Final answer:
Shoring is required when trenching in soil to ensure stability and safety. The depth at which shoring is needed depends on factors like soil type and slope. Different shoring systems can be used to support the soil and prevent cave-ins.
Step-by-step explanation:
When trenching in soil, shoring is required at a certain depth to ensure the stability and safety of the trench. The depth at which shoring is required depends on several factors such as the type of soil, the slope of the trench walls, and the presence of nearby structures or utilities. Generally, shoring is needed when the trench depth exceeds 1.2 meters (4 feet) in loose or unstable soil.
There are different types of shoring systems that can be used to support the soil and prevent cave-ins. These include timber shoring, aluminum hydraulic shoring, and steel trench boxes.
For example, if the soil is cohesive or has a high clay content, shoring may be required at shallower depths due to the increased risk of collapse. On the other hand, if the soil is more stable and compact, shoring may be needed at greater depths. It is important to assess the soil conditions and consult applicable regulations or guidelines to determine the specific depth at which shoring is required.