The Occupational and Safety Health Administration (OSHA) defines an excavation as any man-made cut, cavity, trench, or depression in the Earth’s surface by earth removal. A protection system for an excavation includes support systems, sloping and benching systems, shield systems, and other systems that provide protection. The two main types of excavation protection are trench excavation protection (see standard specification Item 402) and temporary special shoring (see standard specification Item 403). The contract plan should show all locations of excavation support and provide note and sketch of estimated length.

For either protection system, the Contractor must be compensated for the method of choice. For example, for temporary special shoring when excavation techniques such as sloped cuts or benching are used to provide the necessary protection, the surface area of payment is calculated based on the area described by a vertical plane adjacent to the structure.