What is the minimum height below the top of a shield to which the sides must be sloped when sloping and shielding are used in conjunction?

When sloping and shielding are used together in excavation work, there is a specific safety requirement to ensure that the soil does not collapse and pose a danger to workers. The minimum height below the top of the shield to which the sides must be sloped is established to provide a safe angle of repose and to mitigate the risk of soil movement or slippage that could endanger individuals working in the excavation.

The correct answer, which indicates a minimum height of 18 inches below the top of the shield, is rooted in safety protocols designed by regulatory agencies. This requirement emphasizes that a proper sloping technique must be employed at this specific height to maintain structural integrity, protect workers from potential hazards, and ensure that the shield can effectively function without being overwhelmed by collapsing soil.

This height is critical because it helps maintain the stability of the excavation while complying with industry safety standards. Sloping the sides effectively minimizes the risk of cave-ins and enhances overall site safety when combined with shielding systems, which themselves provide additional protection against unexpected soil failure.