Piles foundation presentation

8/13/2019 Piles foundation presentation

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FAILURE OF QAYYUM AVENUE

IN THE NAME OF ALLAH

THE BENEFICIENT, THE MERCIFUL


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GEOTECHNICAL

CONSIDERATIONS

IN DESIGN OF

PILE FOUNDATIONS


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PRESENTATION DELIVERED BY:

MUHAMMAD JAVED 2K4-SOIL-MUHAMMAD TARIQ 2K4-SOIL-USMAN ALI 2K4-SOIL-!

PRESENTATION DELIVERED TO:

PROFESSOR YAQOOB

MS" SOIL MECHANICS # FOUNDATION ENGG 2004-2005


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INTRODUCTION TO PILE FOUNDATIONS

CONDITIONS DICTATING USE OF PILES

CLASSIFICATION OF PILES

CLASSIFICATION BASED ON MATERIALS

ESTIMATION OF PILE LENGTH

GEOTECHNICAL INVESTIGATIONS

SEQUENCE OF PRESENTATION


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ESTIMATION OF PILE CAPACITY

PILE LOAD TEST

PILE GROUPS # BEARING CAPACITY OF

PILE GROUPS

QUESTIONS $ ANS%ERS SESSION

SEQUENCE OF PRESENTATION


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INTRODUCTIONINTRODUCTION


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INTRODUCTION

Piles are the col!"ar ele!e"ts i" the

#o"$atio"s %hich ha&e #"ctio" o# tra"s#erri"'

loa$s #ro! s(er strctre thro'h %ee)

co!(ressi*le strata or thro'h %ater o"to

sti##e"e$ or !ore co!(act a"$ less

co!(ressi*le soils+


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The !a *e re-ire$ to carr (li#t loa$s %he"

se$ to s((ort tall strctres s*.ecte$ to

o&ertr"i"' #orces #ro! %i"$ or %a&es+

Piles se$ i" !ari"e strctres are s*.ecte$ to

lateral loa$s #ro! the i!(act o# *erthi"' shi(s

a"$ #ro! %a&es+

INTRODUCTION


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Co!*i"atio"s o# &ertical a"$ hori/o"tal loa$s

are carrie$ %here (iles are se$ to s((ort to

s((ort retai"i"' %alls, *ri$'e (iers a"$

a*t!e"ts a"$ !achi"er #o"$atio"s+

INTRODUCTION


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CONDITION0 DICTATIN1 U0E OF PILE0

%&'( )&' *++', ./ 1', 3 /

&/& ".6+,'/7' 1(8 ).. '1

). *++.,) )&' .18 ),1(6/))'8

7 )&' *+',),*")*,'; +/' 1,'

*'8 ). ),1(6/) )&' .18 ).

*(8',/( 7'8 ,." 1 &.( /(


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%&'( 7'8 ,." / (.) ."1)'8 1)

,'1.(17' 8'+)&; +/' 1,' *'8 ).

,18*1 ),1(6/) ),*")*,1 .18 ).

)&' ./= T&' ,'/)1("' ). )&'

1++/'8 ),*")*,' .18 / 8',/>'8

61/(


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2he" s*.ecte$ to hori/o"tal #orces, (iles

#o"$atio" ca" resist * *e"$i"', %hile still

s((orti"' &ertical loa$s tra"s!itte$ * the

s(erstrctre+ This sitatio" is 'e"erall

e"co"tere$ i" the $esi'" a"$ co"strctio" o# earth

retai"i"' strctres a"$ #o"$atio" o# tall

strctres that are s*.ecte$ to hi'h %i"$ a"$ earth

-a)e #orces


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In many cases, expensive and collapsible soils may be

encountered at the site, the soil may extend to a great

depth below the ground surface. Expansive soil swells

and shrinks depending on increase or decrease of

moisture content. The swelling pressure of such soils

can be considerably high. Pile foundations are best

alternate when piles are extended beyond the active

zone, which undergo swelling and shrinking.


