IS 2720 4 1985

IS : 2720 ( Part 4 ) - 1985Indian Standard ( Reaffirmed 2006 ) METHODS OF TEST FOR SOILS PART ( 4 GRAIN SIZE ANALYSIS Second Revhion ) Second Reprint SEPTEMBER UDC 0 BUREAU MANAK 624’131’431’6 Copyrfghf 1986 OF BHAVAN, INDIAN 9 NEW GI 8 1994 BAHADUR STANDARDS SHAH ZAFAR MARG DELHI-110002 Jumuzrv 1986 IS :2720 (Part 4) - 1985 Indian Standard METHODS OF TEST FOR SOILS PART 4 GRAIN SIZE ANALYSIS ( Second Revision) 0. FOREWORD 0.1 This Indian Standard ( Part 4) ( Second Revision ) was adopted by the Indian Standards Institution on 25 January 1985, after the draft finalized by the Soil Engineering Sectional Committee had been approved by the Civil Engineering Division Council. With a view to establishing uniform procedures for determination of different characteristics of soils and also for facilitating comparative studies of the results, this standardon methods of test forsoils ( IS : 2720 ) is being issued in parts. This part which was originally published in 1965 and revised in 1975 deals with the method for the determination of grain size distribution in soils. An analysis of this kind express quantitatively the proportions by mass of the various sizes of particles present in the soil. In a soil the gravel, sand silt and clay fractions are recognized as containing particles of decreasing magnitude. The actual range of dimensions of the particles are given in IS : 1498-1970*. The results of a grain size analysis may also be represented graphically in the form of a grain size distribution curve in which the cumulative percentages finer than known equivalent grain sizes are plotted against these sizes, the latter being on a logarithmic scale. The results of grain size analysis are widely used in soil classification. The data obtained from grain size distribution curves is used in the design of filters for earth dams to determine the suitability of soils for road construction. 0.2 0.2.1 In this second revision of the standard, brought in line with IS : 1498-1970+. A plummet alternative method has been included. grain sizes have been balance method as an 0.3 In reporting.the result of a test or analysis made in accordance with this standard, if the final value, observed or calculated, is to be rounded off, it shall be done in accordance with IS : 2-1960t. *Classification and ( jrsr r&km ). *Ruler for routiding identification off numerical of roil for values ( rcvirsd). 3 general engintermg purposes fS : 2720 ( Part 4 ) - 1985 1. SCOPE 1.1 This standard ( Part 4 ) covers the method determination of grain size distribution in soils. for the quantitative -1.l;l Two methods are iven for finding the distribution of grain sizes larger than 75-micron I s Sieve; the first method, wet sievings shall be applicable to all soils and the second, dry sieving, shall be applicable only to soils which do not have an appreciable amount of clay. 1.1.2 For the determination of distribution of grain sizes smaller than 75-microns the pipette method is given as the standard method; the hydrometer method is given as a subsidiary method. This method shall not applicable if less than 10 percent of the material passes the 75-micron IS Sieve ( determined as given in 4 ). 2. TERMINOLOGY 2.1 For the purpose of this IS : 2809-1972. shall apply. 3. FIEVE ANALYSIS 4.75 mm IS SIEVE standard, the OF SOILS FRACTION (DRY METHOD ) definitions given RETAINED in ON 3.1 Apparatus 3.1.1 Balance - sensitive to 0.1 percent of the weight of sample to be weighed. 3.1.2 Sieves- IOO-mm IS Sieve, 75-mm and J-75-mm IS Sieve conforming ’ 4 : 460 ( Part 1 )- 1978t. IS Sieve, 19-mm IS Sieve to the requirement of 3.1.3 Rubber Pestle and Mortar 3.2 Preparation of Sample -The soil sample received from the field shall be prepared as specified in IS : 2720 (Part 1 )-1983:. The soil fractions retained on and passing 4’75-mm IS Sieve shai. be taken separately for the analysis. - The portion of the soil sample retained on 4*75-mm 3.3 Procedure IS Sieve, selected as given in 3.2, shall be weighed and the mass recorded *Glossary of terms and symbols relating to soils mechanics (fist reotiion ). *Specification for test sieves : Part 1 Wire cloth test sieves ( suondrcuirion ). :Methods of test for soils: Part 1 Preparation of dry soil sampler for va:iour ( rrcond w:’ :e?I) . 4 tests 1985 the mass of the sample uncorrected for hygroscopic moisture.2. if necessary.mm 4 2 475 mm 1’0 0’5 The mass of the material retained on each sieve shall be recorded.1. Any particles may_ be tested to see if they will fall through but The material from the sieve may be Ihey shall not be pushed through.5 1. the to be obtained from the analysis.5 12’5 3. Other sieves may be introduced between the sieves mentioned in 3. the water content of the material shall be determined in accordance with 5 . with the rubber pestle in the mortar taking care to see that individual soil particles are not broken and re-sieved to make The quantity taken each sure that only individual particles are retained. sieve shall be agitated so that the sample rolls in irregular motion over the Sieve. as NOTE quantities 1 -Depending on thr maximum size of material in the soil.13 depending upon the additional information that may be desired While sieving through each sieve.5 0.5 10 6. the mass of soil sample taken for analysis present in substantial may be as follows: Mass to be taken Moxit~m Size of Material Present in Substnntiol Quantities mm for Test kg 75 60 40 25 25 13 19 6. time for sieving on each sieve shall be such that the maximum weight of material retained on each sieve at the com$etion of sieving does not exceed the values given in Note 2. The sample shall be separated into various fractions by sieving through the Indian Standard Sieves specified in 3. If the sample appears to contain over 5 percent moisture. rubbed. The quantity of the soil sample~taken shall depend on the maximum particle size contained in the soil ( see Note 1 ).IS t 2720 ( Part 4) .75 4-75 0’4 weight of material NOTE 2 -Maximum completion of sieving shall be as follows: to be retained IS Sirrc Dtsignahon 450~mm Dia Simgs kg on each sieve at the 300~mm ~Dia &L&S kg 80-mm 15 6 20. 1.1985 When IS : 2720 ( Part 2 )-1973” and the masses corrected accordingly. the gravel shall be washed on 4*75-mm IS Sieve using sodium hexametaphosphate solution. or more large metal or plastic watertight 4. if necessary.2 Siems .1. If the soil contains more than about 20 percent gravel particles and the fines are very cohesive with considerable amounts adhering to the gravel after separation.IS m:2720 ( Part 4 ) .1.1. 4. and 75-micron IS Sieve. For further analysis a fresh portion of the fraction passing 4’75-mm IS Sieve shall be taken.4 Calculations .6 Mortar with a Rubber Cove+ Pestle 4. The sieves should be periodically checked up for aperture sizes. tspecificationfor test aiever: Part 1 Wiro clofh tentliev*m ( suodr&rion ). Sensitive to 0. 3.1.The percentage of soil retained on each sieve shall be calculated on the basis of the total mass of soil sample taken and from these results the percentage passing through each -of the sieves shall be calculated.8 Rt@r -- *Methodsof test for Ioils:Part 2 Determinationof water content ( rrcmdr&&m). 4. 4.5 Brushes - sieve brushes and a wire brush or similar stiff brush. 6 .1 Balance weighed.The following Indian Standard IS : 460 ( Part 1 )-19787: 2-mm IS Sieve.Thermostatically controlled to maintain the temperature between 105 and 1 lO”C. the sample contains less than 5 percent moisture it is not necessary to determine the water content for dry weight computations and all the determinations may be made on the basis of wet weight only.1.1.1 percent of the mass of sample to be 4. with interior of non-corroding material. 