I.S. 4968-2 Method for Subsurface Sounding for Soils _part II - Dynamic Method Using Cone and...

7/29/2019 I.S. 4968-2 Method for Subsurface Sounding for Soils _part II - Dynamic Method Using Cone and Bentonite Slurry

1/11

IS : 4968 ( Part II ) - 1976Indian Standard ( Reaffirmed I* )

METHOD FORSUBSURFACE SO-UND-ING FOR SOILS

PART II DYNAM IC METHOD USING CONE ANDBENTONITE SLURRYf First Revision

Second Reprint JUNE 1990( Incorporating Amenrlment Ko. 1 )

UDC 624.131.381

@ Copyright 1982BUREAU OF INDIAN STANDARDSMANAK BHAVAN, 9BAHADUR SHAH ZAFAR MARG

NEW DELHI llOO@2Gr 3 April 1977

( Reaffirmed 1997


2/11

IS : 4968 ( Part II ) - 1976Indian Standard

METHOD FORSUBSURFACE SOUNDING FOR SOILSPART 41 DYNAMIC METHOD USING CONE ANDBENTONITE SLURRY

I First Revision 1Soil Engineering Sectional Committee, BDC 23

ChairmanPRor DINEBH MOHAN

RepresentingCentral Building Research Institute ( CSIR ),Roorkee

MembnsADDITIONAL DIRECTOR RESEARCH Railway Board ( Ministry of Railways )( RDSO )DEPUTY DIRECTOR RESEARCH( RDSO ) ( Alfq~~at~PROF ALAM SINQH University of J odhpur, J odhpurLT-COL AVTAR SINGR Enainecr-in-Chiefs Branch. Army HeadquartersMAJ R. R. SUD~INDRA ( Alrernatrj _DR A. BANERJ EE The Cementation Co Ltd, CalcuttaSHRI S. GUPTA ( Alternate )SHRI K. N. DADINASear A. G. DASTIDARSH~ R. L. DEWAN*DR G. S. DHILLON

In personal capacity ( P-820, #P, New Aliporc,Calcutta 700053 )In personal capacity ( 5, Hungerford Court, 12/lHungerford Street, Calcutta 700017 )I rrigation ResearchInstitute, Khagaul, PatnaIrrigation Department, Government of PunjabRESEAIWH OFFICER ( SBILS)( IPRI ) ( Altcrnatc)SHRI A. H. DIVANJ I Rodio Foundation Engineering Ltd; and Haaarat &Co, BombaySnnr A. N . J ANGLE ( Alkrnntc )DR SHASHI K . GUL HATI Indian Institute of Technology, New DelhiDR G. V. RAO ( Alternate )SHRI V. G. H~GDP: National Buildings Organization. New DelhiSERIS. H. BALCIXANDANI Alfcrnafe )

( Continued on page 2 ),*Also represents Indian Geotechnical Society, New Delhi

BUREAU OF INDIAN STANDARDSThis publication is protected under the Indian CopyIighf Acf ( XIV of 1957 ) andreproduction in whole or in part by any means ucept with written permission oftbe publisher shall be deemed to be an infringement of copyright under the said Act.


3/11

IS : 4968 ( Part II ) - 1976

.

( Cunlinued rom page 1 )Members

%IIltI 0. P. hfALHoTltASHRI J. S. MAXYARepresenting

Public Works Department, Government of PunjabRoads Wing, Ministry of Shipping and Transport,New DelhiSHRIN. Sm ( Alternate )SJlltI C. D. h~XJXiUJ~ Public Works Department. Government of UttarPradesh -Srnu D. C. CHATURVEDI ( Alternate ).~JllZI R. S. MELKOTP Central Water Commission, New Delhi

