CIV 418 GEOTECHNICAL ENGINEERING FINAL
EXAMINATION
Comprehensive Final Examination & Verification Solutions Bank | 55 Multiple-Choice Questions
1. Which soil classification system relies primarily on the Liquid Limit (LL) and Plasticity Index (PI)
plotted on a plasticity chart?
A) AASHTO Classification System
B) USDA Soil Textural System
C) Unified Soil Classification System (USCS)
D) Wentworth Scale
The Unified Soil Classification System (USCS) uses the plasticity chart (LL vs. PI) to differentiate fine-grained
soils like clays and silts. The AASHTO system also uses Atterberg limits but follows a different group index
rating.
2. In soil mechanics, the ratio of the volume of voids to the total volume of soil is known as:
A) Void ratio
B) Porosity
C) Degree of saturation
D) Specific gravity
Porosity is defined as the volume of voids divided by total volume. Void ratio, by contrast, is the ratio of void
volume to the volume of solids.
3. Darcy's Law for fluid flow through permeable soil media is valid under which flow condition?
A) Turbulent flow
B) Laminar flow
C) Transitional flow
D) Compressible flow
Darcy's Law assumes that fluid velocity is directly proportional to the hydraulic gradient, which holds true only for
laminar flow through soil pores.
4. Which laboratory test is most suitable for determining the coefficient of permeability of coarse-
grained soils like sand and gravel?
A) Constant head permeability test
B) Falling head permeability test
, C) Standard Proctor test
D) Unconfined compression test
The constant head permeability test is used for highly permeable coarse soils where a continuous high discharge
rate can be maintained. Falling head is used for low permeability fine-grained soils.
5. Terzaghi's one-dimensional consolidation theory assumes that soil deformation and pore water
expulsion occur in:
A) All three principal directions simultaneously
B) Radial directions only
C) The vertical direction only
D) Horizontal directions only
Terzaghi's simplified 1D theory assumes strain and fluid flow happen exclusively along the vertical axis under
horizontal confinement.
6. The effective stress concept in saturated soils was established by Terzaghi as:
A) Effective Stress = Total Stress + Pore Water Pressure
B) Effective Stress = Total Stress - Pore Water Pressure
C) Effective Stress = Pore Water Pressure / Total Stress
D) Effective Stress = Total Stress * Void Ratio
Effective stress represents the stress carried by the soil skeleton and is calculated by subtracting pore water
pressure from total stress.
7. Quick sand condition occurs in cohesionless soils when the effective stress becomes:
A) Equal to the total stress
B) Greater than the overburden pressure
C) Zero due to upward hydraulic gradient
D) Maximum at the soil surface
When seepage water flows upward with a critical gradient, seepage pressure balances the buoyant unit weight of
soil, reducing effective stress to zero and causing loss of shear strength.
8. In a Standard Proctor compaction test, maximum dry density is achieved at:
A) Zero air voids moisture content
B) Optimum moisture content (OMC)
C) Fully saturated moisture content
D) Liquid limit moisture content
EXAMINATION
Comprehensive Final Examination & Verification Solutions Bank | 55 Multiple-Choice Questions
1. Which soil classification system relies primarily on the Liquid Limit (LL) and Plasticity Index (PI)
plotted on a plasticity chart?
A) AASHTO Classification System
B) USDA Soil Textural System
C) Unified Soil Classification System (USCS)
D) Wentworth Scale
The Unified Soil Classification System (USCS) uses the plasticity chart (LL vs. PI) to differentiate fine-grained
soils like clays and silts. The AASHTO system also uses Atterberg limits but follows a different group index
rating.
2. In soil mechanics, the ratio of the volume of voids to the total volume of soil is known as:
A) Void ratio
B) Porosity
C) Degree of saturation
D) Specific gravity
Porosity is defined as the volume of voids divided by total volume. Void ratio, by contrast, is the ratio of void
volume to the volume of solids.
3. Darcy's Law for fluid flow through permeable soil media is valid under which flow condition?
A) Turbulent flow
B) Laminar flow
C) Transitional flow
D) Compressible flow
Darcy's Law assumes that fluid velocity is directly proportional to the hydraulic gradient, which holds true only for
laminar flow through soil pores.
4. Which laboratory test is most suitable for determining the coefficient of permeability of coarse-
grained soils like sand and gravel?
A) Constant head permeability test
B) Falling head permeability test
, C) Standard Proctor test
D) Unconfined compression test
The constant head permeability test is used for highly permeable coarse soils where a continuous high discharge
rate can be maintained. Falling head is used for low permeability fine-grained soils.
5. Terzaghi's one-dimensional consolidation theory assumes that soil deformation and pore water
expulsion occur in:
A) All three principal directions simultaneously
B) Radial directions only
C) The vertical direction only
D) Horizontal directions only
Terzaghi's simplified 1D theory assumes strain and fluid flow happen exclusively along the vertical axis under
horizontal confinement.
6. The effective stress concept in saturated soils was established by Terzaghi as:
A) Effective Stress = Total Stress + Pore Water Pressure
B) Effective Stress = Total Stress - Pore Water Pressure
C) Effective Stress = Pore Water Pressure / Total Stress
D) Effective Stress = Total Stress * Void Ratio
Effective stress represents the stress carried by the soil skeleton and is calculated by subtracting pore water
pressure from total stress.
7. Quick sand condition occurs in cohesionless soils when the effective stress becomes:
A) Equal to the total stress
B) Greater than the overburden pressure
C) Zero due to upward hydraulic gradient
D) Maximum at the soil surface
When seepage water flows upward with a critical gradient, seepage pressure balances the buoyant unit weight of
soil, reducing effective stress to zero and causing loss of shear strength.
8. In a Standard Proctor compaction test, maximum dry density is achieved at:
A) Zero air voids moisture content
B) Optimum moisture content (OMC)
C) Fully saturated moisture content
D) Liquid limit moisture content
