A utility trench will be entered by workers and is 5 ft deep in soil that is not stable rock. What cave-in protection threshold applies?
Correct Answer
C) At 5 ft or deeper, a protective system is required unless an allowed exception applies
Excavations 5 ft deep or greater generally require a protective system unless the excavation is entirely in stable rock or another specific exception applies. Other choices confuse the professional-engineer design threshold or omit the 5 ft trigger.
Why This Is the Correct Answer
Excavations 5 ft deep or greater generally require a protective system unless the excavation is entirely in stable rock or another specific exception applies. Other choices confuse the professional-engineer design threshold or omit the 5 ft trigger.
Why the Other Options Are Wrong
Option A: Protection begins only at 8 ft and leave excavation protective systems unchecked
In general project requirements, Protection begins only at 8 ft is the wrong selection for Excavation protective systems: Protection begins only at 8 ft uses the wrong excavation protective-system trigger or exception.
Option B: Protection begins only at 10 ft and use that item to close excavation protective systems
The trap in B is Protection begins only at 10 ft. That selection is wrong because Protection begins only at 10 ft uses the wrong excavation protective-system trigger or exception.
Option D: Classify the condition as a protective system is optional if the trench is less than 20 ft
Choice D (A protective system is optional if the trench is less than 20 ft) is rejected because A protective system is optional if the trench is less than 20 ft uses the wrong excavation protective-system trigger or exception.
Memory Technique
Use a cover note memory cue for excavation protective systems: the stem's condition unlocks At 5 ft or deeper, a protective system is required unless an allowed exception applies.
Reference Hint
Open 29 CFR 1926 OSHA Construction Standards; use 29 CFR 1926.652(a)(1) to confirm that Excavations 5 ft deep or greater generally require a protective system unless the excavation is entirely in stable rock or another specific exception applies.
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