SJ I RI c. SUDlifNDRA ( AhWIUf~ )SIIRI I. K. NXWKAJAN Central Road Research Institute ( CSIF ) , New DelhiREPXIQS~NTATI~ERESEAJKJX OFFICER Hindustan ~nrtruc~ti;d~ Lg;rcthbay Building e Laboratory,ChandinarhDJ Z K. R. S~SZ;XA Engineering?&earch Laboratory, HyderabadSECI:PTAI~Y Central Board of Irrigation & Power, New DelhiDI.:PUTYSECI~ET.ARY ( Alfcrnafe )+Dr: SXIAXIYHER R.\KASH University of Roorkee, RoorkeeDa GOP~L R;\NJ,~x ( :lltemate )Slit31 l-1. D. S~~AI~>IA Irrigation Research Institute, RoorkeeSCPEJHNTE~UI~G ENGINEER Publi;adorks Department, Government of Tamil

Es~r.rj~~cls ENCXEER ( Alfernofe )SJIRI B. T. Uswlmca Concrete Association of India, BombaySJII~~ I. hf. hfr:soN ( 9lfernatc )Slllrr H. c. VLxx4 All India Instruments Manufacturers & DealersAssociation, BombaySJ IRI V. K. Vnsvn~va~ ( Altcrnntc )SirI I). I\.IITHA 1jIXH.4, Director General, IS1 ( Es-oficio Member )L)irector ( Civ Engg )

SHRI G. RAMANDeputy Director ( Civ Engg ), IS1

Site Exploration and Investigation foi FoundationsSubcommittee, BDC 23 : 2

Convener5nn1 R. S. MELKOTE

MembersCentral Water Commission, New Delhi

SHRI C. STJDIXINDRA Allernate toShri R. S. Melkote )PROF ALAM SINOS University of Jodhpur, JodhpurLT-COL A~TAX SINGE Engineer-in-Chiefs Branch, Army HeadquartenMAJ R. R. SUDHI~DBA ( Allnnolr )( Continuednpage9 )

*Aho repmenu Institution of Engineers (India 1, Delhi Ccntre.2


4/11

IS : 4968 ( Part I I ) ,- 197 sIndicin Standard

METHOD FORSUBSURFACE SOUNDING FOR SOILSPART II DYNA MIC METHOD USING CONE ANDBENTONITE SLURRY

tFirst Revision 10. FOREWORD

0.1 This Indian Standard ( Part II ) ( First Revision ) was adopted bythe Indian Standards Institution on 22 December 1976, after the draftfinalized ~bythe Soil Engineering Section&l Committee had been approved.by. the Civil Engineering Division Council.0.2 Dynamic cone penetration test is a simple device for probing the soilstrata and it has an advantage over the standard penetration test thatmaking of a bore hole is avoided. Moreover, the data obtained by cometest provides a continuous record of soil resistance. The resistancejv,, ( ne Note ) to penetration in terms of blows per 30 cm of penetrationof the cone specified in this standard and developed by the CentralBuilding Research Institute, Roorkee, has been co-related quantitative1to the standard penetration value N obtained in accordance wityhIS:2131-1963*. Studies with a view to establish a definite co-relation-between flrbr and N values for different regions of the country are.inprogress. The Sectional Committee responsible for the preparation ofthis standard decided to publish this standard in the meantime so thatit could serve as a basis of test to various investigators and others engagedin subsurfacd exploration for foundations and thus make the results ofinvestigations comparable.

NOTE - The resistance to penetration in the standard penetration test ( IS : 2131-19635 ) shall be designated as N, that to a 50 mm con: [ scs IS : 4968 ( Part I )-1976t 3 as $,d an4 that to a 62.5 mm cone using bentonite slurry as h&r.0.3 This standard was first published in 1968. In this revision several.changes have been made taking into consideration thC experience gainedin conducting the test and in the manufacture of the equipment. Themajor changes made relate to the material of the cone and the hammer,

*Method for standard penetration test for soil:.tMcthod for subsurface soundinff for soils: Pat t I Dynamic method using 50 mm conewithout bentonite slurry. (firrf rrrisia ).3


