CSLB C-12 Earthwork and Paving (Trade Exam) — All Questions

A grade stake reads "C 0.8." What does it tell the operator?

• a.The compaction must reach 0.8 of maximum density
• b.The finish grade is 0.8 foot below the existing ground at the stake✓
• c.The stake is offset 0.8 foot from the centerline
• d.The finish grade is 0.8 foot above the existing ground at the stake

C stands for cut: the finish is below the existing ground, so 0.8 foot of material is removed. An F stake would show the finish above ground, offsets are written as separate distances, and compaction is not communicated on a grade stake.Surveying and grade-control practice

A 22-foot-wide pavement has a crown at its centerline and a 2 percent cross slope each way. How much lower is each edge than the centerline?

• a.2.2 feet
• b.0.02 foot
• c.0.44 foot
• d.0.22 foot✓

Half the width is 11 feet, and 11 × 0.02 = 0.22 foot. Using the full 22 feet gives 0.44, 0.02 forgets the width, and 2.2 feet shifts the decimal.Grade-control practice (cross slope)

Under the State earthwork specification, how must the grading plane be prepared where hot mix asphalt is to be placed?

• a.No higher than the established grade
• b.Within 0.5 foot above or below the grade
• c.Within 0.05 foot above or below grade✓
• d.Within 0.10 foot below the established grade

Where HMA is placed the grading plane may not vary more than 0.05 foot above or below the established grade. Half a foot is the slope tolerance for excavation slopes, a grading plane no higher than the grade is the rule for concrete base rather than asphalt, and 0.10 foot below grade alone ignores the allowance above grade.Caltrans 2024 Standard Specifications §19-1.03C

How far may the finished aggregate base surface vary from the grade established by the engineer?

• a.Not more than 0.25 foot
• b.Not more than 0.05 foot✓
• c.Not more than 0.01 foot
• d.Not more than 0.5 foot

The finished aggregate base surface must not vary more than 0.05 foot from the established grade. Half a foot is the slope tolerance, 0.01 foot is the curb straightedge tolerance, and a quarter foot is a figure with no basis in the specification.Caltrans 2024 Standard Specifications §26-1.03E

A new curb and gutter is checked with a 10-foot straightedge. How flat must the top and face of the curb and the gutter surface be, except at grade changes or curves?

• a.Within 0.05 foot
• b.Within 0.1 foot
• c.Within 0.02 foot
• d.Within 0.01 foot✓

The curb top and face and the gutter surface must be flat to within 0.01 foot under a 10-foot straightedge. The sidewalk finish tolerance is 0.02 foot, the base tolerance is 0.05 foot, and 0.1 foot is far too loose.Caltrans 2024 Standard Specifications §73-2.03A

The completed surface of a cold-planed pavement is checked with a 12-foot straightedge parallel to the centerline. What is the maximum variation?

• a.0.03 foot of depth plus 0.03 foot of slope
• b.0.05 foot
• c.0.15 foot
• d.0.02 foot✓

The planed surface may not vary more than 0.02 foot under a 12-foot straightedge parallel to the centerline. The 0.05 foot figure is the base tolerance, 0.15 foot is the drop-off limit between open lanes, and 0.03 foot is the allowed depth adjustment and the transverse slope variation, which are not added to the straightedge limit.Caltrans 2024 Standard Specifications §39-3.04C(2)

What cross fall must each embankment layer have while it is being constructed under the State specification?

• a.At least 8 percent
• b.Greater than 10 percent
• c.Level, to give a flat compaction surface
• d.Less than 5 percent✓

Each embankment layer is built with a cross fall of less than 5 percent so that it sheds water without being steep enough to slide. A level layer would hold water, and cross falls of 8 percent or more than 10 percent are steeper than the specified limit.Caltrans 2024 Standard Specifications §19-6.03C

Under the Cal/OSHA soil classification, what is the minimum unconfined compressive strength of Type A soil?

• a.1.5 tons per square foot✓
• b.3.0 tons per square foot
• c.1.0 ton per square foot
• d.0.5 ton per square foot

Type A soil is cohesive soil with an unconfined compressive strength of 1.5 tons per square foot or greater. Half a ton per square foot is the Type C ceiling and the Type B floor, 1.0 ton per square foot is not a class boundary, and 3.0 tons per square foot is not a threshold in the classification.8 CCR §1541.1 Appendix A

How is a clean sand with water seeping from the trench wall classified?

