Soil Behavior

Question 1

What is the shear strength of soil

Answer 1

The resistance to shear deformation along a failure surface

Question 2

What are the two components of shear strength?

Answer 2

Cohesion and effective friction angle

Question 3

What is the relationship between the Ground water Table and effective stress and shear strength?

Answer 3

Groundwater table increases, effective stress and shear strength decrease

Question 4

What are the strength indices used to approximate shear strength?

Answer 4

California Bearing Ratio (limestone), Standard Penetration Test Blow Count, Modulus of Subgrade Rxn

Question 5

What does compaction do to engineering behavior of soil?

Answer 5

Density soil by removing air - economical to improve soils engineering behavior
Strength increases, compressibility decreases, permeability decreases

Question 6

Standard v Modified Proctor Tests

Answer 6

Modified has higher compactive effort

Question 7

What is relative compaction?

Answer 7

Lever of compaction owner needs (Cr) _ 90-95% of Proctor test

Question 8

Name two methods to measure dry unit weight in the field?

Answer 8

Sand Cone Test (Destructive) & Nuclear Density Gauge (Non-Destructive)