AN EXCAVATION METHOD

摘要

A method of excavating a hard material, particularly and underground ore body, is provided wherein a series of holes are formed in the body and some of the holes pressurised at the same time as further holes are being formed. Pressurisation of the holes, preferably by initiation of propellant filled cartridges in the holes, causes the material to break and the broken material is removed concurrently with further hole formation and pressurisation.