piling md
Transcript of piling md
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: PROJECT SITE :
HIDCO CONVENTIONCENTRE,
NARKELBAGAN, KOLKATA,
WEST BENGAL
PROJECT UNDERTAKEN BY:
LARSEN & TOUBRO LTD.
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The com!e" #$ %'h$ ()om $he
e%$)#%ce
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P!#% o( $he *ho!e )o+ec$
Schem#$c -#')#m
D/C PILING
PREFACE:
The report is prepared after the training andobservation done at Project-site of WBHIDCOCo%0e%$o% Ce%$)e, being an engineer trainee underGeo$)e#$ L$-.
The project is undertaken by L#)1e% & To23)oL$-. A part of piling works is being conducted byGeo$)e#$ L$-.
The start date of the construction project was
16.06.01! " the e#pected end date is 1$.0%.016.&ver '600 piles are to be constructed a(ong which
$00 nu(ber of pilling is conducted by Geo$)e#$ L$-.
All of the( are done by D/C !%' (ethods.
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The whole project report is subdivided in the
following sections)
1. *ntroduction. &bjectives and classi+cation of piles
and piling (ethods,. Principle of / piling!. Apparatus used$. ield procedure / piling
6. /onclusion
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1. *T2&3/T*&
Piles are the columnar structure, the most common type of
deep foundation, that safely transfer loads from the super structure to more competent subsurface strata by means of friction, end bearing or a combination of both. Piles can bebroadly classified based on the following parameters.
1. Method of installation of piles – Driven (displacement) pilesor bored (replacement) piles.
. !ype of material used for piling – "oncrete, steel, timber piles etc.
#mong these, concrete piles can be classified further as pre$cast and cast in situ concrete piles. !hough there are a varietyof piling options, the most common type of piles used for ma%ority of construction wor&s in 'ndia are bored cast in situconcrete piles.
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. &bjectives and classi+cation of piles and
piling (ethods
unctions of piles)
The (ajor uses of piles are)1. To carry vertical co(pression load' eg. bearing
piles' friction pile. 4*5. 1. To resist uplift pressure' eg. tension piles or
uplift piles or anchor piles. 4*5. ,. To resist hori7ontal or inclined loads' eg. 8atter
piles. 4*5. ,
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etting up piles
epending up on the setting up principle' pilescan be of two types' eg. D1!#ceme%$$4e and Re!#ceme%$ $4e' each has its own
advantages and disadvantages. or -1!#ceme%$!%' me$ho-' piles are driven into the groundpushing the soil out of its way. isplace(ent piling isgood for conta(inated sites where it costs a lot to(ove the soil out.
3sing the )e!#ceme%$ !%' me$ho-, (uckis dug out and replaced with the pile. uch bigger piles
can be casted by replace(ent (ethod.
Direct Mud Circulation (DMC !%' me$ho-or si(ply / Piling (ethod is an e#a(ple ofreplace(ent piling (ethod. This (ethod is the principlesubject of interest in this report.
The advantages of displace(ent piling are)-
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• 9elf testing as driven to refusal or :set:
• o pile arising to dispose of
• ;ittle disturbance
•;i(ited access
• ?ectively vibration free
• *nstalled into non cohesive and water bearing soils
•
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ground level' water jet strea(s are used and then a
typical chisel cuts the relatively softer soil. 8ore holes
of several depths 4for e#a(ple 10(' 1$(' 0(' $('
,0(' etc. and dia(eter 4for e#a(ple $00(( $0(('1000(( etc. are dug as per design re@uire(ents. *t
can be understood @uite clearly that the nearby soil can
collapse. To prevent the collapse so(e special safety
(easures are considered during the operation which
will be discussed in later sections.
After the bore hole is dug and the collapse of
subsoil around the hole is safely prohibited' areinforce(ent cage is entered into the borehole and
concrete is +lled fro( the botto( of the hole with the
help of pipes' typically designed for this operation'
called the Tre(ie pipes. 3sually concrete is left B days
to harden and gain full strength' but so(eti(es using
ad(i#tures they are prepared within 1 days.
!. Apparatus used*. / rig
• T T2*P& 9C9T>
ain shear leg) it is the longer leg than the other
two that carries the load.
The length is .$(.
The length can be adjusted. Dith the help of
0(( dia pins
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The side shear legs) there are two side shear
legs' 6.,( long and they (ainly support the tripod
syste(.
The side legs (ust be placed at least 1.$( away
fro( the centre of the piles.
• 8A9> /;
These are standard * section' c( thick and there
are grooving in it that holds the shear legs onto theground with the help of base cannel pin.
• 9;*P &=>2 D>;
ia(eter !$0(( Thickness $0((&peration The rope slips over this
wheel or Pulley
• 9;*P &=>2 D>>; 2
ia(eter E $00((
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• 9.&. D>; P*
ia(eter 6$((;ength 00((&peration This is very i(portant pin'
because it holds the 9.&.