• a.Type B
• b.Stable rock
• c.Type C✓
• d.Type A

Granular soils such as sand are Type C, and submerged soil or soil from which water is freely seeping is also Type C. Type A is cohesive and strong, Type B is intermediate, and sand is not rock.8 CCR §1541.1 Appendix A

Which condition disqualifies a clay from being classified as Type A?

• a.It is moist from a recent light rain
• b.It holds a vertical cut for a few minutes
• c.It is gray and sticky in color and feel
• d.It has been previously disturbed✓

Soil that is fissured, subject to vibration, previously disturbed, in steeply dipping layers or otherwise less stable cannot be Type A. Moisture, holding a cut, color and stickiness are not disqualifiers.8 CCR §1541.1 Appendix A

In the plasticity test, what thread diameter is rolled from a moist sample to see whether the soil is cohesive?

• a.1 inch
• b.1/2 inch
• c.1/8 inch✓
• d.1/32 inch

The sample is molded into a ball and rolled into threads as thin as 1/8 inch; if a 2-inch length can be held on one end without tearing, the soil is cohesive. A 1-inch or 1/2-inch thread is too thick to show cohesion, and 1/32 inch is thinner than the test thread.8 CCR §1541.1 Appendix A(d)(2)

What is the correct formula for relative compaction?

• a.In-place wet density divided by laboratory optimum moisture content
• b.Laboratory maximum density divided by in-place density, times 100
• c.In-place dry density divided by maximum dry density, times 100✓
• d.In-place moisture content divided by dry density

Relative compaction compares the field dry density to the maximum dry density from the laboratory test, expressed as a percentage. Using wet density, moisture content or an inverted ratio does not measure compaction.Caltrans 2024 Standard Specifications §19-5 (relative compaction); California Test 231

A field sample has a wet density of 130 pounds per cubic foot and a moisture content of 8 percent. What is its dry density?

• a.119.6 pounds per cubic foot
• b.140.4 pounds per cubic foot
• c.120.4 pounds per cubic foot✓
• d.130.0 pounds per cubic foot

Dry density = wet density ÷ (1 + moisture content) = 130 ÷ 1.08 = 120.4. Subtracting 8 percent of the wet density gives 119.6, adding 8 percent gives 140.4, and 130 ignores the water.Soil mechanics practice (dry density)

A competent person presses a thumb into a large clump of fresh spoil. The thumb easily penetrates several inches and the soil can be molded by light finger pressure. What does this indicate?

• a.Cohesive soil of about 0.5 ton per square foot or less (Type C)✓
• b.Dry granular soil that crumbles into loose grains
• c.Stable rock that can be cut with vertical sides
• d.Cohesive soil of 1.5 tons per square foot or more (Type A)

Easy thumb penetration of several inches indicates low unconfined compressive strength, about 0.5 ton per square foot or less, which classifies cohesive soil as Type C. Dry granular soil crumbles into loose grains instead of molding into a clump, Type A soil can be indented by the thumb only with very great effort, and stable rock cannot be penetrated.8 CCR §1541.1 Appendix A(d)(2)(C)

At what depth do the Cal/OSHA rules generally require a protective system in an excavation, unless it is in stable rock?

• a.5 feet or more, or any sign of cave-in✓
• b.12 feet or more, unless the soil is Type A
• c.20 feet or more, when an engineer requires it
• d.3 feet or more, or when the soil is Type C

A protective system is required at 5 feet or more, and also in shallower excavations where a competent person finds an indication of a potential cave-in. Three feet is too low a trigger and soil type does not move it, 12 feet is the Type A short-term slope limit, and 20 feet is the engineer-design threshold, so neither starts the protective-system duty.8 CCR §1541.1(a)(1)

What is the maximum allowable slope for an excavation less than 20 feet deep in Type B soil?

• a.1-1/2:1
• b.2:1
• c.3/4:1
• d.1:1✓

Type B soil may be sloped at 1 horizontal to 1 vertical (45 degrees). The 3/4:1 slope is Type A, 1-1/2:1 is Type C, and 2:1 is flatter than required.8 CCR §1541.1 Appendix B, Table B-1

A 6-foot-deep trench in Type C soil with a 3-foot bottom width is sloped at the maximum allowable slope. What is the top width?

