GEOTECHNICAL ENGINEERING FINAL EXAM – LATEST
QUESTIONS AND ANSWERS | SOIL BEARING CAPACITY AND
FOUNDATION DESIGN–COMPLETE STUDY GUIDE | PRACTICE
QUESTIONS AND ANSWERS-RATIONALES | EXAM PREP |
DOWNLOAD INSTANT PDF | GUARANTEED PASS || LATEST
EXAM 2026-2027
1. A geotechnical engineer is evaluating a saturated clay deposit for a multi-story building.
Which laboratory test is most appropriate for determining the undrained shear strength of
the clay core samples without allowing moisture loss during the testing phase?
A. Direct shear test
B. Unconsolidated-undrained (UU) triaxial test
C. Consolidated-drained (CD) triaxial test
D. Standard Proctor compaction test
Answer: B
This test is performed on saturated clay samples without permitting drainage during either the
consolidation or shearing stages, thereby preserving the in-situ moisture condition and
yielding the undrained shear strength (cu).
2. During a subsurface exploration program for a bridge foundation, standard penetration
tests (SPT) are performed. What is the standard hammer weight and drop height specified
for this testing procedure?
A. 140-pound hammer dropped from a height of 30 inches
B. 100-pound hammer dropped from a height of 24 inches
C. 250-pound hammer dropped from a height of 18 inches
D. 50-pound hammer dropped from a height of 36 inches
Answer: A
The standard penetration test utilizes a drop hammer weighing 140 pounds falling freely
through a standardized height of 30 inches to drive a split-barrel sampler into the soil.
3. When analyzing the grain size distribution of a cohesionless sandy soil, a sieve analysis is
performed. Which parameter represents the slope of the grading curve and is calculated as
$D_{60}/D_{10}$?
A. Coefficient of curvature
B. Plasticity index
C. Coefficient of uniformity
,D. Compression index
Answer: C
The coefficient of uniformity is a quantitative measure of particle size range and is defined
mathematically as the ratio of the diameter corresponding to 60 percent finer to that of 10
percent finer.
4. A soil sample has a total mass of 1800 grams and a dry mass of 1500 grams. What is the
gravimetric moisture content of the soil?
A. 15.0 percent
B. 20.0 percent
C. 25.0 percent
D. 30.0 percent
Answer: B
Gravimetric moisture content is calculated as the mass of water divided by the dry mass of the
soil: $((1800 - 1500) / 1500) \times 100 = 20.0$ percent.
5. A cohesive soil exhibits a liquid limit of 50 percent and a plastic limit of 20 percent. If the
natural water content of the in-situ soil is 35 percent, what is the liquidity index?
A. 0.35
B. 0.50
C. 0.65
D. 0.80
Answer: B
Liquidity index is defined as the ratio $(W - PL) / (LL - PL)$. Substituting the given values
yields $(35 - 20) / (50 - 20) = = 0.50$.
6. Which clay mineral is most commonly associated with severe swelling and shrinking
behavior upon moisture variations, posing significant structural hazards to shallow
foundations?
A. Kaolinite
B. Illite
C. Montmorillonite
D. Quartz
Answer: C
,Montmorillonite possesses an expanding crystal lattice structure with weak interlayer bonding
and high specific surface area, allowing extensive water molecule absorption and severe
volume changes.
7. A geotechnical consultant is designing a shallow strip footing on a dense sand layer.
Which failure mode is typically characterized by distinct shear surfaces extending to the
ground surface accompanied by considerable heaving and sudden collapse?
A. General shear failure
B. Local shear failure
C. Punching shear failure
D. Creep failure
Answer: A
General shear failure occurs in dense or stiff soils, marked by well-defined failure wedges,
continuous slip surfaces reaching the surface, and a sudden, catastrophic load drop.
8. Terzaghi’s ultimate bearing capacity equation for a strip footing includes three distinct
bearing capacity factors. What physical soil property primarily dictates the magnitude of
the factor $N_{\gamma}$?
