What is the term for the side of a trench that needs to be properly maintained for safety?

The term for the side of a trench that requires proper maintenance for safety is referred to as the angle of repose. This concept describes the maximum angle at which a slope can be inclined without the risk of material sliding or collapsing. It is crucial in trench safety because a trench's walls need to be stable to prevent cave-ins, which can be deadly for workers inside the trench.

Understanding the angle of repose allows workers to determine how steep the trench walls can safely be, taking into consideration the type of soil and environmental factors. Proper maintenance involves ensuring that the walls are sloped at or below this angle to mitigate risks. This is essential in creating a safe working environment and complying with regulations regarding trench safety.