27 per- m-'

--

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. -. c b . ? . ; l t l ~ c : r e r ' i ~ be f r e e ,;;iljr,

-- --- - ---- L nsi.ii-\ 1 ~ ~ : ~ . - a i 3 . ~ r ~ ; i ~ n a i deZ2.c:c2~i 331 c3 ei'ficit-R.? a t t h e , i l e iL.tea i h e z u .

leaiti:j- 7. , , -- i j s i n ~ ; ;-Ch ~ 1 . 3 ~ 9 ~ € . a jl?-aljisi s' ; k l b c € n t g e Z1 i f e r e s e 5 ----- -

--

I n or8uer t o avoid this e r r x in c o r r ~ g u t a t i ~ n of def-

l e c t i ~ n v a l u e s , ~ ~ ~ u f i e d v a l u e s o f depth. o f r ' i x i t y f ~ r f i x e d

headed p z t i a l l y ercbeddec! &11k I n cohes ive aria cohesi3nlecs

sails f ~ r v a i 3 u s u n s u y g o 2 t e ~ l c r g t h s a 8 2; esen ted in Pig.

13 ' a e s e v a l ~ ~ s =e ~ ; ~ ; i c , * b l e oniy when the re is no v';rAd- c.d load. %hen t i l e re i s v e r x i c d load, i t . s h ~ u l d be r e a l i s e d

t h a t use of ' t q u i v a l e a t C a t i l e v e r I L e t h ~ d t v i i l l r e s u l t

i n m d e r estig.a+don or' d e f l e c t i o n s .

ti) 3ree-free ~ i l e .- W e t L ! _ u i v c e n t C a x T j l e v e r i,.eti;9ut

~ k v i ~ u s l y sucges t s tcac i c e u .o~ . sn t t h e f i x e d end sf w e

er;ui . t ra lent c ~ n t i l e v e r is design rn3sel;t;. 3ov;cvzr, i t i s

f~und m;.-..t in ct2-se of f r a e iic;;aed p i l e t:Ie i i x e d cnd r..orr,ent 3 f the ' e ; u iva l en t ~ ~ " n t i l e - r e l . ' i s n i g h e r tilacl t i e 3c-t;~~l

I

:( e

n ~ i m l ~ noo!ent o b t j n e d u;i^.; t n e 2r.o:s-sd t l iemy i n t h e

\ -- J. p i l e s h h f t . $.trice i n o r l $ e ~ * r.; ;et t h ~ liirt? i.;-Xi~liIL 0011.5.k'lt

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f ron; the ' bc ;u iva len t C a n t i l e v e r 3. ~ t i i o d ' . r educ t ion factors;

based on the r e s u l t s o f the p r e s e n t a n d y s i s a e suggested

and - . the sane we preseri ted in Eig. 16. 2.3 I-

----- ------------

i I I I , i k m CONSTANT

1-3 0 ' 2 L 6 8

10

i!e,,z

F R E E STANDING LENGTH , 21

2.1

Big. 12 .Biodified depth 9f fixity f o r f ixed f r e e p l h . I F

\ AFTER DIVlSSON AND

\ ROEINSON ( 19651

\ - \ ---- - PROPOSED THEORY

FREE-FREE PILE - k r CONSTANT

\ \ SR ST

Z r n a x u 4

1.9 1 ------- o w - - - - - -

\

F R E E STANDING LENGTH. 21

pig. 1 6 S e d u c t i a n f a c t o r f o r maximam p o s i tipa, '

moment f o r a free headed pile

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. - i l i j 2 i x e d - 3 e t y l i a . - ;z is + . L i ~ L ~ t h h t in Ck9e fi:,:Ed

h a i d e d .iis ivhen t h e r e is no ver.';ic.;l 13aiJ cfie Kocent sbt;hir.ed f ror . the ' iquivalen ' , C=it . i lever l i ~ t f i a d t 1 .$B -. . -

~ : s tllf rlYBTi:ES ~e$ t ! ! 3: f i x i t y f . j l coilesivf s o i l arlu l . C y '

i n case of cohesisnlesi ; s o i l j found t o b e in 9 3 ~ 8 w r E ~ - .>

r e n t 1,vitn ale a c t u z l nofieri-t. vorl.ent v;>ues ,s coziPuted

using t h e ~ r o 2 s s e d o,il t i i l ied i jepal of f i x i t y (Big. lt;) a e id ;?:)oli agreement only f-r u n s u p y o ~ t f d l e r l ~ t i : ~ ec;ilzi t o a d

51.eater ' c h a 2 . l h e r e l ' j r e , v,il-.n u c i ~ k ule r[.sdij'ir;d ec;u-ivl:- - l e n t l eng th , a c o z r e c t i 3 n f d ~ t 3 2 . 8s g iven i n 2 ig . 17

1-0 -

C/o- - k =CONSANT -- ---k *hi,"

0.8 - PROPOSED DEPTH

Zmax OF FIXITY

0.6 I I 0 0.5 1 SO 1.5

, I J

2.0

F R E E STANDING LENGTH , 21

?ig .l7 . h e d u c t i ~ n f a c t o r f o r p i l e head m~ment for a f ixed headed p i l e

1. v e r t i c a l 1323 i ; icre&ses 1 k t e r . d c e f l e c t i ~ n a d r;i;-ai-

i l ~ n ! ~0n;en t sigrii. fi c ~ ~ L J ? . 2h 3 i:-, crekse in s i l e helid d e f l e c t -

i s n and riisinurfi Koc.en-!! G U E t~ :, v e r t i c a l l o a d 3f 10 2 e r c e n t

3f t lcckl ing l o a d can bc sf z b a u t 7 p e r c e n t t~ 1 6 percent ;

cle;endir<; on t h e degre;: o f f i x i t y of t h e p i l e h e ~ ~ d .

