Trench Safety: Retaining Walls
Excavation and trenching are among the most hazardous operations in the construction industry. In fact, cave-ins pose the greatest risk among excavation-related incidents that result in employee fatalities. For this reason, it is important that employers only allow their employees to enter a trench with necessary safe guards in place.
Any excavation or trench that is greater than 5 feet deep must use a cave-in protection system. Cave-ins can be prevented with the use of retaining walls. Retaining walls are built to retain or support the lateral or horizontal pressure caused by the soil. Retaining walls can be constructed concrete, steel, or other approved materials. Supporting the sides of the excavation and shielding the work area from the excavation can be done with a simple protective design or a more complex design, depending on the employer’s needs. Even though the employer has some influence on the design of retaining walls, the wall must meet or exceed OSHA specifications. These specifications can vary based on different environmental factors.
There are many factors that can influence the protective system design. For example, traffic, soil classification, moisture, weather, overhead and underground utilities, and the proximity and physical condition of nearby structures can all affect the design of a retaining wall. Another important factor in the design process is proper use and installation. The structural members of the support system must be securely fastened to prevent unwanted movement or failure.