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F.*(81)/.( .< *"& ),*")*,';

*"& 1 ),1(6//.( ).', .? to @? !+

I" or$er to -ali# #or se as a (ile, the ti!*er shol$

*e strai'ht, so"$, a"$ %ith ot a" $e#ects+

Pile ti(s shol$ "ot ha&e a $ia!eter less tha" >?!!+

The (iles ca(acit is li!ite$ to @3? to"s as these

(iles ca""ot %ithsta"$ har$ $ri&i"' stress+


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TIMBER PILE0

The allowable load carrying capacity of wooden piles

may be given as

Q all 9 A( #%

!here,

A( 9 /verage area of xsection of pile#% 2 /llowable stress for the timber


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0electi"' the t(e o# (ile to *e se$ a"$ esti!ati"'

its "ecessar le"'th is #airl a $i##iclt tas) that

re-ires a 'oo$ .$'!e"t+

Piles ca" *e $i&i$e$ i"to three !a.or cate'ories$e(e"$i"' o" their le"'th a"$ !echa"is! o# loa$

tra"s#er to the soil+

POINT BEARIN1 PILE0

FRICTION PILE0

COMPACTION PILE0


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I# *e$ roc) or roc)3li)e !aterial is locate$ at a 'i&e" site

%ith i" a reaso"a*le $e(th that has *ee" %ell

esta*lishe$ * soil3*ori"' recor$s, (ile ca" *e

e7te"$e$ to the roc) laer+

I" this case, the lti!ate ca(acit o# the (iles e"tirel

$e(e"$s o" the loa$3*eari"' ca(acit o# the #ir!

!aterial+

I" !ost o# the cases, the "ecessar le"'th o# the (ile

ca" *e #airl %ell esta*lishe$+

POINT BEARING PILES


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I"stea$ o# *e$roc), i# a #airl co!(act a"$ har$ strat!o# soil is locate$ at a reaso"a*le $e(th, (iles ca" *e

e7te"$e$ a #e% !eters i"to the har$ strat!+

For these t(es o# (iles, the lti!ate (ile loa$ ca" *e

e7(resse$ as+B

@+? B

CL

?+Q

?+@Q

B

>+B

@+? B

The e7te"t o# e7(loratio" is "ot

li!ite$ solel * the /o"e o#

i"#le"ce * the loa$e$ (iles,

*t is li!ite$ o" other #actors ,

'ro"$%ater re'i!e, hi'hl

hetero'e"eos soil co"$itio"s

or the e##ects o# (ili"' o"

a$.ace"t strctres+

The /o"e o# i"#le"ce is a 'oo$

starti"' (oi"t, si"ce it -ali#ies

to so!e $e'ree the lateral a"$

&ertical e7te"t o# the stresse$

/o"e+

For isolate$ (ile 'ro(s "$er a

si"'le col!" #or i"sta"ce6, the

stress /o"e *ase$ o" the s(rea$

o# loa$ co"ce(t is relati&el

!ch shallo%er as sho%"+

DEPTH OF E;PLORATION


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DEPTH OF E;PLORATION

DEPTH0 BELO2

BA0E OF PILE0

B@

DEPTH0 BELO2 FOUNDATION

B

>+B

@+? B

CL

?+Q

?+@Q

B

>+B

@+? B

A si"'le (ro&i"' *ore hole

shol$ *e ta)e" i" this case

to a $e(th i" access o# @T+

I" or$er to e"sre that

("chi"' thro'h a

relati&el stro"' strat!

i"to a %ea)er strat! ca"

"ot occr+

Roc) *eari"' strat! at the

ti( o# e"$ *eari"' (iles

shol$ *e a$e-atel

i"&esti'ate$ (articlarl%here hea& col!" loa$s

are to *e tra"s!itte$ to

si"'le or s!all 'ro(s o#

hi'hl loa$e$ (iles+

DEPTH OF E;PLORATION G 1ROUND 2ATER CONDITION0


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DEPTH OF E;PLORATION G 1ROUND 2ATER CONDITION0

2here (iles are to *e #o"$e$ i" a *eari"' strat! o# li!ite$ thic)"ess, a lar'e

"!*er o# *ores(ro*i"' are i!(lie$ (ossi*l s(ace$ o" a close$ 'ri$+

I" 'ro"$ co"$itio"s %hich are )"o%" to *e o# hetero'e"eos "atre a -ali#ie$

'eolo'ist shol$ *e i"&ol&e$ %ith the %or) #ro! a" earl sta'e+

The i"&esti'atio" o# 'ro"$ %ater co"$itio"s is (erti"e"t as it !a i"#le"ce the

choice o# (ile t(e a"$ rate o# %ater i"#lo% that !a occr $ri"' the i"stallatio" o#

