A major issue surrounding existing OSHA standards for excavations, trenching, and shoring is the classification of soils. Soil classification provides an empirical estimation of the soil's stability. If the potential for cave-ins or other dangerous movements of ground is thought to exist, appropriate decisions to provide adequate protection must be reached. It also presents a simplified soil classification system for use in determining appropriate side-sloping requirements and for calculating the lateral soil pressures imposed on shoring systems. Table 1 suggests that compliance with existing regulations or adherence to recommended work practices might have prevented important causative circumstances in each of the four fatal incidents.
Stable rock is exempt.
One hydraulic shore was in use on an intersecting trench. The goal is to learn how such fatalities can be prevented. As an obvious first step in preventing such fatalities in the future, we conclude that all such operations should be done only in full compliance with existing OSHA standards. We urge safety and trade associations, underground utility companies, municipalities and other local governments responsible for underground utility services, as well as state OSHA consultative services to bring these recommendations to the attention of employers engaged in excavations. Thank your for your help in protecting the lives and health of America's workers.