What is the maximum allowable slope for a general excavation of 20 feet or less?

For a general excavation that is 20 feet or less in depth, the maximum allowable slope is a ratio of 3/4:1. This means that for every foot of vertical drop, the slope must extend 3/4 of a foot horizontally. This slope ratio is considered effective in preventing soil collapse and ensuring worker safety during excavation activities.

According to OSHA standards, maintaining slopes at this ratio minimizes the risk of cave-ins, which can occur when excavated earth becomes unstable. The 3/4:1 slope offers a balance between safety and practicality, allowing for an adequate working space while reducing the likelihood of accidents.

Other slope ratios, such as 1/2:1 or steeper slopes like 2:1 or 1:1, either make the excavation less stable or impractical for such a depth, as they can lead to potential hazards that endanger workers. Therefore, the choice of a 3/4:1 ratio is significant in promoting a safe working environment in compliance with established safety regulations.