5/11

PS ; 4968 Part II ) - 1976and the criteria for stopping of the driving of the cone. The diameter ofthe cone has been changed to 625 mm and the provision permitting theuse of cones of other diameters has been withdrawn. Additionalinformation has been given on the bentonite slurry used in the test.Correlations between J Vebr nd N values have also been included.0.4 Correlation between. cone penetration values obtained using 625 mmcone ( J Vcar , and penetration values obtained by-other methods may be*developed for a given site by conducting the latter tests adjacent( about 3 to 5 m ) to the location of the cone test. However, for mediumto fine sands the following relationships between the standard penetration,value (N) obtained in accordance with IS : 2131-1963* and the conepenetration value ( Ncer ) in accordance with method specified in thisstandard [ IS : 4968 ( Part II ) ] have been developed by the CentralBuilding Research Institute, Roorkee. These relationships when utilizedshall be used with caution.

a) When the 625 mm cone is driven dry up to 9 m (withoutbentonite slurry ):x cbr = l-5 X . . ..up to a depth of 4 mN cbr = 1.75 N_....for depths of 4 to 9 m

b) When the 62.5 mm cone,is penetrated by circulating slurry:J vbc =N

0.5 In the formulation of this standard due weightage has been given tointernational co-ordination among the standards and practices prevailing.in different countries in addition to relating it to the practice in the fieldin this country.,0.6 In reporting the result of a test or analysis made in accordance withthis standard, if the final value, observed or calculated, is to be roundedoff, it shall be done in accordance with IS : 2-1960t.

-1. SCOPE1.1 This standard ( Part II ) covers the procedure of dynamic..driving ofa 62.5 mm cone and thereby obtaining a record of resistance of the soil.The cone is directly driven into the ground and for eliminating thefriction on the driving rods bentonite slurry is used. The use of bentoniteslurry may not be necessary when the investigation required is up to adepth of 6 m only.

*Method for standard penetration test for soils.tRuler for~roundiug off numerical values ( rovisrd ).4


6/11

IS t 4968 (Part II ) l 19762. EQUIPMENT2.1 cone -The cone shall be of suitable steel with the tip hardened.The dimensions and the shape of the cone shall be as given in Fig. 1.The cone should be suitably threaded to enable it to be attached toA rods used for driving.

VANES

ASIZE DRILL ROO

VANESIN THE PLACEOF VANES GRAVELTRAP MAY BE P~vloED 1

FIG. I CON& Ass&hL5


7/11

IS :.4968 ( Part II ) - 19762.2 Driving Rods - The rods used for the test should be A rods ofs_uitable lengths with threads for joining A rod coupling at either end.The rods shouid be marked at every 100 mm.

NOTE - The OUIW and internal diameter of A rods are 4127 and 28.57 mmrespectivrly.2.2.1 Fonr mildsteifv&es as show&in Fig. 1 (see also 2.6 ) shall bewelded to the driving rod immediately above the cone. .4s an alternative,a gravel trap about 150 mm high of wire gauze of 5 mm mesh may beprovided on the rod immediately above the cone.

2.3 Driving Head -The driving head shall be of mild steel withthreads at either end for A rods coupling ( set Note under 2.2 ). It shallhave a diameter of 100 mm and a length of 100 to 150 mm.2.4 Hoisting Equipment - Any &table hoisting equipment, like atripod may be used. The equipment shall be designed to be stable underconditions of impact of the hammer over the driving head when the coneis driven during the test. Provision shall be made to enable the operatorto climb up the equipment for fixing the pulley, ropes, etc. A typical setup using a tripod is shown in Fig. 2. Suitable guides shall be providedfor keeping the driving rods vertical and in position.2.5 Hammer -The hammer used for driving the cone shall be of mildsteel or cast iron with a base of mild steel. It shall be 250 mm high andof suitable diameter. The weight of the hammer together wirh the chainshall be 65 kg. It shall have a hole at the centre running throughout itslength and of suitable diameter for the A rod ( see Note under 2.2 ) and/orguide to pass freely through it. The clearance between the rod and/orguide and the hole in the hammer,shall be about 5 mm.

