2911 1 4

1. 15: 2911 (Part 1/Sec 4) - 1984
(Reaffirmed 1997 )

Indian Standard

CODE OF PRACTICE FOR DESIGN
AND CONSTRUCTION OF PILE FOUNDATION
PART 1 CONCRETE PILES
Section 4 Bored Procast Concrete Piles

(Third Reprint JULY 1994)

UDC 62415434 [ 691-327 ] : 006-76

© Copyright 1984

BUREAU OF INDIAN STANDARDS
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI-10002

Get July 1984

2. 19 + 2911 ( Part 1/Sec 4) - 1994

Indian Standard

CODE OF PRACTICE FOR DESIGN
AND CONSTRUCTION OF PILE FOUNDATION

PART1 CONCRETE PILES

Section 4 Bored Precast Concrete Piles

Foundation Engineering Sectional Committee, BDC 43

herman Reprveting
mo Ouen Son EEngineersin-Ghie's Branch, Any Headquarters
Mende

Cou KP, Ascaso ( Alternate ro

“Fig Omar Sr Anica Pradesh Es asec Lalo
RU eae res, Government” of Andhra. Prado
amant con Belding, Rewnrch Inikute (CSIR),

DARK

Suera, E Cuarta "Gamme India Led, Do
oat Aliete)

Calcuta Por Trust, Calcuta

PV AT “The Concrete Asociacion of India, Bombay
Sane RK. Das Gore"? Simplex Concrete ET
‘Saar Hi. Cou Biswas ( Altes

Sun À: Dasa ‘th personal capacity (5 Hunger Curt 121
“agro Sher Cata
V. G. Deaneaxon ‘he Pre Piling Co (1) Pet Ltd, Bombay
yon (CSMRS Geauga Sel & Material Recatch Station, New
Pyrery Diweeron (CSMRS ) {Aa}
Su RH Dover Kia Fondations und Comtevcion Pvt Lid,

Sut A. N Jason (Alte)
PA Stop Comltant ad, Bombay

(Contd pate y

RE
BUREAU OF INDIAN STANDARDS
‘This publieation in protected under the Indio Copie Aa (XIV of 1987) and
reproduction in whole or in part by any means except with writen permision of the

3. 15 : 2911 (Part 1/Sec 4) - 1984

(Conte io pace 1)

Mene Rap
Da Jaooısz Nana Indian Geotechnical Society, Now Dele
o Sw Sango (Alana) QE *
Sang Aer Rose Ja G. 5. Jia e Anociater, Roorkee
‘you Vinay Kean Jaro (Alri
NTE ‘reek Aucheity af ndis, New Delhi
Si Ac Ko Migas { rot)
Jon Dinzeren | Bacto) Matinal Bildings Organisation, New Deli

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Da RC Kast Indian faite of Technology, Bombay
Bunn. Re Korman BENS Dans € Go Pot Lis, Gear
‘Shin’ Hox (leet)
Sunt AvP. Maton Genial Warchousing Corporation, New Dei
Sum Ÿ. D, Manon Nekemies Late Hontbay
SS Murmerome In perl Capacy 1044, Sint Hour, Napa
Ste Raed, Bonde)
Sans TK. D. Mower Bagincers ind Limited, New Dei
Sung iment ( Alterna)
Seat he Ky Pavey “The Hindustan Construction Co Led, Bombay
‘Sha Y. M Mao (Alice)
sung BER Pesan Gemindia Co Ltd, Bombay
Sant A VR the fesithoaite Bora & Jeep Construction Co
Lee ee
Da VV. 5 Rao Nagadh Connie Pet Lid, New Delhi
Ploy Gora Rayas Unicas of Raorkee, Kontkes
Sing Anses Risnssonaxr Cement Corporation of Inda, New Delhi
OS. Suivasava (Alma
Da A Sanos ‘allege of Engineeias, Guindy, Madras
Sue Boss sema (Alert
Sun N. Sieaoune ‘Mininry of Shipping and Transport

‘Suna Be Sanam (Alerta)
Sormunrasnixe Exogwenn, Central Publie Works Department
Danone)
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Felina

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Y remar ‘Taian nao Tecos, Now Di
Sumy GS Director Genera, 151 ( Eafe Mente }

"irector (ÓN Enge )

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Senior Deputy Disco (Cie Bogs)

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4. 15 2911 ( Part 1/Sec 4 )- 1984
Indian Standard

CODE OF PRACTICE FOR DESIGN
AND CONSTRUCTION OF PILE FOUNDATION

PART 1 CONCRETE PILES

Section 4 Bored Precast Concrete Piles

0. FOREWORD

0.4 This Indian Standard ( Part 1/Sce 4) was adopted by the Indian
Standards Institution on 27 February 1981, after the draft finalized
by the Foundation Engineering Sectional Committee had been approved
by the Civil Engineering Division Council.

02 Pies find application in foundation to transfer loads from a structure
Lo competent subunface strata having adequate load-bearing capacity. The
load amer mechanism from a pl lo the surrounding ground à comple
Sed and cull yee aly dti ug aplican of aed
foundations I in practice over many decades. Broadly, le transfer
Heads cier sebsandally by Misión along de halo Gor banal
by the end bearing, Piles are used where either of the above lond transfer
mechanism is poste depending upon the bel stratification at a partic
ular ste. Construction ‘of pile foundations requires a careful cholce of
piling sytem, depending upon the subsoil conditions, the load character
His af stricture andthe Hans of total settlement, diferent see.
ment and any other special requirement of a project. The Installation of
piles demands eareful contol on poston, alignment and depth and involve
Fpecaized skill and experience

0.3 This standard ( Part 1 ) was originally published in 1964 and included.
provisions regarding driven cast sma ples, precast conerete piles, bored
(east ini) and undercamed piles, including Tod tering. Sabscquenty
Portions pertaining to nderrearned pllefxndations were deleted and which
Are now covered. in 18: 2011 { Part 3). Ar that time it was decided
tha the provisions regarding other types of piles should alo be published
Separately for the ease of Teference and to take into account the recent
&elopments in this feld. Consequently 181 291) ( Part 1)-1964* has

9 and construcion of ple foundation: Part 1 Load bes

5. 1S : 2911 ( Part 1/Sec 4 ) - 1984

been revised in various sections. So far the following sections have been
formulated.