• a.15 feet
• b.21 feet✓
• c.12 feet
• d.27 feet

Type C allows 1-1/2:1, so each side runs 6 × 1.5 = 9 feet and the top width is 3 + 9 + 9 = 21 feet. Fifteen feet uses 1:1, 12 feet counts one side only, and 27 feet uses a 2:1 slope.8 CCR §1541.1 Appendix B

In trenches 4 feet or more in depth, how far may an employee have to travel laterally to reach a ladder, stairway or ramp?

• a.No more than 25 feet✓
• b.No more than 100 feet
• c.No more than 10 feet
• d.No more than 50 feet

A means of egress must be located so as to require no more than 25 feet of lateral travel. Fifty feet would be the spacing between ladders (25 feet each way), 100 feet is not a rule, and 10 feet is stricter than the order requires.8 CCR §1541(c)(2)

Excavated soil and equipment must be kept at least how far from the edge of an excavation, unless retaining devices are used?

• a.10 feet
• b.6 inches
• c.2 feet✓
• d.6 feet

Materials and equipment are kept at least 2 feet from the edge or restrained by retaining devices that prevent them from falling or rolling in. Six inches is too close to prevent a fall into the excavation, while 6 and 10 feet are farther than the rule requires.8 CCR §1541(j)(2)

When must the atmosphere in an excavation be tested?

• a.In trenches over 20 feet deep that are in Type C soil
• b.Before entry into an excavation over 2 feet deep, in every soil type
• c.After a worker reports dizziness or illness in the excavation
• d.Before entry over 4 feet deep where a hazardous atmosphere may be expected✓

Testing is required before employees enter excavations greater than 4 feet deep where a hazardous atmosphere or less than 19.5 percent oxygen exists or could reasonably be expected, such as landfill areas. A 2-foot trigger, waiting for illness and a 20-foot Type C rule are not the criteria.8 CCR §1541(g)(1)(A)

When is an employee permitted inside a trench shield?

• a.Not during installation, removal or vertical moves✓
• b.During installation, because the shield protects the worker
• c.While a crane is lifting the shield into position
• d.When the trench is shallower than 8 feet deep

Employees may not be in shields when the shields are being installed, removed or moved vertically, because a suspended or shifting box is itself a hazard. The shield protects workers only once it is set, so installation is the very time to stay out; a crane lift is the same hazard, and a depth limit of 8 feet does not change the rule.8 CCR §1541.1(g)(1)(D)

In what order are members of a trench support system removed?

• a.From the top downward while the trench stays open
• b.In the order that is fastest for the crew
• c.All members at once after the trench is emptied
• d.From the bottom upward, while backfilling✓

Removal begins at and progresses from the bottom, with members released slowly so any sign of failure is noticed, and backfilling progresses together with removal. Top-down or simultaneous removal would leave the lower walls unsupported.8 CCR §1541.1(e)(1)(E), (F)

What is the maximum loose thickness of each embankment layer under the State specification?

• a.4 inches
• b.12 inches
• c.18 inches
• d.8 inches✓

Each embankment layer must not exceed 8 inches loose before compaction, and clods larger than 8 inches must be broken up. Four inches is thinner than needed, and 12 and 18 inches are too thick for compaction energy to reach the bottom.Caltrans 2024 Standard Specifications §19-6.03C

What relative compaction is required in the top 2.5 feet below finished grade under the traveled way and 3 feet each side?

• a.At least 85 percent
• b.At least 90 percent
• c.At least 100 percent
• d.At least 95 percent✓

The State specification requires at least 95 percent relative compaction for 2.5 feet below finished grade for the width of the traveled way plus 3 feet on each side. Ninety percent is the minimum elsewhere in embankment, 85 is below any stated minimum, and 100 percent is not required.Caltrans 2024 Standard Specifications §19-5.03B

In embankment areas that are not required to be compacted to 95 percent, what minimum relative compaction applies?

• a.90 percent✓
• b.85 percent
• c.95 percent
• d.80 percent

Embankment areas not required to reach 95 percent are compacted to at least 90 percent. Eighty-five and 80 percent are below any stated minimum, and 95 is the figure for the critical zones.Caltrans 2024 Standard Specifications §19-5.03C

What is the maximum compacted thickness of any one layer of aggregate base?