4.3 Oven.4 Trays or Bucket -two trays or a bucket about 30 cm in diameter and -30 cm deep ( convenient sizes of the trays are in the range of 45 to 90 cm” and 8 to 15 cm deep ).1. 425-micron Sieves conforming to IS Sieve.1 Apparatus 4.7 Mechanical Sieve Shaker ( Optional ) 4. SIEVE ANALYSIS OF SOIL PASSING +75 AND RETAINED ON 75-MICRON IS SIEVE mm IS SIEVE 4. not overlbaded in the process ( see Note 3 ). tSpecification for sodium carbonate.The portion of the soil passing 4*75-mm IS Sieve obtained as given in 3.2 correspond to the limits of coarse.1. The fraction retained on each sieve should be weighed separately and the masses recorded. Care shall be taken to see that the sieves are sieve is substantially clean. anhydrous (second rcuision ). --1985 pure ) or a ) and sodium ) or any other 4. just passes the 4’75-mm IS Sieve or less The fraction shall be weighed too-1 percent if the largest size is smaller.The amount of dispersing-agent may be varied depending on the type of soil.The sieves listed in 4. The mix should be thoroughly stirred and left for soaking. NOTE 1 .3. The oven-dried material shall then be riffled so that a fraction of This shall be about 200 g if a substantial convenient mass is obtained.1. $Classification and identification of soils for general engineering (Jrsr reLGwl ) . The riffled and weighed fraction shall be spread out in the large tray or bucket and covered with water.1 Analysis by Wet Sieving . A dispersing agent may not be required in the case of all soils. Alternatively.2 (see Note 2 ) either by hand or by using mechanical sieve shaker. *Specification for sodium hydroxide.1. 7 purposes . and the masses recorded. The soil soaked specimen should be washed thoroughly over the nest of sieves specified in 4. 4. of its total mass and the mass recorded. The fraction retained on the sieve should be tipped without loss of material in a try.3 Procedure 4. analytical reagent ( second reui~ion ). Other sieves may be introduced depending on the additional information that may be desired to be obtained from the analysis. proportion of the material only.. NOTE 2 .3.2 shall be oven-dried at 105 to 110°C.sodium hexametaphosphate ( chemically mixture of sodium hydroxide ( conforming to IS : 376-1976* carbonate ( analytical grade conforming to IS : 296-19747 dispersing agent which has been found suitable. dried in the oven and sieved through the nest of sieves specified in 4.1 Two grams of sodium hexametaphosphate or one gram of sodium hydroxide and one gram of sodium carbonate perlitre of water used should then be added to the soil ( see Note 1 ). medium and fine sand specified in IS : 1498-1970$. in such cases the wet sieving may be carried out without the addition of dispersing agent.IS:2720 (Part4) 4.1.2 Reagents . The fraction retained on each sieve should be emptied carefully without any loss of material in separate Oven dried at 105 to 110°C and each fraction weighed separately trays.2 ( see Note 2 ) nested in order of their fineness with the finest sieve ( 75-micron IS Sieve ) Washing shall be continued until the water passing each at the~bottom. the soaked soil specimen may be washed on the 75-micron IS Sieve until the water passing the sieve is substantially clean. No .1. 5. The combined gradation on the basis of the total soil sample taken for analysis shall then be calculated.2 shall be oven-dried at 105 to 110°C and weighed to 0.particle shall be pushed through the sieve. The amount retained on the sieve shall be weighed.on the sieve. The soil fraction retained on each sieve shall be carefully collected in containers and the mass of each fraction determined and recorded.1985 N~%TE 3 .1 Pipette Method ( Standard Method ) 5.4 Calculation .1.2. 4. The material retained on the sieve shall be rubbed with the rubber pestle in mortar in re-sieved to make sure that only individuaA particles are retained .0 In the case of clayey soils this method shall not be used. The percentage of soil fraction retained on each sieve shall be calculated on the basis of the mass of the sample passing 4’75-mm IS Sieve taken for the initial analysis. The sieve or sieves shall be agitated so that the sample rolls in irregular motion over the sieve.5micron 4.3.2. GRAIN SIZE ANALYSIS OF THE FRACTION 75-MICRON IS SIEVE OUT OF THE PORTION 4’75-mm IS SIEVE PASSING PASSING 5.2 Analysis on the 2@mm 200 50 25 by Dry Sieving 4. A minimum of 10 minutes shaking shall be used.3 ( see .1.1 The portion of thesoil passing 4. wet sieving shall be used.3.Note 2 of 4.3.The cumulative mass of soil fraction retained on each sieve shall be calculated.3.3. The material retained in the receiver shall be transferred to a steel tray and the receiver fitted to the nest largest sized sieve. The contents of the steel tray shall then be placed on this sieve and the operations indicated above repeated.75-mm IS Sieve obtained as in 3. These operations shall be repeated through all the sieves specified in 4. 4.IS : 2720 ( Part 4 ) .The permissible sieves shall be as follows: maximum mass of sample IS S&c Design&m diameter Madmum Mass of Sum& II Z-mm 425-micron 7.1.1 ).1 percent of its total mass.0 This method is not applicable if less than 10 percent of the material passes 75-micron IS Sieve as obtained in 4. Care shall be taken to ensure that sieving is complete. 8 . If a mechanical shaker is available these-tests may be performed in one operation. plastic or hard rubber. The shaft shall be of such length made of metal.1 Samplingpipcttc .of the type illustrated in Fig. The bottles or crucibles shall be weighed to the nearest 0.001 gram. -5.Any other suitable dispersing dswice.1.8 Oven . 5.1. The motion of the soil suspension shall be su!Kcient ~to mix the contents thoroughly but it shall not be so vigorous that the particles will be crushed or lost through splashing. fitted with round stoppers or crucibles with suitable lids approximately 25 mm in diameter and 50 mm high. e .1 Apparatus 5.3 Weighing bottles .o 5.1.1.required number. temperature and air-jet dispersing be used.IS : 2720( Part 4 ) .4 Constant temperature bath -.capable of being maintained at 27 f O*l”C. 3 shall be provided to hold-the sample while it is being dispersed.6 Siwes - 2-mm. 4).1. NOTE . The container and baffles shall be of such material as will not be attacked by the reagents placed in the container.2 Glass sedimentation tubes . neither shall it be so sluggish as to leave unmixed material in the bottom of the container. device 5.1. 5.1.5 Stirring apparatus . into which the sedimentation tube can be immersed up to The bath shall not vibrate the sample ( optional ).1.7 Balance -to 75-micron weigh up to 0. The’pipette shall be so arranged that it can be inserted to a fixed depth into a sedimentation tube when the latter is immersed in a constant temperature bath ( see also Fig.thermostatically controlled to maintain of 105 to 1 lO”C.a minimum of two of 50 mm diameter and approximately 350 mm long marked at 500mml volume with rubber bungs to fit.a mechanical ~stirring device in which a suitable mounted electric motor turns a vertical shaft at a speed of 8 000 to 10 000 rev/min when loaded.1.1. A specia! dispersion cup conforming to either of the designs shown in Fig. that the stirring paddle will operate neither less than 20 mm nor more than 35 mm above the bottom of the dispersion cup.1.1.001 g. 5. 