What is a defining attribute of type C soil in excavation safety?

A defining attribute of type C soil in excavation safety is its low unconfined compressive strength. Type C soils are typically loose, granular materials, such as sand and gravel, which have a high potential for instability, particularly when wet. The low unconfined compressive strength indicates that these soils can give way more easily under load or disturbance, making them a significant risk factor during excavation activities.

In excavation safety practices, understanding the properties of type C soil is crucial because it dictates the necessary precautions and protective measures. For instance, trenches in type C soil generally require more stringent safety measures, such as shoring or trench boxes, to prevent cave-ins and ensure worker safety. This attribute is critical because it informs workers and site managers about the inherent risks associated with this type of soil, enabling them to implement the necessary protections effectively.