Digging and digging trenches are among the most dangerous construction operations. OSHA defines an excavation as any cut, cavity, ditch or artificial depression on the surface of the earth formed by the removal of land. A ditch is defined as a narrow underground excavation that is deeper than wide and measures no more than 15 feet (4.5 meters). Dangers of digging trenches and excavations Los Excavation risks represent the greatest risk and are much more likely than other accidents related to excavations to cause the death of workers. Other potential risks include falls, falling loads, dangerous atmospheres and incidents related to mobile equipment. Trench landslides cause dozens of deaths and hundreds of injuries every year.
Do not enter an unprotected ditch! Trenches 5 feet (1.5 meters) deep or more require a protection system unless the excavation is completely carried out in stable rock. Trenches 6.1 meters (20 feet) deep or more require that the protection system be designed by a registered professional engineer or based on tabulated data prepared and / or approved by a registered professional engineer.
There are different types of protection systems. The tilt involves cutting the wall of the trench at an angled angle away from the excavation. Shoring requires the installation of aluminum hydraulic supports or other types of supports to prevent soil movement and flooding. The shield protects workers by using trench boxes or other types of supports to avoid landslides. The design of a protection system can be complex because it has to take into account many factors: soil classification, depth of cut, water content of the soil, changes due to weather or climate, surcharge charges (e.g., Deterioration , other materials to be used in the ditch) and other operations in the neighborhood.
OSHA standards require that trenches be inspected daily and that conditions be changed by a competent person before worker entry to ensure the elimination of excavation hazards. A competent person is a person who is able to identify existing and predictable hazards or working conditions that are dangerous, unhealthy or dangerous for employees and that is authorized to take immediate corrective measures to eliminate or control these hazards and conditions.
OSHA requires safe access and exit to all excavations, including stairs, steps, ramps or other safe means of departure for employees working in excavations of trenches 4 feet (1.22 meters) or deeper. These devices must be located within 25 feet (7.6 meters) of all workers.
Keep heavy equipment away from the edges of the ditch. Keep surcharge charges at least 2 feet (0.6 meters) from the edges of the trench. Know where the underground public services are located. Low oxygen test, dangerous fumes and toxic gases. Inspect the trenches at the beginning of each shift. Inspect the trenches after a storm. Do not work under high loads.
