Trench collapse causes deaths in the US. Sloping, shoring, screening and slide rail systems are effective safety measures. Workers should undergo training to reduce injuries. OSHA requires safety precautions.
Between 1990 and 2000, 771 deaths were attributed to trench collapse in the United States. Trenches are deep holes dug in the ground for construction purposes, in most cases. Supporting trench walls to prevent trench collapse is important for worker safety. Effective forms of trench safety include slopes, shoring and screens.
Sloped walls can help prevent trench collapse by shifting the weight of the soil away from the workers. Slope involves excavating the trench walls at an angle away from the trench opening. The end result is similar to a funnel, with more earth being deposited away from the opening. Soil removal is also important to prevent trench collapse. If placed immediately outside the trench walls, the increased weight can affect the strength of the wall.
Shoring up trench walls involves placing metal plates on both sides of the trench. The walls can be held in place with spacers cut to the width of the trench or by the use of a hydraulic system. Hydraulics provide constant, even pressure on the walls to prevent collapse.
The pressure can be adjusted to match the width of the wall. For example, if the trench walls become narrow, hydraulic pressure can be released on narrow shoring plates. The reverse is also true. Even pressure is applied to the walls to prevent the trench from collapsing. Shoring usually only supports two sides of the trench.
Screening is similar to shoring, but with this method all four sides of the trench can be protected. A common type of shield is the trench box. Trench boxes are often assembled outside the trench and lowered into place. Many boxes come in standard sizes, typically ranging from 8 feet (about 2.4m) to 24 feet (about 7.3m).
Spacers placed between the screens keep the barriers in place. Barrier width is often adjusted by removing spacers that are too long or too short and replace them with correctly sized dividers. Hydraulics are not typically used with trench boxes.
Slide rail systems, another shield used to prevent trench collapse, can be more effective in some types of excavation. Slideway systems usually include metal walls lowered into a trench. Braces with attached rollers are used to hold the barriers in place. Rollers allow for easy mounting and removal of retaining walls. Slide rails can be moved as trenches deepen, with additional panels easily added to increase length and height.
Contractors and construction workers commonly undergo trench collapse training before starting work on an excavation site. Education about the dangers associated with trench construction can reduce the number of workplace injuries. In the United States, safety precautions are required by the Occupational Safety and Health Administration (OSHA).
Protect your devices with Threat Protection by NordVPN
