NICET SOILS LEVEL 1 EXAM
2025-2026 | Questions &
Answers | Compaction + Soil
Classification | Pass
Guaranteed - A+ Graded
ART I: MULTIPLE CHOICE (Q1–Q60)
P
Q1 (Compaction – Proctor): How many layers and blows per layer are required for the Modified
Proctor test using a 4‑inch (101.6 mm) mold (Method A or B)?
A. 3 layers, 25 blows
B. 5 layers, 25 blows
C. 3 layers, 56 blows
D. 5 layers, 56 blows
[CORRECT] D
Rationale: ASTM D1557 / AASHTO T180 specifies 5 layers and 56 blows per layer for the
4‑inch mold (Method A or B). Option A describes the Standard Proctor (ASTM D698 / AASHTO
T99). Option C is not a standard combination, and Option B incorrectly applies Standard Proctor
blows to Modified Proctor layers.
Q2 (Compaction – Proctor): A technician performs a Standard Proctor test on a silty sand. After
the third point, dry density decreases even though moisture content increased. What should
they conclude?
A. The test should be restarted with a new sample
B. The optimum moisture content has been exceeded
C. The mold volume is incorrect
D. The soil is not suitable for compaction testing
[CORRECT] B
Rationale: Per ASTM D698, once dry density decreases with increasing moisture, the peak
(maximum dry density) has been passed, indicating the optimum moisture content (OMC) has
been exceeded. Option A is incorrect because this is expected behavior; Option C would cause
consistent errors, not a peak; Option D is false as all soils can be tested.
, 3 (Compaction – Proctor): What is the primary difference between ASTM D698 (Standard
Q
Proctor) and ASTM D1557 (Modified Proctor)?
A. Mold size
B. Compactive effort (energy per unit volume)
C. Type of soil tested
D. Method of moisture content determination
[CORRECT] B
Rationale: The primary difference is compactive effort—Modified Proctor applies approximately
56,000 ft-lbf/ft³ versus Standard Proctor's 12,400 ft-lbf/ft³. Both use similar mold sizes (Option A
is incorrect); both test the same soil types (Option C is incorrect); and moisture content is
determined the same way per D2216 (Option D is incorrect).
Q4 (Compaction – Proctor): For a one‑point Proctor method, what minimum information is
required from the test?
A. Only the wet density
B. Wet density and moisture content of the point
C. Maximum dry density from a previous full Proctor
D. Specific gravity of the soil solids
[CORRECT] B
Rationale: The one‑point Proctor requires wet density and moisture content to plot a single point
on the family of curves and estimate OMC and MDD. Option A is insufficient without moisture
content; Option C is not required for the one‑point method itself; Option D is used for other
calculations but not one‑point Proctor.
Q5 (Compaction – Proctor): When plotting a Proctor curve, the x‑axis represents moisture
content and the y‑axis represents:
A. Wet density
B. Dry density
C. Void ratio
D. Degree of saturation
[CORRECT] B
Rationale: ASTM D698 and D1557 require plotting dry density (not wet density) versus moisture
content to determine maximum dry density (MDD) and optimum moisture content (OMC).
Option A (wet density) would not show the characteristic peak; Options C and D are not
standard Proctor plot parameters.
Q6 (Compaction – Proctor): A soil sample for Proctor testing is received at the laboratory with a
natural moisture content of 8%. The technician should:
A. Begin testing immediately at 8% moisture
B. Dry the sample to near zero moisture before testing
C. Add water to achieve approximately 4% below expected OMC and test multiple points
D. Discard the sample if it is not at OMC
[CORRECT] C
Rationale: ASTM D698 requires preparing samples at moisture contents bracketing the
expected OMC, typically starting 4–6% below OMC and adding water incrementally. Option A
would yield only one data point; Option B is unnecessary and would alter soil properties; Option
D is incorrect as samples are rarely received at OMC.
