Experiment # 1 Grain Size Analysis Sieve Analysis
Soil Types Coarse Soil Gravel (G ) Sand ( S ) Fine Soil Silt ( M ) Clay ( C )
Grain Size Analysis * Sizes of solid particles * Their Proportion in the soil mass
According to the ASTM *Differentiate between coarse and fine using Sieve No. 200 Size mm *And between Grave and Sand using Sieve No. 4 Size 4.75mm
OBJECTIVES To Determine Grain Size analysis. To classify the soil.
Apparatus Set of Sieves Mortar and rubber-tipped pestle. Riffle box or Splitter Balance Brush Mechanical shaker
Sample Preparation Air-dried. Sandy Soil ( Jahra Sand) Minimum weight of Sample = 110 Used about 500 gm.
REQUIRED MEASUREMENTS 1. Weight of each sieve. 2. Total weight of dry soil samples, Ws. 3. Weight of each sieve and retained soil. 4. Weight of oven dried soil passing No. 200 sieve.
CALCULATIONS 1. Cumulative weight retained = summation of weight retained on this sieve and the upper sieves 2. Percent retained: 3. Percent passing (or percent finer than): Percent passing = 100 (cumulative percent retained)
Sieve No. Sieve diameter (mm) Sieve weight (g) Sieve weight (g) Weight of sieve + soil (g) Weight of soil retained (g) Cumulative soil retained (g) Cumulative percent retained Cumulative percent retained Percent passing Percent passing pan
Grain Size Distribution Curve
where, D10 = grain diameter at 10% passing D30 = grain diameter at 30% passing D60 = grain diameter at 60 % passing Two criteria must be applied in making this determination The first criterion is the coefficient of curvature, Cc: The second criterion is the coefficient of uniformity, Cu
For a soil to be well graded, the following must be satisfied: 1 < Cc < 3 and Cu > 4 (for gravel) Cu > 6 (for sands) If the soil fails one, or both, of these criteria, it is considered to be poorly graded. Special cases of poorly graded soils are gap-graded and uniformly graded soils
Type Of Compaction Curve
Hydrometer Analysis: To Determine Grain Size Distribution for fine soil