Excavation and trench work are the most hazardous construction operations. The Occupational Safety and Health Administration (OSHA) defines excavation as any trench, cut, or cavity that is made by man. These depressions in the ground are made by removing the earth. A trench is a narrow underground area that has been excavated to be deeper than it is wide, but it cannot be wider than 15 feet. So why is trench safety so important?
There are dangers with any construction work, but when it comes to trenching there is a risk that a cave-in could occur. Cave-ins could result in the loss of life and are much more likely to cause fatalities than any other excavation-related accident. There are many other risks, such as falling loads, falls, and the risks of working with mobile equipment. There are hundreds of workers injured and dozens killed by trench cave-ins every year.
Properly Protect Yourself From Trench Collapses
Workers should never enter a trench that isn’t protected. Trenches that are at least five feet deep should have a protective system unless it is in solid rock that is stable. Trenches that are 20 feet deep require a protective system to be designed by an engineer or be based on tabulated data that has been prepared and reviewed by a qualified engineer.
Many effective protective systems are used for trenches. Shielding uses trench boxes or supports to keep the dirt from caving in. Shoring involves the installation of aluminum hydraulic or other kinds of supports to stop cave-ins or the movement of the dirt. Sloping is an approach that involves cutting back the trench wall at an angle that is away from the point of excavation.
The design of a protective system can be complex since there are a variety of factors that must be taken into consideration. The engineer must consider the soil classification, the depth of the cut, the soil’s water content, climate or weather changes, and any other operations in the area. OSHA requires that the trenches be inspected on a daily basis, and if there are problems that arise, they must be corrected by a competent individual who is trained to handle such problems.