1.1: Introduction (General Concepts)

Question 1

16.7 kN/m3 or 106 lb/ft3

Answer 1

Firm or hard sand

Question 2

18.4 kN/m3 or 117 lb/ft3

Answer 2

Compressible sand

Question 3

13.4 kN/m3 or 85 lb/ft3

Answer 3

Ordinary earth (as found in dry locations)

Question 4

16.0 kN/m3 or 102 lb/ft3

Answer 4

Soft earth (primarily silt)

Question 5

18.9 kN/m3 or 120 lb/ft3

Answer 5

Clay

Question 6

the rate of change of head with distance

Answer 6

Hydraulic gradient

Question 7

Q = Aki

Answer 7

Darcy’s Law

Question 8

What is the clay-sized fraction according to Atterberg’s study?

Answer 8

percentage by weight of particles smaller than 2 microns in size

Question 9

What are the three consistency limits of cohesive soils described by Atterberg?

Answer 9

Liquid limit, plastic limit, and shrinkage limit.

Question 10

What important role did Atterberg realize about clay particles in soil?

Answer 10

clay particles affect the consistency and behavior of cohesive soils

Question 11

difference between the liquid limit and the plastic limit of a soil

Answer 11

Plasticity Index