• a.0.25 foot
• b.0.50 foot✓
• c.0.67 foot
• d.1.0 foot

The compacted thickness of any one aggregate base layer must not exceed 0.50 foot, and a base thicker than that is built in at least two approximately equal layers. The 0.67-foot limit belongs to structure backfill, 0.25 foot is thinner than the limit requires, and 1.0 foot is thicker than the specification allows.Caltrans 2024 Standard Specifications §26-1.03D

What is the maximum layer thickness for structure backfill before compacting, when compaction is by mechanical equipment?

• a.2 feet
• b.4 feet
• c.0.50 foot
• d.0.67 foot✓

Structure backfill layers may not exceed 0.67 foot (8 inches) before compacting. Four feet is the limit for ponding and jetting, 0.50 foot is the aggregate base limit, and 2 feet is not specified.Caltrans 2024 Standard Specifications §19-3.03E(1)

Backfill may be placed against a cast-in-place concrete retaining wall when the concrete has reached which condition?

• a.When the forms have been stripped and the surface looks hard
• b.At 1,000 psi, even if the wall is a few days old
• c.At least 2,500 psi, or 28 days in place✓
• d.After 7 days in place, if the wall is dry

The specification requires at least 2,500 psi or 28 days in place before backfill is placed against such walls. A hard-looking surface after stripping, 1,000 psi at an early age, and 7 days with a dry wall all fall short of that criterion.Caltrans 2024 Standard Specifications §19-3.03E(1)

In which zone is ponding and jetting of structure backfill not allowed?

• a.The lower 4 feet of the backfill below the footing
• b.Within 50 feet of an abutment wall
• c.The upper 4 feet below finished grade✓
• d.In granular soil near the abutment wall

Ponding and jetting is not allowed in the upper 4 feet below finished grade, and it must be supplemented by vibratory or other compaction equipment. The lower layers may be jetted if the material is self-draining, a 50-foot distance from the wall is not the rule, and soil type alone does not decide the zone.Caltrans 2024 Standard Specifications §19-3.03E(1)

A grade stake at the edge of a base reads "C 0.4" to top of base. Existing ground at the stake is 98.20 feet and the instrument height is 103.00 feet. What rod reading puts the rod bottom at top of base?

• a.4.80 feet
• b.5.20 feet✓
• c.4.40 feet
• d.97.80 feet

Cut 0.4 puts the top of base at 98.20 − 0.40 = 97.80, and the rod reading is HI − 97.80 = 5.20 feet. Adding the cut instead gives a top of base of 98.60 and a reading of 4.40, 4.80 is the reading at the existing ground, and 97.80 is the elevation, not the rod reading.Surveying and grade-control practice

Plans show cold planing to a depth of 0.20 foot. Within what range may the planed depth be adjusted to achieve a uniform profile?

• a.0.15 to 0.25 foot
• b.0.10 to 0.30 foot
• c.0.20 to 0.23 foot
• d.0.17 to 0.23 foot✓

The planed depth may be adjusted by up to plus or minus 0.03 foot from the depth shown, which is 0.17 to 0.23 foot, while the average depth must be at least the depth shown. The wider ranges have no basis and the one-sided range ignores the downward adjustment.Caltrans 2024 Standard Specifications §39-3.04C(2)

If a ski device is used to control a cold planing machine, what must it be?

• a.Two 10-foot sections hinged together
• b.At least 30 feet long, rigid and one piece✓
• c.Flexible, so that it follows the pavement surface
• d.A short flexible ski of about 6 feet that follows local bumps

The State specification requires a ski used for cold planing to be at least 30 feet long, rigid and a one-piece unit, with the entire length used to activate the sensor, so that it averages the surface. A flexible ski, a short ski of about 6 feet and two hinged 10-foot sections would all follow local bumps and defeat the purpose.Caltrans 2024 Standard Specifications §39-3.04C(1)

Grade-checkers and surveyors working on foot around earthmoving equipment must do what?

• a.Wear high-visibility safety apparel✓
• b.Stand directly behind scrapers to check grades
• c.Work at night
• d.Carry a radio instead of apparel

Cal/OSHA requires employees on foot such as grade-checkers and surveyors who are exposed to vehicular traffic to wear high-visibility safety apparel, and operators must know where they are. Night work, standing behind scrapers and a radio substituted for apparel do not protect them.8 CCR §1590(a)(5)

A planed lane remains open to traffic next to the adjacent open lane. What is the largest allowed drop-off between the adjacent lanes?

