Unformatted text preview: ring Grain Size Analysis Department of
Civil and
Environmental
Engineering Fine Portion calculating the % retained & % passing for the 1.18mm sieve example
Calculate a “Factor Number” first as follows: Using the % passing for the 4.75mm sieve (32.6%), find your factor number. 4.75mm % passing Fine Total wt. “before wash” Example: 4.75 percent passing is 32.6% Fine total wt before wash is 250.0 g = 32.6 ÷ 250.0 = 0.1304 (factor number) To Calculate % Passing % passing = factor number × cumulative wt. Example: 1.18mm cumulative weight is 17.0g Factor number as calculated is 0.1304 % passing = 0.1304 × 17.0 = 2.2 then, = % passing on the 4.75mm – 2.2 = 32.6 – 2.2 = 30.4% To Calculate % Retained % retained = 100 – Calculated % passing Example: 30.4% is the percent passing for the 1.18mm sieve, as calculated above % passing = 100 – 30.4 = 69.6%
69.6 is the percent retained, and 30.4 is the percent passing for the 1.18mm sieve Use this process to calculate all the percentages for the fine portion. Note: youalways subtract from the 4.75mm % passing for each value in the fine portion. Winter 2013 7 CIVE 153 – Earth Engineering Grain Size Analysis Department of
Civil and
Environmental
Engineering 4. Using the Unified Soil Classification System, calculate the following: a. The percent of gravel – i.e. the material passing the largest sieve and retained on the No. 4 (4.75mm) sieve b. The percent of sand – i.e. the material passing the No. 4 (4.75mm) sieve and retained on the No. 200 (75µm) sieve c. The percent of silt and clay – i.e. material finer the No. 200 (75µm) sieve d. Coefficient of gradation (Cc) e. Uniformity coeffiecient (Cu) 5. Define the D60, D10 and D30 from your particle size distribution graph. Where: D60 = grain diameter (mm) corresponding to 60% passing, D10 = grain diameter (mm) corresponding to 10% passing, and D30 = grain diameter (mm) corresponding to 30% passing by weight 6. Calculate water content for the material tested in the lab from the information...
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 Winter '13
 GiovanniCascante
 Civil Engineering, grain size analysis, Earth Engineering

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