A. Cohesion intercept
B. Internal friction angle
C. Total unit weight
D. Poisson ratio
Answer: B
The bearing capacity factor $N_{\gamma}$ is exclusively a function of the soil shear strength
parameter, specifically the angle of internal friction, governing the contribution of soil weight.
9. In the context of effective stress principles in saturated soils, how is the total vertical
stress at a given depth calculated?
A. Pore water pressure minus effective stress
B. Sum of effective stress and pore water pressure
C. Effective stress multiplied by the void ratio
D. Buoyant unit weight multiplied by total depth
Answer: B
Total vertical stress is the total overburden pressure exerted by the combined mass of soil
solids and pore water per unit area, representing the sum of effective stress and pore water
pressure.
, 10. When performing a falling head permeability test on a fine-grained silty sand, what
primary hydraulic parameter is being evaluated?
A. Consolidation settlement rate
B. Coefficient of permeability
C. Preconsolidation pressure
D. Swelling pressure index
Answer: B
The falling head permeability test is specifically tailored for fine-grained soils to measure the
rate of water flow through a known cross-section, directly yielding the hydraulic conductivity
or permeability coefficient.
11. A geotechnical report indicates that a cohesive clay layer is normally consolidated.
What term describes the maximum past vertical effective stress experienced by this soil
stratum?
A. Present overburden pressure
B. Preconsolidation pressure
C. Swelling pressure
D. Critical confining stress
Answer: B
Preconsolidation pressure represents the highest effective stress that a soil stratum has
experienced in its geologic history, determining whether a soil is overconsolidated or normally
consolidated.
12. What primary field instrument is installed in a borehole to monitor changes in pore
water pressure over time during embankment construction or slope stabilization?
A. Inclinometer
B. Piezometer
C. Extensometer
D. Settlement plate
Answer: B
Piezometers are specialized geotechnical sensors engineered to measure groundwater
pressures and pore fluid responses within soil layers under varying load conditions.
13. A cantilever retaining wall retains a backfill of dry granular sand. According to
Rankine active earth pressure theory, how is the active lateral earth pressure coefficient
($K_a$) expressed in terms of the internal friction angle ($\phi$) of the backfill?
QUESTIONS AND ANSWERS | SOIL BEARING CAPACITY AND
FOUNDATION DESIGN–COMPLETE STUDY GUIDE | PRACTICE
QUESTIONS AND ANSWERS-RATIONALES | EXAM PREP |
DOWNLOAD INSTANT PDF | GUARANTEED PASS || LATEST
EXAM 2026-2027
1. A geotechnical engineer is evaluating a saturated clay deposit for a multi-story building.
Which laboratory test is most appropriate for determining the undrained shear strength of
the clay core samples without allowing moisture loss during the testing phase?
A. Direct shear test
B. Unconsolidated-undrained (UU) triaxial test
C. Consolidated-drained (CD) triaxial test
D. Standard Proctor compaction test
Answer: B
This test is performed on saturated clay samples without permitting drainage during either the
consolidation or shearing stages, thereby preserving the in-situ moisture condition and
yielding the undrained shear strength (cu).
2. During a subsurface exploration program for a bridge foundation, standard penetration
tests (SPT) are performed. What is the standard hammer weight and drop height specified
for this testing procedure?
A. 140-pound hammer dropped from a height of 30 inches
B. 100-pound hammer dropped from a height of 24 inches
C. 250-pound hammer dropped from a height of 18 inches
D. 50-pound hammer dropped from a height of 36 inches
Answer: A
The standard penetration test utilizes a drop hammer weighing 140 pounds falling freely
through a standardized height of 30 inches to drive a split-barrel sampler into the soil.
3. When analyzing the grain size distribution of a cohesionless sandy soil, a sieve analysis is
performed. Which parameter represents the slope of the grading curve and is calculated as
$D_{60}/D_{10}$?
A. Coefficient of curvature
B. Plasticity index
C. Coefficient of uniformity
,D. Compression index
Answer: C
The coefficient of uniformity is a quantitative measure of particle size range and is defined
mathematically as the ratio of the diameter corresponding to 60 percent finer to that of 10
percent finer.
