CALIFORNIA CERTIFIED ENGINEERING GEOLOGIST
(CEG) EXAMINATION 2026-2027 EDITION 100
QUESTIONS AND CORRECT ANSWERS WITH
RATIONALES LATEST VERSION 2026-2027 (VERIFIED
ANSWERS) ALREADY GRADED A+
1. A CEG evaluates a slope underlain by interbedded sandstone and claystone. The claystone
beds dip out of the slope at 20°, and a persistent joint set strikes parallel to the slope face and
dips 60° into the slope. Which type of slope failure is most likely to control stability?
A. Wedge failure on intersecting joints
B. Planar failure along the claystone bedding
C. Circular failure through the rock mass
D. Toppling failure of sandstone blocks
Answer: B
Rationale: The claystone bedding planes dip out of the slope at a shallow angle, creating a
potential plane of weakness for planar sliding. While the joint set dips into the slope and does
not daylight, planar failure along claystone is the kinematically feasible mode. Wedge failure
requires two intersecting discontinuities that daylight; toppling would require steeply dipping
planes into the slope, not out of it.
2. According to the California Building Code, a geotechnical investigation for a structure
assigned to Seismic Design Category D must include an evaluation of:
A. Liquefaction potential and lateral spreading
B. Wind-borne debris impact
C. Snow load drifting
D. Thermal expansion of concrete
Answer: A
Rationale: In high seismic design categories, the code mandates assessment of liquefaction,
lateral spreading, and other seismic hazards. Wind debris and snow loads are structural
considerations but not the primary focus of the geotechnical seismic evaluation. Thermal
expansion is a material design issue.
,3. A standard penetration test (SPT) sampler driven in a dense sand yields 50 blows for the
second 6-inch increment and 55 blows for the third. What N-value should be recorded?
A. 50
B. 105
C. 105 (refusal)
D. 55
Answer: B
Rationale: SPT N-value is the sum of blows for the last two 6-inch increments (6 to 18 inches),
so 50 + 55 = 105. The first 6-inch seating drive is excluded. Refusal is typically defined as 50
blows in a single increment without full penetration, not the sum.
4. A CEG maps a fault trench and finds Holocene-age colluvial wedges and fissure fills
indicating multiple surface-rupturing events. Under the Alquist-Priolo Act, this fault would be
classified as:
A. Inactive
B. Potentially active
C. Active
D. Pre-Quaternary
Answer: C
Rationale: The Act defines an active fault as one with evidence of surface displacement during
Holocene time (approximately the last 11,700 years). Colluvial wedges from multiple events
confirm Holocene activity. Potentially active faults show Quaternary displacement but no
proven Holocene rupture.
5. For a purely cohesionless sand, the effective stress shear strength envelope on a Mohr-
Coulomb plot passes through the origin. This indicates:
A. Cohesion intercept is zero and strength depends solely on friction angle
B. Friction angle is zero
C. Pore pressure is always negative
D. The sand is normally consolidated
Answer: A
Rationale: Clean sands have negligible effective cohesion (c'=0); shear strength is given by τ =
σ' tan(φ'). A zero intercept means the failure envelope starts at the origin. Normally
consolidated clays also exhibit c'≈0, but the statement specifically describes cohesionless soil
behavior.
6. When a borehole encounters a highly fractured, intensely weathered granitic rock that can
be broken by hand and crumbles easily, the material should be logged as:
,A. Residual soil
B. Completely weathered rock
C. Slightly weathered rock
D. Fresh rock
Answer: A
Rationale: If the material behaves as a soil (can be crumbled by hand, relict texture but no
rock strength), it is logged as residual soil (grade VI). Completely weathered rock (grade V)
retains rock fabric but can be broken by hand without crumbling into soil. The distinction is
important for engineering properties.
7. A site investigation reveals the presence of chrysotile asbestos in naturally occurring
ultramafic rock. Under California regulations, a CEG must:
A. Ignore the finding as it is natural
B. Identify it as a hazardous mineral and recommend an asbestos management plan in
accordance with Air Resources Board and local requirements
C. Remove all rock immediately
D. Label the site as a Superfund site
Answer: B
Rationale: Naturally occurring asbestos (NOA) is a regulated hazardous material. The CEG
must recognize it, inform the client, and recommend appropriate dust control, air monitoring,
and handling procedures per local air district and Cal/OSHA requirements. Immediate
removal without a plan may cause exposure.