, 7 (Compaction – Proctor): During a Modified Proctor test, the technician notices the compactor
Q
rammer is dropping from 18 inches instead of the specified 12 inches. The test results will:
A. Be unaffected
B. Show higher maximum dry density
C. Show lower maximum dry density
D. Be invalid and must be repeated
[CORRECT] D
Rationale: ASTM D1557 specifies a 12‑inch (305 mm) free‑drop height; any deviation
invalidates the test. Option A is incorrect because drop height directly affects compactive
energy; Options B and C are irrelevant because the test must be repeated with proper
equipment.
Q8 (Compaction – Proctor): The correction for oversize particles (retained on the ¾‑inch sieve)
in a Proctor test is applied when:
A. More than 5% by mass is retained on the ¾‑inch sieve
B. More than 30% by mass is retained on the ¾‑inch sieve
C. Any amount is retained on the ¾‑inch sieve
D. Only when testing rock fill
[CORRECT] B
Rationale: ASTM D1557 Method C and D698 Method C apply when more than 30% by mass is
retained on the ¾‑inch (19.0 mm) sieve, using correction equations based on the percentage of
oversize material. Option A refers to the limit for standard testing without correction; Option C is
too broad; Option D is not the specific criterion.
Q9 (Field Density Testing): The sand cone method (ASTM D1556) determines in‑place density
by:
A. Measuring the weight of soil removed and the volume of the hole using calibrated sand
B. Directly measuring soil moisture with a nuclear gauge
C. Calculating volume from rubber balloon displacement
D. Weighing the soil and dividing by the mold volume
[CORRECT] A
Rationale: ASTM D1556 measures the mass of soil removed from a test hole and determines
the hole volume by filling it with calibrated sand of known density. Option B describes nuclear
gauge testing; Option C describes the rubber balloon method (D2167); Option D describes
laboratory mold testing.
Q10 (Field Density Testing): Before using a sand cone apparatus for field density testing, the
technician must determine:
A. The specific gravity of the soil
B. The density of the sand (sand cone factor)
C. The Atterberg limits of the soil
D. The organic content of the soil
[CORRECT] B
Rationale: ASTM D1556 requires calibration of the sand density (sand cone factor) by filling a
container of known volume. Without this calibration, hole volume cannot be accurately
determined. Options A, C, and D are unrelated to sand cone calibration.
2025-2026 | Questions &
Answers | Compaction + Soil
Classification | Pass
Guaranteed - A+ Graded
ART I: MULTIPLE CHOICE (Q1–Q60)
P
Q1 (Compaction – Proctor): How many layers and blows per layer are required for the Modified
Proctor test using a 4‑inch (101.6 mm) mold (Method A or B)?
A. 3 layers, 25 blows
B. 5 layers, 25 blows
C. 3 layers, 56 blows
D. 5 layers, 56 blows
[CORRECT] D
Rationale: ASTM D1557 / AASHTO T180 specifies 5 layers and 56 blows per layer for the
4‑inch mold (Method A or B). Option A describes the Standard Proctor (ASTM D698 / AASHTO
T99). Option C is not a standard combination, and Option B incorrectly applies Standard Proctor
blows to Modified Proctor layers.
Q2 (Compaction – Proctor): A technician performs a Standard Proctor test on a silty sand. After
the third point, dry density decreases even though moisture content increased. What should
they conclude?
A. The test should be restarted with a new sample
B. The optimum moisture content has been exceeded
C. The mold volume is incorrect
D. The soil is not suitable for compaction testing
[CORRECT] B
Rationale: Per ASTM D698, once dry density decreases with increasing moisture, the peak
(maximum dry density) has been passed, indicating the optimum moisture content (OMC) has
been exceeded. Option A is incorrect because this is expected behavior; Option C would cause
consistent errors, not a peak; Option D is false as all soils can be tested.
, 3 (Compaction – Proctor): What is the primary difference between ASTM D698 (Standard
Q
Proctor) and ASTM D1557 (Modified Proctor)?
A. Mold size
B. Compactive effort (energy per unit volume)
C. Type of soil tested
D. Method of moisture content determination
[CORRECT] B
Rationale: The primary difference is compactive effort—Modified Proctor applies approximately
56,000 ft-lbf/ft³ versus Standard Proctor's 12,400 ft-lbf/ft³. Both use similar mold sizes (Option A
is incorrect); both test the same soil types (Option C is incorrect); and moisture content is
determined the same way per D2216 (Option D is incorrect).
