While the broad category of Specific Excavation Requirements is the most commonly cited section of the OSHA Construction Standard for Excavations (CFR 1926 Subpart P), citations related to the Requirements for Protective Systems carry significantly higher penalties.1 Specific Excavation Requirements within the Requirements for Protective Systems include, among other things, locating and protecting existing utilities, determining and controlling potentially hazardous atmospheres, and providing access and egress with ladders and/or ramps. Advanced Engineering Investigations is routinely asked to investigate fires and explosions stemming from failures to protect existing utilities. However, the Requirements for Protective Systems focus solely on shoring, shielding, or otherwise protecting workers inside an excavation from injury or entrapment due to cave-ins, rock slides, or failures of adjacent structures.
Shoring systems actually apply pressure to the soil walls, preventing soil cave-ins from occurring in the first place, while shielding systems only protect workers in the event that a cave-in occurs or a rock rolls down the spoils pile. Another means of reducing the risk of injury is to slope or bench the soil walls of the excavation. OSHA provides prescriptive, worst-case-scenario, designs for the various protective systems, and manufacturers can provide pre-engineered rental equipment. However, many sites utilize engineered site-specific designs prepared by geotechnical and structural consultants, which are also considered acceptable by OSHA. Regardless of the system utilized, OSHA requires a dedicated “competent person” to perform daily inspections of the excavation and protective systems. The competent person must be able to identify existing and predictable hazards and must have the authority to take corrective measures.
1 ww.osha.gov/pls/imis/citedstandard.sic – 1794 Excavation Work, October 2010 through September 2011 statistics.
Mr. Burnett is a registered professional engineer, licensed in 10 states. Mr. Burnett has investigated many construction site accidents and cases involving worker injury.