ABSTRACT
Rock excavatability may represent a significant cost in a project from digging, ripping, or breaking of material. The material factors of strength and rock fractures are significant components of excavation assessment. Other controlling factors include the type of plant, space, and type of excavation. The contractual definition of rock is not the same as its geological definition. Appropriate plant and attachments for ripping and breaking influence the productivity. Mineral hardness affects equipment wearing rates. After excavation, the volume of material required to be transported is not the material volume specified in the bills of quantities. Bulking factors are required to assess both for design of cut-to-fill balance and the transport volume. Case studies show (1) the variation of material through a cutting, its bulking and relative usage for costing for tender purposes; and (2) the variation of unit weight of material used as fill.
