Models and mechanisms of drilling-induced sinkhole in China

The present paper distinguishes the four general types of collapsed sinkholes induced by drilling in regions where non-indurated sediments (clay, silt, and sand) overlie unknown caves or open voids in underlying lithified karst rocks. These sinkhole models are classified into balance arch, hourglass, vibration, and subjacent drilling-induced erosion forms. A mechanical model was built for each type to assess the collapse probability. Drilling operations using boreholes facilitate rapid, turbulent, and erosive flow. These activities resulted in the 26 sinkholes that have been attributed to constructions in China in the last several years. Awareness of potential collapse conditions should allow construction projects to avoid high-risk settings that result in economic losses, environmental concerns, and life-threatening accidents caused by such rapid collapse of the land surface. Awareness and close monitoring of high-risk conditions during borehole monitoring should minimize the hazard.