Soil Tests: Soil Testing – Laboratory Tests

Question 1

What are common laboratory tests for soil classification?

Answer 1

Sieve Analysis – Determines grain size distribution.
Atterberg Limits – Measures soil consistency (LL, PL, PI).
Proctor Test – Determines maximum dry density (MPD) and optimum moisture content (OMC).
CBR Test – Measures California Bearing Ratio for load-bearing capacity.
Triaxial Test – Determines shear strength.
Water Permeability Test – Measures how easily water moves through soil.

Question 2

What is a sieve analysis?

Answer 2

A test that determines soil particle sizes by passing soil through standardized sieves.

Question 3

What is the coefficient of uniformity (Cu)?

Answer 3

Cu = D60 / D10

Indicates whether the soil is well-graded or poorly graded.

Question 4

What is the coefficient of curvature (Cc)?

Answer 4

Cc = (D30)^2 / (D10 × D60)

Indicates missing grain sizes in soil distribution.

Question 5

What is the Proctor Test used for?

Answer 5

Determines the maximum dry density (MPD) and optimum moisture content (OMC) for soil compaction.

Question 6

What is the California Bearing Ratio (CBR) test?

Answer 6

A test to evaluate the bearing capacity of subgrade soil by measuring penetration resistance.