California Certified Engineering Geologist (CEG)
Exam 2026 Actual Exam 2026/2027 Practice
Questions with Detailed Answers and Rationales
– Pass Guaranteed – A+ Graded
Engineering Geology Principles & Site Characterization (18 questions)
Q1: When logging core from a granite intrusion, you record a total core run of 150 cm
with 85 cm of sound, unweathered core pieces longer than 10 cm. What is the Rock
Quality Designation (RQD) for this run?
A. 43%
B. 57% [CORRECT]
C. 67%
D. 85%
Correct Answer: B
Rationale: RQD is calculated by summing only the pieces of sound core longer than 10
cm, then dividing by the total run length. Here, 85 cm divided by 150 cm gives you about
57%, which puts this rock in the "fair" quality category—something you'd note in your
field book when characterizing the rock mass for foundation design.
Q2: During a site reconnaissance in the Coast Ranges, you encounter a granitic rock
where the feldspars are chalky white and the biotite is stained brown. The rock can be
broken by hand with moderate effort. What weathering grade does this represent?
A. Fresh rock (Grade I)
B. Slightly weathered (Grade II)
C. Moderately weathered (Grade III) [CORRECT]
D. Highly weathered (Grade IV)
Correct Answer: C
,Rationale: When you can break the rock by hand but it's still mostly intact with
discoloration and staining of minerals, you're looking at moderate weathering—Grade
III—which typically shows that significant strength reduction has occurred and you'd
likely recommend deeper foundations or ground improvement.
Q3: A soil sample retrieved from a boring has 65% passing the No. 200 sieve, a liquid
limit of 38, and a plasticity index of 16. How would you classify this soil using the
Unified Soil Classification System (USCS)?
A. CH
B. CL [CORRECT]
C. ML
D. SC
Correct Answer: B
Rationale: With more than 50% fines and a liquid limit under 50, you're in the CL or ML
range; since the plasticity index of 16 plots above the A-line (0.73(38-20)=13.14), this
soil classifies as lean clay (CL)—a common finding in the residual soils of California's
Coast Ranges.
Q4: You're evaluating bearing capacity for a spread footing founded on dense,
well-graded sand with an SPT N-value of 35. What approximate bearing capacity value
would you expect for general shear failure conditions?
A. 1,000 psf
B. 4,000 psf
C. 8,000 psf [CORRECT]
D. 20,000 psf
Correct Answer: C
Rationale: Dense sand with N-values in the mid-30s typically yields allowable bearing
pressures around 6,000 to 10,000 psf depending on width and depth; 8,000 psf is a
reasonable working value you'd use for preliminary foundation sizing before running the
full Terzaghi calculations.
Q5: A medium stiff clay layer beneath a proposed warehouse shows a compression
index (Cc) of 0.25, an initial void ratio of 0.8, and is expected to experience a stress
increase of 2 tsf. Which statement best describes the settlement potential?
A. Negligible settlement less than 0.5 inches
,B. Immediate elastic settlement only
C. Consolidation settlement will be the primary concern [CORRECT]
D. Heave is likely due to swelling
Correct Answer: C
Rationale: With a measurable compression index and significant stress increase on clay,
you're looking at time-dependent consolidation settlement—this is what keeps us up at
night with structures on Bay Mud or similar deposits, requiring preloading or deep
foundations to limit differential settlement.
Q6: Under the AASHTO classification system, which group typically includes gravelly
soils with excellent bearing characteristics for highway subgrades?
A. A-1-a [CORRECT]
B. A-3
C. A-6
D. A-7-6
Correct Answer: A
Rationale: AASHTO A-1-a represents the premium materials—well-graded gravels and
sands with minimal fines—that provide the best support for pavement sections and
typically don't require stabilization or extensive processing.
Q7: You're reviewing lab data for a site in the Central Valley and see two samples:
Sample A has LL=55, PL=30; Sample B has LL=35, PL=15. Which sample likely presents
greater expansion potential when wetted?