• a.1.0 foot
• b.0.05 foot
• c.0.15 foot✓
• d.0.50 foot

Where lanes are open to traffic the drop-off between adjacent lanes may not be more than 0.15 foot (about 1.8 inches). A 0.05-foot limit is the base tolerance, and 0.50 foot and 1.0 foot would be hazardous.Caltrans 2024 Standard Specifications §39-3.04C(2)

Any point on a completed excavation slope in soil must be within what distance of the planned slope under the State specification?

• a.2 feet
• b.5 feet
• c.0.05 foot
• d.0.5 foot✓

Excavation slopes in soil must be within 0.5 foot of the planned slope, and slopes in rock within 2 feet. The 0.05-foot figure is the grading-plane tolerance, and 5 feet has no basis.Caltrans 2024 Standard Specifications §19-2.03G

For median and side slopes of 6:1 or flatter, within what distance must completed slopes be from the established grade, and flowlines?

• a.Slopes within 1 foot and flowlines within 0.2 foot
• b.Slopes within 0.05 foot and flowlines within 0.01 foot
• c.Slopes within 0.2 foot and flowlines within 0.1 foot✓
• d.Slopes within 0.5 foot and flowlines within 0.5 foot

Flat median and side slopes are held to 0.2 foot, and flowlines graded to drain must be within 0.1 foot of the established grade. Half a foot is the general excavation slope tolerance, 1 foot with 0.2 foot is looser than stated, and 0.05 foot with 0.01 foot is tighter than stated.Caltrans 2024 Standard Specifications §19-2.03G

Base paid by the ton will be placed on a grading plane. How high above the established grade may the grading plane be at any point?

• a.Within 0.05 foot above
• b.Within 0.20 foot above
• c.Within 0.10 foot above✓
• d.Within 0.50 foot above

If subbase or base to be placed is paid by the ton, the grading plane at any point is within 0.10 foot above the established grade; if paid by the cubic yard it is within 0.05 foot. Half a foot and 0.20 foot are too loose, and no height at all above grade is the rule for concrete base and pavement, not for base paid by the ton.Caltrans 2024 Standard Specifications §19-1.03C

A gutter flowline drops 0.9 foot in 60 feet. What is its grade?

• a.6.7 percent
• b.1.5 percent✓
• c.15 percent
• d.0.15 percent

0.9 ÷ 60 = 0.015, which is 1.5 percent. Fifteen percent shifts the decimal, 0.15 percent shifts it the other way, and 6.7 percent inverts the ratio.Grade-control practice (percent slope)

Why must a machine-control model or stringline be checked against a known benchmark before grading begins?

• a.The machine corrects errors in its own reference by itself
• b.Benchmarks are required when grading by hand
• c.The machine reproduces whatever reference it is given✓
• d.Checking is needed when the soil is wet

Automatic controls follow the model or string faithfully, so an error in the reference is built perfectly into the grade. Machines do not detect a bad reference, benchmarks apply to all methods, and soil moisture is unrelated.Grade-control practice

A moist soil sample is dried and the weights are 500 grams wet and 450 grams dry. What is the moisture content?

• a.1.1 percent
• b.10.0 percent
• c.90.0 percent
• d.11.1 percent✓

Moisture content is water weight divided by dry weight: (500 − 450) ÷ 450 = 0.111 = 11.1 percent. Ten percent divides by the wet weight, 90 percent is the dry share of the wet weight, and 1.1 percent shifts the decimal.Soil mechanics practice (moisture content)

Field dry density is 108.0 pounds per cubic foot and the laboratory maximum dry density is 115.0. What is the relative compaction?

• a.7.0 percent
• b.93.9 percent✓
• c.106.5 percent
• d.94.9 percent

Relative compaction = 108.0 ÷ 115.0 × 100 = 93.9 percent. Inverting the ratio gives 106.5, 94.9 is an arithmetic slip, and 7.0 is the difference between the densities.Caltrans 2024 Standard Specifications §19-5.03 (relative compaction)

A lift tests at 93.9 percent relative compaction in the top 2.5 feet below finished grade under a traveled way. What follows?

• a.It passes, because 90 percent is the minimum
• b.It fails the 95 percent minimum and is reworked✓
• c.It passes, because compaction is judged on the daily average
• d.It is accepted if the soil is granular

The top zones require at least 95 percent, so 93.9 percent fails and the lift is reworked, usually by adjusting moisture and rolling again. The 90 percent minimum applies outside those zones, averaging is not the criterion, and soil type does not change the percentage.Caltrans 2024 Standard Specifications §19-5.03B

What should be done with fill material that contains excessive moisture?

