21 questions

Subsurface, Surface, and Elevated Piping Work

Soil with water freely seeping from the trench wall is classified as which type?

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

Submerged soil or soil from which water is freely seeping is Type C.Cal. Code Regs. tit. 8, 1541.1 App. A

Subsurface, Surface, and Elevated Piping Work

What is the maximum slope for a 15-foot-deep excavation in Type B soil?

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

Type B soil allows a maximum slope of 1H:1V for excavations less than 20 feet deep.Cal. Code Regs. tit. 8, 1541.1 App. B

Subsurface, Surface, and Elevated Piping Work

An 8-foot-deep excavation in Type A soil has an unsupported vertical lower portion. How tall may that vertical portion be?

  • a.8 feet
  • b.3-1/2 feet✓
  • c.18 inches
  • d.5 feet

In Type A soil, excavations 8 feet or less deep with unsupported vertically sided lower portions may have a maximum vertical side of 3-1/2 feet.Cal. Code Regs. tit. 8, 1541.1 App. B

Subsurface, Surface, and Elevated Piping Work

A 4-foot trench in running sand shows raveling. Is a protective system required?

  • a.No, because sand drains well
  • b.No, because it is under 5 feet
  • c.Yes, if the competent person sees cave-in potential✓
  • d.Only if the trench is over 100 feet long

The under-5-foot exception applies only when a competent person finds no indication of potential cave-in.Cal. Code Regs. tit. 8, 1541.1

Subsurface, Surface, and Elevated Piping Work

Workers must cross a trench 7 feet deep and 24 inches wide. Are walkways with guardrails required by section 1541(l)?

  • a.No, it is under 30 inches wide✓
  • b.Yes, for any trench over 5 feet
  • c.Yes, for any trench over 6 feet
  • d.No, walkways are never required

Walkways or bridges with guardrails are required over excavations more than 6 feet deep and wider than 30 inches; both conditions must be met.Cal. Code Regs. tit. 8, 1541

Subsurface, Surface, and Elevated Piping Work

How often must a competent person inspect an excavation that workers enter?

  • a.Daily and after rainstorms✓
  • b.Only when first opened
  • c.Only after an earthquake
  • d.Weekly

Inspections are daily before work and as needed, and after every rainstorm or other hazard-increasing occurrence.Cal. Code Regs. tit. 8, 1541

Subsurface, Surface, and Elevated Piping Work

Before entering a 6-foot trench near buried fuel tanks, what is required?

  • a.A spotter at the surface only
  • b.A second ladder only
  • c.A wider trench bottom
  • d.Testing the trench atmosphere✓

Where a hazardous atmosphere could reasonably be expected, such as near stored hazardous substances, the atmosphere is tested before entry into excavations over 4 feet deep.Cal. Code Regs. tit. 8, 1541

Subsurface, Surface, and Elevated Piping Work

A shield sits in a trench with sloped upper walls. How far must its sides extend above the vertical walls?

  • a.At least 18 inches✓
  • b.At least 6 inches
  • c.Flush with the vertical wall
  • d.At least 36 inches

Shield sides must extend at least 18 inches above the vertical walls of compound excavations.Cal. Code Regs. tit. 8, 1541.1

Subsurface, Surface, and Elevated Piping Work

Where must the approved design for a trench support system be kept while it is being built?

  • a.On the job site✓
  • b.At the Cal/OSHA district office
  • c.At the engineer's office
  • d.With the equipment supplier

At least one copy of the design must be kept at the jobsite during construction of the protective system.Cal. Code Regs. tit. 8, 1541.1

Subsurface, Surface, and Elevated Piping Work

Which members does the Appendix C timber shoring table size?

  • a.Crossbraces, uprights and wales✓
  • b.Hydraulic cylinders
  • c.Sheet piles and tiebacks
  • d.Only the uprights

Appendix C selects crossbraces, uprights and, where required, wales for trenches up to 20 feet deep.Cal. Code Regs. tit. 8, 1541.1 App. C

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Subsurface, Surface, and Elevated Piping Work

When must sediment be removed from a Type 2 inlet sediment trap on Caltrans work?