1 fitted with a pressure and suction inlet and having a capacity of approximately 10 ml. such as mrchanical which produce comparable disprrsion bottle shaker of the soil may 425-micron.1. will interior of non-corroding material.1. 5.1. 500 ml mark. ak.1.1985 5. 2 and. ‘IS Sieves and receiver. The shaft ihall be equipped with a replaceable stirring paddle of either of the types shown in Fig.1. FIG.IS t 2720 ( Part 4 ) . All dimensions in millimetres.Bore of tube to be 4 mm 4 where possible.1985 BUB CAPACITY NOTE .1 SAMPLING PIPETTE 10 . 3.IS : 2720 ( Part 4 ) . DISPERSION Curs 11 BRASS BASE-I cb . 2 STIRRING PADDLES FOR STIRRING APPARATUS BAFFLE RODS- . PLAN All dimensions in millimctres. FIG..1985 CHROMIUM PLATED 7 PUNCH 54or02 1*25mm THiCK SHEET --_I_ -7 All dimensions in millimetres..*-. . FIG. 1.21 Glass rod .1.12 Cortical beaker .22 5.89 ml of concel. 5.1. ( about 500 ml ).1.1.Dissolve 33 g of sodium hexametaphosphate and seven grams of sodium carbonate in distilled :Nafcr to make one litre of solution.This solution is unstable and shall be freshly prepared approximately once a month.IS : 2720 ( Part 4) .Sollltion hexametaphosphate has been found to be ineffective when d.1.1.9 Sbl.1.10 Desiccator 5.1.18 Wash bottle - about containing 10 cm distilled in diameter.Buchner 5.1. 100 ml capacity.2.15 Measuring cylinder 5.a!ing with certain highlv flocculated soils. shall be of analytical 20 volume quality.1985 5. accurate The reagents Hydrogen peroxide - to 0*5+X. agent 12 which has been proved suitable fat .X.1.1.1 0 to 5O”C.14 Filter flask - ml or one litre or Hirch to take the funnel 5. SOYE 3 -Any other dispersing dispersing soils may be Gsed. In such cases incomplete dispersion obtained is indicated by the formation of relatively large crumbs or flocks of soil which fall rapidly through the water leaving a sharply defined clear Inyrr above the suspension and in such cases dispersion may be carried out by adding N sodium hydroxide solution at the rate of 4 ml per 10 g of soil.1.1. NO.. 5.1.about 15 to 20 cm long.650 glass to fit and a smaller beaker. .13 Ftct~~cl-.1. 5.16 Pipette - about capacity and a cover 7 cm in diameter.11 Evuvclpcratingdish 5.YGTE 1-.1.2.19 Filter papers 5.1. water. 4 to 5 mm in diameter fitted at one end with a rubber policeman.1.1.I*E2 .2.18 ) diluted with distilled water to make one litre of solution. 5.1. 5.1.3 Sodium hexametaphosphate solution .1. The datp of preparation shall be recorded on the bottle. solution. zmfc-h 5.1.2 Hydrochloric acid approximately N solution .13 Thermometer - Reagents - 5. 5.1.1.1.trated hydrochloric acid ( specific gravity 1. 25 ml capacity.1.1.20 Blue litmus pape: 5.17 Glass jilter j%nnel 5J. 1.4. From this mass the internal volume ( Vr ml) of the pipette and the tap shall be calculated to the nearest 0’05 ml.1.1985 5. 50 g with a sandy soil and about 20 g with a clay soil.1. The actualmass of soil required may vary according to the type of soil. 5. shall be followed for further analysis. 4).1.) and placed in the 650-ml conical beaker. After cooling 75 ml of hydrogen peroxide shall be added and the mixture allowed to stand overnight *Methods of test for soils: Part 21 Determination of total soluble solids (jirst revisit ).2. The other sample shall be sub-divided by #fling.1977*.1.1 has been collected. 50 ml of distilled water shall be added to this and the soil suspension gently boiled until the volume is reduced to about 40 ml.3 and 5. In case it is more than one percent.3. 5. The water contained in the pipette and tap E shall be discharged into a glass weighing bottle of known mass and the mass determined.3 Procedure 5.3.The percentage of soluble salts in the soil shall be determined as specified in IS : 2720 ( Part 21 ) . the soil shall be washed with water before further treatment taking care to see that soil particles are not lost (see Note 1). 5. Fig.0 If the soil fraction passing 75-micron IS Sieve during wet sieving specified in 4. By means of a rubber tube attached to C. Where necessary.2 Prc-treatment cfsoils .3. Three determinations of the volume shall be made and the average taken. The tap E shall be ciosed and Surplus water drawn up into the the pipette removed from the water.3. this can be oven-dried and used for pipette analysis.3. The other relevant portions of the procedure specified in 5.1. cavity above E’ shall be poured off through F into the small beaker by opening the tap E in such a way as to connect D and F.3. provided the soil has been pre-treated as specified in 5.1. water shall be sucked up in the pipette until it rises above E.The sampling pipette shall be thoroughly cleaned and dried and the nozzle shall be immersed in The tap B shall be closed and the tap E opened ( see distilled water. 13 . This sample shall be weighed to O*OOl g ( W. tMethods of test for soils: Part 2 Determination of water content ( second r&ion ).1 Calibration of sampling Pipette .3.1. the oven-dried fraction shall be powdered in a mortar with a rubber covered pestle taking care that the individual grains are not crushed.riflling from water content ( w ) of one sample shall be prescribed in IS : 2720 (Part 2 )-1973t.1. The determined by the method the soil passing 4’75-mm IS Sieve obtained as about 30 g shall be obtained by. 25 to 50 g ( depending on the soil type) of this soil shall be used for the andlysis.3. 85.1.IS : 2720 ( Part 4) .3. Two samples out of described in 32 weighing the bulk sample. if necessary.1985 covered with cover glass. Lateritic soils will also be attacked by the acid but unless they need not be given the acid treatment.3 direct to the soil taken for analysis. therefore. The dish and contents shall be dried in an oven maintained at 105 to 110°C.1. be necessary to adopt different methods of treatment with these and other soils having similar special characteristics. NOTE 1 . help. In the case of soils containing no calcium compounds or soluble salts and having a low organic content ( less than 2 percent ) the pretreatment prescribed may be omitted and the dispersing agent shall be added as prescribed in 5. The mass of the soil remaining a~fter pretreatment shall be recorded ( wb ). The solution shall be stirred with a glass rod for a few minutes and allowed to stand for about one hour or for longer periods. for shall be 14 carried out only soils containing . The wet soil on the filter paper and funnel shall be transferred without any loss whatsoever to the glass evaporating dish ( weighed to 0.Acid treatment insoluble calcium salts. The mixture after pre-treatment with peroxide and acid or acid alone shall be filtered using the Buchner or Hirch funnel and washed with warm water until the filtrate shows no acid reaction to litmus. As soon as vigorous frothing has subsided and when there is no further reaction by the addition of fresh hydrogen peroxide.Owing to~the removal of calcium. The suspension shall then be gently heated. The treatment shall be continued till the solution gives an acid reaction to litmus.3. they contain calcium NOTE 2 . more acid may be required. Care shall be taken to avoid frothing over and the contents of the beaker shall be agitated frequently either by stirring or by shaking the beaker.IS : 2720 ( Part 4 ) . In the case of soils containing calcium compounds ( see Note 2 ) the mixture shall be allowed to cool and about 10 ml of hydrochloric acid shall be added. the above method is not suitable for the determination of the particle size distribution in soils predominantly containing chalk or lime and it may. etc. Dispersion may be assisted by rubbing the particles of soil in the suspension againrt the side of the evaporating dish with a In some cases a longer mixing time may glass rod fitted with a rubber policeman. iron. be used. The dish and contents shall then be cooled in a desiccator and weighed to -O*OOl g.001 g ) using a Only a minimum quantity of distilled water shall jet of distilled water. If the soil contains considerable amount of calcium salts. by the acid during the pretreatment of the soil. the volume shall be reduced to about 30 ml by boiling. G . and HSedimentation tube.Sampling pipette. FIG. 1 NOTE.lS:2720(Partt)-1985 SCALE IN cm AND mm A AND Bd SLIDING PANEL\ CONSTANT TEMPERATURE BATH \ l. 4 ARRANGEMENTFORLOWERINGTHE SAMPLINGPIPETTE 15 . 