Soils

[Calixico]

Could someone please help me on identifying these two soils using this system. I find USCS must easier to solve, and even with the textbook open, I still don't get it.

Soil A:

Percent finer than # 10 sieve =83

Percent finer than # 40 sieve = 48

Percent finer than # 200 sieve = 20

LL= 20

PI= 5.

Soil B:

Percent finer than # 10 sieve =100

Percent finer than # 40 sieve = 92

Percent finer than # 200 sieve = 86

LL= 70

PI= 32.

I keep coming up with the wrong answer. The correct choice should be A-1 and A-7-5 respectively for soil A and B

Question,. Do I need to use the analysis for sieve 10 and sieve 40 in the solving the problems?

 

[Alpha]

Could someone please help me on identifying these two soils using this system. I find USCS must easier to solve, and even with the textbook open, I still don't get it.
Soil A:

Percent finer than # 10 sieve =83

Percent finer than # 40 sieve = 48

Percent finer than # 200 sieve = 20

LL= 20

PI= 5.

Soil B:

Percent finer than # 10 sieve =100

Percent finer than # 40 sieve = 92

Percent finer than # 200 sieve = 86

LL= 70

PI= 32.

I keep coming up with the wrong answer. The correct choice should be A-1 and A-7-5 respectively for soil A and B

Question,. Do I need to use the analysis for sieve 10 and sieve 40 in the solving the problems?

If you refer to the CERM there is some fine print at the bottom of the Table 35.4 that gives the key to the classification. Two rules to follow:

1. Start from Left to Right of the table.

2. Use the process of elimination.

The first from the left consistent with the test data is correct, hence A-1 for Soil A and A-7-5 for Soil B.