IS 291 1 (Part 1ISee 2 ) : 2010

Indian S~andard DESIGN AND CONSTRUCTION OF PILE FOUNDATIONS - CODE OF PRACTICE

PART 1 CONCRETE PILES

Section 2 Bored Cast In-situ Concrete Piles

( Second Revision )

ICS 91.100.30 : 93.020

O BIS 2010

B U R E A U O F I N D I A N S T A N D A R D S MANAK BHAVAN, 9 B W U R SHAH M A R MARC;

NEW DELHI 110002

May 2011 Price Group 9

Soil and Foundation Engineering Seclional Cornmiltee, CED 43

FOREWORD

This Indian Slandard (Pan IlSec 2) (Sccond Revision) wns adopred by the Bureau of Indian S~mdards, alter [he draft finalized by the Soil and Founda~ion Enginccring Sectional Commitlee had been approved by the Civil Engineering Division Council.

Piles find application in foundations to ~nnsfcr loads from a structure lo compelent subsurface slrata having adequate load-bcaring capacity. The load translcr mccbanism from a pilc to the surrounding ground is complicated and is not yct fully underslood, alhaugh application of piled foundations is in pracrice over many dccades. Broadly, pilcs wmfcr axial loads either subs!mriaIly by friclion along its shah andlor by [he end-bearing. Piles are used where eilher of thc above load lransfer mechanism is possiblc dcpcnding upon lhe subsoil slrntilication a1 a particular site. Construction of pile foundalions require a carcful choicc OZ piling systcm dcpcnding upon the subsoil conditions. thc load characteristics of a strucrure and he limitarions of total sertlernent, diffcrcntid scttlcment and any other special rcquiuimcnt of a project. The installar ion of piles demands carehl conk01 on position, alignment and depth, and involve specialized ski1 I and experience.

This standard was originally published in 1964 and includcd provisions rcgarding driven cast in-sirrr piles. prccast concrctc pilcs, borcd pilcs and under-reamed pilcs including load lcsling of piles. Subsequently the portion pcttaining to undcr-rcamcd pile foundalions was deletcd and now covcrcd in IS 291 1 (Pan 3) : 1980 'Code of practice lor design and construction of pilc foundarions: Pari 3 Under-reamed piles Vjrsl revision)'. At ha t timc it was also decided thal [he provisions rcgarding other types of piles should also be published separalely for case of rcfcrcncc and to take into account che recent dcvclopments in this field. Consequently h i s slandard was revised in 1979 into three sections. h l e r , in 1984, a new scction as (Part IISec 4) was introduced in this part of the slandard to cover Lhe provisions of bored precast concrete pilcs. The portion relaring to load rest on pilcs has been covered in a sepantc part, namcly. IS 291 1 (Parr 4) : 1984 'Code of prac~ice for design and consrruclion of pile foundations: Par1 4 t o a d test an pilcs'. Accordingly IS 291 1 has bccn published in four p a r k The olher parts of h e srandmd are:

Pan 2 Timber piles

Pan 3 Under-reamed piles

Part 4 Load test on piles

Othcr scclions of Part 1 are:

Scction 1 Driven casL i l l-si~u concrele pilcs

Scction 3 Drivcn precast concrete piles

Section 4 Precast concrctc pilcs in prebored holes

It has bccn felt h a t the provisions regarding thc diflcrenl types of piles should be furlher reviscd to tnkc into accaunr [he recent devclopmcnts in [his field. This rcvision has been broughl out to incorporate these dcvclopmcnts.

In thc prcscnt rcvision following major rnodiFications have been made:

a) Definitions of various terms have been modified as pcr Ihc prevailing engineering practice.

b) Minimum diamerer of pile has becn specified.

c) Procedures for calculation of bcaring capacily, s~ruclural capacity, (actor of safely, lalcral load capacily, overloading, elc, have also k e n modificd to bring them at par with [he present practices.

(Conrinued on fliird cover)

(Continued lrom second cover)

d) Dcsign parameters with respec( 10 adhesion facror, carth pressurc cocfficicnl. modulus of subgrade rcaclion. elc, have been revised lo make them consis~ence w i h the outcome of modcm research and construclion praclices.

e) Minimum gradc of concrcle to bc uscd in pilc foundations has been revised to M 25.

Provisions for special use of large diameler bored casl in-siru reinforced cernenl concrele piles in marine srruclures have been added.

Bored cast k-siru pile is formcd within the ground by excavating or boring a hole within it, with or without [he aid of a temporary casing (to kccp thc holc stabilized) and subscqucntly filling it with plain or rcinforccd concrclc. These piles are parlicularly applicable in cerrain subsoil condirions where penelrarion ro rr pre- dctcrrnined deplh is essenlial.

The recornmcnda~ions for delailing for earthquake-resisranr consrruction given in IS 13920 : 1993 'Ducrile detailing of reinforced concrete structures subjecled ro seismic forces - Code of pnctice' should be taken into consideralion, where applicable (ree also IS 4326 : 1993 'Earlhquake resistant design and conslruclion o l buildings - Code of pncticc').

Thc cornposi~ion of !he Cornmitree responsible for that Formulalion of this s~andard is given in Annex G.

For [he purposc of dcciding whclher a particular requirement of this standard is cornplicd with, h e Final value, o b s c ~ c d or calculared, expressing h e result OF a lest or analysis shall be rounded off in accordance with IS 2 : 1960 'Rules for rounding off numericnl values (revised)'. The number of significan~ places remined in the roundcd off valuc should bc hc same as l h a ~ of hc spccificd valuc in h i s standard.