4 Sedimentation .2 j ml sodium hexametaphosphate solution shall be added to the soil in the evaporating dish together with about 25 ml of distilled water and the soil brought into suspension-by stirring with a glass rod. 16 . Approximately 10 seconds shall be taken to complete this operation.1.2 and the cumulative percentages of the soil fraction retained on each sieve shall be calculated. It shall be lowered with great care some 15 seconds before the sample is due to be taken. The suspension.3 Dispersion of soil .25 ml of sodium hexametaphosphate shall be added from a pipette to a graduated 500-ml sedimentation tube ( comparison tube ) and diluted with distilled water to exactly 500 ml. such as the bottle shaker. Particular care shall be taken to wash off all traces of suspension. ml ) drawn up into the pipette. The suspension shall then be transferred to %micron IS Sieve placed on a receiver and the soil shall be washed on this sieve using a jet of distilled water from a wash-bottle. Any soil adhering to the dish shall be rubbed off with the rubber policeman. The rubber bungs shall then be carefully removed without agitating the tubes.Any other suitable stirring device other than the one specSed in 5.1. NOTE . They shall then be replaced in the apparatus. The tap E shall be opened and a sample The pipette and the bore in the tap ( V. may be used and the stirring time shall be adjusted suitably.1985 5. that has passed through this sieve shall then be transferred to _the sedimentation tube using the glass funnel and the volume of liquid is made up to 500 ml with distilled water. The pipette with the tap E closed shall be lowered vertically into the soil suspension until the end is 100 & 1 mm below the surface of the suspension. The material retained on the 75-micron IS Sieve may be oven-dried and treated as prescribed in 4.3.3. adhering to the dispersion cup. the rubber bungs inserted and the tubes allowed to stand until they have reached the The tubes with their contents shall then be temperature of the bath.1. This sedimentation tube together with the tube containing the soil suspension shall be immersed in the constant temperature bath (where used ). solution 5. The amount of water used shall not exceed 150 ml..IS : 2720 ( Part 4) . The amount of distilled water used during the operation shall not exceed 150 ml. thoroughly shaken by inverting the tubes several times.5. the temperature of the bath noted ( see Notes 1 and 2 ).3. The soil suspension shall then be stirred well for 15 minutes or longer in the case of highly clayey soils (see Note ). The mixture shall be warmed gently for 10 minutes and then transferred to the cup of the mechanical mixer using a jet of distilled water to wash all traces of the soil out of the evaporating dish.1. simultaneously starting the stop watch. 3 ( a). This procedure shall be repeated at the end of each time corresponding to particle diameters O-02 mm. NOTE 1 . therefore. Between any of the times in which the above sampling is taking place.4. 0. NOTE 2 .4.3 (a).1. The weighing bottles and contents shall be-placed in the oven maintained at 105 to 110% and the sample evaporated to dryness. The temperature shall be noted at the time of sampling and suitable correction made in the calculation of the equivalent diameter of soil grains on the basis of equation in 5.68.002 mm.IS : 2720 (Part E shall be filled ~with solution shall and tap E then closed. 0. land W.. The specific gravity of the soil fraction passing the 75-micron IS Sieve shall be determined by the method specified in IS: 2720 ( Part S/Set 1 )-1980*. the test may be performed at room temperature. W. heating of the suspension procc’ss. The suspension : Part 3 Determination 17 causes convection should. be washed into the weighing bottle by allowing distilled water from the bulb A to run through B. After each the suspension. Distilled water shall then be allowed to run from the bulb funnel A into D and out through F until no solution remains in the system. WS. of specific gravity. The mass of solid material in the sample shall be determined ( N’S ). sampling operation the pipette shall be withdrawn taking approximately 10 seconds to complete from -the During the sampling a small amount of the suspension may have been drawn up inta the bulb D above the bore of the tap E. Section currents be kepr 1 Fine . This surplus shall be washed away into the beaker down the outlet tube F by opening the tap E in such a way as to connect D land F. 0’001 mm calculated on the basis of equation given in 5. . for each respective sampling time ). operation. D and E into the pipette.1985 operation take 10 seconds to complete. This 4 ) . Table 1 gives the time of settling to a depth of 100 mm of particles of various diameters for temperatures ranging from 10 to 35°C for an average specific gravity of soil of 2.1. A tared weighing bottleshall be placed under the end of the pipette and the tap E opened so that the contents of the pipette are delivered Any suspension left on the inner walls of the pipette shgll into the bottle. a sample ( ‘/p ml ) shall be taken from the tube containing the sodium hexametaphosphate solution.006 mm.If a constant temperature bath is not available for the test. After cooling in a desiccator the weighing bottle and contents shall be weighed to the nearest 0’001 g and the mass of the solid material in the sample determined ( WI.Asymmetrical which affect the sedimentation *Methods of test for soils grained soils (first revision ) . muss in pre-treatrwxt .It is not necessary to measure the specific gravity of every sample used for fine analysis. GI = specific gravity of water. should NOTE 3 .f direct sunlight and away from any local source of heat. .G.4 Calculations 5.IS : 2720 ( Part 4 j .The loss in mass in pretreatment of the soil in percentage shall be calculated as follows: P = 100 - Wb( 100--~-_ tw) ___. W= air dry moisture and content of the soil taken for analysis. 5. depth.1985 out c.1. It is essential that the specific gravity used is that of the fraction passing 75-micron IS Sieve. G = specific gravity of the soil fraction tation analysis. at I.1. Wb = mass of soil after pre-treatment. used in the sedimen- in g/cm’.4.3 Sedimentation a) Diameter of particle . An average value for samples from the same area or soil type in an area may be used without loss of accuracy. = coefficient of viscosity of water in poises temperature of suspension at the time df sampling. in cm.The diameter of the particle in suspension at any sampling time t shall be calculated from the formula: 980 ( G .4. bv keeping a cover on the measuring be retarded Evaporation cylinder between readings. in mm. 18 the or sampling in minutes.2 Sieving . W.The percent of soil sample passing each of the &eves used in the analysis shall be calculated using the mass of the pre-treated soil ( WtJ ).1. 