  • a.Only at the end of the project
  • b.When it is completely full
  • c.After every working day
  • d.When its volume is reduced by about half✓

Caltrans requires removing sediment from a Type 2 inlet sediment trap when its volume has been reduced by approximately one-half.Caltrans Standard Specifications (2025) 13-6

Subsurface, Surface, and Elevated Piping Work

What must surround a covered soil stockpile on a Caltrans job?

  • a.A concrete washout
  • b.A sediment barrier✓
  • c.A chain-link fence
  • d.A drainage inlet

Caltrans covers active and inactive soil stockpiles and surrounds them with a linear sediment barrier.Caltrans Standard Specifications (2025) 13-4

Subsurface, Surface, and Elevated Piping Work

Who classifies a tunnel for gas before bidding?

  • a.The tunneling contractor
  • b.The local fire department
  • c.Cal/OSHA's Division✓
  • d.The pipe manufacturer

The owner submits geological information and the Division classifies the tunnel before bidding and underground work.Cal. Code Regs. tit. 8, 8422

Subsurface, Surface, and Elevated Piping Work

What kind of drilling fluid may be used for directional boring on Caltrans work?

  • a.No fluid of any kind
  • b.An oil-based mud
  • c.A water-based fluid✓
  • d.Diesel fuel as a lubricant

Mineral slurry or wetting solution may lubricate the tool and stabilize the hole; it must be water based.Caltrans Standard Specifications (2025) 20-2.07

Subsurface, Surface, and Elevated Piping Work

An operator marks a gas line with two marks showing the pipe's outside edges. How far does the tolerance zone extend?

  • a.24 inches from the midpoint
  • b.12 inches from each mark
  • c.36 inches from each mark
  • d.24 inches from each mark✓

When the marks show the width of the installation, the tolerance zone is 24 inches from each outside marking.Gov. Code 4216

Subsurface, Surface, and Elevated Piping Work

An excavator gouges a sewer force main during trenching. When must the regional notification center be told?

  • a.Only if it leaks
  • b.Within 10 working days
  • c.Within 48 hours✓
  • d.At the end of the project

Damage to any subsurface installation is reported to the operator immediately and to the regional notification center within 48 hours.Gov. Code 4216.4

Subsurface, Surface, and Elevated Piping Work

A new water main will run parallel to a line carrying disinfected tertiary recycled water. What minimum horizontal separation applies?

  • a.10 feet
  • b.4 feet✓
  • c.2 feet
  • d.25 feet

New water mains are at least 4 feet horizontally from, and one foot above, parallel lines carrying disinfected tertiary recycled water or storm drainage.Cal. Code Regs. tit. 22, 64572

Subsurface, Surface, and Elevated Piping Work

How far must a new water main be from the nearest edge of a septic leach field?

  • a.10 horizontal feet
  • b.25 horizontal feet✓
  • c.100 horizontal feet
  • d.4 horizontal feet

New water mains may not be within 25 horizontal feet of a cesspool, septic tank, leach field or seepage pit.Cal. Code Regs. tit. 22, 64572

Subsurface, Surface, and Elevated Piping Work

How far in advance is the engineer notified of a pressure test on Caltrans work?

  • a.7 days
  • b.48 hours✓
  • c.2 hours
  • d.10 days

Caltrans requires notifying the engineer at least 48 hours before performing a pressure test.Caltrans Standard Specifications (2025) 20-2.01A(4)(b)

Subsurface, Surface, and Elevated Piping Work

How soon after mixing must slurry cement backfill be placed?

  • a.Within 24 hours
  • b.Within 8 hours
  • c.Within 4 hours
  • d.Within 1 hour✓

Slurry cement backfill is placed within 1 hour of mixing; nothing is placed on top for at least 4 hours.Caltrans Standard Specifications (2025) 19-3.03F

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Subsurface, Surface, and Elevated Piping Work

What must be done at the end of each day with the ends of installed corrugated PVC pipe that were not backfilled?

  • a.Cover them each day✓
  • b.Cut them back 2 feet
  • c.Leave them open to drain
  • d.Fill them with sand

Caltrans requires covering the ends of installed corrugated PVC pipe that were not backfilled at the end of each day.Caltrans Standard Specifications (2025) 64-2.03

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