co"&e"tio"al *ore$ (ile+

O*ser&atio" o# the i"'ress o# %ater i"cl$i"' the le&el at %hich %ater see(s a"$

collects shol$ *e !a$e a"$ "ote$+

The hea$s o# %ater recor$e$ * o*ser&atio" i" *ore holes or !easre!e"t o#

le&els i" (ie/o!eters !a *e s*.ecte$ to seaso"al &ariatio"s a"$ i$eall

!easre!e"ts shol$ *e collecte$ o&er a (erio$ o# !o"ths %here the le&els are

collecte$+

Che!ical attac) o# steel or co"crete (iles !a occr $e to $issol&e$ salts i"

aci$ic %ater sch co"$itio"s shol$ *e a$e-atel i"&esti'ate$+

Che!ical tests o" soil sa!(les shol$ also *e carrie$ ot to 'i&e a$$itio"al

i"&esti'atio"+

TYPICAL IN-SITU TESTS #


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THEIR APPLICATION TO PILE DESIGN

IN-SITU TESTS APPLICATION TO PILE DESIGN

VANE TEST

F., 6'1*,'6'() .< *(8,1/('8 ),'()& /( .


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THEIR APPLICATION TO PILE DESIGN

IN-SITU TESTS APPLICATION TO PILE DESIGN

MENARDPRESSUREMETE

R

E)/61)' .< 6.8** .< ./


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ESTIMATION OF PILECAPACITY

E0TIMATION OF PILE CAPACITY


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The lti!ate loa$ carri"'

ca(acit o# a (ile ca" *e

'i&e" * a si!(le e-atio"

as the s! o# the loa$

carrie$ at the (ile (oi"t

(ls the total #rictio"al

resista"ce 40)i" Frictio"6

$eri&e$ #ro! soil3(ile

i"ter#ace as sho%" i" #i'+

i+e+,

Q9 Q( = Qs

Q

Qs

Q(

-

D

L 9 L*

L 9 le"'th o# e!*e$!e"t

L*9 le"'th o# e!*e$!e"t i" *eari"' strat!

ESTIMATION OF PILE


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CAPACITYPOINT BEARING CAPACITY;

Q+:

Accor$i"' to Ter/a'his E-atio", the e-atio" #or lti!ate *eari"'ca(acit is 'i&e" * the e- 4i" 'e"eral6or Depth, 0D,

:c =? @ (0D) (-N/)

=D

E0TIMATION OF PILE CAPACITY


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SOLUTION

F,/")/.(1 ,'/)1("'


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ALLO%ABLE PILE CAPACITY

O("' )&' ).)1 U)/61)' .18-"1,,/( "1+1"/) /

8')',6/('8 7 *66/( )&' +./() 7'1,/( "1+1"/) 1(8

)&'


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Design Example

Re#er to the e7a!(le (ro*le!s, esti!ate the lti!ate

loa$ #or the (iles, si"' a #actor o# sa#et o# +

S0l$2i0n

%U&%P6%S

%U& 7)!6,)! & 88! 9N

% all& %S/ FS & 88!/7 &)7"77


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PILE LOAD TEST

PILE LOAD TEST


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PILE LOAD TEST

BEAM

TE0T PILE

HYDR 5AC

SCHEMATIC DIAGRAM OF PILE LOAD TEST ARRANGEMENT

Fi' sho%s a sche!atic

$ia'ra! o# the Pile Loa$

test arra"'e!e"t i" the

#iel$+

This arra"'e!e"t is #ortesti"' i" A7ial

Co!(ressio"+

The loa$ to the Pile is

aa((lie$ * a H$ralic

5ac)+

PILE LOAD TEST


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PILE LOAD TEST

I" !ost lar'e Pro.ects, a s(eci#ie$ "!*er o# Pile

Loa$ Tests !st *e co"$cte$ o" Piles+

This is (ri!aril *ecase o# the "relia*ilit o#

(re$ictio" !etho$+

Vertical a"$ Lateral Loa$ *eari"' Ca(acit ca" *e

teste$ i" the #iel$+

0te( loa$s are a((lie$ to the (iles a"$ s##icie"t ti!e

is allo%e$ to ela(se a#ter each ste( loa$ so that the

settle!e"t rate reaches a s!all &ale+

PILE LOAD TEST


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PILE LOAD TEST

The settle!e"t o# the (ile is recor$e$ * !ea"s o#

Dial 1a'es+

The a!o"t o# loa$ a((lie$ #or each ste( %ill &er

$e(e"$i"' o" local *il$i"' co$es, !ost *il$i"'