4. A soil sample has a total mass of 1800 grams and a dry mass of 1500 grams. What is the
gravimetric moisture content of the soil?
A. 15.0 percent
B. 20.0 percent
C. 25.0 percent
D. 30.0 percent
Answer: B
Gravimetric moisture content is calculated as the mass of water divided by the dry mass of the
soil: $((1800 - 1500) / 1500) \times 100 = 20.0$ percent.
5. A cohesive soil exhibits a liquid limit of 50 percent and a plastic limit of 20 percent. If the
natural water content of the in-situ soil is 35 percent, what is the liquidity index?
A. 0.35
B. 0.50
C. 0.65
D. 0.80
Answer: B
Liquidity index is defined as the ratio $(W - PL) / (LL - PL)$. Substituting the given values
yields $(35 - 20) / (50 - 20) = = 0.50$.
6. Which clay mineral is most commonly associated with severe swelling and shrinking
behavior upon moisture variations, posing significant structural hazards to shallow
foundations?
A. Kaolinite
B. Illite
C. Montmorillonite
D. Quartz
Answer: C
,Montmorillonite possesses an expanding crystal lattice structure with weak interlayer bonding
and high specific surface area, allowing extensive water molecule absorption and severe
volume changes.
7. A geotechnical consultant is designing a shallow strip footing on a dense sand layer.
Which failure mode is typically characterized by distinct shear surfaces extending to the
ground surface accompanied by considerable heaving and sudden collapse?
A. General shear failure
B. Local shear failure
C. Punching shear failure
D. Creep failure
Answer: A
General shear failure occurs in dense or stiff soils, marked by well-defined failure wedges,
continuous slip surfaces reaching the surface, and a sudden, catastrophic load drop.
8. Terzaghi’s ultimate bearing capacity equation for a strip footing includes three distinct
bearing capacity factors. What physical soil property primarily dictates the magnitude of
the factor $N_{\gamma}$?
A. Cohesion intercept
B. Internal friction angle
C. Total unit weight
D. Poisson ratio
Answer: B
The bearing capacity factor $N_{\gamma}$ is exclusively a function of the soil shear strength
parameter, specifically the angle of internal friction, governing the contribution of soil weight.
9. In the context of effective stress principles in saturated soils, how is the total vertical
stress at a given depth calculated?
A. Pore water pressure minus effective stress
B. Sum of effective stress and pore water pressure
C. Effective stress multiplied by the void ratio
D. Buoyant unit weight multiplied by total depth
Answer: B
Total vertical stress is the total overburden pressure exerted by the combined mass of soil
solids and pore water per unit area, representing the sum of effective stress and pore water
pressure.
, 10. When performing a falling head permeability test on a fine-grained silty sand, what
primary hydraulic parameter is being evaluated?
A. Consolidation settlement rate
B. Coefficient of permeability
C. Preconsolidation pressure
D. Swelling pressure index
Answer: B
The falling head permeability test is specifically tailored for fine-grained soils to measure the
rate of water flow through a known cross-section, directly yielding the hydraulic conductivity
or permeability coefficient.
11. A geotechnical report indicates that a cohesive clay layer is normally consolidated.
What term describes the maximum past vertical effective stress experienced by this soil
stratum?
A. Present overburden pressure
B. Preconsolidation pressure
C. Swelling pressure
D. Critical confining stress
Answer: B
Preconsolidation pressure represents the highest effective stress that a soil stratum has
experienced in its geologic history, determining whether a soil is overconsolidated or normally
consolidated.
12. What primary field instrument is installed in a borehole to monitor changes in pore
water pressure over time during embankment construction or slope stabilization?
A. Inclinometer
B. Piezometer
C. Extensometer
D. Settlement plate
Answer: B
Piezometers are specialized geotechnical sensors engineered to measure groundwater
pressures and pore fluid responses within soil layers under varying load conditions.
13. A cantilever retaining wall retains a backfill of dry granular sand. According to
Rankine active earth pressure theory, how is the active lateral earth pressure coefficient
($K_a$) expressed in terms of the internal friction angle ($\phi$) of the backfill?