NOTE - An automatic arrangement for controlling the drop of the hammer may bepreferred if available.2.6 Pumping Unit for Bentonite Slurry - It consists of slurry pumpof capacity 35 to 45 l/min at a pressure of 700 to 850 kN/m* ( 7 to85 kgf/cm2 ) with a suction hose assembly and a swivel assembly. Forbetter circulation of slurry at greater depths a vank borer consisting offour vanes and a number of drill holes for the escape of slurry may beprovided in between the driving rod and the cone (see Fig. 1 andFig. 2 ).

i 3. PROCEDUREi , 3.1 The vane shall be connected to the driving rods, with the vaneborer/gravel trap in position. The driving head with the guide rod shallbe fixed on the driving rods. This assembly shall be kept in position withthe cone resting vertically on the-ground at the point to be tested. Forthe circulation of slurry. the guide rod shall be connected te a water6


8/11

IS : 4968 ( Part II ) - 1976swivel preferably through a flexible tube connection and then throughanother flexible tube to the pumping unit for bentonite slurry. Theswivel assembly shall be held in position by a rope passing over the pulleyp,rovided for that purpose. The slurry tank shall be filled with bentoniteslurry of suitable consistency ( see Note ). The slurry should generallybe prepared separately and stored in drums. The tank end of the inlettube to the pump shall be provided with suitable protection againstentry of debris and it shall be kept immersed in the slurry tank. Thehammer, to which a rope has been attached for operation, shall be slidover the guide rod, to rest on the driving head. A typical assembly ofthe equipment for test using a tripod is shown in Fig. 2.

NOTE - In the case of medium to fine sand, 5 percent bentonite slurry has beenfound useful, In the case of coarse sand, slurry of thicker consistency subject tocirculation requirements may be needed. In the case of hard water, addition of1 percent soap solution has been found useful to get a better ~suspension of thebentonite.

3.2 The cone shall be driven by allowing the 65 kg hammer to dropfreely through a height of 750 mm on the driving head. A drum typewinch fixed to central leg of the tripod may be used for lifting the dropweight provided the free fall of the hammer is not affected. The drivingof the cone and the pumping in of the slurry shall be startedsimultaneously. Driving shall not be done for more than 30 cm at atime after which it shall be stopped for a minute or two. Pumping shall,however, be continued. This helps in keeping the hole lined and alsoavoids the choking of the holes provided in the cone. The driving rodsshall be given a few turns ( about 4 or 5 turns ) every now and then sothat the hole above the cone is maintained. Efficient circulation ofslurry is necessary for eliminating friction on the rods. The number ofblows for every 100 mm penetration of the cone shall be recorded. Theprocess shall be repeated till the cone is driven to the required depth(.sec Note ).NOTE - In order to avoid damage to the equipment, driving may be stopped whenthe number of blows exceeds 35 for 100 mm penetration when the cone is driven dryand 20 for 100 mm penetration when the cone is penetrated by circulating slurry.

4. REPORT4.1 The number of blows ( .MOb, should be reported as a continuousrecord for every 300 mm penetration either in a tabular form or as agraph between Near and depth. Records of the test shall also includethe following:

-a) Date -of probing;b) Location;c) Elevation of ground surface;

7


9/11

IS:4966 (Part lI)-1976d) Depth of water table and its likely variation, from availableinformation;e) Total resistance at the required levels;f) Any interruptions in probing with reasons;g) Any other information available, for example, type of soil; and -h) Diameter of the cone used in the tgst.

LSLURRYANK

DRLVING ROD

CONE

FIG. 2 A TYPICAL SET UP FOR DYNAMIC CONE PENETRATION TEST8


10/11

IS : 4968 ( Part II ) - 1976( Continuedfrom page 2 )

Members RepresentingDa A. BANEBJEEDR A. K. CHATTERJ EE Cemrntation Company Ltd, BombayPubl;lcrad~~ks Department, Government of UttarSHRI R. C. DESAI Rodio Foundation Engineering Ltd; and Hazarat &Co, BombayDEPUTY DIR_ECT~R RESEARCHRailway Board ( Ministry of Railways )

