Excavation in Construction/Trenching
Working in an excavation is one of the most hazardous jobs in the construction industry. Most excavation accidents are the result of cave-ins or collapsing excavation walls. There are, however, a number of procedures and protective systems designed to protect you in or around an excavation.
Never enter an unprotected trench.
Workers must be protected from cave-ins by an adequate protective system in trenches that are 5 feet deep or deeper.
A daily inspection of the excavation, adjacent areas, and protective systems by a competent person is required. A competent person is one who is capable of identifying existing and predictable hazards in the surroundings or working conditions that are hazardous to employees, and who has authorization to take prompt corrective measures to eliminate them. The competent person for excavations and trenching performed by the University is the Civil Engineering Manager or his designate.
When used, sloping of the excavation walls must be adequate for the type of soil. A competent person must determine soil type.
Trench boxes or shields must be used in accordance with the manufacturer’s recommendations, or as designed and approved by a registered professional engineer.
Ramps, runways, ladders, or stairs must be used for access if the trench is greater than four feet deep. Access must be provided within 25 feet of a work area.Any material or equipment, including spoil, that could fall or roll into an excavation must be placed at least two (2) feet from the edge of the excavation. All surface encumbrances that may create a hazard to workers must be removed or supported.
A registered professional engineer must design excavations that are more than twenty feet deep.
A warning system for pedestrian and vehicular traffic must be in place around all excavations. The warning system must consist of barricades, hand or mechanical signals, or stop logs and flashing lights at night.
Adequate protection from hazards associated with water accumulation must be in place before working in excavations.
Employees exposed to public vehicular traffic must be provided with and wear reflective warning vests.
Where workers or equipment are expected to cross over an excavation, walkways with standard guardrails must be provided.
Credit to: Environmental Health and Safety 262 Alexander Street Princeton, NJ 08540