Dheel with the tripod
syste( and the entire
vertical loads act on it.
• P;35>
*nside ia(eter E $0((
• 939P>9*& P;AT> F this is called into action if
so(ehow the chisel is stuck in the borehole.
Pulleys are attached here and the chisel is pulled
out.
9uspension Plate
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• A* 9A2 ;>5 P* F 0(( dia.
**. Dinch
/apacity , Ton 4&ther capacities can
be of 1 Ton .$ Ton $ Ton
.$ Ton etc.riven wheel dia(eter %00((
***. iesel engine
• 39> * D*/< 4239T& AG>
u(ber of
cylinder
! ,
iesel
consu(ption
.1 litHhr 1.$ litHhr
obil
consu(ption
4fresh engine
0.$ lit per days 0.$ lit per days
obil
consu(ption
4older engine
0.$ lit per 1
hours
0.$ lit per 1
hours
• 39> * P3P 4G*;&9G>2 AG>
u(ber of cylinder iesel consu(ption 1.$ litHhrobil consu(ption $0(l per 1 hours
*=. 8ailer or 9lush Pu(p
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;ength
00((*nside ia(eter !$0((
Deight 0.$ Ton
=. 5uide casing
;ength
$0((*nside ia(eter
$$0(( Thickness of casing ,0((
Thickness of collar 0((
=*. /hisel or /hopper
Thickness of sheet B0((
*nside ia(eter
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!00((;ength
$00((
u(ber of no77le !
. / rod
;ength 4( . ,
,.$ia(eter 4(( %$ $
6$ Thread length 4(( 10 Thread type Tapered* of tapered king end
4((
B0
* of @ueen end 4(( 10
Tapered thread end of / rods
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B. 2ope
ia(eter F 0((
%. Tre(ie pipe
* $ inch& 6 inch
Thickness of sheet 1((
10. =ertical pu(p
Power source >lectrically operatedPower 10
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=ertical Pu(p in 8entonite tank
1. Dash vat This is where the (uck (i# with water gets stored'
the (uck gets precipitated and the water beco(es
reusable.
1,. Tre(ie fork
3sed to insert the tre(ie pipes and taking out /
rods.
$. ield procedure / piling
• or e#ecuting / piling (ethod which is
approved as per *9 %11 under speci+cations ofbored cast in situ piles. The positioning of pointswhere the piles are proposed to set up' arechecked by the surveyor.
/ piling 2ig set-up and initiation of boring
using the 8ailer
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• After the point for boring operation is set out by
the surveyor the tripod is paced such that eachside legs are at least 1.$( away fro( the point'keeping the centre of borehole e#actly in thecentre.
• The bailer is then attached with the rope and the
boring operation is initiated.
• After bailer reaches its full length into the soil' the
guide casing is inserted into the hole for fartheroperations.
*nsertion of the guide casing
• To prevent the side collapse and caving in' a guide
casing of $$0(( dia and of $0(( length is
placed on the top of the bore hole and ha((ered
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by the bailer to insert it into the soil. This will bewithdrawn after concreting is over.
8oring with /hisel
• &nce the guide casing is placed' the boring is
started with chisel.
• The chisel has ! no77les fro( where water jet is
forced on the hard soil layer as the boring
progresses.
Progression of boring and addition of
/ rods
• / rods are added one after another as the depth
increases.
• The / head are attached on top of the / rods
which has the plunge which receives the waterfro( delivery hose.
• The whole syste( is pulled up by the rope and the-9hackle with the help of the winch syste( andthen left to fall free' so that the chisel at thebotto( cuts the soil and the boring progresses.
• The loose soil produced by boring' (i#es with
water and co(es up and is stored in the wash vat'where the soil gets precipitated and the water is
again usable.
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Taking out of the / rods and /hisel
and *nsertion of the reinforce(ent cage• After the boring is co(plete up to the desired
depth' the / rods are re(oved one by one usingthe / fork and the chisel is also re(oved.
• Then the steel reinforce(ent cage is inserted and
welded where ever there are joints.
/oncreting and +nali7ation of the
process
• The tre(ie pipes are inserted one by one using the
Tre(ie fork and then the bore hole is washed withthe 8entonite water and the uck is co(pletelyre(oved and the hole is +lled with bentonite slurry.
• The Transit (i#er arrives and the
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• The T puts concrete (i# into the hopper and the
valve opens. The bore hole is gradually +lled withconcrete which is co(pacted by gradual vibrationof tre(ie pipes. This +lling of concrete fro( thebotto( is done to avoid segregation of theconcrete (i#.
• As the concrete +lls the hole fro( botto('
8entonite slurry escapes the hole. The tre(ie pipesare detached one by one and thus the hole gets+lled co(pletely.
• After the hole is fully +lled' the concrete is left Bdays to gain full strength. After B days the guidecasing is re(oved and the pile is ready.
