ABSTRACT
This chapter presents an innovative approach to characterize geotechnical conditions of soil and rocks in the ground of hilly natural terrains. The hillside terrain at Po Shan was formed via a long and natural process. It experienced numerous geological and geotectonic movements, physical and chemical weathering and deterioration. The issue is how to safely, accurately, economically and environmental-friendly characterize the mechanical conditions of soil and rocks in hilly natural terrains. Since the drilling and monitoring can be carried out quickly and flexibly, many holes can be drilled and monitored in the hillside. The spatial distribution of the geomaterial strength along each hole can be revealed and inter-related. Hydraulic rotary core drilling techniques are usually time-consuming and costly although they can provide undisturbed soil and rock samples. The air-driven rotary percussive drilling equipped with drilling process monitoring are portable, flexible, reliable and economic in-situ techniques.
