Trenching and excavations are the most dangerous hazardous construction tasks that workers can be responsible for. Both operations go hand in hand. According to OSHA, excavations refer to any man-made cavity, trench or depression on the surface that resulted from earth removal. A trench is the result of an excavation and which is deep and 15 feet wide.
Trench collapse is a hazard that few contractors take seriously since most don’t take the weight of soil into account. A single cubic yard of soil amounts to 4000 pounds which is the weight of a small pickup truck. When a trench caves in, unprotected workers are buried under that mass instantly which can prove fatal.
It’s just physics. It does not take much to crush a worker under that much soil. The good news is that disaster can be avoided if a few simple precautions are set in place:
Keep the surface clean
A trench collapses when its walls fail to contain the pressure of the tones of soil pressing on it. Even though this can be problematic in any depth, it can accelerate if other materials are piled at the edge. To prevent trench collapse due to the extra weight:
- Move extra excavation materials at least 2 feet away from the trench
- If there isn’t room, remove the materials from the site
- Remove personnel from the edge of the trench who are not working on it
- Keep all equipment away from the site to prevent cave-ins and blunt force trauma
- How trench workers can stay safe on-site
- Workers who work in or around trenches should follow these steps to remain safe:
- Don’t enter trenches that have not been reinforced or inspected at the start of the day or after a rainstorm.
- Don’t work under suspended loads
- Never start digging till all underground utilities in the area have been accounted for.
- Keep materials and soil piles at least 2 feet away from the edges
- Make sure air tests are carried out if the trench is more than 4 feet deep. Oxygen deprivation is the second leading cause of fatalities in unregulated trenches.
- Evacuate the trench immediately if you smell a strange odor or see rainwater accumulating at the bottom. Either of these could compromise trench structure or weaken it thus making a cave-in imminent.
As such construction site personnel should be trained to report unsafe trench conditions to their supervisors immediately.
The ‘competent person’ as per OSHA standards
OSHA describes a ‘competent person’ as anyone in the construction site who is trained to determine hazards. The individual must also be given the authority to deploy corrective measures to remove those risks.
Some of the tasks that this individual is responsible for during an excavation include:
- Classifying the soil onsite
- Supervising equipment for water removal
- Inspecting protective systems that are in place
- Designing and implementing ramps
- Site inspections
Soil classification is especially important since it allows site workers to determine the stability of the soil they will be working in. This can be affected by soil type as well as how much water it holds. Vibrations from heavy equipment and tools that are being used on the site are also factored in.
According to OSHA, the ‘competent person’ should be able to identify risk factors that can threaten the health and wellbeing of trench workers. By doing this, onsite supervisors can reduce injuries and eliminate fatalities.
OSHA 30 Hour Construction Industry Outreach
A comprehensive construction safety program can go a long way in eliminating all of the aforementioned threats. Protect your site crew by signing up for 360Training’s OSHA 30 Hour Construction Industry Outreach training program. The training is designed for anyone who works in the construction industry such as foremen, safety directors and foremen to name a few.
Once the course is complete, students will receive their completion card within 6 to 8 weeks. The program is an orientation to occupational health and safety for workers who are protected by OSHA regulations. Sign up for the course and ensure your site workers remain safe onsite whether they are working in the trenches or around them.