8. In a seismic refraction survey over a two-layer earth, the crossover distance is the point
where:
A. The direct wave and refracted wave arrive at the same time
B. The source is turned off
C. The S-wave overtakes the P-wave
D. The geophone spacing is doubled
Answer: A
Rationale: The crossover distance is the offset at which travel times for the direct wave and
the head wave (refraction from the deeper layer) are equal. Beyond this distance, the
refracted wave is the first arrival. This concept is used to determine layer velocities and
depths.
9. A 20-foot-thick clay layer has a consolidation settlement estimated at 3 inches under an
applied load. How much settlement would be expected if the layer were 40 feet thick with
identical properties and loading?
, A. 3 inches
B. 6 inches
C. 1.5 inches
D. 9 inches
Answer: B
Rationale: For a uniform load, consolidation settlement is proportional to the thickness of the
compressible layer (assuming the same stress increase and soil properties). Doubling the
thickness from 20 ft to 40 ft roughly doubles the settlement, from 3 in to 6 in. Non-linearity
from preconsolidation could alter this, but given identical conditions, linear scaling applies.
10. A CEG is responsible for performing an engineering geologic evaluation of a proposed cut
slope. The most critical engineering property to determine for design of the cut angle in a
fractured rock mass is:
A. Uniaxial compressive strength of intact rock
B. Shear strength along discontinuities (joints, bedding)
C. Rock color
D. Porosity
Answer: B
Rationale: Stability of rock cuts is governed primarily by the orientation and shear strength of
discontinuities, not intact rock strength, unless the rock mass is massive. Joint roughness,
infilling, and persistence control the friction angle and cohesion along potential failure planes.
11. During a Cone Penetration Test (CPT), the pore pressure measured behind the cone tip (u₂)
is used to:
A. Calculate friction ratio
B. Correct the cone tip resistance to total stress
C. Estimate hydraulic conductivity directly
D. Determine soil grain size precisely
Answer: B
Rationale: Pore pressure measurements allow correction of the cone resistance (qc) to total
tip resistance (qₜ) by accounting for pore pressure effects on the unequal end area. Friction
ratio uses sleeve friction and qc; CPT does not directly measure hydraulic conductivity or exact
grain size, though correlations exist.
12. The Seismic Hazards Mapping Act designates zones of required investigation for
liquefaction. A site within such a zone requires that the investigation be performed by:
A. Any licensed contractor
B. A geotechnical engineer or CEG working under responsible charge
(CEG) EXAMINATION 2026-2027 EDITION 100
QUESTIONS AND CORRECT ANSWERS WITH
RATIONALES LATEST VERSION 2026-2027 (VERIFIED
ANSWERS) ALREADY GRADED A+
1. A CEG evaluates a slope underlain by interbedded sandstone and claystone. The claystone
beds dip out of the slope at 20°, and a persistent joint set strikes parallel to the slope face and
dips 60° into the slope. Which type of slope failure is most likely to control stability?
A. Wedge failure on intersecting joints
B. Planar failure along the claystone bedding
C. Circular failure through the rock mass
D. Toppling failure of sandstone blocks
Answer: B
Rationale: The claystone bedding planes dip out of the slope at a shallow angle, creating a
potential plane of weakness for planar sliding. While the joint set dips into the slope and does
not daylight, planar failure along claystone is the kinematically feasible mode. Wedge failure
requires two intersecting discontinuities that daylight; toppling would require steeply dipping
planes into the slope, not out of it.
2. According to the California Building Code, a geotechnical investigation for a structure
assigned to Seismic Design Category D must include an evaluation of:
A. Liquefaction potential and lateral spreading
B. Wind-borne debris impact
C. Snow load drifting
D. Thermal expansion of concrete
Answer: A
Rationale: In high seismic design categories, the code mandates assessment of liquefaction,
lateral spreading, and other seismic hazards. Wind debris and snow loads are structural
considerations but not the primary focus of the geotechnical seismic evaluation. Thermal
expansion is a material design issue.
,3. A standard penetration test (SPT) sampler driven in a dense sand yields 50 blows for the
second 6-inch increment and 55 blows for the third. What N-value should be recorded?
A. 50
B. 105
C. 105 (refusal)
D. 55
Answer: B
Rationale: SPT N-value is the sum of blows for the last two 6-inch increments (6 to 18 inches),
so 50 + 55 = 105. The first 6-inch seating drive is excluded. Refusal is typically defined as 50
blows in a single increment without full penetration, not the sum.