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F J ~ f i x e d headed g i l e s , the t tse 3f values of fixity sugges- m . .

ted by i j a v i s e ~ n r;nd I i o b i n s ~ n (1965) w i l l r e s u l t i n s i g n i f i - ../I

c s n t e r r o r , p ; ; i r t i c i l l s l y r"~r p i l e s having snialler unsupg3r-

t ed l e n g t h s hherei l i . t h e e r r o r i n com;?uted d e f l e c t i o n could

be ~ f the wCer ol' 2 0 percen t . Therefore , va lues of d e p t h of

f i x i t y for f i x e d headed p i l e s we suggested based on t h e

r e s u l t s o f the 2 r z s e n t analysis.

3 . 'khe f i x e d e ~ i d r;~n.ent as obta ined fror!: the 'Equivalen t C a n t i l s v e r L e th3dq i s nuch l u r g e r t h a n t h e naximo! moment o b t d a e d using t h e rL csen t r i g o r o u s a n a l y s i s , Therefore, tile

suggested correctl .- .n f a c t o r s s h ~ u l d be used t o o b t d n the

d e s i g n :~ .ment f r 3 ~ tilo c o q ~ t ' e d valLles o f f i x z d .:r_d 7-3!3- ,2t

3 f t h e er-1;.iviileiit c ~ n t i l e v e r .

k5 $.UiS\iC&j

1 , , . < , 1 , . - r / 9 ' L a t e r a l 3-csist;nce of p i l e s in C.2hc- :jive a ~ i i s ' , 2 o~ i . . nz~ l nf ' +he L. o i l i: .echmics ma Povadatiom Z i v i z i s n, L C $ , ~Tol.>t),lTo *jI.i:2, P r o c , ~ a g e r 3E25 ,pp -27-63.

F q

2. Dn.-vi~on,6.. i.( 1560; , 'Beh3v i .mr 3f F l e x i b l e V e r t i c a l iji l r ; ? ~ Subjec ted t:, l : . o~?~cn t ,Shc . s and d i a l Jioaa' ,Ph.T).thesie subnitteci t o Ur,ivcr si-'i;;. 3f 1 LlAnoir., i : rbsna , llinais, ' i . ;d

3 . D,.7~isson,l. .:i. ; a d k9bin;~n,K.L,( lcJ6>) , 'Bending and 3i3ucl.;- l i n g .;f kar . . t ia i ly E ~ : ~ e d d e d E i l e s ( , kroc.'VI ICLBJ?E '491.2, ~2.233-246,

4 , Leyden,!Y.V.( 1971) , ' i l a s t i c k l a s t i c Analysis ~f L a t e r a l l y L3aded t 'ree S t ~ q d i n g i'i l e s ' , DL INGLNIE;;~~E/J~G L ~ / N B 2 ' j / 11 J U N I 1371.

5, a c k , and L~ese,L.C.,(lC,~),~Generalized S o l u t i c ~ n s f o r L a t e r a l l y io?. ted 2 i l e z 1 , d m r n d o f the S o i l L.ech+ n i c s and Y o u n d ~ t i r ~ n s a i v i s i o n , k C E , V o l .E6, ND.SB:~, 3a3er ij3.262;) ~ J S ,63-5 1.

6. Oteo,C.b.(l '>&,lj , I i , ;Sic$lified i;na.l;rsis ~f ;t'.iles qri,& L a t e r a l b a d & ' , li ICLI-TE, S t ~ c k h ~ 1 . m .

C - r . xaaszruy, G. j 1'; 74.1, F l e x u r a l Zehaviour r>f A x i a l l y a d

L a t e r z l l y Lo a ~ e C I n d i v i uuzl ~ . i l e s sad G r o u p s of P i l e s t , rh.3. t l ;ct is s ~ . ; i i i t t t~ i ; i?dixL ln;jtiL-iut& or" :, c i ~ n z e , 3 3ngi-ii~re, l i l d i - .

6. hed3.y, .k.L . sad ? . l i ~ m , ~ k : _ ~ , ,;.S . j l i r / G ) , ' i;i;ckling of &11gr ,?nd ; Z . . i . ~ ; , l ) - -1;. e ~ c i e d L ' i l e ~ ' , J ' ~ u z ; ~ L ; ~ 3f ~ & e : o i l iQLech- . . . ,:nits and 'I':zunitaJ<iclr,s 3iv.~s;.;:n, ~ ' J L , ~ ~ o . z 1 ~ . 6 . m.