A. Sample A due to higher plasticity index [CORRECT]
B. Sample B due to lower liquid limit
C. Both samples have equal expansion potential
D. Neither sample shows expansive characteristics
Correct Answer: A
Rationale: Sample A's plasticity index of 25 indicates a highly plastic clay, and in the
Central Valley's cyclic wet-dry climate, those high-PI soils can wreak havoc on
foundations with volume changes of 10% or more—definitely the one you'd flag for
special foundation design.
Q8: During a rock slope assessment, you calculate the Rock Mass Rating (RMR) as 42.
What general description and support requirement would you expect for this slope?
, A. Very good rock, no support needed
B. Good rock, spot bolting
C. Fair rock, systematic support required [CORRECT]
D. Poor rock, heavy support
Correct Answer: C
Rationale: An RMR of 42 falls squarely in the "fair" category—this rock will stand
temporarily but needs systematic bolting and possibly wire mesh to prevent raveling
and wedge failures, especially if water gets into the joints.
Q9: In a saturated soil profile, which condition represents the effective stress at a depth
of 20 feet below ground surface, given total unit weight of 130 pcf and groundwater at
10 feet depth?
A. 2,600 psf
B. 1,988 psf [CORRECT]
C. 1,300 psf
D. 624 psf
Correct Answer: B
Rationale: Total stress is 2,600 psf, pore pressure from 10 feet of water is about 624
psf, giving you effective stress around 1,976 psf—it's this effective stress that actually
controls soil strength and settlement, not the total weight of the overburden.
Q10: A site investigation reveals brown silty clay with slickensides, high plasticity, and
wet conditions at 8 feet depth. What engineering behavior is most concerning for
foundation design?
A. Liquefaction during seismic events
B. Expansion potential with moisture changes [CORRECT]
C. Frost heave in winter months
D. Capillary rise causing evaporation
Correct Answer: B
Rationale: Those slickensides and high plasticity point to an expansive soil—likely a
former mudstone or weathered shale—that will shrink and swell with seasonal moisture
changes, potentially exerting thousands of pounds per square foot of uplift pressure on
slabs and foundations.
Exam 2026 Actual Exam 2026/2027 Practice
Questions with Detailed Answers and Rationales
– Pass Guaranteed – A+ Graded
Engineering Geology Principles & Site Characterization (18 questions)
Q1: When logging core from a granite intrusion, you record a total core run of 150 cm
with 85 cm of sound, unweathered core pieces longer than 10 cm. What is the Rock
Quality Designation (RQD) for this run?
A. 43%
B. 57% [CORRECT]
C. 67%
D. 85%
Correct Answer: B
Rationale: RQD is calculated by summing only the pieces of sound core longer than 10
cm, then dividing by the total run length. Here, 85 cm divided by 150 cm gives you about
57%, which puts this rock in the "fair" quality category—something you'd note in your
field book when characterizing the rock mass for foundation design.
Q2: During a site reconnaissance in the Coast Ranges, you encounter a granitic rock
where the feldspars are chalky white and the biotite is stained brown. The rock can be
broken by hand with moderate effort. What weathering grade does this represent?
A. Fresh rock (Grade I)
B. Slightly weathered (Grade II)
C. Moderately weathered (Grade III) [CORRECT]
D. Highly weathered (Grade IV)
Correct Answer: C
,Rationale: When you can break the rock by hand but it's still mostly intact with
discoloration and staining of minerals, you're looking at moderate weathering—Grade
III—which typically shows that significant strength reduction has occurred and you'd
likely recommend deeper foundations or ground improvement.
Q3: A soil sample retrieved from a boring has 65% passing the No. 200 sieve, a liquid
limit of 38, and a plasticity index of 16. How would you classify this soil using the
Unified Soil Classification System (USCS)?
A. CH
B. CL [CORRECT]
C. ML
D. SC
Correct Answer: B
Rationale: With more than 50% fines and a liquid limit under 50, you're in the CL or ML
range; since the plasticity index of 16 plots above the A-line (0.73(38-20)=13.14), this
soil classifies as lean clay (CL)—a common finding in the residual soils of California's
Coast Ranges.