Section 1 Driven cast insite conerete piles

Section 2 Bored cas ist piles

Section 3. D

n precast concrete piles

Section 4 Bored precast concrete piles

0.3.1 This section covers the bored: precast concrete piles which have

0.4 Bored precast concrete pile isa pile constructed in a casting yard and
sulsequendy lowered imo pre-bored holes and the space growed. These
piles find wide applications where safety against chemical aggresive subsoil
And the ground water condition le needed: Sach protecion I pasible with
bored precast concrete piles, because these are made using vibrated dense,
‘matured concrete, with low water cement ratio and are not mbjected to
driving streses. These are also useful where artesian conditions exist or
Where local abstractions are encountered above the founding level or
subsoi water flow exis. They also offer facility for applying protective
eating on the pile surfaces, The provision in respect ol segmental pies
With properly designed jeints are under consideration of the Committee
And i provision will be covered at a later stage.

0.5 The Sectional Committee responsible for the preparation of standard,
while formulating this standard, gave due consideration to the available
experience in this country in pile construction and also the limitations
regarding the availability of pling plant and equipment,

0.5.1 The information furnished by the various construcion agencies
and specialist fiems doing piling work in this country and technical discas-
sions thereon considerably assisted the committee in formulation of this
code.

0.6 For the purpose of deciding whether a particular requirement of this
standard is complicd with, the final value, observed or calculated, expres
ing the result of a test, shall be rounded offin accordance with 152-1060",
The number of significant places retained in the rounded off value should
be the same as that of the specified value inthis standard.

“Holes for rounding a mamerical vales (rad).

4

6. 1812911 (Part 1/Sec 4) =1984
1. SCOPE

1.1 This standard ( Part 1/Sec 4) covers the design and construction of
load bearing bored precast concrete pile which transmit the load of the
structure to the strata where resistance is adequate

[Nore — ‘This standard i used om sumption that strength of rout ll

the spice ball be at feat equivalent to that of srrouniing sl and dhe an ion
‘developed on the pile mall be determined by probative u,

2. TERMINOLOGY
20 For the purpose of this standard, the following definitions shall apply.

2.1 Allowable Load — The load which may be applied to a pile after
taking into account its ultimate load capacity, pile spacing, overall bearing
capacity of the ground below the pile, the allowable setlement, negative
sin friction and the loading conditions including reversal of loads, ete

22 Batter Pile ( Raker Pile ) — The pile which is installed at an angle
to the vertical

23 Bearing Pile — A pile formed in the ground for transmiting the load
fof structure tothe oll by the resistance developed at is tp andor along
{ts surface, À may be formed either vertically or a an inclination ( Bauer
Pie) and may be required o take up.

24 Bored Precast Pile — A pile constructed in reinforced concrete in
a casting yard and subsequentiy lowered into prebored holes and space
routed.

2.5 Gat-off Level — Itis the level where the installed pile is cut-u to
upper the pl caps or beams or any oer structural component at that
level

286 Factor of Safety — The ratio ofthe ultimate load capacity of a pile,
to the safe load ofa pie

27 Safe Load — The load derived by applying a factor of safe on the
‘Stina toad capacity of the ple ar a SCS in he end tet

nnn a ee
3a ete Le Copy The pen nd es

29 Working Load — The load assigned to a pile according to design

5

7. 1S 2911 (Part 1/Sec 4) - 1984
3. NECESSARY INFORMATION

3.1 For the satisfactory design and construction of bored precast piles, the
flowing information à nee)

a EP a Ek

type of
the

Gods of practice or tubwetace investigation for foundations (fat ase
{Code of pete for planing and deign of ports and barba Pare Sie invest
slo {fet oo

8. 18 : 2911 ( Part 1/Sec 4) - 1984

4. EQUIPMENT AND ACCESSORIES
4.1 The equipment and accessories will depend on the type of bored pre-
‘east piles chosen in a job and would be selected giving dur consideration
to the subsoil strata, ground-water conditions, type and founding material
and the required penetration therein wherever applicable.

42 Among the commonly used plants, tools and accessories, there exist a
large variety; suitability of which depends on the subsoil conditions,
manner of operation, ete.

Boring operations are generally done by any appropriate method
with or without temporary casing. Boring may be carried out using mud
stabilisation if required.

43 Handling Equipment for Lowering — Handling equipment such
as crane, derricks, movable gantry, may be used for handling and lower“
ing of the precast piles in the bore. ‘The choice of equipment will depend
upon length, mass, and other practical requirements.

44 Grouting Plant — The mixing of the grout can be carried out in any
suitable high speed collidal mixer. For grouting a suitable grout pump
with sürringlagitating arrangement may be used.

5. DESIGN CONSIDERATION

5.1 General — Pile foundations shall be designed in such a way that the
load from the structure it supports, can be transmitted to the soil without
causing any soil falure and without causing such setlement differential or
total under permanent transient loading as may result in sructural damage
andjor functional distress. The pile shaft should have adequate structural
Capacity to withstand alll onde ( vertical, axial or otherwise) and moments
which are to be transmitted to che subuoil and shall be designed according
to IS: 456.1978%. The shaft of bored precast piles may be of circular or
octagonal shape, and may be of solid ection or with a central hollow core.
The limiting size of the pile will depend mainly on available handling
equipment and the mass of the pile shaft to be handled.

52 Adjacent Stractares

5.2.1 When working near existing structures care shall be taken to avoid
any damage to such structures. In the case of bored pile care shall be
taken to avoid effect due to loss of ground; when boring is carried out
sing mud, the stability of the bore particularly adjacent to loaded founda-
tions shall be examined.

5.2.2 In case of deep excavations adjacent to piles, proper shoring or
‘other suitable arrangement shall be done to guard against the lateral move-

ent of soil stratum or releasing the confining sol stress

a and eeinforced concrete (tid reson).

Gode of prac

Cr

1

9. 18 à 2911 ( Part 1/Sec 4) - 1984

$ Soil Resistance — The bearing capacity of à pile is dependent on
the properties of the si in whichis embedded, "Axil Toad rom à pile
is normally transmite 10 the soil through skin fiction along te shaft and
bear u, A horizontal oa ona veri pl transmit
{the subsoil primarily by horizontal subgrade reaction generated In the
upper part of the shaft.” A singe pel mormally designed o cary load

mits ax. Transvers load bearing eapacty ola single ple dependa
fon the sol reacion developed and the Knuckural capacity of the halo
under bending. In case the horizontal load are of higher magnitude it
Js sential to Invesigate the phenomenon using principles of Horizontal
subsoil reaction adopting appropriate vaca for horizontal md of he
Soil “Alternatively piles ina be installed im ake.

