An open excavation that usually does not require shoring is classified as a ______.

• A. Pit
• B. Trench
• C. Shaft
• D. Quarry

Answer: (A)

Open excavations are described by their shape and depth. When an excavation is narrow and deep, the side walls are prone to collapse, so protective measures like shoring, shielding, or proper sloping are required. A pit, by contrast, is an open and broader excavation that is usually shallow, so it typically doesn’t require shoring. This is why it’s classified as a pit.

The other types represent different conditions: a shaft is a vertical or near-vertical opening used for access and usually needs protective systems; a trench is a long, narrow excavation that depth makes it necessary to shore or shield the walls; a quarry is a large-scale excavation for extracting stone or ore and involves different safety considerations.