Is it permissible to undercut the sides of an excavation?

Undercutting the sides of an excavation is generally considered unsafe and is not permissible because it compromises the stability of the excavation and increases the risk of cave-ins. The walls of an excavation need to be maintained at a safe angle to prevent soil from collapsing, which could endanger workers within the site. Undercutting disrupts the natural angle of repose of the soil and can lead to an unexpected failure of the soil structure, posing a significant hazard.

Regulations and standards, such as those established by the Occupational Safety and Health Administration (OSHA), emphasize the importance of maintaining safe excavation practices, which include avoiding undercutting. Safe excavation practices require that the excavation sides remain properly shored or sloped, according to the type of soil and conditions present. Therefore, the prohibition against undercutting is rooted in the commitment to worker safety and the prevention of potentially deadly accidents.