53.1 The ultimate load capacity of a pile may be estimated using a
suitable stati formula. “However, e should preferably be determined by
an inital load test [see IS: 2913 ( Part 4.1904 JP. The crow sectional
area for the purpose of the calculation. shall be the concrete section
eluding the gro where chemical aggresion à Hey to ind sting

‘The setlement of pile obtained at safe Joad/working load from load
test results on à single pile shall not be direcdy used ln forecasting the
setdement of structure [se IS: 8009 (Pare 2319601].

‘The average settlement may be astesied, It would be more appro-
ag to ames De average lement an the assaf sul dat nd
loading details of the structure as a whole using te principles of sol
mechanics Miss

53.11 Static fomula — By using static formula, the estimated value
of ultimate load capacity ola typical ple is obtained, the accuracy being
dependent on the reliability of the formula and the reliability of the
able vil properties for various sata,” The soll proper to be
adopted in such formula may be assigned from the results of laboratory
Len and field tess ike sandard penetration teu (se 18 2151-19815}
Results of cone penetration tests may also be utilized where necesa

correlation with soil results data has been established ( se 19 : 49

(Part 1 )-1976§ ], 15 : 4968 ( Part 2 )-1976§, 18 : 4968 (Part 9 }-19765,
‘Two separate static formula commonly applicable for cohesive ar

“Gade of practise for design and construction pile foundation: Part 4 Lond tat
en pie (Anl een

Foods f practic fr calalation of sulement of foundations: Fart 2 Deep founda
vig mee yeti ate eat gs

Method for nandard penetration tn for ae (et rien

Pts fr one sado sl

Tint "Dyas mated ng 30 mm cone without estos Sorry (jet

Part 1 Dorm method using cone and Denon
TE Sate cone penetration tet (fou ein),

8

lore (fa eso)

10. 18: 2911 ( Part 1/See 4) - 1984

cohesiontss sol respectively are indicated in Appendix A to serve only
332 guide: Other ahernative formula may also Le applicable, depending
On the subsoil characteristics and method of instalation of piles,

5.4 Negative Skin Friction or Dragdown Force — When a soil
siratum through which a pile shaft has penetrated into an underlying
hard stratum, compresses as a result of either it being unconsolidated or
it being under a nevly placed fil or at a result of remoulding of the pile,
A dragdown force is generated along the pile shaft up to a point in depth
Where the surrounding soil does not move downward relative to the pile
shaft.

Note — Estimation of this dragdown force is sl under research studies and
comiderationty although afew emptrical approaches are in use for the same, The
oncept i constantly Under revision and, therefore, no defaite propos is enbodied
Soin tender

55 Structural Capacity — The" piles shall have necessary structural
strength to transmit the loads impored on it, ultimately to the si

5.5.2 Arial Capacity — Where a pile is wholely embedded in the soil
(having a undratned shear svength not less than 01 kgffem®) in axial
Sarmying capacity isnot limited by ite strength as a long column. Where
piles are installed through very weak soils ( having an undeained shear
Rrength less than 0-1 kgfjcmt) special considerations shall be made to
determine whether the shat would behave as long columa of not; i
‘necessary suitable reductions shal be made for its structural strength follow
Ing the normals tructural principles covering the buckling, phenomenon.
When the Anished pile projects above ground level and x" not secured
agalosı buckling by Adequate bracing, the effective fength vil be governed
iy Faity conditions! mposed on by the structure it supports and by the
ature of the soi into which itis installed. The depth below the ground
Zarco to the lower point of contrafleure vacks with the type of the sol
A ’ıratum of liquid mud should be treated as fit was water, The degree
ot nity of the postion and inclination of the pile top and che restraint
Provided by any bracing shal be estimated following accepted rurtral
Principles. The permisible stress shall be reduced in accordance with
Eimilar provisions’ for reinforced. concrete ‘columns as lid down in
IS: 45601976"

5.5.2 Lattal Load Capacity — A pile may be subjected to transverse force
om a number of causes, such as wind, earthquake, water current, earth
[cs cf of moving vehicles or hi lant and equipment, ae. The
Iateral load carrying capacity of à single pile depends not only on the

wizontal subgrade modulus of the surrounding soil but also on the

"Code of prete for plan and reinforced concrete (sind rein

9

11. 18 + 2911 ( Part 1/Sec 4) - 1984

steactral sucngth ofthe pie shat against bending consequent upon applic.
dion ofa lateral toad, While considering Interal load of pil fect of
ater coewsten loads inching the anal fond on te pl, soul be taken
into consideration for checking the structural capaci of the sha À
sende method era posible forte determina othe depth
Sy of piles required for desig i given in Appendix B, Other accep
ico eu as de method of Reese and MANGA may abe be uch
"ora Bocas of lid informatie en han medal of vl, aná
ca e am ls Spee tn Sey de
Saye check by a's el nt
3.53 Roker Pila — Raker piles are normally provided where vertical
piles cannot resist the required applied horizontal frees. In the. rei
Trina desea the load on a rater ls general considered fo be Ana,
‘The dutribaton of lond between raker and venca per in a group may
be determined by graphiea or analytical mechod Where necenary, due
‘Gerrans be made foe Rod ending indice y eu
the ple cap movement, parelany when the cap à gid: Freestanding
Taker piles are subjected to bending moments due to their own mas, oF
Este (res rom other eases Raker ples embedded infil or consid
ting deposi, may become laterally ended owing to the sctement of the
di ll

5.6 Spacing of Piles -- The centre-to-centre spacing of piles should be
considered from two aspects
a) practical aspects of installing the piles, and
D) the nature of the load transfer to the soil and possible reduction
in the bearing capacity of a group of pies there
The choice of the spacing is normally made on semi-empirical
approach.

5.6.1 In case of piles which are predominantly resting on hard stratum

and deriving their capacity mainly from end bearing, the spacing will be
governed by the competency of the end bearing strata, The minimum
Spacing in such cases, shall be 2-5 times the diameter of the pile, In case
of piles esting on rock, the spacing of twice the diameter of the pile may
e adopted,
2 Piles deriving their bearing capacity mainly from friction shall be
sufficiently apart to ensure that the Zones of soils from which the piles
derive their support do not overlap to such an extent that their bearing
values are reduced, Generally the spacing in such cases shall not be lest
than three times the diameter of the pile.

5.6.3 The spacing should not be so close as to cause direct contact
between two adjacent piles in a group, the deviations at depths arising
out of the tolerance allowed in the installation. This would mean the

10

12. TS : 2911 (Part 1/Sec 4) - 1984

minimum spacing would, to some extent, depend on the length of piles
installed.

