Application of the Circucore Pro Method in the Boardwalk underneath Island Eastern Corridor Project

Abstract

Marine foundation works in Hong Kong are often carried out under stringent environmental and site constraints, particularly in waterfront developments where control of ground disturbance and environmental impact is critical. Conventional down-the-hole (DTH) drilling methods utilise high-pressure air flushing, which may induce outward pressure transmission into the surrounding ground and contribute to disturbance of the soil stress regime. These effects may lead to increased turbidity, dust, and noise, which require careful management, in sensitive environments. In the Boardwalk underneath Island Eastern Corridor (IEC) project, an alternative drilling approach, namely the Circucore Pro (CP) Method, was adopted to mitigate these potential effects. The method is developed with reference to fundamental geotechnical principles governing effective stress, pore pressure response, and soil–fluid interaction. By directing flushing air within the drill rod, the method limits the release of excess pressure into the surrounding ground and reduces disturbance during drilling.