Determine Particle Size Distribution Of Soil

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This test is done to determine the particle size distribution of soil as per IS: 2720 (Part 4) – 1985. The appratus required to do this test :-
i) A set of fine IS Sieves of sizes – 2mm, 600µm, 425µm, 212µm and 75µm
ii) A set of coarse IS Sieves of sizes – 20mm, 10mm and 4.75mm
iii) Weighing balance, with an accuracy of 0.1% of the weight of sample
iv) Oven
v) Mechanical shaker
vi) Mortar with rubber pestle
vii) Brushes
viii) Trays

PREPARATION OF SAMPLE
i) Soil sample, as received from the field, should be dried in air or in the sun. In wet weather, the drying apparatus may be used in which case the temperature of the sample should not exceed 60oC. The clod may be broken with wooden mallet to hasten drying. Tree roots and pieces of bark should be removed from the sample.

ii) The big clods may be broken with the help of wooden mallet. Care should be taken not to break the individual soil particles.

iii) A representative soil sample of required quantity as given below is taken and dried in the oven at 105 to 120oC.

determine-particle-size-distribution-of-soil

Procedure to determine Particle Size Distribution Of Soil
i) The dried sample is taken in a tray, soaked in water and mixed with either 2g of sodium hexametaphosphate or 1g of sodium hydroxide and 1g of sodium carbonate per litre of water, which is added as a dispersive agent. The soaking of soil is continued for 10 to 12hrs.

ii) The sample is washed through 4.75mm IS Sieve with water till substantially clean water comes out. Retained sample on 4.75mm IS Sieve should be oven-dried for 24hrs. This dried sample is sieved through 20mm and 10mm IS Sieves.

iii) The portion passing through 4.75mm IS Sieve should be oven-dried for 24hrs. This oven-dried material is riffled and about 200g taken.

iv) This sample of about 200g is washed through 75µm IS Sieve with half litre distilled water, till substantially clear water comes out.

v) The material retained on 75µm IS Sieve is collected and dried in oven at a temperature of 105 to 120oC for 24hrs. The dried soil sample is sieved through 2mm, 600µm, 425µm
and 212µm IS Sieves. Soil retained on each sieve is weighed.

vi) If the soil passing 75µm is 10% or more, hydrometer method is used to analyse soil particle size.

HYDROMETER ANALYSIS
i) Particles passed through 75µm IS Sieve along with water are collected and put into a 1000ml jar for hydrometer analysis. More water, if required, is added to make the soil water suspension just 1000ml. The suspension in the jar is vigorously shaken horizontally by keeping the jar in-between the palms of the two hands. The jar is put on the table.

ii) A graduated hydrometer is carefully inserted into the suspension with minimum disturbance.

iii) At different time intervals, the density of the suspension at the centre of gravity of the hydrometer is noted by seeing the depth of sinking of the stem. The temperature of the suspension is noted for each recording of the hydrometer reading.

iv) Hydrometer readings are taken at a time interval of 0.5 minute, 1.0 minute, 2.0 minutes, 4.0 minutes, 15.0 minutes, 45.0 minutes, 90.0 minutes, 3hrs., 6hrs., 24hrs. and 48hrs.

v) By using the nomogram given in IS: 2720 (Part 4) – 1985, the diameter of the particles for different hydrometer readings is found out.

REPORTING OF RESULTS
After completing mechanical analysis and hydrometer analysis, the results are plotted on a semi-log graph with particle size as abscissa (log scale) and the percentage smaller than the specified diameter as ordinate

sample-test

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Comments
  • j.j.patel April 9, 2009 at 7:14 am

    it is very good site for me because i am lecturer.
    please do include other aggregate test also.

  • Prakash Ch. Pant August 22, 2009 at 7:25 am

    This is a very good and important site for every Civil Engineer.
    i feel lucky after finding this site.

  • thulani November 23, 2009 at 4:01 am

    why do we have to determine particle ditribution of soil?

    • Stewart Rotherham July 15, 2010 at 6:08 am

      Because the particle distribution is critical to the behaviour of the soil under loads and in contact with water. If we know the particle size distribution of a particular soil, we can make a very good prediction of how it will behave as a foundation for – or component of – our works (buildings, dams, roads etc.) As a result of knowing how the soil is likely to behave, we can design our works accordingly to give them durability and safety.

    • svsr mahesh August 27, 2011 at 1:41 am

      To know the percentage of sand, silt,morum which is useful for classification of soils

  • Sulymon, Nurain Adeyinka December 31, 2009 at 11:15 am

    As a student of civil engineering, I find this site to be very helpful

  • Idalia February 3, 2010 at 2:44 am

    I am Happy beause now I will not have to go back searching through all moy notes. I am a postgraduate student of Civil Engineering and I have found this site to be very useful. Thank You

  • Willem UK September 29, 2010 at 7:08 am

    how do link the fineness modulus to the soil distribution?

  • karsh October 5, 2010 at 11:02 pm

    state uses for hydrometer test data?

  • milind December 23, 2010 at 8:44 pm

    its a very good site.

  • arif March 8, 2011 at 10:03 am

    very good site……….want to learn more about the sieve analysis

  • gunda July 2, 2011 at 4:53 am

    why do we have to sieve a soil sample before soaking when performing wet sieve analysis

  • david achea September 24, 2011 at 4:54 am

    pls i need a full detailed sieve analyses with results, thank

  • pankaj October 9, 2011 at 2:43 am

    what is the purpose of using semi log graph in sieve analysis

  • Pratik Biswas December 22, 2011 at 4:46 am

    THIS IS THE BEST SITE FOR INTERN CIVIL ENGINEERS.

  • Sujoy roy January 8, 2012 at 5:57 am

    Can u please brief the Zone of Sand …
    How to find the zone ???

  • Parveen sharma February 14, 2012 at 10:13 am

    Now i have the details of wet sieve analysis.this site is very good.

  • Fatima March 26, 2012 at 5:21 pm

    Hi all,
    I’ve carried out this experiement at uni but because I was absent for a few classes I’m feeling abit lost. What would be a good conclusion for this experiment?

    Many thanks,

  • anil deep February 15, 2013 at 3:33 am

    there are no Passing Limits of soil on each sieves.Because its required as per formate of P.M.G.Y.S Project.

  • Post a comment

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