5. H = height of fall of the particles and t = time elapsed before sampling. where P = loss in mass in percentage.4. II/‘..1. = mass of air dry soil used. 5. in g/cm3. ) where D = diameter of particle in suspension.1 Loss in . 1 16.9 50.9 16’5 273 266 259 253 247 121 118 115 113 110 68 66 65 63 62 44 42 41 40 39 30’3 29.8 39.7 28.0 26.7 47’3 46.y8 5 86 5.2 20’4 14’7 11.4 58’8 41.4 27.TABLE T~MPERXTURE “C 1 RATE OF SETTLING OF PARTICLES AT VARIOUS TEMPERATURES ( AvEnahP: SPECIFIC GRAVITY OF .41 2.7 14.2 194 18.7 70. .55 2.6 76.1 10’8 9.2 15’8 14.1 -38.9 39’9 39’1 38.0 87.2 25.3 367 357 347 337 328 319 163 158 154 150 14ti 142 92 89 87 84 82 80 59 57 55 54 52 51 40.0 26.10 2’04 1.54 7.1 13’8 11’4 11.41 3.8 44’9 43.8 32.0 92 8’8 -‘d g 2395 23.77 3.3.:::: 26.6 17.1 54.5 30’7 29.03 ‘04 .6 9.28 3.3 18.6 19’4 15.64 62.68 644 44.9 9.38 57.9 226 231 221 100 102 98 38 56 55 36 37 35 25.72 72.0 25.1 241 107 60 39 26’8 20’9 15.38 7.6 310 302 294 287 280 138 134 131 127 124 78 76 74 72 70 50 48 47 4ti 45 34’5 33’6 32.6 12.9 .8 23*1 22’5 21.6 35.004 ‘005 ‘006 *007 .l 54.50 22.1 46.4 32‘4 31.44 22.2 15.Ol ‘02 .9 18’4 17’9 17. =.37 9’10 8’86 4.2 53.8 29’2 28.9 22.3 21.7 17’3 16.11 12.6 23.4 19’0 14.66 2’60 2.2 24.20 3.9 10.8 80.6 49.4) DIAMETER.8 59.1 30’4 29.12 2’78 2’84 2’72 1.6 38.85 1’80 1’76 1.9 18..12 3.6 10’4 10’2 10’0 9.01 5.7 42’5 41. 13.6 245 19.1 25’5 24.1 64’2 62.2 17.2 19.9 31.16 2.1 17.06 ‘07 _ -h---_ r‘___--*--_-__-~ ~__~_~-__~~h~~~~~~~_~_~ r--a fall ( Time -roTor of 100 mm) c_____h_____7 r_____-h ____ ___~ ~~-~_~~__~_h~_~~ min s h .4 21’9 21’4 17’0 16.3 17’0 16% 16.4 p: N 0 .4 14.9 21.%IL ASSUMED As 2’68 ) ( Claus8 5.6 74’6 57.1 48.5 8.6 10.y 26.98 1.8 22’4 21.56 1’60 1’53 60.9 18’5 19.62 3.28 2.80 39.5 13’2 12.8 78.1 20’7 17’7 17.48 36.4 IO.5 32 22.4 40.2 13.8 15’5.83 8.64 YE.0 20’7 20’2 19’6 19.9 19.6 16.28 4.1.9 43.2 17.41 1.9 29.2 23.57 7.8 23.3 37.81 6’71 2.5 37.2 28’4 27:6 22.1 13’8 13’5 13’2 216 221 206 202 198 96 94 y2 y0 89 54 53 52 51 50 34 23’9 34 23.0 51’5 50.73 8’18 .7 27.5 33.4 38.2 31.0 24.0 52.1 20.2 51.7 16.34 2.7 34.49 33’64 32’73 31’89 31’10 8.4 31’8 30’9 30’0 29.7 236 105 59 38 26.05 .1 35’1 34’2 33.98 ‘3.6 8.1 11.7 27.8 21.53 440 4.!9 2446 6’25 6’40 6.4 14.2 36.3 20.8 lP’4 12’1 11’8 Il.55 2’50 2.G2 5’50 2.3 14’4 14.8 39.yl I.1 12 8 12’5 12’2 IO.0 18.008 ‘009 .50 1’47 1’44 1.81 28’12 28’78 7.0 22.4 10.2 92.95 22.6 6’54 2.6 85.55 28.5 27.2 29’3 28.08 ‘09 *l ___--7 (1) (2) (3) (4) (5) (6) (7) (8) (9) (lo) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) 10 11 12 40.1 61.39 35.5 36.19 9’91 9’63 9.0 22.6 90.74 .9 69’2 67.22 98.45 1.05 1’89 1.3 48.45 2.8 8.3 13’9 13’5 13.&I3 .6 18.5 30’28 29.45 10.0 95.3.55 37.3 37.1 68.5 15.7 21.5 14’1 13.5 24’8 24.48 2.0 18’1 15’0 15.5 28’8 28.4 “4.1 26’9 26.4 219 21.7 31.93 2.1 18.4 13.5 56.16 4.5.6 53.6 5ij.4 37’5 36.64 7.86 3.4 25.4 33 22’9 32 22.3 55.5 11.G 23.21 7.8 25.03 6.5 36’4 35.5 65.04 3.3 30.1 ‘3.1 12’7 34.9 45.5 21.99 1’94 82.7 31.36 3.5 23..3 14% 14.4 8.7 47.9 24.1 27’8 23.8 20.8 16.5 17.8 17.5 60. mm ~________----_---_____~__-*------_-----_----------_--) ‘001 -002 . &: . g .0 66.1 7.5 19.7 34.7 40.6 22. _ MS. or W. etd J w* v.. = mass of sodium hexametaphosphate solution. Or C++I or CV.1985 b) Percenlage jner than D 1) The mass of solid material in 500 ml of suspension for each respective sampling time shall be calculated from the formula: MI or M2 or MS or h4.orM.x diameter 1oo wb where ML? M2 1 M.1.etc)--M.4 shall be calculated on the basis of the total soil sample taken for anaiytis. = mass of solution. in 500 ml of in VP ml from respective samplings.IS : 2720 ( Part 4 ) . or W. etc.. in 500 ml of 5. 20 . of particles D shall be calculated from the formula: in VP ml of for respective finer than ~~.. 2) The percentage by mass (W). W. in 500 ml from respective hexametaphosphate WI-l Wz I 7 t = mass of material samplings. > = mass of material M& I etc J MS = mass of sodium solution.3.. and in ml of sample pipetted = volume samplings.4 ~omhitxd gradation-Combined gradation for each of the particle sizes covered by 5. samplings. I M. in g “P where MI7 M..4. or We x 5oo = . = mass of material in 500 ml from respective sodium hexametaphosphate and soil after pre-treatment.1. etc.(M1orM.orM. ) = mass of Ma I etc J M. d) The basis of the scale shall be density ( g/ml ) at 27°C. such as will hinder cleaning or drying or permit air bubbles to be trapped.4 Water-bath or constant temperature room ( optional ) -for maintaining the soil suspension at a constant temperature during the hydrometer analysis. 6.2.1.1.1.3 Thermometer -to coves the range 0. material passes 75-micron IS Sieve. b) The hydrometer having a surface shall be graduated on the tension of 55 dynes/cm. hydrometers.7 Balance - as specified as specified *Specification for density accurate in 5. . at intervals of O*OOO5.1.5 Stirring apparatus - 5. e) The maximum permissible scale error on the hydrometer or minus one scale division. every alternate line shall extend beyond the shortest lines.2.6.6 Sieves - 5. basis of a liquid c) The graduation lines shall b. to 0. 5.0 This method is not applicable. A recommended scale is shown in Fig. Such a device is illustrated in Fig.1.2 Hydrometer Mcth6d ( Subsidiary 5.two of 1 000 ml capacity ground glass or rubber stoppers about 7 cm diameter and 33 cm marked at 1 000 ml volume.2. 5. 5 and fulfilling a) There shall be no abrupt changes in the cross section of the hydrometer.1.50°C accurate in with high to 0*5”C.2 Glass measuring cylinders . Method if ) less than 10 percent of the 5.1 Hydrometer -of the following requirements: the type illustrated in Fig.2.2.1985 5.IS : 2720 ( Part 4 ) . 21 in 5. f) The other general IS : 3104-1965*. 5.2. every tenth graduation shall exceed that of all the intervening lines and shall be numbered in full.2.01 g.1 Aj$aratus 5.1.1.2. 5.1. A satisfactory water tank is an insulated tank that maintains the temperature of the suspension at a convenient constant temperature.2.1. requirements shall satisfy is plus those specified 5.5.1. IS : 2720 ( Part 4 ) . .Ti-?L - T 4*7# 130 TO 150 - _I 1010 20 t. 5 in millimetres. HYDROMETER 22 1 .005+ + 1*010 -$- bOl!j g . I\ t 50 A DDDnY 29 TO 31 6 All dimensions FIG.1985 0.995 z lD000 -g 1. thermostatically of 105 to llO”C.2.2. 1 000 ml .2. of 100 ml capacity.17 Wash ~bottle - 10 cm in diameter. a temperature watsh 5.10 Desiccator 5.1. about or conical 15 cm in diameter.2.12 Porcelain evaporating Wide-mouth 5.1.1.19 about Blue litmus paper 23 water.9 stop THICK CASING controlled of non-corroding with interior BATH to maintain material.-GALVANIZED STEEL SHEET rOVERFlOW 25 mm WOOD L INLET 1 L8RASS PLATE 5” mm THICK CORK INSULATION All dimensions FIG.1.13 -conical dishes jask four.1. 5.2. WATER ILLUSTRATED 5. 6 in millimetres.2.funnel.1.1. beaker - of rapacity.2.1.LSr2720(Part 4)-1985 .1.18 Filter papers 5.1.2.2.16 Measuring cylinder - 5.1.1.11 Centimetrc Jcalc 5.14 Buchner or Hirch funnel - -5.2. 5.2.8 Oven.2. containing distilled 5.15 Filter jlask - 4. to take the. 2.20 Glass rod diameter. N sol&on .3.hydrometer shall be weighed to the nearest O-1 g.IS : 2720 ( Part 4 ) .2.3 and Notes 1.2. 5.2.The volume of the hydrometer bulb ( Vh ) shall be determined in one of the following ways: 4 the volume of water displaced-Approximately 800 ml of water shall be poured into the 1 000 ml sneasuring cylinder.2. 