CE 123 Howewok #1 Soiutons Problem 2 (i): A 800 g sample of moist soil with a mo
ID: 1765232 • Letter: C
Question
CE 123 Howewok #1 Soiutons Problem 2 (i): A 800 g sample of moist soil with a moisture content of 13% was placed on a stack of 200 sieve and then "washed forcing minus #200 sized particles to pass through. The soil rtained on #200 was then oven dried and its mass was found to be 256 g. The soil had no vels. Atterberg's limit tests were performed separately and following results were obtained: LL 80, PL-50. Using USCS classification, classify the soil. Mention symbol and description. Show your work (% Gravel, % Sand, % Fines and flowchart steps) to get full credit. (5 points)Explanation / Answer
weight of sample =800g
moisture content (w)=13%
so, weight of dry sample=800/(1+w) =800/1.13 =708g
soil retain on #200 sieve =256 g
% of soil retain = 256/708*100 =36.16%
so more than 50% passes through #200 no sieve , so it is Silt and Clay
Liquid limit (WL)=80>50 so,High plasticity
from the equation of A line, Ip=0.73(WL-20)
= 0.73(80-20) = 43.8
Now, here Ip=WL-PL=(80-50)=30
so, the point is below A line ( as 30<43.8)
so this is Silt.
So the soil is , Silt with High plasticity - MH