5.1 Pile Grouping — In order to determine the bearing capacity of a
‘group of pile, & mutnber of efliieney equations are in use. However, Ms
Yery dial do establish the accuracy of these efficiency equations 32 the
‘behaviour of pies group is dependent on many complex factors. Tt is
ai us odie cath caso para on tt ow me

5.7.1 The bearing capacity ofa pile group may be either:

8) equal to the bearing capacity of individual piles multiplied by the
number of piles in the group, or

b) it may be less.

5:72 In case of piles deriving their support mainly from fiction and
connected by a pile Cap, the group may be visualized to transmit load 19,
the soil, as if from a column of soil enclosed by the piles

capacity of the group may be computed following this concept, taking into
account the frictional capacity along the perimeter of the column of soil
as above and the end bearing of the said column using the accepted
principles of soil mechanics.

5.7.2.1 When the cap of the pile group is cast directly on reasonably
firm stratum which supports the piles it may contribute to the bearing
‘capacity of the group. The additional capacity along with the individual
‘capacity of the piles multiplied by the number of piles in the group should
not be more than the capacity worked out in 5.7.2.

5:73 When a moment is applied on the pile group either from super
are or ava consequence unavoidad Inacio of gala
the adequacy of the pile group in existing the applied moment should be
checked. In case ola single ple subjected to moments due to lateral forces
‘or eccentric londing beams may be provided to restrain the pile cap
‘Mtceively fom lateral or rotational movement,

5.74 In case of structure supported on single pllefgroup of piles, result-
ing into large variation in the number of ples from column 19 column, it
is likely, depending on the type of subsoil supporting the piles, to result in
a high’ order of differential settlement, Such high order of differential
Settlement may be either catered for in the structural design or it may be
vably reduced by judicious choice of variations in the actual pile load-
ings. For example, a single piles cap may be loaded to 9 level higher than
that of à pile in a group in Order to achieve reduced differential tetlement
between two adjacent pile caps supported on different number of piles.

u

13. 18 42911 ( Part 1/Sec 4) - 1984

5.8 Factor of Safety and Safe Load
5.8.1 Factor of safety should be judiciously chosen after considering

a) the reliability of the value of ultimate load capacity ofa pile,
b) the type of superstructure and the type of loading, and
€} allowable totaljdifferential setlement of the structure.

5.8.2 The ultimate load capacity may be obtained whenever practicable,
from a load test (initial) [ eo 15: 2911 ( Part 4 )-1984* ]

5.83 When the ultimate load capacity is computed from static formula
the factor of safety would depend on the reliability of the formula depend
ing on a particular site and locality and the reliability of the subsoil para
meters employed in such computation. The minimum factor of safety on
static formula shall be 2:3. ‘The final election of factor of safety shall take
into consideration the load settlement characteristics of the Structure as à
whole at a given site.

5.8.4 Factors of safety for assesing safe load on piles from load test
data should be increased in unfavourable conditions where
3) settlement is to be limited or unequal settlement avoided as in the
fase of accurately aligned mechinery er a superstructure with
Fragile finishings,
b) large impact or vibrating loads are expected,
©) the properties of the soil may be expected to deteriorate with
time, and
4) the live load on a structure carried by friction piles is a consider.
able portion of the total load and approximates to the dead load
in ts duration,

59 Transient Loading — The maximum permisible increase over the
safe load of pile as arising out of wind loading, is 25 percent. In case
Of loads and moments arising out of earthquake effects, the increase of
safeload on a single pile may be limited to the provisions contained in
TS : 1899-1975. For transient loading arising out of superimposed loads
no increase may be generally allowed.

5.10 Overloading — When a pile in a group, designed for a certain safe
load is found, during or after execution, to fall just short of the load
required to be carried by it, an overload up to 10 percent of the pile
Capacity may be allowed on’each pile. The total overloading on the

ase al pain oc design and construction of pile foundations: Part 4 Load test
om piles (fed ro)
Holaa fo eribguake resistant design of structures (tid ssl) +

12

14. 15 + 2911 ( Part 1/Sec 4 ) - 1984

group should not be more than 10 percent of the capacity of the group and
not more than 40 percent ofthe allowable load on a single pile. This
subject to the increase of the load on any pile not exceeding 10 percent of
its capacity.
5.11 Lifting and Handling Stresses — Stresses induced by bending
in the cross section of a precast pile during lifting and handling may be
estimated just as for any reinforced concrete section in accordance with
relevant provisions of 18 : 456-1978*, The calculations with regard to
moments depending on the method of support during handling will be as
given below. Excessive whippinese in handling precast pile may generally
bbe avoided by limiting the length of pile to a maximum of 50 times the
Teast width
Member of Points — Lacation of Pont of Support from Bending Moment
of Pick Up and in Tome of Length of Pile for to be Allowed

Minima Moments “for Design
One 0-298 2 a
a wz
Two 02071 pe
0-148 L, the middle point Wh
aie will be at the centre =
where

W = mass of pile in kg, and
L = length in metres.

During hoisting the pile will be suspended at one point near the
head and the bending moment will be the least when itis pulled in a
distance of 0:293 Z, and the value of bending moment will be:

WL

35
5.12 Reinforcement — The longitudinal reinforcement shall be provided
in for the entire length preferably of high yield strength to withstand the
handling stresses to the extent to meet requirement as given in 5.11. All
the main longitudinal bars shall be of the tame length. The area of the
main longitudinal reinforcement of any type and grade shall not be les
than O-t perdent of the cross section area of the piles or as required to
cater for handling streues whichever is greater. The lateral seinforce-
ment shall be links or spirals preferably of not less than 6 mm diameter
bars. ‘The cover of concrete over all the reinforcement including bend.
ing wire should not be les than 40 mm, but where the piles are exposed

Cde of pracic for plain and reinforced concrete hid rao).

3

15. 18: 2911 ( Part 1/Sec 4) - 1984

to the sea water or water having other corrosive contents the cover should
be mo where less than 50 mm. À thin yauge sheathing. pipe of approxi=
mately 40 mm diameter may be attached to the reinloreement cage, in
fate of aoid piles to form the central duct for pumping. grou to the
Bottom of the bore
5.13 Design of Pile Cap

5.13.1 The pile caps may be designed by assuming that the load from
colon is dispersed at 18° from the top of the cap upto, the mid-depth of
the pile cap fom the base of the cola or pedestal. The reaction from
pie? may alo be taken to be distributed at 45° Kom the edge of the pil,
Up to the midedepth of the pile cap. On this bas the maximum bending
moment and shear fees sould be worked ut at erica sections. The
meihads of analysis and allowable sreses should be in accordance with
15: 456-1976

5.192 Pile cap shall be deep enough to allow for necessary anchorage
of the column and pile reinforcement

5.183 The pile cap should normally be rigid enough so that the
impose load could be distributed on the piles in a group equitably.