5. the error due to the inclusion of this stem volume may be neglected. This includes the volume of bulb plus the volume of the stem below the 1900 graduation mark.2.1 Volume .1 Hydrogen peroxide 5.1.2.3 Sodium hexametaphosphate and 3 ~thereunder.2. The mass in grams shall be recorded as the volume of the hydrometer in millilitres.3.2. The sectional area ( .2 Calibration a) The sectional area of the 1 000 ml measuring cylinder in which the hydrometer is -to be used shall be’ determined by measuring the distance between two graduations.1985 5.A ) is equal to the volume included between the two graduations divided by the measured distance in centimetres between them. The reading of the water level shall be observed and recorded.1. b) From the mass of the hydrometer - The.1.2.2. From The hydrometer shall be immersed in the water and the level shall again be observed and recorded. b) The distance from the lowest calibration mark on the stem of the hydrometer to each of the other major calibration marks ( Rh ) shall be measured and recorded. 5.2 Reagents- about 15 to 20 cm long and 4 to 5 mm in The reagents shall be of analytical quality.2. 24 . For practical purposes the error due to the -inclusion of this stem may be neglected.2. 2 of Hydrometer 5.3 Calibration solution - See 5. The difference between the two readings shall he recorded as the volume -of the hydrometer bulb in millilitres plus the volume of For practical purposes that part of the stem that is submerged.See 5.2.2.2 Hydrochloric acid See 5. 5.1.1. 5. IS x2720 ( Part 4 ) . f 1 The effective depth (HR) corresponding to each of the major calibration marks ( & ) shall be calculated from the following formula : where HR = effective depth. 5. The difference c . one. .3(a). two The relationship between HR and & may be plotted as a smooth curve which may be used for finding the effective depth ( H. and then raising it slowly until the surface seen as an ellipse becomes a straight line.) corresponding to hydrometer readings ( & ) obtained during test. HI = length from neck of bulb. the point where the plane intersects t!ie hydrometer scale shall bi determined. liquid.i985 4 The distance from the neck of the bulb to the nearest calibration mark shall be measured and recorded. 4 The distance ( h ) from the neck to the bottom of the bulb shall be measured and recorded as the height of the bulb. If an asymmetrical bulb is used. the centre of volume can be determined with sufficient accuracy by projecting the shape of the bulb on to a sheet of paper and locating the centre of gravity of the projected area. By placing the eye slightly above the plane of the surface of the liquid. Rn is the sum of the distance h/2 locates the centre of volume of asymmetrical NOTE -The bulb.The hydrometer shall be inserted in a 1 OOO-mi measuring cylinder containing about 700 ml water. By placing the eye slightly below the plane of the surface of the. = volume of hydrometer A = area of measuring NOTE -The factor %in-tbe bulb. in ml.2. in cm. to graduation Rb.3 Meniscus correction .2. the point where the upper limit of the meniscus intersects the -hydrometer scale shall be determined.4.3. V. h = twice the length from neck of bulb to its centre of volume. in cm. and cylinder in cm:.d of half. 4 The distance H corresponding to a reading distances measured in ( b ) and ( c ). above equation shall not be applied to hydrometer reading taken after periods of sedimentation and four minutes as specified in 5. 1.4. The moisture content ( w )of one sample shall be determined by The other sample shall the method given in IS : 2720 ( Part 2 )-1973*.01 g ) using a jet of distilled water. When the treatment is complete the solution more acid may be required. be accurately weighed ( W. shall have an acid reaction to litmus.The determined. the soil shall be washed taking care to see the soil particles ). The actual amount of soil required will vary according to the type of soil.3.2 percentage of soluble salts shall be one percent. In the case of soils containing calcium compounds (see Note 2 under 5.4 Procedure 5. Two samples each of mass 50 to 100 g approximately shall be obtained by riffling from the air dried sample passing the 4’75-mm IS Sieve obtained as in 3.1985 between the two readings shall be recorded as the meniscus correction Cm.1. In case it is more than with water before further treatment. The mixture shall then be filtered and washed with warm water until the filtrate shows no acid reaction to litmus.3. As soon as vigorous frothing has subsided the volume shall be reduced to about 50 ml by boiling. This is a constant for a given hydrometer.2. The dish *Methods of test for soils : Part 2 Determination of water conqt f second raision ). The damp soil on the filter paper and funnel shall be transferred without any loss whatsoever to the evaporating dish ( weighed to 0.2. 150 ml of hydrogen peroxide shall then be added and the mixture stirred gently with a glass rod for a few minutes after which it shall be covered with a cover glass and left to stand overnight.1’2 direct to the soil taken for analysis.2. 50 g with a clay soil and 100 g with a sand soil. are not lost (see Note 1 under 5. In the case of soils containingno calcium compounds or soluble salts and having a low organic content ( less than 2 percent ) the pre-treatment prescribed may be omitted and the dispersing agent shall be added as in 5.2 ) the mixture shall be allowed to cool and about 50 ml of hydrochloric acid added. With very organic soils additional peroxide may be required to complete the oxidation.01 g and placed inthe wide mouth conical flask.1 Prc-treatment of soil .IS : 2720 ( Part 4 ) . If the soil contains a considerable amount of calcium salts if necessary.3. The mixture in the conical flask shall be gently-heated. ) to the nearest 0. c . Only the minimum quantity of distilled water shall be used. The solution shall be stirred with a glass rod for a few minutes and allowed to stand for one hour or for longer periods. Care shall be taken to avoid frothing over and the contents of the dish shall be periodically stirred. 5. 3 4 Sedimentation A rubber bung shall be inserted in the mouth of the measuring cylinder which shall then be shaken vigorously and finally be inverted end -over end.2. Immediately the shaking has ceased. 5.1 and the cumulative percentages of the soil fraction retained on each sieve shall be calculated. The hydrometer shall be removed. Hydrometer readings shall be taken after periods of half. The dish and contents shall then be transferred to the desiccator and allowed to cool. two and four hours after shaking ( see Note ). rinsed in distilled water arid kept in a cylinder of distilled water at the same temperature as the soil suspension. The soil suspension shall then be stirred well for 15 minutes.1985 and contents shall be placed in an oven and dried at 105 to 1lOW. After 4 hours hydrometer readings shall be taken once or twice within 24 hours. The suspension shall then be transferred to the 75-micron IS Sieve placed on a receiver and-the soil shall be washed on this sieve using a jet of distilled water from a wash bottle.01 g. The hydrometer shall then be removed slowly. 15 and 30 minutes. Particular care shall be taken to wash off all traces of suspension adhering to the dispersion cup.IS L2720 ( Part 4 ) . They shall then be weighed to 0.To the soil in the evaporating dish 100 ml of sodium hexametaphosphate solution shall be added and the mixture shall then be warmed gently for about 10 minutes and then transferred to the cup of the mechanical mixer using a jet of distilled water to wash all traces of the soil out of the evaporatmg dish. the measuring cylinder shall be allowed to stand ( in the constant temperature bath. one. This suspension shall then be used for the sedimentation analysis.2. The material retained on the 75-micron IS Sieve may be over-dried and analysed as specified in 4. The amount of water used may be about 150 ml.4. The amount of distilled water during this operation may be about 500 ml. one.4.3. b) The hydrometer shall be re-inserted in the suspension and readings taken after periods of 8. rinsed and placed in the distilled water after each reading. and ‘the mass of soil remaining after pre-treatment shall be recorded ( Wa ). if used ) and the stop watch started. 