SafetyCâu 93 / 110
A trench is dug in Type C soil, which OSHA requires to be sloped at 1.5 to 1 (horizontal to vertical). For a trench 8 ft deep, how wide must the sloped opening be beyond the trench bottom on each side?
a.12 ft each side
b.8 ft each side
c.4 ft each side
d.16 ft each side
Giải thích
At 1.5 to 1, horizontal run = 1.5 x depth = 1.5 x 8 = 12 ft of slope on each side beyond the trench bottom. Type C is the least stable soil and requires the widest, flattest slope. Type A allows 0.75 to 1 and Type B 1 to 1, so knowing the soil class sets the excavation width.
Trích dẫn luật: 29 CFR 1926.652Luyện miễn phí toàn bộ 110 câu hỏi — không cần đăng ký.
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