This paper presents a method for obtaining valuable additional information from automatic drilling
process monitoring in conventional drillhole site investigation. A digital drilling process monitor (DPM) is
developed and used to automatically and continuously monitor and record the operational process while a hole
is being drilled in ground using a hydraulic rotary machine. The DPM data are examined in detail for an
enhanced recording and understanding of the ground profile while drilling. The extra information from the
DPM is validated with information from conventional manual drillhole logging. The DPM results can improve
geotechnical knowledge and engineering practice in Hong Kong and other mountainous regions.published_or_final_versio
