Question

please do a and b neat and clear

Problem 5 (3 points) The sieve analysis of two soils and the liquid and plastic limits of the fraction passing through the No. 40 sieve are given below. Classify the soils by the AASHTO classification system and give the group index for each soil. Soil 1 2 Liquid limit Sieve analysis-Percent finer No.10 No. 40 No. 200 85 55 45 94 80 63 28 40 Plasticity index 20 21 b. Determine the group symbols and group names of the soils given in problem 5a using the Unified soil classification system.

Answer 1

a) Soil 1: Pesont fines No. lo =85 N0.40 = 55 No.200 = 45 L.L =28 P. I = 20 No. 40 = 55 (751) No. 200 = 45 (>36) soil is of sill-day materials L.L = 28 (40) P-I = 20 (>11) Soil is A-6 (clayey soils) Group Inders GI = 0.29 + 0.005 aC+0.0) bd a=108% cro b=30 . d=10 GI = 0.2(10) + 0.005xloxo+0.01% 3010 = 2+3=5

Soil 2: Percent fines No. 10 = 94 No. 40=80 N0.200= 63 L.L =40 P. I =2) No. 200 - 63 (>36) soil is of silt - clay materials 1. L=40 (max.40) P.I=21 (>11) Soil is A-6 (clayey soils) G. I = 0.20 +0.0050c + 0.0) bd a=28 c=0 b=0 d=11 G. I = 0.2 (28) = 5.6 b) Uscs classification Solli Sand ñ 40% P. I based on A-line = 0.73 (L.L-20) = 0.73(8) = 5.84 Group Symbol: SE clayey sand 45%

Soila: Fines +63% (>50-) P. I based on A-line = 0.73(L.L-20) 50.23(20) = 14.6 Gooup Symbol :CL Lean clay