ABSTRACT
Today, underground facilities in rocks are used extensively for military applications and civil defence (Zhao et al., 1999). Because of their depth and hardened status, many of these strategic hard and deeply buried targets could only be put at risk by earth penetrating weapons (EPW). With the development of precision guidance systems, the scenario of an EPW hitting its target has become highly probable, and some weapons are even capable of penetrating deeper when assisted by a pilot-hole. This has posed great challenges to defence engineers and scientists working in both the field of weaponry and protective technology. Baty, Lundgren and Patterson (2003) recently reported on penetration tests conducted on concrete and in situ weathered granite with predrilled holes to understand the terra-dynamics of pilot-hole assisted penetration. Antoun, Lomov and Glenn (2003) have also undertaken a computational study to investigate the penetration efficiency of a sequence of penetrating bombs into granitic hard rock. However, the amount of non-classified literature on projectile penetration in rock materials remains small and limited.