5. two and four minutes.2. The suspension that has passed through the sieve shall be transferred to the 1000 ml measuring cylinder and made up to exactly 1 000 ml with distilled water. The ~hydrometer shall be immersed to a depth slightly below its floating position and then allowed to float freely.2 Dispersion of soil . the exact periods of sedimentation 27 . If the variation in temperature is likely to be greater than this the constant temperature bath should be used ( see also Note 2 under 5. In taking all readings.E) shall be calculated.3.1. 4 The temperature of the suspension shall be observed and recorded~once during the first 15 minutes and then after every subsequent reading. Alternatively. Ten seconds shall be allowed for each operation.2. d) The correction ( x ) to be ‘applied for the dispersing agent shall be ascertained by placing exactly 50 ml of the sodium hexamctaphosphate solution in a previously weighed glass weighing bottle and after evaporating the water by drying at 105 to 1 WC in an oven. insertion and withdrawal of the hydrometer before and after taking a reading shall be done carefully to avoid disturbing the suspension unnecessarly.4.The loss in mass in pre-treatment bf the soil shall be calculated using the formula given in 5. provided they give nearly equally spaced points on the grain size distribution curve.5 Gal:ulalions 5. the mass of dispersing agent ( W. A chart of such corrections for all temperatures may also be prepared for ready use. The dispersing the formula: agent correction (x ) shall then be calculated from x = 2 M’d This correction is independent of the temperature.4 ).5%. NOTE-The temperature of the suspension over the period of the test should not differ from the mean temperature by more than &2”C in order not to cause an error in the particle size of more than 2 percent.5.IS:2720(Part4)-1985 being noted. the correction may be obtained directly by making up a 1 000 ml cylinder full of distilled water containing the same proportion of dispersing agent and at the same temperature.1.2. Finally a reading may be taken at the end of 24 hours. and placing the hydrometer in this solution. This requirement will generally be fulfilled if the maximum difference in room temperature is not greater than about 8°C. NOTE-Other suitable time intervals may be used. Vibration of the sample shall be avoided. The temperature shall be read with an. Hydrometer readings shall also be taken in pure distilled water at the corresponding temperatures and the temperature correction ( iUt ) calculated as the difference between this reading and the reading corresponding to the density of water at the calibration temperatures. The corrected zero reading may then be read directly. 5.1. accuracy of at least f 0. This correction shall be corrected for temperature.1 Loss in mass in p-treatment . . . in poises.2. NOTE - = meniscus correction. and taking of hydrometer reading in minutes.2 ( f)].2.3.__980(G-G.The percent of soil sample passing each of the sieve used in the analysis shall be calculated using the mass of the pre-treated soil and as percentages of the total soil sample taken for analysis. = hydrometer reading corrected for meniscus.3.5. 5. in cm [JCCNote under 5. P = coefficient of viscosity of water at the temperature of the suspension at the time of taking the hydrometer reading.5.2.The diameter of the particle in suspension at any sampling time 1 shall be calculated from the formula: a) Diameter of D- ___. HR = effective depth corresponding to Rb (see 5.l8:2728(Part4)-1985 5.3 Sedimentation the pad&s . 7.2 ). R’b = hydrometer reading at the upper rim of the meniscus. soil fraction used in the Gl = specific gravity of water. A nomographic chart for solving the above equation is given in Fig. in mm.2 Sieving.) Ha t where D = diameter of particle in suspension.2. The hydrometer reading corrected calculated from the following formula: for meniscus ( Rh ) shall be Rh = Rgh + C. G = specific gravity of the sedimentation analysis. 29 c . where R. and t = time elapsed between the beginning of sedimentation. and C. 3ou . VELOCITY (8) (‘~1 cm/o -2.2 -6 -7 -6 -9 -10 -12 14 OF 90 ‘C _:o” 6' 25 70 20 60 15 50 f IO tT) .7 16 2.1 -5 -2.6 2.>4 . 7 NOMOGRAPHICCHART BULB .2*5 2.9 16 2.3 TEMPERATURE KEY 30 3’1 3.2 FIG.9 120 OF -2. The pointer shall be allowed on to move over the scale. W. 5. A pinion knob and a rack and pinion arrangement facilitates easy movement of this scale arm assembly to move up and down as desired. (G.3.2. The scale arm shall be fixed on two blo&ks acting as guides to move on the upright pillar. RI.2 L Apparatus 5. at any time.3. These percentages shall then be expressed as combined percentages of the total soil sample taken for analysis. and agent correction.1 Plummet balance . Mt x = temperature = dispersion correction.3. 31 . This permits. Wb = weight of soil after pre-treatment. to directly read percentage of soil in suspension with easy computation of diameter of the particle by Stoke’s law.‘> where G.IS : 2720 ( Part 43 . 5. = specific gravity of soil particles. The values of W shall be calculated for all the values of D obtained and shall be expressed as percentages of particles finer than the corresponding value of D.3 PLUMMET BALANCE ( Alternative Method ) 5. is obtained by reading the decimals only and placing the decimal point between the third and the fourth decimal places).1985 b) Percentage finer than D .Figure 8 illustrates the ~basic components. 5. The only manipulation is adjustment of the height of the balance so that the plummet sinks to the right depth.The percentage by mass ( W) of particles smaller than corresponding equivalent particle diameters shall be calculated from the formula: w= 100 G. -1) tRh + Mt .1 Principle -Plummet balance is essentially a specific gravity balance and is designed on the principle that adjustment for depth of immersion of the plummet is more rapid requiring less precision than adjustment for weight. The plummet balance consists of a base with three levelling screws over which an upright pillar is fixed. A light weight pointer beam mounted with the help of steel pivot and jewel bearings on to the scale arm. At the end of this scale arm a scale shall be fixed. Rh = hydrometer reading corrected for meniscus (for the type of hydrometer graduations illustrated in Fig. 5.is then operated to bring the centre of the plummet at a depth of 9 cm or any other specified depth at which the usual readings are taken.3 Disfieraion of soil - The procedure is same as in 5.1. A plumb bob shall be provided on the scale arm carrier for adjustment of the level of the instrument.3.3. 8.2. A plummet made of perspex with a string and hook for hanging to the pointer shall be provided. Make a mark on the string.A rubber bung shall be mouth of the measuring cylinder which shall then be and finally be inverted end over the end. Two rider weights provided with the apparatus shall be used for checking calibration and for any adjustment. The balance is now ready for use. 5. The weight marked 100 when hung on to the hook provided for hanging the plummet on the beam should read 100 and when the weight marked zero is hung the pointer should read zero.4.3.2 Glass measuring cylinders .The material retained on the 75 micron IS Sieve is oven dried and analysed as specified in 4. If the pointer does not read zero then adjust the screw.2.3.1985 The pointer has two adjusting screws allowing the adjustment of the zero reading. 