/oncreting
6. /onclusion
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/ piling is the (ost co((on piling (ethods used in*ndia. or (oderate si7ed piles' that is !$0(( to1000(( dia(eter and $( to ,0( depth pilesI it isalso (ost convenient and econo(ic way of piling.;arger piles that are of dia(eter up to 1$00(( canalso be founded by this (ethod' but those are not thatconvenient. &ther process like 2educed ud /irculation42/ is also in use.
LATEST TRENDS IN PILING & FOUNDATION ENGINEERING.
Preamble *ood, "lothing and shelter are the basic needs of human beings from the beginning of life on earth
and the human race are vying each other to achieve the same. +ecause of this all the good lands on earth are
used for horiontal developments during old civiliations and the developments where mainly near -iver +an&s
and ea ports. +ecause of the shortage of land rban areas vertical growth of buildings have become a
necessity. !he earlier structures in the world having significant heights are /utab Minar in Delhi and 0eaning
!ower of Pia in 'taly. !echniues have been evolved after nd 2orld war in 3uropean and #merican countries
for improving the various types of foundations to ta&e up under ground railway wor& and constructing high rise
buildings such as ears !ower in "hicago, 2orld !rade "entre in 4ew 5or&, !win !owers in Malaysia and +ur%Dubai !ower in Dubai business district which is above 167 stories and 877 meter above ground level. !o support
these types of structures deep and large diameter piles are essential which can be done by direct mud circulation
method or by -otary -igs supported by bentonite slurry system. +oth the methods are approved by +ritish and
'ndian standards and are used in 'ndia 9 abroad depending on the speed by which the pro%ect has to be
completed. -otary method has got more speed when compared to DM" method and the disadvantage is that it
cannot cut through hard roc&s effectively. !he DM" system is widely used '4 'ndia for providing pile foundations
for buildings up to 67 stories (167 meters) and the piles can be done upto depths of :7 meter from ground level
and diameters can vary from 677 to 1677mm. !his is cost effective and we recommend this system for 'ndia and
abroad for diameters from 677mm to 1677mm and depth up to :7 meters.
Types of Piling +ecause of the agricultural and 'ndustrial revolution building rules has come in to effect inprominent towns of 3urope and the 1st town planning act of ; is in 1
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concrete or the safe bearing capacity of the founding strata. 'f the concrete is wea& and the founding strata is
strong there will be structural failure of the concrete or if it is vise versa the founding strata will fail.
!he method of piling from place to place will vary such as dia meter, depth etc. and in !rivandrum generally the
depth is 6 to 7 mtrs, in ;ochi depth from 7 to :7 mtrs etc. 'n ;ochi some of the areas where roc& is not
available, the pile is rested on coarse sand strata where the 4$value is more than 177. +efore ta&ing a decision
to rest the pile on sand the thic&ness of the sandy strata should also be analyed, because the sandy strata willbe very thin and if clay strata is under laying the piles will not ta&e the desired load.
!e"#o$ S"a"emen" % D! Piling
*or e?ecuting DM" piles (Direct Mud "irculation piles ) method which is approved as per ' 777mm dia depth up to :7 mtrs. !hese types of piling are mainly used for industrial purposes
where large areas are available for development and time is the main factor. !he capacity of the rigs are
classified based on torue it can produce and it various from B to C7 and this is designed based on hardness of
the roc& it can cut. !he roc& is mainly cut by -otary method using !ungsten carbide bits or diamond bits. 'f the
roc& is too hard then it is cut by using core barrel using Diamond bits and this is very e?pensive. !he production
of -otary rigs has to be a minimum of 177 mts per day to cover the cost and if the production is low, then the cost
will increase. #lso in transporting and deploying these machines wide approach roads are reuired as the
machine weights from C7 tons to B7 tons and the length of the ;elly bar from 1 mtrs to 16 mtrs. *or residential
buildings now a days @ydraulically operated rotary rigs are used mounted on lorries and these also give desiredresult and less e?pensive when compared to modern rotary rigs.
b' !e"#o$ of "es"ing Fo(n$ing S"ra"a!he basic method for ascertaining the strata for founding is standard
penetration test and if the 4$value is more than 177, then it is considered as reasonably good founding strata for
piling.
)' on)re"e !he concrete mi? used for piling is M6,M>7,M>6 etc. in 'ndia and outside the country MC7 is the
minimum standard for piling and if goes to M87. !he strength of the concrete as ascertained by cube test after >
days, Bdays, 1days, 8days, etc. !he wor&ability of the concrete is assessed by ta&ing the slump at site it
should be from 167 to 187mm.
$' Pile "es" T#e piles are "es"e$ for "#e follo*ing
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• 'nitial vertical load test
• 'nitial lateral load test
• 'nitial pullout test
• -outine vertical load test
• -outine lateral load test
• -outine pullout test
• Dynamic load test (4ondestructive)• 'ntegrity test.
#s per the 'ndian standard 1 times the design load is tested and the settlement of the piles should be below
1mm.!he relevant ' code is as follow '