4. A CEG maps a fault trench and finds Holocene-age colluvial wedges and fissure fills
indicating multiple surface-rupturing events. Under the Alquist-Priolo Act, this fault would be
classified as:
A. Inactive
B. Potentially active
C. Active
D. Pre-Quaternary
Answer: C
Rationale: The Act defines an active fault as one with evidence of surface displacement during
Holocene time (approximately the last 11,700 years). Colluvial wedges from multiple events
confirm Holocene activity. Potentially active faults show Quaternary displacement but no
proven Holocene rupture.
5. For a purely cohesionless sand, the effective stress shear strength envelope on a Mohr-
Coulomb plot passes through the origin. This indicates:
A. Cohesion intercept is zero and strength depends solely on friction angle
B. Friction angle is zero
C. Pore pressure is always negative
D. The sand is normally consolidated
Answer: A
Rationale: Clean sands have negligible effective cohesion (c'=0); shear strength is given by τ =
σ' tan(φ'). A zero intercept means the failure envelope starts at the origin. Normally
consolidated clays also exhibit c'≈0, but the statement specifically describes cohesionless soil
behavior.
6. When a borehole encounters a highly fractured, intensely weathered granitic rock that can
be broken by hand and crumbles easily, the material should be logged as:
,A. Residual soil
B. Completely weathered rock
C. Slightly weathered rock
D. Fresh rock
Answer: A
Rationale: If the material behaves as a soil (can be crumbled by hand, relict texture but no
rock strength), it is logged as residual soil (grade VI). Completely weathered rock (grade V)
retains rock fabric but can be broken by hand without crumbling into soil. The distinction is
important for engineering properties.
7. A site investigation reveals the presence of chrysotile asbestos in naturally occurring
ultramafic rock. Under California regulations, a CEG must:
A. Ignore the finding as it is natural
B. Identify it as a hazardous mineral and recommend an asbestos management plan in
accordance with Air Resources Board and local requirements
C. Remove all rock immediately
D. Label the site as a Superfund site
Answer: B
Rationale: Naturally occurring asbestos (NOA) is a regulated hazardous material. The CEG
must recognize it, inform the client, and recommend appropriate dust control, air monitoring,
and handling procedures per local air district and Cal/OSHA requirements. Immediate
removal without a plan may cause exposure.
8. In a seismic refraction survey over a two-layer earth, the crossover distance is the point
where:
A. The direct wave and refracted wave arrive at the same time
B. The source is turned off
C. The S-wave overtakes the P-wave
D. The geophone spacing is doubled
Answer: A
Rationale: The crossover distance is the offset at which travel times for the direct wave and
the head wave (refraction from the deeper layer) are equal. Beyond this distance, the
refracted wave is the first arrival. This concept is used to determine layer velocities and
depths.
9. A 20-foot-thick clay layer has a consolidation settlement estimated at 3 inches under an
applied load. How much settlement would be expected if the layer were 40 feet thick with
identical properties and loading?
, A. 3 inches
B. 6 inches
C. 1.5 inches
D. 9 inches
Answer: B
Rationale: For a uniform load, consolidation settlement is proportional to the thickness of the
compressible layer (assuming the same stress increase and soil properties). Doubling the
thickness from 20 ft to 40 ft roughly doubles the settlement, from 3 in to 6 in. Non-linearity
from preconsolidation could alter this, but given identical conditions, linear scaling applies.
10. A CEG is responsible for performing an engineering geologic evaluation of a proposed cut
slope. The most critical engineering property to determine for design of the cut angle in a
fractured rock mass is:
A. Uniaxial compressive strength of intact rock
B. Shear strength along discontinuities (joints, bedding)
C. Rock color
D. Porosity
Answer: B
Rationale: Stability of rock cuts is governed primarily by the orientation and shear strength of
discontinuities, not intact rock strength, unless the rock mass is massive. Joint roughness,
infilling, and persistence control the friction angle and cohesion along potential failure planes.
11. During a Cone Penetration Test (CPT), the pore pressure measured behind the cone tip (u₂)
is used to:
A. Calculate friction ratio
B. Correct the cone tip resistance to total stress
C. Estimate hydraulic conductivity directly
D. Determine soil grain size precisely
Answer: B
Rationale: Pore pressure measurements allow correction of the cone resistance (qc) to total
tip resistance (qₜ) by accounting for pore pressure effects on the unequal end area. Friction
ratio uses sleeve friction and qc; CPT does not directly measure hydraulic conductivity or exact
grain size, though correlations exist.
12. The Seismic Hazards Mapping Act designates zones of required investigation for
liquefaction. A site within such a zone requires that the investigation be performed by:
A. Any licensed contractor
B. A geotechnical engineer or CEG working under responsible charge
