CCI Foundation & Soil Analysis 3

Question 1

Which condition describes 'quick condition' or 'quicksand' in cohesionless soils?

Accepted Answer

Upward seepage force equals the effective weight of the soil

Answer

Quick condition occurs when upward hydraulic gradient causes seepage force to equal the buoyant weight of soil, eliminating effective stress.

Question 2

A geotechnical inspector observes 'heave' at the bottom of an excavation in soft clay. The most likely cause is:

Accepted Answer

Insufficient passive resistance against base instability

Answer

Bottom heave in soft clay excavations results from inadequate shear strength to resist the net vertical stress difference at the base.

Question 3

In a soil boring log, the abbreviation 'SP' under USCS refers to:

Accepted Answer

Poorly graded sand

Answer

SP = Poorly Graded Sand in the Unified Soil Classification System, indicating uniform or gap-graded sand with insufficient fines.

Question 4

Which laboratory test determines the maximum dry density and optimum moisture content of a soil?

Accepted Answer

Proctor compaction test

Answer

The Proctor compaction test (standard or modified) establishes the compaction curve to find maximum dry density at optimum moisture content.

Question 5

What is the primary purpose of a surcharge load applied near an existing foundation?

Accepted Answer

It increases lateral earth pressure on the foundation or retaining structure

Answer

A surcharge near a foundation or retaining wall increases the lateral earth pressure that must be resisted by the structure.

(CCI) Certified Construction Inspector Practice Test