EXCAVATION DEFINITIONS:

 1.               Excavation

Any man-made cavity or depression in the earth's surface, including its sides, walls, or faces, formed by earth removal and producing unsupported earth conditions because of the excavation.

2.               Trench Excavation

A narrow excavation made below the surface of the ground.  In general, the depth is greater than the width, but the width of a trench is not greater than 4.5 meters (15 feet).

3.               Accepted Engineering and Construction Practices

Plans for excavations and protective system, methods shall be submitted to Loss Prevention before work startup.

4.               Protective Systems

Methods used to protect employees from cave-ins, from materials that could fall or roll into the excavation onto the workers or from the collapse of adjacent structures.  Protective systems include supports, sloping and benching, shields, and other means to protect workers.

5.               Shoring

Hydraulic, timber, or mechanical systems that support the sides of an excavation, designed to prevent cave-ins.

6.               Hydraulic Shoring

A pre-engineered support system of aluminum hydraulic cylinders (cross-braces) used with vertical rods (uprights) or horizontal rods designed specifically to support sidewalls of an excavation to prevent a cave-in.

7.               Benching

A method of protecting employees from cave-ins by excavating the sides of an excavation to form one or a series of horizontal steps, with a vertical rise between steps.

8.               Sloping

 A method of excavating in which the sides of excavation are laid back to a safe angle to prevent cave-ins.  (The safe angle required varies with different types of soil, exposure to the elements, and superimposed loads.  There is no single angle of repose.  Soil classification must be identified to select safe sloping and benching methods.)