Q4 (Compaction – Proctor): For a one‑point Proctor method, what minimum information is
required from the test?
A. Only the wet density
B. Wet density and moisture content of the point
C. Maximum dry density from a previous full Proctor
D. Specific gravity of the soil solids
[CORRECT] B
Rationale: The one‑point Proctor requires wet density and moisture content to plot a single point
on the family of curves and estimate OMC and MDD. Option A is insufficient without moisture
content; Option C is not required for the one‑point method itself; Option D is used for other
calculations but not one‑point Proctor.
Q5 (Compaction – Proctor): When plotting a Proctor curve, the x‑axis represents moisture
content and the y‑axis represents:
A. Wet density
B. Dry density
C. Void ratio
D. Degree of saturation
[CORRECT] B
Rationale: ASTM D698 and D1557 require plotting dry density (not wet density) versus moisture
content to determine maximum dry density (MDD) and optimum moisture content (OMC).
Option A (wet density) would not show the characteristic peak; Options C and D are not
standard Proctor plot parameters.
Q6 (Compaction – Proctor): A soil sample for Proctor testing is received at the laboratory with a
natural moisture content of 8%. The technician should:
A. Begin testing immediately at 8% moisture
B. Dry the sample to near zero moisture before testing
C. Add water to achieve approximately 4% below expected OMC and test multiple points
D. Discard the sample if it is not at OMC
[CORRECT] C
Rationale: ASTM D698 requires preparing samples at moisture contents bracketing the
expected OMC, typically starting 4–6% below OMC and adding water incrementally. Option A
would yield only one data point; Option B is unnecessary and would alter soil properties; Option
D is incorrect as samples are rarely received at OMC.
, 7 (Compaction – Proctor): During a Modified Proctor test, the technician notices the compactor
Q
rammer is dropping from 18 inches instead of the specified 12 inches. The test results will:
A. Be unaffected
B. Show higher maximum dry density
C. Show lower maximum dry density
D. Be invalid and must be repeated
[CORRECT] D
Rationale: ASTM D1557 specifies a 12‑inch (305 mm) free‑drop height; any deviation
invalidates the test. Option A is incorrect because drop height directly affects compactive
energy; Options B and C are irrelevant because the test must be repeated with proper
equipment.
Q8 (Compaction – Proctor): The correction for oversize particles (retained on the ¾‑inch sieve)
in a Proctor test is applied when:
A. More than 5% by mass is retained on the ¾‑inch sieve
B. More than 30% by mass is retained on the ¾‑inch sieve
C. Any amount is retained on the ¾‑inch sieve
D. Only when testing rock fill
[CORRECT] B
Rationale: ASTM D1557 Method C and D698 Method C apply when more than 30% by mass is
retained on the ¾‑inch (19.0 mm) sieve, using correction equations based on the percentage of
oversize material. Option A refers to the limit for standard testing without correction; Option C is
too broad; Option D is not the specific criterion.
Q9 (Field Density Testing): The sand cone method (ASTM D1556) determines in‑place density
by:
A. Measuring the weight of soil removed and the volume of the hole using calibrated sand
B. Directly measuring soil moisture with a nuclear gauge
C. Calculating volume from rubber balloon displacement
D. Weighing the soil and dividing by the mold volume
[CORRECT] A
Rationale: ASTM D1556 measures the mass of soil removed from a test hole and determines
the hole volume by filling it with calibrated sand of known density. Option B describes nuclear
gauge testing; Option C describes the rubber balloon method (D2167); Option D describes
laboratory mold testing.
Q10 (Field Density Testing): Before using a sand cone apparatus for field density testing, the
technician must determine:
A. The specific gravity of the soil
B. The density of the sand (sand cone factor)
C. The Atterberg limits of the soil
D. The organic content of the soil
[CORRECT] B
Rationale: ASTM D1556 requires calibration of the sand density (sand cone factor) by filling a
container of known volume. Without this calibration, hole volume cannot be accurately
determined. Options A, C, and D are unrelated to sand cone calibration.
