Mechanical sieve analysis – The process of analyzing the particle size present in soil by using mechanical means, is known as mechanical sieve Analysis. By performing mechanical sieve analysis, a particle size distribution curve is plotted for grading of soil.
Procedure
i) Arrange the set of I.S. sieves in descending order i.e. coarser sieve at top and finer sieve at bottom.. The I.S sieve set must include sieves of size 4.75mm, 2.36mm, 1.18mm, 600µ,150µ,75µ. ii) Take 500-1000gm oven dried soil sample and put it on topmost sieve. Keep lid and pan at top and bottom respectively. iii) Now, shake this assembly of sieve on mechanical sieve shaker for 10-15 minutes, so that soil sample will be sieved completely. iv) Take the weight of soil mass retained on each sieve separately in gms. v) Calculate % finer for each sieve using following tabular format.
vi) Finally, plot the particular size distribution curve on a semi log graph paper as sieve size versus % finer of soil to classify soil as shown in Fig.6(b) vii) From above graph, soil is classified based on grading curves as follows
a) Well graded soil b) Poorly or gap graded soil
c) Fine grained soil d) Coarse grained soil
e) Uniformly graded soil
Mechanical sieve analysis – The process of analyzing the particle size present in soil by using mechanical means, is known as mechanical sieve Analysis. By performing mechanical sieve analysis, a particle size distribution curve is plotted for grading of soil.
Procedure
i) Arrange the set of I.S. sieves in descending order i.e. coarser sieve at top and finer sieve at bottom.. The I.S sieve set must include sieves of size 4.75mm, 2.36mm, 1.18mm, 600µ,150µ,75µ. ii) Take 500-1000gm oven dried soil sample and put it on topmost sieve. Keep lid and pan at top and bottom respectively. iii) Now, shake this assembly of sieve on mechanical sieve shaker for 10-15 minutes, so that soil sample will be sieved completely. iv) Take the weight of soil mass retained on each sieve separately in gms. v) Calculate % finer for each sieve using following tabular format.
vi) Finally, plot the particular size distribution curve on a semi log graph paper as sieve size versus % finer of soil to classify soil as shown in Fig.6(b) vii) From above graph, soil is classified based on grading curves as follows
a) Well graded soil b) Poorly or gap graded soil
c) Fine grained soil d) Coarse grained soil
e) Uniformly graded soil