Final answer:
Type C-60 soil is a classification used to guide safety measures in trenching and excavation, providing an opportunity to choose appropriate protective systems such as vertical shores or shield systems.
Step-by-step explanation:
The definition of type C-60 soil is a classification used in construction and engineering to identify a specific type of soil that affects the safety measures used in trenching and excavation work. The classification provided by manufacturers is intended to give a competent person the opportunity to assess whether a trench or excavation can be safely supported using different types of protective systems. For type C-60 soil, the competent person may decide to use vertical shores, shield systems, or other methods like horizontal shoring, sloping, or benching according to the conditions and requirements of the job.