SafetyQuestion 663 of 700
A contractor wants to use a benched (stepped) excavation wall as the protective system. In which soil is benching NOT permitted?
a.Stable rock
b.Type A soil
c.Type B soil
d.Type C soil
Explanation
Correct: benching is not allowed in Type C soil because it is too unstable to hold vertical steps; Type C must be sloped, shored, or shielded. Benching is permitted in Type A and Type B soils under the allowable configurations, and stable rock is competent enough to stand vertically. The key limitation is that Type C cannot be benched.
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