5.13.4 In case of a large cap, where diferent settlement may be
imponed between piles under the same cap, due consideration for the
comequential moment should be given

5.18.5 The clear overhang of the pile cap beyond the outermost pile
in the group shall normally be 100 to 150 mm depending upon the pile
5.13.6 The cap is generally cast over a 75 mm thick levelling course of
concrete. The clear cover for main reinforcement in the cap stab shall
not be less than 60 mm,
5.13.7 The pile should project 50 mm into the cap concrete
5:14 The design of grade beams if used shall be as given in IS: 2911
(Part 371980.
6. MATERIALS
6.1 Cement — The cement used shall conform to the requirements of
18: 269-19765, 15: 455-1965, 15: 8041-1978, 15: 1489-19709, and
15 1 6909-1973** as the case may be.

‘Gade of practice or plain and peufoced concrete {bird ee).
{Gade of peace for Seaign and coran of ple fovadatons à Part 9 Under
rec pile foundations (Jon vais).

"Specibattn (o ordinary and low beat Portland cement (ind iin.

Speciation for Portland sag coment | tard vay

[specification for asi hardening Portland seen | fat eso)

SSpecitcaion fr Portond porteana cement send satan

RSG reihen foe super alpin cement

1

16. 18 12911 (Part liSee 4) - 1984

62 Steel — Reinforcement steel shall conform to 1 part Eje

16629, TS : 1139-1966, or IS : 1785-19664, or 1S : 22

63 Concrete

6.3.1 Materials and method of manufacture for cement concrete shall
in general be in accordance with the relevant requirements given in IS
45619705, The stress in concrete due to working load and during
handling, pitching and driving of the pile should not exceed than those
stipulated la 18 156-1070 according to the grade of concrete used and
having due regard to the age of piles atthe time of handling,

6.3.2 The grade of concrete should be preferably not less than M2.
7. WORKMANSHIP

TA As far as possible in-situ extensions shall be avoided. The casting
yard for all concrete piles should preferably be so arranged that they can
be lifted directly from their beds and transported to the piling fame with
a minimum of handling. The casting yard should have a well-drained
surface to prevent excessive or uneven Seulement due to softening during
manufacture and curing.

7.2 As far as practicable each longitudinal reinforcement shall be in one
Jength, In cases where joints in reinforcing bars cannot be avoided, the
joints in bars shall be staggered. ‘Tae hoops and links for reinfor

Shall Be tightly agains longitudinal bar and De bound to them by wel
fr by eying with mild steel wire, the free ends of which should be turned
into the interior of the ple. The longitudinal bars may be held apart by
temporary or permanent spreader forks not more than 155 m apart
The reinforcement shall be checked for tightness and position immediately
before concreting

73 Casting and Caring

7.3.1 The piles should be cast in a continuous operation from end to
end of each plle.. The concrete should be thoroughly compacted against
the forms and around the reinforcement by meant of immersion and/or
shutter vibrators. The faces of the pile including those exposed at the

®speciicaion for mild tel and medium tense tel bars ad hard dawn steel,
vena one rarement Fr ME and sed ees rd
repped lied mild seo] medium tonite tet and high yield
steep se nnd concrete elfercemen bed)

‘Boece foe older nel High enga debemcd ban for cora

prete ation for aeractaral sect (etandaed quality) (MAR bio)

¡Codo of practice for plain and -toforced concreto (id ren

15

17. 18 + 2911 ( Part 1/Sec 4) - 1984

top of pile should be dense as far as posible. Immediately on completion
of the casting the top surface should be finished level without excessive
trowelling. Care should be taken to ensure that vibration from adjoining
‘works does not effect the previously placed concrete for piles during the
setting period.

73.1.1. All shuttering shall be placed on firm supports capable of
withstanding the loads of thuttering, wet concrete and incidental load of
‘workmen, 30 that cast piles are straight and free from deformations. The
shuttering shall be coated with oil on the inside face

73.2 Though from consideration of speed and economy precast
concrete es will have to be place with the east posible delay ater
«casting, i shall be kept in mind that a thorough curing and hardening is
necessary before the piles are placed and proper schedule to take care of
thls shall be decided for the operations of casting, stacking and placing.
The most importan: factors effecting the time of euring are the method of
curing, weather during hardening, probable hardness of placing and the
method of lifting and pitching.

7.3.4 Before the operation of handling the piles, the minimum periods
counted from the time of casting as given in 1S: 496-1978" shall be
followed

74 Sorting and Handling

7.4.1 Piles shall be stored on firm ground free from abiliy to unequal
sulnidence or stlement under the mass of the mack of piles The pes,
Shall be placed on timber supports which are tly level and spaced so as
to avoid undue bending in the pile. The support shall be vertically one
shove the other. Spaces shal be left round the pesto enable them to be
liked without dic. The order of stacking shall be such that the
older piles can be withdrawn for placing without disturbing the newer
ples "Separate sacks shall be provided for diferent lengths of pies

reversing Y eded duty virago arrangement Hal e ae
tp enable dep to be watered if weather conditions se vequre, For
etaled precautions with regard to curing operations reference may De
made to IS : 456-1978*, mas dé

7:42 Care shal be taken a al stages ol transporting, ling and handl-
ing of the pies that they are not damaged or cracked. During ane.
pétition, the piles aha be upported af the appropriate Ming holes
ed tor ate purposes" fhe les ace pu down tempora, ater

ing ited, they hal be placed on els of blocks loete atthe Liking
point.

Gode of practice for plata and reinforced concrete (third resin)

16

18. 15 : 2911 ( Part l/Sec 4) - 1984

7.5 Control of Pile Instal

7.5.1 Bored precast piles shall be constructed by suitable choice of boring
and installation techniques covering the manner of soil stabilization, that
is, use of casing and/or use of drilling mud and choice of boring tools in
order to permit a satisfactory installation ofa pile at a given site. Sufficient
‘detailed information about the subsoil conditions is esaential to predeter-
mine the details of the installation technique. The bottom end of the pile
shall have proper arrangements for cleaning and groutin

