Shoring is positive ground support for one or more excavated faces that stops soil moving and so prevents collapse. It is used where location or depth make benching and battering impracticable, and is common in trenches in unstable ground such as soft or wet ground, sand, silt or soft moist clay. Shoring should be used where the ground will not stand unsupported and benching or battering is not practical or effective, and where someone could be buried, struck or trapped by material forming or next to the excavation side. A competent person such as an engineer should always design it to suit the specific site conditions. Where the same risk applies to those installing the shoring, other controls must protect people entering the excavation.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.