• a.Do not compact it until it is dry enough✓
• b.Add a layer of dry soil on top and continue
• c.Compact it immediately to squeeze out the water
• d.Roll it with a vibratory roller at maximum amplitude

The specification says not to compact material containing excessive moisture until it is dry enough, because wet soil will not reach density and may pump. Rolling it, capping it or vibrating it harder does not fix the moisture.Caltrans 2024 Standard Specifications §19-5.03A

Borrow material has a sand equivalent of 8. Where may it not be placed?

• a.Below 10 feet of fill, and nowhere else
• b.Within 2.5 feet of finished grade✓
• c.In landscaped areas of the project
• d.Anywhere in the roadway prism

The specification does not allow borrow or excavation material with a sand equivalent below 10 within 2.5 feet of finished grade, where plastic fines would weaken the pavement support. The material is not banned everywhere, and no depth-based or landscaping exception is stated.Caltrans 2024 Standard Specifications §19-6.02A

What does Cal/OSHA's Appendix A require as the basis for classifying a soil deposit?

• a.The employer's best estimate based on the last job
• b.A single visual inspection of the spoil pile alone
• c.One visual and one manual test by a competent person✓
• d.A written laboratory report from an accredited testing firm

The classification is made by a competent person from at least one visual and one manual analysis, using the tests in Appendix A or other accepted methods. A laboratory report is not required, a guess from a prior job is not an analysis, and one visual look is not enough.8 CCR §1541.1 Appendix A(c)

Which soil is classified as Type B?

• a.Clean sand and loamy sand
• b.Cohesive soil at 2 tons per square foot
• c.Angular gravel, silt and sandy loam✓
• d.Submerged soil or soil from which water is seeping

Granular cohesionless soils including angular gravel, silt, silt loam and sandy loam are Type B. Sand and loamy sand are Type C, submerged soil is Type C, and a strong undisturbed unfissured cohesive soil is Type A.8 CCR §1541.1 Appendix A

Unsuitable material is found below the grading plane in an excavation area. What does the State specification require?

• a.Leave it in place and place the aggregate base directly on top of it
• b.Cover it with geosynthetic fabric and place the base on top
• c.Excavate and dispose of it, then backfill and compact✓
• d.Mix it with imported base rock to dilute its effect

Unsuitable material below the grading plane is excavated and disposed of as ordered, and the space is backfilled with suitable material placed and compacted under the compaction section. Leaving, mixing or covering it would leave a weak layer under the pavement.Caltrans 2024 Standard Specifications §19-1.03B

A contractor plans controlled blasting near occupied buildings. How far ahead must written notice be given to occupants within 330 feet?

• a.30 days before the contractor mobilizes
• b.On the morning of the blast, after the last drilling
• c.24 hours before the first shot of each day
• d.At least 7 days before starting or resuming✓

Written notification is required at least 7 days before controlled blasting starts or resumes to occupants within 330 feet, with notice again on the day of blasting. Twenty-four hours and same-morning notice are too short to prepare occupants, and 30 days is longer than the 7 days stated.Caltrans 2024 Standard Specifications §19-4.04C(1)

A cut is found to contain hazardous soil. What does the State specification say about using the excavated material in embankments?

• a.It may be used if covered with 2 feet of clean soil
• b.It is not used as fill; it is handled as hazardous✓
• c.It may be spread thinly on the side slopes as fill
• d.It may be buried under the pavement if it is compacted

The excavated material is used for embankments and backfill unless it is hazardous, so hazardous soil is handled as hazardous material. Burying, capping or spreading it are not permitted uses.Caltrans 2024 Standard Specifications §19-1.03A

A Type B excavation was cut at 1:1, and tension cracks now show at the top edge. What must be done?

• a.The slope must be cut back to a minimum of 1-1/2:1✓
• b.It must be cut to a steeper 3/4:1 slope
• c.Keep the slope and seal the cracks with spoil
• d.It must be left alone until the cracks widen

Signs of distress require the actual slope to be at least 1/2 horizontal to 1 vertical less steep than the maximum, so 1:1 becomes 1-1/2:1. Sealing the cracks with spoil leaves the unsafe slope in place, 3/4:1 is steeper, and waiting for the cracks to widen invites a cave-in.8 CCR §1541.1 Appendix B(c)(3)(B)