抄録
It is essential to know the properties of the rock ahead of the face when digging a tunnel. We examined long-hole exploration drilling as a method of determining the rock properties with the objective of establishing an improved procedure for such surveys. This report describes the results of the development of an improved system for exploration drilling. For convenience, the system, including its data-storage package, was designed to be mounted on a drill jumbo. A large-diameter rod was used at the tip of the extension rods to prevent deviation of the hole, after testing had indicated that this was an issue. A rod with an integrated coupling sleeve was employed to reduce the time required for the test. Dedicated software was also developed to enable semi-automated processing of the data. The above features make the system convenient to use, and provide accurate data of the rock properties ahead of the tunnel face.
