Ground characterization using breaking-action-based zoning analysis of rotary-percussive instrumented drilling

In this article, we conducted in-situ rotary-percussive instrumented drilling monitoring and associated data analysis in parallel to determine weathering grades of rock mass and their corresponding spatial distribution. The influence of the mechanism of percussive drilling on the variations of drilling parameters is discussed. Three kinds of breaking actions in percussive drilling were summarized based on over 600 monitored soil nail holes. On the basis of breaking action identification, we propose a new breaking-action-based zoning analysis to remove the variations of drilling parameters caused by percussive drilling itself, only leaving the rock-dependent variations. In a case study, we verified the ground characterization results using this methodology with two sets of parallel drillhole loggings. The comparison results showed that this methodology offers great potential in ground characterization.