7.5.2 Conta of Alignment — Pils shall be installed as accurately as pose
ble according to the designs and drawings either vertically or lo the
specified batter. Greater care should be exercised in respect of installation
Gf single pile or piles in two pile groupe, As a guide, for vertical piles à
Seviation of 1: percent and for taker ples deviation of à percent should
hot be normally exceeded although in special case a closer tolerance may
Ve mecesary. Piles should mot deviate more than 75 sum or DIE which.
ever is Les ( 75 mun or D/lO whichever i more in case of piles having
diameter more tha 600 mm ) From their designed postions at the work:
ing level. In the case ofa single ple in a column the poskional tolerance
should not be more than 30 mm or Dit whichever i les { 100 mm in case
of piles having diameter more than 600 mn ). Greater tolerance may be
prescribed fr piles driven over water and for raking ples, For piles tobe cut
OR at a substantial depth ( below ground level} or height ( above-ground
level) the design should provide for the worse combination of the, above
tolerance in. position and inclination, In case of piles deviating beyond
there limits and to auch an extent thet the peral, eccentsiity cannot
be taken care of by a redesign of the pile cap of pile es, the ptes shoul
be replaced or supplemented by one ur more additonal ples, Incase 0
piles, with non-circular rose section « D should be taken as the dimensions
Bt the pile, along which the deviation is computed. In such cases the
permissible deviation in each direction bon be diferent depending upon
the dimension of the pile along that direcion

2.6 Flushing — The central duct/hole shall Le connected to à suitable
pump and water driling fluid allowed to flow through the bottom of the
pile removing loose material,

7.7 Grouting — Sand and cement grout mixed with water in a high
speed collidal mixer is tobe fed into the pile with a grout pump of suite
able capacity connected to the central duct through a manifold. À grout
of sand and cement with additives as necessary, ol strength not les than
Y +2 cement and sand ( see also Note under 1.1) suitable for pumping into
the annulus, may also be used. The temporary easing here used shall be
removed in stages with the rise of the level of grout. After final removal
of the temporary casing, the grout level shall be brought up to the top by
pouring in additional grout as required.

7

19. 1812911 (Part 1/Sec 4) - 1984

7.8 Defective Pile — In case, defective piles are formed, they shall be
removed or el in place whichever is convenient without alfecing perfor=
sance of the adjacent piles or the cap as a whole. Additional piles shall be
provided to replace them,

79 Any deviation from the designed location alignment or load capacity
of any pile shall be noted and adequate measures taken well before the
concreting of the pile cap and plinth beam if the deviations are beyond.
the premise limi ———°

7.10 Recording of Data
7.10.1 A competent inspector shall be present to record the necessary
information during Installation of piles apd the data to be recorded shall
include:
3) the sequence of installation of piles in a group;
») the dimensions ofthe pie including the reinforcement details and
mark ofthe pile
€) the depth placed;
4) cut off leveliworking level and
€) any other important observation.
710.2 Typien data shect for facility of recording piling data are shown
in Appendix & ” —_—

7.11 Stripping Pile Heads

TALI The concrete should be stripped to a level such chat the remain
ing concrete of a pile will project minimum 50 mm into the ple cap, The
effect of this projection on the positon of any reinforcement in the pile
cap should be considered in design. The pile reinforcement should be left
with adequate projecting length above the cut off level for proper embed-
ment into the pile cap. _Expoting such length should be done carefully to
avoid shattering or otherwise damaging the rest of the pile. Any cracked.
or defective concrete should be cut away and made good with new concrete
properly bonded to the ol.

7.12 Lengthening Piles — Where a pile is to have another length cast
fon to ie before or during placing the longitudinal reinforcement should
preferably be jointed by full penetration butt welding. The concrete at the
{op of the original pile should be cut down to expose not less than 200 mm
of the bars, The bars should be held accurately and rigidly in position
during welding. | Where facilites at site are insuficient 10 make good butt
Welding practicable the joint may be made by lapping. The reinforcement
at the head of the pile will need to be exposed for a distance of 40 times
the bar diameter and the new bars overlapped for this distance. If the
bonds are lapped, spot welding shall be done. As an alternative special
Dot aid nut joins may be provided,

18

20. 18 : 2911 (Part 1/Sec 4) 1964
APPENDIX A
(Clause 5.3.1.1)
LOAD CARRYING CAPACITY STATIC FORMULA

A-1. PILES IN GRANULAR SOILS

ALI The ultimate bearing capacity ( Qu ) of piles in granular soils is
given by the following formula: =

Qu Ay EDI Met Po Me) D À Porta du

where
Ap = crosssectional area of pile toe in in cm;

D = stem diameter in em;

y = effective unit weight of soi at pile toe in kgflemt;

— efective overburden pressure at pile toc in kgffem*s

= bearing capacity factors depending upon the angle of

internal friction at toe;

SUmmation for n layers in which pie is installed;

Km conficient of earth pressure;
Pa = effective overburden pressure in kgfemt for the 4% layer
‘where 4 varies from Lo ay “ ”
3 = angle of wall friction between pile and soil, in degrees
(may be taken equal to $ } a

An = surface arca of pile stem in em in the #8 layer where,
varies from on.

[Nore 1 — 2 factor an b taken for general shes failure as per LS: 540919019

Nore 2— Na factor will depend, apart from nature of sil on the type of pie
and Va mea ‘of cometo, fot bored plc, the value of ig coeeonding ts
Ange of hearing moine pare given I Pe Ty Ths D base on Derrame
ate for DID af D up tog = 8 and Ves curves yond § = 85

Nore 3— The ae
HR bacon | and

nur cotBeient K depends onthe natur of oi rata,
nr. For bored piles loot medium eat,
id be ued

= Fond of practice for determination of beating capacity of shallow foundations
Craie

19

21. 15 + 2911 (Part 1/Sec 4) - 1984

ws
|
i
-
a
10) a …$

20 2% 30 35 40 4
ANGLE OF INTERNAL FRICTION $

Fro 1. Brawno Caractry Factor X, ron Bono Pres

22. 18 à 2911 ( Part 1/Sec 4) - 1984

Nove 4 Tte angle of wall tition may be taken qual to angle of shear
resistance of sol

Noes 5 — tn working out ple capacities sing ti formula, for piles longer
than 180 20 pile dames, maxime afectivo overburden at the pile Gp ahosid
correspond 1 pile length equal to 13 to 20 ameter

A-2. PILES IN COHESIVE SOILS

A-2.1 The ultimate bearing capacity of piles (Qu) in cohesive soil is
graby da fee di

Qa Ay Ne Oy ta Oy
where
Ay = cross sectonal aren of pile toe in cm?
No = bearing capacity factor usualy taken as 9,
Gy = average cobesion at ple tip in km,
a = reduction factor,

© = average cohesion throughout the length of pile in kgj
and

Au = surface area of pile shaft in en.

