Excavation Safety
The purpose of the engineer classifying the soil is to determine what protective measures are required to prevent a
cave-in and keep workers safe around excavations. Sloping, shoring, and shielding are the three standard preventive
measures used in excavations.
Sloping the sides of an excavation is one way to prevent a cave-in. The amount of sloping required is dependent upon the
OSHA soil classification. However, it is critical that the engineer looks at the bore logs or soils report
prior to making such decisions.
Benching is a protective measure achieved by excavating the sides of an excavation to form one or a series of horizontal
levels or steps, usually with vertical or near-vertical surfaces between levels.
Shoring is a protective measure that uses mechanical reinforing to stabilize the walls of the excavation.
Such structures should be designed by qualified individuals who have the appropriate knowledge, training, and experience.
Shielding involves the use of trench boxes in the excavation. Do not subject a trench box to loads exceeding those which
the system was designed to withstand. Install and remove trench boxes in a manner that protects employees from cave-ins.
Workers should never be inside of a trench box as it is being moved.