The Occupational Health and Safety Administration (OSHA) provides detailed excavation shoring requirements for workers engaged in this type of hazardous construction work. It is important to rigorously adhere to these requirements in order to prevent potential accidents.
There are two primary types of shoring for excavation: timber and aluminum hydraulic. The depth and width of the excavation trenches will usually determine the type of shoring that is used. In some cases a shield system will be used to prevent collapses or cave-ins, while in others, a shoring system may be sufficient.
If employees are working in trenches that are 4 or more feet deep, then OSHA requires safety measures for accessing and exiting the excavation site. This includes using ladders, steps, ramps or other approved methods. These need to be located within 25 feet of everyone working on the site.
When trenches are over 4 feet deep, testing for potential atmospheric hazards needs to be conducted. At this depth, there may be low oxygen levels, hazardous fumes, or toxic gases present.
Trenches that are 5 or more feet deep require a protective system. One exception to this is when the excavation site is located in stable rock.
When trenches are 20 or more feet deep, the protective system must be designed by and/or approved by a registered professional engineer. This is because they will be able to determine the right type of system needed to provided the most effective protection.
If a shield is being used to shore up the sides of a trench, further excavation is only allowed under certain conditions. In some cases, however, earth excavation is permitted 2 feet below the shield when it is designed to handle these forces and is believed to be stable both behind and below the support system
Additional excavation shoring requirements pertain to the soil and other materials that are removed from the trench. These need to be piled a minimum of 2 feet away from the edge.
There are additional excavation shoring requirements and guidelines available from OSHA. While there may be some similarities with different types of excavation jobs, each one needs to be fully assessed so that the proper requirements and safety protocols are followed.