co$es re-ire that each ste( loa$ *e a*ot >th o#

the (ro(ose$ %or)i"' loa$+

A#ter reachi"' the $esire$ (ile loa$, the (ile is

'ra$all "loa$e$+

13/0, #

Fi' sho%s the loa$


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13/0I45

&

ETT1E6E4T

413/0I45

#*

&t $*%&t $+%

&e $*% &e $+%

#+

PLOT OF LOAD Vs TOTAL SETTLEMENT

'

settle!e"t cr&es

#or loa$i"' a"$

"loa$i"'+

For a" 'i&e" loa$

Q, "et (ile

settle!e"t ca" *e

%ritte" as690 t4>630e4>6

72he" Q 9 Q@,

0 "et4@690 t4@630e4@6

2here'

SPACING OF PILES IN PILEGROUP


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GROUPBRITI0H CODE OF PRACTICE @??S@

LEN1TH OFPILE

MINIMUM PILE 0PACIN1 FOR

Frictio" (iles i"sa"$

Frictio" (ile i"cla

Poi"t *eari"'(iles

Less tha" >@ ! D D D

>@ To @ ! D D D

More tha" @ ! D D D

D is the (ile $ia!eter or lar'est si$e+ Pile s(aci"' is !easre$ at (ile ct3

o## le&el, "less ra)i"' (iles are se$, i" %hich case the s(aci"' is

!easre$ at ! *elo% ct3o## le&el


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BEARING CAPACITY OF PILE

GROUP

SECTION VIE%


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PLAN VIE%



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GROUP

Number of Piles in group = n!

n"

Also #g$ %g

#g= (n&)d ' "(")

%g= (n"&)d ' "(")



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GROUP

F0r Piles in San::

Q53*4 23((2-28 4D Q*

P((2

%&',':

Q53*4 U)/61)' B=C .< +/' ,.*+

D P/' 8/16')', ., 1,') /8'

P P',/6')', .< )&' -'")/.( .<

BEARING CAPACITY OF PILEGROUP


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GROUP

F0r Pile in ;la3s:

Q* ((239A+C*3+4 +"*L #

Q* L5B5C*3+4N" 2 3L5 B5C*L

C.6+1,/( )&' >1*' .< Q*


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Design Example

Deter!i"e the Allo%a*le Beari"' Ca(acit o# the

'ro( (ile si"' the #actor o# sa#et o# +

Gi#e

"> 9 , "@9 , D 9 ?!!, $ 9 >@@?!! a"$ L 9 >!+

The (iles are s-are i" 73sectio" G e!*e$$e$ i" a

ho!o'e"eos cla %ith C9 ? N!@+

BEARIN1 CAPACITY OF PILE 1ROUP


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SOLUTION

Qu = n1n2 (A!Cu("# $ "%u&L#

A" = ('.')#('.')# ='.' *2

P = (+#('.')# = 1.22 *

A,Cu= -' N/*2 S0 0* 34"5 (Cu6, #

= '.78 ,08

Qu = (+# (# 9(#('.'#(-'# $ ('.7#(1.22#(-'#(1)#:



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SOLUTION

A%ain fro) E+n, the !lti)ate #lo"' "apa"ity is:

.u/ L%0%1u2p3N"4 5 62L%5 0%31u7L

L% / 2n89 83d 5 6 2D63

/ 2;-838&66 5 )

0% / 2n69 83d 5 6 2D63

/ =-8 8&66 5 )



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SOLUTION

L0% / 8>6&;> / >&;@

L%0% / =&?@>6&;> / 8&;;

Fro) Graph: N"4 / B&@

0lo"' 1apa"ity / 2=&?@>326&;>3256&;>323

/ 6


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Piles foundation presentation

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