Nora 1 — The following values of « may be taken depending upon the cons

tency ofthe wile
Consume Mal alu fa
Soft to very soft <4 07

Medium 4108 os
seit sis 04
hard >15 03

Nom 2 — (a) Static formula may be ud asa guide ony for beating capacity
estimate. Bester reliance may be put on load vent on ples

(9) For working out safe load a minimum factor of safety 25 should be weed
on the ultimace Beating Capac estimated by sate formule

Nora 9 may be taken to vary from 0 0 3 depending upon the comi
tency af the soll. Higher values of up to one may be used forsale ols, provided

A-2.2 When full static penetration data is available for the entire depth,
the following correlations may be used as a guide for the determination of
shaft resistance of a pile.

a

23. 1S + 2911 (Part 1/See 1) - 1984

Tap ai Loc Side Pion
te
Clas and peas where goto Bo Sh
Gays <h
Silty clays and silty sands “fe
Sande <h
‘Coarse sands and gravels te

Ja = local side fection
For non-homogeneous sols the ultimate point bearing capacity may
be calculated using the following relationships:
fat fet
FI + es
ne 7
where
du — ultimate point bearing capacity,
Geom average static cone resistance over a depth of 2 d below
the base level of the pile,
de static cone resistance over the same 2 d below
da = minimum
the pile tip
dex average of the minimum cone resistance values in the
‘over a height of 8 d above the base level of the

pile, and
d «> diameter of the pile base or the equivalent diameter for a
non-cireular cross section.
A23 The correlation between standard penetration test value Nand
‘atic point resistance ge given below may be used for working the shaft
resistance and skin friction of pies

Soil Type SN
Clays 20
Sis, sandy sits and slightly cohesive sil sand mixtures 2:0
Clean fine to medium sands and slightly sky sands 3-4
Course sands and sands with lite gravel 56
Sandy gravels and gravel, 210

2

24. 15: 2911 (Part 1/Sec 4 )- 1904

APPENDIX B
( Clause 5.5.2)

DETERMINATION OF DEPTH OF FIXITY OF PILES

B-1. For determining the depth of fixity for calculating the bending
moment induced by horizontal load, the following procedure may be
followed.

Estimate the value of the constant of modulus of horizontal subgrade
reaction my ofthe modula of subrado reaction Kf soi om Table oF
Table 2.

Determine from appropriate graphs given in Fig. 2 and Fig. 3 the
value of Z, the equivalent length of cantilever giving the same deflection
at ground level as the actual pie.

‘TABLE 1 ‘TYPICAL VALUES OF m.

Son Tere

Loose sand
Medium and
Dense sand

TABLE 2 “TYPICAL VALUES OF K FOR PRELOADED CLAYS

‘Uncemenxo Con

ton — Rasozor Vanwes Ponant Vator

BS “ork ore
tejen te
Eos mn
6510 150 orn

3

25. 18 «2911 ( Part Sec 4) - 1904

+ T
ACTE
Y

IS
3.
FIXED HEAD |
| |
i L
Potkg fen?)

di diameter of pile

Fro. 2 Ld Versus m,

Eee u ee

KGglems)

4g det of pile
wie. 3 Ta Vinos K

2

26. 15 :2911 ( Part 1/Sec 4) - 1984

APPENDIX C
Clause 7.10.2)

DATA SHEETS

Sie,
Tide,
Date OÙ ERQUY ne
Date piling commenced.
Actual or anticipated date
Number of pile

x completion of piling work,

TEST PILE DATA
Pile: Pile test commenced.
Pile test completed

Pile pe: ees
(Benton propicany systems if any)
rt sos gg nm

Pile specication | Reinforeemenk. No. dia fr... dep)
=

Sequence of ping "From conte towards Ihe periphery Ham

Faro een toward theo

Concrete Mix ratio 1 -

isch after, days
Quantity of cement per mit...
Extra cement added if any

Details of drilling mud if used

Time taken for concreting: .

Quantity of concrete — Actual:
‘Theoretical

25

27. 15 :2911 (Part 1/See 4)- 1984

“Vest loading

Capacity of jack
anchor piles used, No, Length,
Distance of test pile from nearest anchor pile...

Test pile and anchor piles were/were not working piles.

Method of taking observations:
Dial gauges/Engincers level
Reduced level of pile 4
General Remarks:

Special dicas encountered:

Results:
Working toad sp

Settlement specified for the test pile

Seulement specified for the structure

Working load accepted for a single pile asa result of the ter.

26

28. 18 12911 (Part 1/Sec 4) - 1984

me of the constructing agency...

Name of person conducting the tes

Name of the party for wham the test was conducted,

BORE-HOLE LOG

1. Site of bore hole relative totes pile positon,

2. Nuts — If no bre hole give best available ground cord

Soil Soil Desergtion Redued Sul Dit Thichnes

Properties Lael Legend Below Y
CL sate
Position of the
toc of pile to be
indicated thus

Standing ground
water level indi
cated thus

METHOD OF SITE INVESTIGATION

wgerjshell andl auger boring/percussion/probing!
shot drilling) subsurface

Trial pitfpos-hole
wath boringsjmud-rotary driling/core-deilin

sounding by cones or standard sampler...

Nore — Graphe, sowing th following relations, shall be prepared and added
tothe report

1) Load ss Time
2) Setiement Land

n

29. 1S : 2911 ( Part 1/Sec 4) - 1984

(Colin from po 2)

Pile Foundations Subcommittee, BDC 43 : 5

ser Representing
Sua M.D. Taca Im gerona! espacio, (Prada Vil, 2 Fos
“Patt Mako oa
Mentes
Sma Cusco Prat Genre Balog Rue Ie. (OSIR ),
Sama K. G. Gano (late) on
Suns A Grosrae Stup Consultants Led, Bombay
Finis India Lid, Now Dei
“Suni Re Baocın (Alert)
San BR face University of Roorkee, Roose
Sim ALN Jao KE ernten “and. Gomaración Pu L
Jes, epee, Rrananen Minty ta
Dr Dugeeron Rrssancn (OE)>
TEL, RDSO (Alera)
San Rita onto Co Ad, Rony
Sun Mi Ro Pons" Gemnindia Co Lid, Bombay
Stns Bs Ramon Pile Foundations Coouraction Co (1) Pot Lid
Cate
¡Suns 8. C. Bose (Altmate
Sormaasniio Es ormpen Cental Public Works Department, Nes Delhi
Bawevsive Exoixnex (Dasiane) V

