Case study of drilling process monitoring from two adjacent holes with two drills

Abstract

The drilling process monitoring (DPM) has been used in site characterization. Information from the drilling monitoring can be added to the existing geological information for more accurate identification of the rock discontinuities and weathered degrees of soils and rocks, because a larger number of drilled holes from rotary-percussive drilling can be used. In this paper, two sets of DPM data from two adjacent holes are examined. The two holes were drilled with two different rotary-percussive drills in soil nailing construction. Based on the monitored data, the interaction of the most important drilling parameters is assessed. The parameters are the drilling rate, the air pressures and the effect of work powers of different drills. The effect of the different drill work powers on the drilling data is identified. So, only the rock dependant variation can be left for sitecharacterization. The results demonstrate that the drilling parameters from different drills can be normalized.