Q4: You're evaluating bearing capacity for a spread footing founded on dense,
well-graded sand with an SPT N-value of 35. What approximate bearing capacity value
would you expect for general shear failure conditions?
A. 1,000 psf
B. 4,000 psf
C. 8,000 psf [CORRECT]
D. 20,000 psf
Correct Answer: C
Rationale: Dense sand with N-values in the mid-30s typically yields allowable bearing
pressures around 6,000 to 10,000 psf depending on width and depth; 8,000 psf is a
reasonable working value you'd use for preliminary foundation sizing before running the
full Terzaghi calculations.
Q5: A medium stiff clay layer beneath a proposed warehouse shows a compression
index (Cc) of 0.25, an initial void ratio of 0.8, and is expected to experience a stress
increase of 2 tsf. Which statement best describes the settlement potential?
A. Negligible settlement less than 0.5 inches
,B. Immediate elastic settlement only
C. Consolidation settlement will be the primary concern [CORRECT]
D. Heave is likely due to swelling
Correct Answer: C
Rationale: With a measurable compression index and significant stress increase on clay,
you're looking at time-dependent consolidation settlement—this is what keeps us up at
night with structures on Bay Mud or similar deposits, requiring preloading or deep
foundations to limit differential settlement.
Q6: Under the AASHTO classification system, which group typically includes gravelly
soils with excellent bearing characteristics for highway subgrades?
A. A-1-a [CORRECT]
B. A-3
C. A-6
D. A-7-6
Correct Answer: A
Rationale: AASHTO A-1-a represents the premium materials—well-graded gravels and
sands with minimal fines—that provide the best support for pavement sections and
typically don't require stabilization or extensive processing.
Q7: You're reviewing lab data for a site in the Central Valley and see two samples:
Sample A has LL=55, PL=30; Sample B has LL=35, PL=15. Which sample likely presents
greater expansion potential when wetted?
A. Sample A due to higher plasticity index [CORRECT]
B. Sample B due to lower liquid limit
C. Both samples have equal expansion potential
D. Neither sample shows expansive characteristics
Correct Answer: A
Rationale: Sample A's plasticity index of 25 indicates a highly plastic clay, and in the
Central Valley's cyclic wet-dry climate, those high-PI soils can wreak havoc on
foundations with volume changes of 10% or more—definitely the one you'd flag for
special foundation design.
Q8: During a rock slope assessment, you calculate the Rock Mass Rating (RMR) as 42.
What general description and support requirement would you expect for this slope?
, A. Very good rock, no support needed
B. Good rock, spot bolting
C. Fair rock, systematic support required [CORRECT]
D. Poor rock, heavy support
Correct Answer: C
Rationale: An RMR of 42 falls squarely in the "fair" category—this rock will stand
temporarily but needs systematic bolting and possibly wire mesh to prevent raveling
and wedge failures, especially if water gets into the joints.
Q9: In a saturated soil profile, which condition represents the effective stress at a depth
of 20 feet below ground surface, given total unit weight of 130 pcf and groundwater at
10 feet depth?
A. 2,600 psf
B. 1,988 psf [CORRECT]
C. 1,300 psf
D. 624 psf
Correct Answer: B
Rationale: Total stress is 2,600 psf, pore pressure from 10 feet of water is about 624
psf, giving you effective stress around 1,976 psf—it's this effective stress that actually
controls soil strength and settlement, not the total weight of the overburden.
Q10: A site investigation reveals brown silty clay with slickensides, high plasticity, and
wet conditions at 8 feet depth. What engineering behavior is most concerning for
foundation design?
A. Liquefaction during seismic events
B. Expansion potential with moisture changes [CORRECT]
C. Frost heave in winter months
D. Capillary rise causing evaporation
Correct Answer: B
Rationale: Those slickensides and high plasticity point to an expansive soil—likely a
former mudstone or weathered shale—that will shrink and swell with seasonal moisture
changes, potentially exerting thousands of pounds per square foot of uplift pressure on
slabs and foundations.