30. BUREAU OF INDIAN STANDARDS

Headquarters
Mandk Bhavan, 8 Bahadur Shah Zafer Mao, NEW DELHI 110002
Talonone 331 O1 81,381 1376 Telogrms : Manakaanatha
(Simon tat tices)
Regional Office: Tantos
Cental? Manek Bhavan, 9 Bahacur Shah Zar Marg, 13910131
NER DELHI 000 EH
Steno + 118 CAT Schema YM. V.1.P-Rond. 302488
Manila, CALCUTTA T6004
Northern : 800 440 440. Sector 35°C, 2184
CHANDIGARH 100038, fr
[412442
Southern: 6.1.1. Compus, MADRAS 600113 HET
a 2018
Metern : Manekaaya, £0 MIDC, Mar. Ando (Easy, 428298
Ya dass
Branch mets
“Push” Nurmiohamod Shaikh Mag. Khanur, 20348
"AMEDABAD 380001 388
Peenye Indust! vo, at Stage, Bangalore Tumkur Rond [28 4968
BANGALORE Senos Er
Gangcti Complex, Bh Floor Bhadbhado Road, T.T.Nager. 88710
BROPAL 202063
Pot Ne. 82/83. Lawie Road, BHUBANESHWAR 751002 83627
BA. Ward No. 38, 1 6. Baron Rand, 6th Oyaen, san
SALA 181008
6-2.60c LN, Gupte Marg ( Nampaly Station Road), 231083
RNOERADAD 0600! ;
a e347
14 Yodisir Mara, © Schema, JAIPUR 302008 sun
117/418 8 Survodaya ag, KANPUR 208006 Bez
Patlouta Indusval Estate, PATNA 800013 02305
Ter No. 4/1421. Unity PO. Palm 621 04
FaIvANDRU 69000 [HI
Inspection Offee (th Sal Point)
Pushparjly Ys Floor. 208:A West High Court Road, an

Shankar Nagar Square, NAGPUR 440010
Institution of Engineers (India) Building. 1332 Shivaji Nagar, — 52435

"Sha Office ln Calcuta 1
Sur Caicara 700072

Sul OMen In Bombay in at Novelty Chambers, Grant
Bombay 40007

"Sales Office In Ba
Bangalore 88000?

5 Chowinghos Ap

M, P.O.Pnesp #7 08 00

31. AMENDMENT NO. 1 OCTOBER 1987
To

: 2911 ( Part 1/Sec 4 )-1984 CODE OF PRACTICE FOR
DESIGN AND CONSTRUCTION OF PILE
FOUNDATION

PART 1 CONCRETE PILES
Section 4 Bored Precast Concrete Piles

(Page 10, clause 85.2, last two sentences ) — Substitute the follow
ing for the existing matter:

‘A recommended method for the determination of depth of fit,
lateral deflection and maximum bending moment required for design,
is given in Appendix B for fully or partially embedded piles. Other
accepted methods, such as the method of Reese and Matlock for fully
embedded piles may also be used.”

(Page 15, clause 62, line 2) — Substitute * 1S : 1786-19883 * for
13919664, or 18: 1786-19663".
(Page 15, clause 6.3.2.) — Add the following new clause after 6.3.2:
6.3.3 For the concrete, water and aggregates specifications laid down
in 1S : 456-1978] shall” be followed in general. Natural rounded
shingle of appropriate size may also be used as coarse aggregate. It
helps to give high slump with less water-cement ratio. For tremie
concreting aggregates having nominal size more than 20 mm should not
be used.”
(Page 15, foot-notes marked with * 1" and‘ * mark ) — Substi-
tute the following for the existing foot-notes:
Specification for high strength deformed sie bars and wires for conerete
reinforcement {third reiten).
(Page 17, clause 7.5.2, fourth and Afıh sentences ) — Substitate
D/6* for * DÍA, at both the places.
( Pages 23 and 24, Appendix B including Fig. 2 and 3 ) — Substitute
the following for the existing appendix and figures:

32. ‘APPENDIX B
(Clause 5.52)

DETERMINATION OF DEPTH OF FIXITY, LATERAL, DEFLECTION
‘AND MAXIMUM MOMENT OF LATERALLY LOADED PILES

B+, DETERMINATION OF LATERAL DEFLECTION AT THE PILE
HEAD AND DEPTH OF FIXITY

BA. The long flesible pile, fully or partially embedded, is treated as a
canilever fined at some depih below the ground level (see Fig. 2).

FREE HEAD PLE

FIXED HEAD PRE

LL) cor pues me sanos
AND womsauLy Loaneo

clays

FOR PILES m
JPRELOADED cı as

L/R OR UT

Fıc.2 DerenumarioN or Deptt Fixire
B-1.2 Determine the depth of fixity and hence the equivalent length of
the cantilever using the plots given in Fig. 2 “ 2
‘where

Ds [He nan 4, [EL Cas and re constants given in

Tables 1 and 2 below, Eis the Young's modulus of the
pile material in kg/cm and 1's the moment of inertia of
the pile cross-section in cmt).
More. Fs. 2 oi fr long ile piles whete the embedded length Lois
plore? in

33. TABLE 1 VALUES OF CONSTANT A, (kalem)
(Clouse 112)

‘Tym or son

Loose sand

Medi. sand

Dense sind

Ver oo nd under
fepeatedlonding or
‘orally leading clays

TABLE 2 VALUES OF CONSTANT X, (en!)

(Clause Bd
Usconeisun Comes awe
nor in bales
020004 295
1102 ro
204 3775
More than 4 19530

1-13 Knowing the length of the equivalent cantilever the pile head
deflection (Y) shall be computed using the following equations;

Och + 1s)" f le

y= Mlb for free head pil
(em)

Ln + Ley „for fixed head pile

Er
where Q is the lateral load in kg.

322. DETERMINATION OF MAXIMUM MOMENT IN THE PILE

B-2 The Bed end moment (Mr )of the equivalent cantilever is higher
than the actual maximum moment (M ) of the pile. The actual maximum
moment is obtained by multiplying the fixed end moment of the
equivalent cantilever by a reduction factor, m given in Fig. 3. The fixed
end moment of the equivalent cantilever is given by:

Mr=Q(Li+ Lr) ‚for free head pile
QU + 1) er ed ad pile

‘The actual maximum moment (M) = m (Mr).

34. to

For Pues IN
PRELOADED CLAYS|
FOR PLES IK
Y, nonwatty
Utle LOADED CLAYS

REDUCTION FACTOR (m)

TT
HR OR fr

3A FOR FREE HEAD PIE

12

— FOR PLES IN PRELOADED CLAYS

.- FOR PILES IN SANOS ANO
NORMALLY LOADED CLAYS

REDUCTION FACTORI

0 os aS 20 35
U/R OR L/T

38 FOR FIXED HEAD PE

Fio, 3 DereRMINATION on REDUCTION FACTORS FOR
COMPUTATION OF MAXIMUM MOMENT IN PILE

ca)