PROFESSIONAL GEOTECHNICAL
ENGINEER EXAM QUESTION AND
CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A
INSTANT DOWNLOAD PDF
1. Which soil property most directly controls shear strength in cohesionless
soils?
A. Plasticity index
B. Void ratio
C. Water content
D. Angle of internal friction
Rationale: In cohesionless soils, shear strength is governed primarily by
particle interlocking and friction, represented by the angle of internal
friction.
2. The Atterberg limits are used to classify which type of soil?
A. Sands
B. Gravels
C. Fine-grained soils
D. Organic peat
Rationale: Atterberg limits describe the consistency and plasticity behavior
of fine-grained soils such as silts and clays.
3. The Standard Penetration Test (SPT) measures:
A. Soil permeability
B. Soil compressibility
C. Soil resistance to penetration
, D. Soil unit weight
Rationale: SPT N-values indicate soil density and strength based on
resistance to hammer-driven penetration.
4. Effective stress in soil is defined as:
A. Total stress minus pore water pressure
B. Total stress minus pore water pressure
C. Total stress plus pore pressure
D. Pore pressure only
Rationale: Effective stress governs soil behavior and is calculated as total
stress minus pore water pressure.
5. Consolidation settlement primarily occurs in:
A. Sands
B. Gravels
C. Clays
D. Rock
Rationale: Low permeability clays undergo time-dependent consolidation
as pore water drains.
6. The coefficient of permeability depends most on:
A. Soil color
B. Grain size and void ratio
C. Mineralogy only
D. Plastic limit
Rationale: Flow paths and pore size, controlled by grain size and void
ratio, dominate permeability.
7. Which failure mode is associated with shallow foundations on soft clay?
A. Punching shear
B. General shear failure
C. Local shear failure
D. Sliding failure
Rationale: Soft clays typically exhibit general shear failure with well-
defined failure surfaces.
, 8. The primary purpose of a geotechnical site investigation is to:
A. Reduce construction time
B. Determine subsurface conditions and engineering properties
C. Locate utilities
D. Design structural members
Rationale: Accurate subsurface characterization is fundamental for safe
and economical design.
9. Bearing capacity factors (Nc, Nq, Nγ) are functions of:
A. Cohesion
B. Unit weight
C. Angle of internal friction
D. Depth of footing
Rationale: These factors are derived from theoretical solutions dependent
on friction angle.
10.Which test best estimates undrained shear strength of clay in the field?
A. SPT
B. CPT
C. Vane shear test
D. Plate load test
Rationale: The vane shear test directly measures undrained shear strength
in soft clays.
11.Settlement due to elastic deformation is called:
A. Primary consolidation
B. Secondary compression
C. Immediate settlement
D. Creep settlement
Rationale: Immediate settlement occurs without drainage, due to elastic
response.
12.The Unified Soil Classification System (USCS) is based on:
A. Soil color and texture
B. Chemical composition
ENGINEER EXAM QUESTION AND
CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A
INSTANT DOWNLOAD PDF
1. Which soil property most directly controls shear strength in cohesionless
soils?
A. Plasticity index
B. Void ratio
C. Water content
D. Angle of internal friction
Rationale: In cohesionless soils, shear strength is governed primarily by
particle interlocking and friction, represented by the angle of internal
friction.
2. The Atterberg limits are used to classify which type of soil?
A. Sands
B. Gravels
C. Fine-grained soils
D. Organic peat
Rationale: Atterberg limits describe the consistency and plasticity behavior
of fine-grained soils such as silts and clays.
3. The Standard Penetration Test (SPT) measures:
A. Soil permeability
B. Soil compressibility
C. Soil resistance to penetration
, D. Soil unit weight
Rationale: SPT N-values indicate soil density and strength based on
resistance to hammer-driven penetration.
4. Effective stress in soil is defined as:
A. Total stress minus pore water pressure
B. Total stress minus pore water pressure
C. Total stress plus pore pressure
D. Pore pressure only
Rationale: Effective stress governs soil behavior and is calculated as total
stress minus pore water pressure.
5. Consolidation settlement primarily occurs in:
A. Sands
B. Gravels
C. Clays
D. Rock
Rationale: Low permeability clays undergo time-dependent consolidation
as pore water drains.
6. The coefficient of permeability depends most on:
A. Soil color
B. Grain size and void ratio
C. Mineralogy only
D. Plastic limit
Rationale: Flow paths and pore size, controlled by grain size and void
ratio, dominate permeability.
7. Which failure mode is associated with shallow foundations on soft clay?
A. Punching shear
B. General shear failure
C. Local shear failure
D. Sliding failure
Rationale: Soft clays typically exhibit general shear failure with well-
defined failure surfaces.
, 8. The primary purpose of a geotechnical site investigation is to:
A. Reduce construction time
B. Determine subsurface conditions and engineering properties
C. Locate utilities
D. Design structural members
Rationale: Accurate subsurface characterization is fundamental for safe
and economical design.
9. Bearing capacity factors (Nc, Nq, Nγ) are functions of:
A. Cohesion
B. Unit weight
C. Angle of internal friction
D. Depth of footing
Rationale: These factors are derived from theoretical solutions dependent
on friction angle.
10.Which test best estimates undrained shear strength of clay in the field?
A. SPT
B. CPT
C. Vane shear test
D. Plate load test
Rationale: The vane shear test directly measures undrained shear strength
in soft clays.
11.Settlement due to elastic deformation is called:
A. Primary consolidation
B. Secondary compression
C. Immediate settlement
D. Creep settlement
Rationale: Immediate settlement occurs without drainage, due to elastic
response.
12.The Unified Soil Classification System (USCS) is based on:
A. Soil color and texture
B. Chemical composition
