Construction site hazards can come in the form of falls from height, explosions, collapsing structures, toxic exposure and vehicle accidents. One of the deadliest accidents is the cave-in or trench collapse. What can be done to prevent this workplace tragedy?
On many construction projects, digging a trench is a necessary step. Even though it is common, there are still numerous significant safety best practices that must be followed. OSHA standards require employers to provide a workplace that is free of hazards. Unless it is made entirely in stable rock, a trench that is five or more feet deep must have a protective system in place. Trenches that are 20 feet deep or greater must have a protective system in place designed by a registered professional engineer or based on tabulated data provided or approved by a registered professional engineer.
The jobsite supervisors must also remember:
- Competent person: OSHA standards require that someone deemed to be a competent person inspect the trench daily or as conditions change to ensure any hazard has been identified and eliminated. The competent person is one who can identify hazards that either currently exist or predict ones that might soon become a reality.
- Entry and exit points: All excavated soil and heavy machinery must be stored away from the trench edges. Additionally, ladders and other emergency access points must be spaced at regular intervals to allow workers to get out of danger.
- Protective systems: Based on the size of the trench, the type of soil and numerous other factors, workers can choose to implement several different types of protective systems. Most often, engineers will select either sloping, shoring or shielding. Sloping entails cutting back a trench wall at an angle inclined away from the excavation. Shoring is the addition of supports to strengthen the trench. Shielding generally entails the use of a “trench box” or other protective structure to prevent soil cave-ins.
A trench collapse can suddenly drop several tons of rock and soil atop workers. Workers can be crushed, trapped and suffocated in an instant. It is critical that supervisors identify hazards and take whatever steps are necessary to prevent fatal work accidents.