5. The pinion knob .3. The pretreatment is done as per the procedure as in 5.2. inserted into the shaken vigorously after the shaking the stand of the This marks the . Thermometer -to 5.2.4.Two 1 000 ml capacity with ground glass or rubber stoppers about 7 cm diameter and 33 cm high marked at 1 000 ml volume.3 Procedure - cover the range up to 50% accurate up to see Fig. beginning of sedimentation. 5.2.1 Initial setting and adjustment level the instrument with the help of plumb bob and levelling screws. Do not tamper with the adjustment of the screw for doing this adjustment.3.2.5”C. Then the plummet shall be hooked to the beam after lowering in a container filled with distilled water.3. adjusting screws shall be used fbr changing the range and the other screw for setting the zero.4 Sedimentation . Immediately has ceased the measuring cylinder is placed on plummet balance and the stop watch is started. 5. 5. If adjustments are necessary at any time to obtain 0 and 100 readings.3.3. This plastic plummet shall weigh 3 gm in water.IS : 2720 ( Part 4 ) .3 0.3.33.2 Prc-treatment of soil . IS : 2720 ( Part 4) .1985 ADJUSTMENT SCREW ADJUSTMENT &EEOLE SHAPED) :A:E c FIG. 8 DETAILSOF PLUMMETBALANCE 33 . two. from the surface of the suspension to centre of the plummet.IS I 2720 ( Part 4) . 5.010 0.8 n E . (cm) tlmin) G = SPECIFIC GRAVITY OF SOIL PARTICLES \\\\+-=G 5 w = 2.24’ 2. D(mml = K/ 2. The percentage of soil irrsuspension is directly read by the pointer and noted down at half.3.5 Data .3.The plummet then shall be lowered into the suspension and hooked on to the balance.1985 5.3.65 to 2. four minutes and subsequently at further intervals lasting over up to six to seven hours. one. 9 to aid in soiving Stoke’s equation for known temperature condition and specific gravity of particles either determined or assumed ( range 2.& = effective depth of immersion of the plummet which is the depth in cm.4 .Particle diameter D in mm is computed detailed below for each of the percentages read out by the pointer. -0.016 DO16 K- FIG. The plummet is brought to the present depth by turning the pinion.3.012 o*ou 0. The balance is sufficiently sensitive to allow readings to be made to the nearest percentage unit in 2 percent suspensions. 9 CHART FOR Am IN SOLVING STOKES EQUATION 34 . and k = coefficient from Fig.008 0. predetermined distance ( say 9 cm) from the mark on the string to centre of the plummet. as %(cm) D(mm)=k t ( min ) where .8). that is.6 Compufations . -t = time in minutes when pointer readings are taken. Time intervals are adjusted such that square root of time can directly be computed. 1985 6. 10. plotting particle size on the log scale against percentage finer than the corresponding size on the 0rdinar. INDIAN MICRONS Grain Fro. A recommended proforma is given in Appendix A. CHART FOR RECORDING GRAIN SIZE DISTRIBUTION 35 . A chart for showing grain size distribution is shown in Fig.1 The results of the grain size analysis shall be reported in a suitable form. A grain size distribution curve shall be drawn on a semi-logarithmic chart.y scale. 10 SlANOARb -SEVES MlLlMlRES size in millimetres. REPORT 6.IS : 2720 ( Part 4 ) . . ..... . . . . . . ... . . .... . .... ..IS : 2720 ( Part 4 ) .*. .. . ..-. . ._ SIEVE ANALYSIS OF FRACTION RETAINED ON 4’75-mm IS SIEVE Weight of total roil sample taken for analysis.. . ... . . .. . . . . . .. .. ..... . ... .. .. ..... .. ... Water content. ... .. . . . . .. ..... . . . . IS SIEVE Dmim- MASS MASS MM* CUMULATIVE MASS SooqL RETAINED SOOFIL CoosNTAINEB RETAINED NATION RxTAINED + MASS CONTAINICE SOIL RETAINED AS PEE- CENTAGE OF SOIL TAXEN SOIL PA~SINC+ A8 PIE%- CENTAOE OF SOIL TAXEN Covrau?m PEBCENTAQE PAZZSIN~u PEBCEXTAGE OF TOTAL SOILSAIFLE SIEVE ANALYSIS OF FRACTION PASSING 4-75-mm IS SIEVE BUT RETAINED ON 7S-MICRON IS SIEVE Mass of partial sample taken for analysis. . . . . ...1 ) FORM FOR THE RECORD OF RESWLTS OF GRAIN SIZE ANALYSIS PROJECT DETAILSor SOIL SABLE ..“.... . . ..... .. . .. . .. .. .. . .~_... . .. .. .. .. .. . . .*.. . . . .. ... ...RETAINED NATION +MAssOF CONTAINER MASS MASS OF OF SOIL CONTAXWEB RETAINED CUMULATIV~LMiss RETAINED SOIL SOIL RI~TAINE~ PASXXO AS PmaASPEBCENTAOEOENTAOE P%AL SOIL TAKEN 36 PA~XAL SOIL S~UCPLE TAIIENFOB ANALY8IO COX~NED PERCIQ~TAOIC PAININGAB PEBCENTAGZ OF TOTAL SOIL SAULE . . ..*. .. .. ... . ... . ... .. .1985 APPENDIX A ( Clause 6. Water content. . ..-. .. . .. ... MASS OF IS SllcVE SOIL -_--Dmsla.... .. . . . ... .... .. . .. . .. ... . . . .. ... ... .. . .. .. . .. .................................PwcmzTAOL TAQN Or TOTAL SAMPLN ...............................COURTNEY MENT --x TAQEOF PERCENPARTXOLSs TAQEOp DIAFINER FINER XETER.......................................... GRAINTRAN THAN D +OVBN D AS ASPERMATEIN DRY Bo:~LE........ was taken ............................... WDATETIXE TEM......... THAN D............................................................. .................. PipItfs Ana&sif............... taken in pipette (Va)...ELAPBED TIME PERATDRE wa~~~ll HPDROYNTER READIN@ Rh (%+Mt-xx) CORRECTED HYDROMETER 37 (percent) ~?QWP.....CENTION SOIL CENTAQE 03' FRACTX~H OF Wa TOTAL vok* 50rml SOIL VU SAMPLE MASS MASS MASS Hydrome........IS:2729(Part4)-1985 ANALYSIS OF SOIL Masr of air dry soils PASSING 75-MICRON IS SIEVE ( W........................ ......... Dispersing agent correction ix)..... Meniscus Density correction ofsoil G.................................................................... Temperature correction (Aft)..........................PEBOENTALOE Co:!CTS~L:D S:L:D MAW Dor TAQN SOIL FINER FINER TAINER TLE -MATE.... THAN DA0 W PERCIEN......~C~I~~ RIAL mm PER................. (Cm)................... agent in the vobme- of suspension sampled .................. ..............................PEB.... Specific gravity Volume of soil of suspension Depth at which sample Mass of dispersing DATE TEMPERATIMN TUREoI ELAPSED BEIORE SUSPENSION SAMPLIND ..MATEOB RIAL RIAL Son.................. Mass ofovendry soil after pre-treatmant LOM in mass in pre-treatment ( Wb)................ in percent ....... ..... ................. Water content of air dry roil (~0)..............&+hft PNRoEN................... MASS COR..............) .........................DIA...................................rr Analysis Hydrometer No.................COMBINED RECT METER CEN............. ................................ HANDA ( Allcrneta) Aaaociated Instrumenta Manufacturera (I) Private SEW M. GUEA SHBI N. Roorkee ( IRI ) Department. S. VERDARJAN ( Ahmale) Ministry of Railways DEPUTY DIRECTOB RESEARCH ( GE-III ) JOINT DIBECTOR RESEAROH ( GE-I ) ( Alternate) Central Soil and Materiala Research-Station. CHATWIWEDI SHRI P. Roorkee DB GOPAL RANJAN DR S. BHATTAC~ARYA ( Ahrnatr ) Indian Institute of Technology. New Delhi DE SHASHI K. N. K. Calcutta SERI H. GIJLHATI University of Roorkee. New DIWWTO~ ( CSM & RS 1 Delhi DEPUTY DIRECTOR ( CSM & RS ) ( Alhrnuta ) Geologista Syndicate Private Limited. Government of Punjab. I(.1985 ( Conlinucd Jm7lpage2 ) Repurnting Members Department. C. New Delhi PROP T.IS : 2720 ( Part 4 ) . JA~ANATEA RAO 38 . Government of Uttar ASSIWANT RESEARCH OFFICER Irrigation Pradesh. 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