( F21z2 ) DIRECTORRESEARCH ( SOILS( RDSO ) ( AltematcjDIRECTORRESEARCH FFICER AItemateDIRECTOB ENERALSHRI S. K. SHOME Afternate )SE.BI P. N. MEHTA Alternate )EXECUTIVE ENGINEER ( SOILMECHANICS IVISIONSHRIT. K. NATARAJANSHRIH. R. PRAMANIKSH~ H. L . SAHA ( Altemab )REPICESENTATIVESaar N. SEN

Maharashtra Engineering Research Institute, Nasik)Geological Survey of India

Publiadorks Department, Government of TamilCentral Road Research Institute ( CSIR ), New DelhiRiver Research Institute, West BengalHindustan Construction Co Ltd, BombayRoad~ewW~n~Mmntry of Shppmg & Transport,

SHRI P. K. THOMAS Alternate )SUPERINTENDINQURVEYOR0~ Central Public Works Department. New DelhiWORKS I )SHRI D. SHAIUKA Cent~~or~e$lding Research Institute ( CSIR ),Sasr V. S. ACXXARWALAlternate )SHKI H. C. VERU Associated Instruments Manufacturers ndia Pvt L td,New DelhiPztos T. S. NAGARAJ Ahnate )

9


11/11

BU REAU OF IN DIAN STAN DARDS .Headquerters:Manak Bhavan, 9 Bahadur Shah tafar Marg, NEW DELHI 110002Telephones: 331 01 31, 331 13 75 Telegrams: Manaksanstha( Common to all Offices )Regional Offices: TelephoneCentral : Manak Bhavan, 9 Bahadur Shah Zafar Marg. 331 01 31NEW DELHI 110002 I 337 1375*Eastern : l/l 4 C. I. T. Scheme VII M, V. I. P. Road, 36 2499Maniktola, CALCUTTA 700054Northern : SC0 445-446, Sector 35-C,

I21843CHANDIGARH 160036 3 1641

I41 24 42Southern : C. I. T. Campus, MADRAS 600113 41 25 1941 2916tWestern : Mamkalaya, E9 MIDC, Marol, Andhdri ( East ), 6 32 92 95BOMBAY 400693.

Branch Offices:OPushpak. Nurmohamed Shaikh Marg, ~Khanpur,AHMADABAD 380001 I2 63 482 63 49+,Peenya Industrial Area 1st Stage, Bangalore Tumkur Road I38 49 55BANGALORE 560058 38 49 56

Ganaotri Complex, 5th Floor, Bhadbhada Road, T. T. Nagar, 6 67 16BH~PAL 462003Plot No. 82/83. Lewis Road. EHUBANESHWAR 7510025315. Ward No. 29, R.G. Barua Rose, 5th Byelane,GUWAHATI 7810035--8--56C L. N. Gupta Marg ( Nampally Station Road ),HYDERABAD 500001R14 Yudhister Marg. C Scheme, JAIPUR 302005

117/418 B Sarvodaya Nagar. KANPUR 208005634716 98 3221 68 7621 82 926 23 05atliputra Industrial Estate, PATNA 800013T.C. No. 1411421. Universitv P.O.. Palayam 16 21 04TRIVANDRUM 695035 16 21 17

Inspection Offices ( With Sale Point ):Pushpanjali. First Floor, 205-A West High Court Road, 2 51 71Shankar Naaar Sauare, NAGPUR 440010

5 36 273 31 7723 1083

Institution of Engineers ( India ) Building, 1332 Shivaji Nagar, 5 24 35PUNE 411005l aIosOffice in Calcutta is at 5 27 09 00Street. Calcutta 700072 Chowringhoe Approach, P. 0. PrinceptSaler Office in Bombay is at Novrlty Chambr$, Grant Roti, 99 85 299ombav 400007$Sales Office in Bangalore is at Unity Building, Nsr&mhwrjr Squaw, 22 36 71Bangalore 560002

Reprography Unit, BIS, New Delhi, India

I.S. 4968-2 Method for Subsurface Sounding for Soils _part II - Dynamic Method Using Cone and...

Documents

Transcript of I.S. 4968-2 Method for Subsurface Sounding for Soils _part II - Dynamic Method Using Cone and...