Trenching can lead to caught-between or struck-by accidents, one of OSHA’s “Fatal Four” accidents leading to death. Trenching safety starts before your team touches the dirt or picks up a shovel. It’s important to call 811 to check for any utilities that may be present at the jobsite. Knowing as much as possible about trenching safety can help save lives on the jobsite.
A Central FL construction lawyer tells you about trenching safety and protective systems in this two-part article. Part one of the article focuses on trenching safety and soil types.
Safety Around the Trench
Any trench 4 feet deep or more must have a fixed means of exit. Ladders must extend 3 feet above the surface of the soil and secured. Heavy equipment needs to be kept at a safe distance from trench edges so it doesn’t cause the trench to collapse.
Any soil removed from the trench, known as spoils, must be kept away from the trench. Temporary spoil must be minimum of 2 feet away from the edge of the trench at its base to prevent it from falling back into the trench. Permanent spoil must be placed farther away from the trench to prevent it from displacing or disturbing the stability of the trench or from falling on workers.
Soil and Trenching
Soil classification is an important factor in deciding what type of protective system to use. OSHA classifies soils into three main types: A, B, and C. A is the most stable, and C is the least stable. Many of Florida’s construction sites have type C soil made of sand, limestone, clay, and organic material. The water table in much of Florida is very close to the surface which further complicates trenching safety as wet soils are less stable. If any piledrivers or other sources of vibration are nearby that can also compromise the stability of soil.
All trenches more than 5 feet deep or showing signs of instability must have a protective system in place. At the beginning of every shift and after rainstorms, an inspection must be performed by a worker to determine if the trench is safe to work in.
Sloping means digging the walls of the trench at an angle that slopes away from the trench to promote safety. The degree of slope needed depends on the type of soil the trench is in. Sloping can only be done if the trench is less than 20 feet. If your site has type C soil, that means that your trench needs a slope of 34 degrees.
Read part two of this article to learn about the other three protective systems.
Disclaimer: The information contained in this article is for general educational information only. This information does not constitute legal advice, is not intended to constitute legal advice, nor should it be relied upon as legal advice for your specific factual pattern or situation.